november 5 - Sociedad Mexicana de Ciencias Fisiológicas

Transcription

ACKNOWLEDGEMENTS
International Brain Research Organization
Carlos Belmonte
President
IBRO-LARC COMMITTEE
Osvaldo Uchitel
President
Luis Aguayo
Jaime Eugenin
Alonso Fernández-Guasti
Mario Guido
Alejo Munera
Luiz Carlos Silveira
Dora Ventura
ACKNOWLEDGEMENTS
Federación de Asociaciones Latinoamericanas y del Caribe de Neurociencias (FALAN)
Rommy von Bernhardi Montgomery
President
Jorge Quillfeldt
Secretary
Rafael Gutiérrez
President of the Scientific Committee
ACKNOWLEDGEMENTS
Sociedad Mexicana de Ciencias Fisiológicas
Gabriela González-Mariscal Muriel
President
Marcia Hiriart Urdanivia
Vice-President
Gina L. Quirarte
Secretary
Yolanda Cruz Gómez
Treasurer
ACKNOWLEDGEMENTS
Neurociencias y Neurobiología de México
Ranulfo Romo
President
Gabriel Gutiérrez Ospina
Secretary
ACKNOWLEDGEMENTS
Universidad Nacional Autónoma de México
Coordinación de la
InvesƟgación Cienơfica
José Narro Robles
Rector
Carlos Arámburo de la Hoz
Coordinador de la Investigación Científica
Héctor Hernández Bringas
Coordinador de Planeación, Presupuestación y
Evaluación, Rectoría
Marcia Hiriart Urdanivia
Directora, Instituto de Fisiología Celular
ACKNOWLEDGEMENTS
Centro de Investigación y Estudios Avanzados-IPN
José Pablo René Asomoza y Palacio
Director
Pablo Rogelio Hernández
Secretario Académico
ACKNOWLEDGEMENTS
Consejo Nacional de Ciencia y Tecnología
Enrique Villa
Director
Leticia Myriam Torres Guerra
Directora Adjunta de Desarrollo Científico
ACKNOWLEDGEMENTS
Secretaría de Educación Pública
Rodolfo Tuirán Gutiérrez
Subsecretario de Educación Superior
Sonia Reynaga Obregón
Directora General de Educación Superior Universitaria
ACKNOWLEDGEMENTS
Universidad Veracruzana
Raúl Arias Lovillo
Rector
Porfirio Carrillo
Secretario Académico
ACKNOWLEDGEMENTS
Scientific Committee
Rafael Gutiérrez
President
Luis Angel Aguilar (Peru)
Juan Bacigalupo (Chile)
José Bargas (Mexico)
Federico Bermúdez-Rattoni (Mexico)
Carlos Beyer (Mexico)
Cecilia Bouzat (Argentina)
Rubén Budelli (Uruguay)
Patricia Cardona (Colombia)
Arturo Hernández (Mexico)
Juan Lerma (Spain)
Hugo Merchant (Mexico)
Jorge A Quillfeldt (Brazil)
Sidarta Ribeiro (Brazil)
Raul Russo (Uruguay)
Gilberto Fernando Xavier (Brazil)
Welcome message
We are especially pleased to welcome in Cancún neuroscientists from Latin America, the Caribbean, North America, Spain, and beyond. The 1st meeting of the Federation of Neuroscience
Societies from Latin America and the Caribbean (FALAN), being held with the 55th National
Congress of Physiological Sciences and Neurosciences and Neurobiology of Mexico (NNM), is
bringing together the wide variety of topics and experimental approaches that characterize contemporary Neuroscience. From ionic channels to mental illnesses, from specific functions of the
brain to its interactions with the immune and endocrine systems, from cell cultures to human
studies, the variety of topics offered in the 42 symposia and in the 11 keynote lectures of this
meeting, reflects the vigor of Neuroscience research in the region. We have also strived to make
this meeting an educational opportunity for students. Through a variety of courses and preconference workshops, they will have the opportunity to acquire skills in specific methodologies
(like scientific writing, stereology, neurobehavioral analysis) and to learn about particular topics
(like epilepsy and drug addiction). The comprehensive, in-depth lectures delivered by eleven
keynote speakers will give us the privilege of acquiring historical and up-to-date perspectives
on central topics of nervous system function.
This varied Academic Program would not have been possible without the generous financial
support of the International Brain Research Organization (IBRO) and several Mexican institutions
dedicated to promoting education and scientific research. The Mexican Society of Physiological
Sciences (SMCF) is grateful to: the National Council of Science and Technology (CONACYT), the
National Ministry of Education (SEP), the National Autonomous University of Mexico (UNAM), the
Center for Research and Advanced Studies of the National Polytechnic Institute (CINVESTAV), and
the University of Veracruz (UV). These various sources of funding were essential, not only for
bringing together the scientists, but for allowing many students from all over the Americas to
attend this meeting.
During the pre-conference and conference days, we hope to have a strong and productive interaction with each other, to identify common interests, to plan future joint projects, to learn about
each other and, overall , to enhance the development of a strong FALAN.
Sincerely,
Rafael Gutiérrez
Gabriela González-Mariscal
Rommy von Bernhardi
Ranulfo Romo
President of the Scientific Committee
President of FALAN
President of SMCF
President of NNM
Index
1.
2.
3.
4.
5.
6.
Overview
Program
Lectures
Symposia
Posters
Authors
Friday 2
Courses
Saturday 3
Courses
Sunday 4
Courses
Monday 5
Tuesday 6
Wednesday 7
Thursday 8
Friday 9
Symposia
Symposia
Symposia
Symposia
Symposia
Coffee and Posters
(on display the whole day)
Coffee and Posters
Coffee and Posters
Coffee and Posters
Coffee and Posters
LECTURE
David Fitzpatrick
Building cortical representations
with experience:
Insights from visual cortex.
LECTURE
Sergio R. Ojeda
Using systems biology to gain
insights into the genetics and
epigenetic mechanisms
controlling mammalian puberty
LECTURE
Alison S. Fleming
Effects of early life experience
on the development of the
central nervous system:
role of maternal care
LECTURE
Maria Fernanda Cerriani
Circadian control of
locomotor output:
from structure to behavior
INFORMATIVE
SIMPOSIUM
Research
in Germany
BUSINESS
SESSION
FALAN
LECTURE
Alberto Pereda
Synaptic transmission mediated by gap
junctions: properties and plasticity
Free
LECTURE
Luis Barbeito
Pathogenic role of phenotypically
aberrant astrocytes in ALS
Free
Free
DISCUSION FORUM
Neuroscience in
Latinamerica:
Where are we?
Where should we go?
Free
Business
session
SMCF
Free
Opening Ceremony
Symposia
Symposia
Symposia
Symposia
LECTURE
Suzana Herculano-Houzel
86 billion brain neurons: the
advantages and costs of the
remarkable, but not extra
ordinary, human brain
LECTURE
Marcelo Rubinstein
Functional dissection of
dopamine D2 receptors by
conditional mutagenesis
LECTURE
Pablo E. Castillo
Endocannabinoid-mediated
plasticity: novel mechanisms
and synaptic rules
LECTURE
José María Delgado García
Learning as a functional state of
the brain: studies in wild type
and transgenic mice
Opening Lecture
Ranulfo Romo
Reception Cocktail
CLOSING
CEREMONY AND DINNER:
from 20 to 24 h
PROGRAM OF ACTIVITIES
NOVEMBER 2
PRE-CONGRESS COURSES
09:00 – 18:00 COURSE
• How to write a scientific paper.
Coordinators: Pascal Poindron and Oscar González-Flores.
ROOM Tenerife 1
NOVEMBER 3
9:00–18:00 COURSES
Coordinators: Pascal Poindron and Oscar González-Flores.
ROOM Tenerife 1
• Neurotoxicity and pharmacoresistant epilepsy.
Coordinator: Luisa Rocha and Sandra Orozco.
ROOM Tenerife 2
• Use of software for behavioral analysis of laboratory animals.
Coordinators: Dan Blumstein, Kurt Hoffman, and Angel Melo.
ROOM Tenerife 3
• Counting cells, synapses and other structures:
An introduction to design based stereology and to the isotropic fractionator.
Coordinators: Jose Maldonado and Suzana Herculano-Houzel.
ROOM Mallorca 1
• Neurobiology of temporal control and perception of time.
Coordinators: José Lino Oliveira Buen, Danielle Marcilio Judice Daher and Francisco Carlos Nather.
ROOM Mallorca 2
• Neuroimmunomodulation:
Bi-directional interactions between the brain and the immune system.
Coordinator: João Palemo Neto.
ROOM Mallorca 3
NOVEMBER 4
9:00–18:00 COURSES
Coordinators:
Pascal Poindron and Oscar González-Flores.
ROOM Tenerife 1
• Neurotoxicity and pharmacoresistant epilepsy.
Coordinator: Luisa Rocha and Sandra Orozco.
ROOM Tenerife 2
• Use of software for behavioral analysis of laboratory animals.
Coordinators: Dan Blumstein, Kurt Hoffman, and Angel Melo.
ROOM Tenerife 3
• Counting cells, synapses and other structures:
an introduction to design based stereology and to the isotropic fractionator.
Coordinators: Jose Maldonado and Suzana Herculano-Houzel.
ROOM Mallorca 1
• Neurobiology of temporal control and perception of time.
Coordinators: José Lino Oliveira Buen, Danielle Marcilio Judice Daher and Francisco Carlos Nather.
ROOM Mallorca 2
• Neuroimmunomodulation:
Bi-directional interactions between the brain and the immune system.
Coordinator: João Palemo Neto.
ROOM Mallorca 3
• Basic applied neuroimmunology.
Coordinators: María Robinson Agramonte and Eduardo Arzt.
ROOM Ibiza
• Short course. Multi-factorial insights on the neurobiological mechanisms of drug addiction.
Coordinator: Jair Guilherme Santos-Junio.
ROOM Menorca
NOVEMBER 4
CONGRESS
ROOM DEL PRADO
18:00-19:00 OPENING CEREMONY
Master of Ceremony: Alonso Fernández-Guasti
Carlos Belmonte, President of the International Brain Research Organization (IBRO)
The role of IBRO in promoting the creation of regional federations of Neuroscience
Rommy von Bernhardi, President of the Federation of Neuroscience Societies from Latin America and the Caribbean
(FALAN) The creation of FALAN, current status and future perspectives
Rafael Gutiérrez, President of the Scientific Committee
The Academic Program of the congress
Osvaldo Uchitel, President of the IBRO-LARC Committee
The contributions of IBRO-LARC to the development of this meeting
Gabriela González-Mariscal, President of the Mexican Society of Physiological Sciences (SMCF)
SMCF as a key promoter of physiological research and education in Mexico: interaction with the international community
19:00-20:00 OPENING LECTURE
L01. Ranulfo Romo
(Instituto de Fisiología Celular, Universidad Nacional Autónoma de México y el Colegio Nacional de México)
President of “Neurosciences and Neurobiology of Mexico”,
Who will deliver the talk: “Conversion of sensory signals into perceptual decisions”
20:00-21:00 RECEPTION COCKTAIL
RESTAURANTE LA PERLA
NOVEMBER 5
9:00–11:00 SYMPOSIA
ROOM PICASSO-MURILLO
1.1. NOVEL ASPECTS IN VISION NEUROSCIENCE: FROM MOLECULES TO EYE
DISEASES AND VISUAL FUNCTION (SYMPOSIUM LARC-IBRO)
Chair: Mario E. Guido
09:00-09:40
1.1.1. Mónica Lamas
Dept. Farmacobiología, Centro de Investigación y de Estudios Avanzados, CINVESTAV. Müller glia in focus.
09:40-10:20
1.1.2. Mario E. Guido
CIQUIBIC-Dpto. Química Biológica, Fac. Cs. Químicas, Universidad Nacional de Córdoba, Argentina.
Non-visual Photoreceptors in the Inner Retina.
10:20-11:00
1.1.3. Dora Fix Ventura
Instituto de Psicologia, Universidade de São Paulo, Brazil.
Pupil Responses in Neuropathies and Melanopsin.
ROOM GRECO-DALÍ
1.2. BRAIN-IMMUNE SYSTEM INTERACTION
Chair: Ruud Buijs
09:00-09:30
1.2.1. Nicolas Cermakian
Douglas Mental Health University Institute,Montreal, QC, H4H 1R3 Canada.
The crosstalk between the circadian and immune systems.
09:30-10:00
1.2.2. Regina P Markus
Institute of Bioscience, University of Sao Paulo, Brazil.
Melatonin and its Involvement in the Immune System.
10:00-10:30
1.2.3. Jorge Morales-Montor
Departamento de inmunología, Instituto de Investigaciones Biomédicas,
Universidad Nacional Autónoma de México, Mexico.
The host-parasite neuro-immuno-endocrine network.
10:30-11:00
1.2.4. Ruud M Buijs
Instituto de Investigaciones Biomédicas UNAM Mexico DF.
Our biological clock tunes the immune system.
ROOM LANZAROTE 1, 2
1.3. NEURODEGENERATION AND EPILEPSY
Chair: Carlos Beas
09:00-09:24
1.3.1. Antonio Camins
Universidad de Barcelona, Departamento de farmacología y Química Terapéutica,
Facultada de Farmacia España. Neurodegeneration mechanisms and cell cycle.
09:24-09:48
1.3.2. Carlos Beas-Zárate
Department of Molecular and Cellular Biology, CUCBA, University of Guadalajara, México.
Neurotoxicity and convulsive susceptibility: astrocyte function.
09:48-10:12
1.3.3. Alberto Lazarowski
INFIBIOC-FFyB and IBCN Fac de Medicina (UBA), Argentina.
Molecular mechanisms of pharmacoresistant epilepsy.
10:12-10:36
1.3.4. Lilia Morales Chacón
International Center of Neurological Restoration (CIREN), Cuba.
Epileptogenicity of the temporal lobe: a digital EEG analysis approach.
10:36-11:00
1.3.5. Luisa Rocha
Center for Research and Advanced Studies, Pharmacobiology Dept. México.
Therapeutic strategies to hinder neurodegeneration in epilepsy.
ROOM MALLORCA 1, 2, 3
1.4. VOLTAGE-GATED ION CHANNELS: NEW INSIGHTS INTO STRUCTURE AND FUNCTION
Chair: Juan Carlos Gómora
09:00-09:24
1.4.1. David Naranjo
Centro Interdisciplinario de Neurociencias /Universidad de Valparaíso, Chile.
Shaker K+ channels (K+ conduction and Mg2+ blockade in Shaker Kv-channel single point
mutant having an unusually high conductance).
09:24-09:48
1.4.2. Jorge Arreola
Universidad Autónoma de San Luis Potosí, México.
Coupling anion permeation to voltaje-dependent gating in ClC choride channels.
09:48-10:12
1.4.3. Froylán Gómez Lagunas
Dept. Fisiología. Fac. Medicina. UNAM. México.
Potassium-dependent dynamics of the pore of Kv channels: inactivated and non-conducting non-inactivated states.
10:12-10:36
1.4.4. Eduardo M. Salinas-Stefanon
Instituto de Fisiología, Univ. Autónoma de Puebla, Mexico.
Structure-function relationship in voltage dependent sodium channels.
10:36-11:00
1.4.5. Juan Carlos Gomora
Depto. de Neuropatología Molecular. División de Neurociencias, Instituto de Fisiología Celular, UNAM. México DF.
T-type calcium channels: from structure to function.
ROOM TENERIFE 1, 2, 3
1.5. SYMPOSIUM OFFERED BY THE URUGUAYAN AND ITALIAN SOCIETIES
FOR NEUROSCIENCES NEUROPLASTICITY AND BRAIN ADAPTATION TO STRESSORS
Chair: L. Annunziato, University of Naples, Italy
09:00-09:30
1.5.1. Ornella Cuomo
Division of Pharmacology, Department of Neuroscience, School of Medicine, Federico II
University of Naples, Naples, Italy.
Endogenous neuroprotection against stroke: preconditioning and remote conditioning.
09:30-10:00
1.5.2. Elisabetta Gerace
Department of Preclinical and Clinical Pharmacology,University of Florence, Italy.
Mechanisms of ethanol dependence in immature and mature organotypic hippocampal slice cultures.
10:00-10:30
1.5.3. Juan Andres Abin
Department of Neurochemistry, Instituto de Investigaciones Biologicas Clemente Estable, Montevideo, Uruguay.
Characterization of new nicotinic agonists: A potential treatment strategy for Parkinson’s disease.
10:30-11:00
1.5.4. Francesco Mattia Rossi
Facultad de Ciencias, UdelaR and Institut Pasteur de Montevideo, Uruguay.
Neuroplasticity in brain disorders: what the visual cortex can teach us.
HALL OF THE CONVENTION CENTER
11:00–13:00 COFFEE AND POSTER SESSION.
NOTE: THE POSTERS ASSIGNED FOR THE DAY WILL BE LEFT ON DISPLAY THE WHOLE DAY
ROOM DEL PRADO
13:00-14:00 LECTURE
L02. David Fitzpatrick
Max Planck Florida Institute, Jupiter Florida, USA.
Building cortical representations with experience: Insights from visual cortex
ROOM MIRÓ
14:00-16:00 INFORMATIVE SYMPOSIUM
RESEARCH IN GERMANY
DAAD, German Service of Academic Exchange Alexander von Humboldt Foundation
DFG, German Society for Research
MPI, Max Planck Institute
ROOM GOYA
14:00-16:00 BUSINESS MEETING REPRESENTATIVES OF FALAN
18:00-20:00 SYMPOSIA
1.6. THE HIPPOCAMPUS AND ITS INVOLVEMENT IN SEVERAL FUNCTIONS OF THE BODY
Chair: Antonio Carlos Roque
18:00-18:40
1.6.1. Martín Cammarota
Laboratory of Behavioral Neurobiology, Biomedical Research Institute-PUCRS, Porto Alegre, Brazil.
On the role of the hippocampus in object recognition memory.
18:40-19:20
1.6.2. Sidarta Ribeiro
Instituto do Cérebro, Universidade Federal do Rio Grande do Norte, Brazil.
Hippocampo-cortical dynamics across the sleep-wake cycle.
19:20-20:00
1.6.3. Norberto Garcia-Cairasco
USP-RP.
Modeling temporal lobe epilepsy: linking behavioral neurobiology to neuroplasticity in hippocampal circuits
ROOM GRECO-DALÍ
1.7. MANIFESTING THE MIND
Chair: Sidarta Ribeiro
18:00-18:30
1.7.1. Jordi Riba
Instituto de Investigación Biomédica Sant Pau de Barcelona, Spain.
Ayahuasca and the Human Brain.
18:30-19:00
1.7.2. Draulio de Araujo
Instituto do Cérebro, Univesidade Federal do Rio Grande do Norte, Brazil.
Functional Magnetic Resonance Imaging and Ayahuasca: studies on mental imagery and internal attention.
19:00-19:30
1.7.3. Arturo A. Vitale
PRALIB, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Argentina.
In vivo studies of radiolabeled N, N- dimethyltryptamine and tryptamine as markers of the indolic hypermethylation:
relationship with human perception alterations in psychiatric pathologies.
19:30-20:00
1.7.4. Eduardo Schenberg
Universidade Federal de Sao Paulo (UNIFESP), Brazil.
Ibogaine in the treatment of drug addiction: an observational study in Brazil.
ROOM LANZAROTE 1, 2
1.8. MEMORY REACTIVATION AND ITS CONSEQUENCES:
RECONSOLIDATION, EXTINCTION AND WHAT ELSE?
Chair: Jorge A. Quillfeldt
18:00-18:30
1.8.1. Francisco Sotres-Bayon
University of Puerto Rico, Puerto Rico.
Prefrontal regulation of fear and vigilance.
18:30-19:00
1.8.2. Federico Bermudez-Rattoni
UNAM, DF, Mexico.
Mechanisms of retrieval and updating of recognition memory.
19:00-19:30
1.8.3. Victor A. Molina
IFEC-CONICET, Departamento de Farmacología, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba,
Argentina. Influence of stress on fear memory reconsolidation.
19:30-20:00
1.8.4. Jorge A Quillfeldt
Department of Psycology, McGill University, Montreal, Canada. PPG Neurociencias UFRGS, Porto Alegre, RS, Brazil.
Periodically reactivated context memory retains its precision and dependence on the hippocampus.
1.9. CONNEXINS IN EXCITABLE CELLS
Chair: Martha Pérez Armendariz
18:00-18:24
1.9.1. E. Martha Pérez Armendariz
Laboratorio de sinapsis eléctricas. Departamento de Medicina Experimental, Facultad de Medicina, UNAM, México.
Connexin 36 in pancreatic beta cells: new functional roles.
18:24-18:48
1.9.2. Rafael Gutiérrez
Departamento de Farmacobiología, Centro de Investigación y Estudios Avanzados del IPN, México.
Mixed electrical-chemical synapse between principal cells in the hippocampus.
18:48-19:12
1.9.3. Francisco F. De-Miguel
Instituto de Fisiología Celular-Neurociencias, UNAM, México.
Dendritic electrical coupling determines the amplitude of chemical synaptic potentials.
19:12-19:36
1.9.4. Juan Carlos Saez
Pontificia Universidad Católica de Chile, Chile.
Hemichannels expressed by glial cells as molecular targets to prevent cell
degeneration under neuroinflammatory condition.
19:36-20:00
1.9.5. Agustín D. Martínez Carrasco
Centro Interdisciplinario de Neurociencias de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile.
Is syndromic deafness a hemichannel disease?
1.10. NON-PITUITARY GROWTH HORMONE: NOVEL ROLES FOR AN ANCESTRAL MESSENGER
Chair: Carlos Arámburo de la Hoz
18:00-18:30
1.10.1 Hugo A. Barrera Saldaña
Departamento de Bioquímica y Medicina Molecular.
Facultad de Medicina de la Universidad Autónoma de Nuevo León. México.
Growth hormone: News from the past and stories with a future.
18:30-19:00
1.10.2. Maricela Luna Muñoz
Departamento de Biología Celular y Molecular, Instituto de Neurobiología,
Universidad Nacional Autónoma de México, México.
Extrapituitary growth hormone in immune system.
19:00-19:30
1.10.3. Steve Harvey
Dept. of Physiology, University of Alberta, Edmonton, Canada.
Extrapituitary growth hormone in the nervous system.
19:30-20:00
1.10.4. Carlos Arámburo de la Hoz
Departamento de Biología Celular y Molecular, Instituto de Neurobiología,
Universidad Nacional Autónoma de México,
México. Extrapituitary growth hormone in the reproductive system.
ROOM DEL PRADO
20:00-21:00 LECTURE
L03. Suzana Herculano-Houzel
Universidadade Federal do Rio de Janeiro, Instituto Nacional de Neurociência Translacional, Sâo Paulo, Brazil.
86 billion brain neurons: the advantages and costs of the remarkable, but not extraordinary, human brain
21:00 POSTER SESSION
NOVEMBER 6
2.1. BASAL GANGLIA: BEYOND MOVEMENT DISORDERS
Chair: Elvira Galarraga
09:00-09:20
2.1.1. Mario Gustavo Murer
University of Buenos Aires School of Medicine, Department of Physiology and Biophysics, Buenos Aires. Argentina.
Circuit mechanisms underlying pathological oscillations in animal models of Parkinson’s disease.
09:20-09:40
2.1.2. Fatuel Tecuapetla
Centre for the Unknown, Champalimaud Foundation, Portugal.
Investigating the role of striatal subcircuits in the performance of action sequences using optogenetics.
09:40-10:00
2.1.3. Luis Alberto Carrillo-Reid
Northwestern University, Feinberg School of Medicine, Dept. of Physiology, Chicago, USA.
Dynamic reconfiguration of neural networks: towards the understanding
of compositional properties in biological systems.
10:00-10:20
2.1.4. Víctor de Lafuente
Instituto de Neurobiologia, UNAM. México.
Not only reward: Dopamine neurons code subjective perceptual experience and uncertainty of decisions.
10:20-10:40
2.1.5. Kuei Y. Tseng
Department of Cellular and Molecular Pharmacology, The Chicago Medical
School at Rosalind Franklin University, North Chicago, IL, USA.
mGluR modulation of calcium-permeable AMPAR-mediated synaptic plasticity
in the nucleus accumbens following prolonged withdrawal from cocaine self-administration.
10:40-11:00
2.1.6. Claudio Da Cuhna
Lab. Fisiologia e Farmacologia do SNC, Dept. Farmacologia, Universidade Federal do Paraná (UFPR), Brazil.
How striatal dopamine modulates aversively-motivated learning.
ROOM GRECO-DALÍ
2.2. MOTIVATION OF REPRODUCTIVE BEHAVIORS
Co-Chairs: Annabel Ferreira and Alonso Fernández-Guasti
09:00-09:24
2.2.1. Gabriela González-Mariscal
Centro de Investigación en Reproducción Animal, CINVESTAV-Universidad Autónoma de Tlaxcala, México.
Rabbit maternal behavior as a model of a specific hormone-related motivation.
09:24-09:48
2.2.2. Annabel Ferreira
Sección Fisiología y Nutrición, Facultad de Ciencias, Universidad de la Republica, Uruguay.
Opposed driving forces: sex and aggression during lactation.
09:48-10:12
2.2.3. Aldo B. Lucion
Departamento de Fisiologia, Instituto de Ciências Básicas da Saúde (ICBS),
Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
Neuroendocrine and behavioral effects of neonatal stress.
10:12-10:36
2.2.4. Raúl Gerardo Paredes
Instituto de Neurobiología, Universidad Nacional Autónoma de México, México.
Hormones and sexual reward.
10:36-11:00
2.2.5. Alonso Fernández-Guasti
Centro de Investigación y Estudios Avanzados, Departamento de Farmacobiología, México.
Motivational aspects of sexual satiety in males and females.
ROOM LANZAROTE 1, 2
2.3. GLIAL CELLS IN NEURODEGENERATION
Chair: Luis Barbeito
09:00-09:30
2.3.1. Silvia Olivera Bravo
Cell and Molecular Neurobiology, Instituto de Clemente Estable, Montevideo, Uruguay.
Neuron-glia interactions in neurometabolic diseases.
09:30-10:00
2.3.2. Patricia Cassina
Facultad de Medicina, Universidad de la República, Uruguay.
Astrocyte-mediated neurotoxicity.
10:00-10:30
2.3.3. Carina Ferrari
Fundación Instituto Leloir, Argentina.
Effect of peripheral inflammation on an inflammatory model of demyelination.
10:30-11:00
2.3.4. Rommy Von Bernhardi
Dpt. Neurology, School of Medicine, Pontificia Universidad de Chile, Santiago, Chile.
Age-dependent changes on the activation of microglia: understanding cytotoxicity in neurodegenerative diseases.
2.4. NEUROIMMUNOMODULATION
Chair: Wilson Savino
09:00-09:30
2.4.1. Wilson Savino
Fundação Oswaldo Cruz, Brazil.
Immunoneuroendocrine imbalance in Chagas Disease
09:30-10:00
2.4.2. Maria Robinson-Agromonte
Dept. Neuroinmunología, Centro Internacional de Restauración Neurológica, Cuba.
Differential regulation of autoimmunity in the central nervous system
10:00-10:30
2.4.3. Carmem Gottfried
Universidade Federal do Rio Grande do Sul, Brazil.
Autism: a neuroimmune disorder?
10:30-11:00
2.4.4. Luis Barbeito
Institut Pasteur de Montevideo, Uruguay.
Modulation of motor neuron disease by systemic immunization to NGF.
2.5. CELL DAMAGE AS A THERAPEUTIC TARGET IN EPILEPSY AND PARKINSON’S DISEASE
Chair: Rui Daniel S. Prediger
09:00-09:30
2.5.1. Rodrigo A. Cunha
Center for Neurosciences and Cell Biology, Univ. Coimbra, Portugal
and Faculty of Medicine, University of Coimbra, Portugal.
Novel adenosine-based therapeutic strategies to manage brain dysfunction and damage upon epilepsy
09:30-10:00
2.5.2. Roger Walz
Universidade Federal de Santa Catarina, Brazil.
Synaptic potentiation and signal transduction in epilepsy: experimental and clinical findings
10:00-10:30
2.5.3. Francisco Ciruela
Universitat de Barcelona, Spain.
Adenosine-dopamine receptor-receptor heteromerization and Parkinson´s disease
10:30-11:00
2.5.4. Rui Daniel Prediger
Departamento de Farmacologia, Universidade Federal de Santa Catarina, Florianópolis, Brazil.
Neuroprotective strategies to manage motor and non-motor symptoms in Parkinson’s disease
11:00–13:00 COFFEE AND POSTER SESSION
ROOM DEL PRADO
13:00-14:00 LECTURE
L04. Sergio Ojeda
Division of Neuroscience, Oregon National Primate Research Center, Beaverton, Oregon, USA.
Using systems biology to gain insights into the genetics and epigenetic mechanisms controlling mammalian puberty
ROOM GOYA
14:00-15:00 SPECIAL LECTURE “HELIO GARCIA-AUSST”
L05. Alberto Pereda
Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine of Yeshiva University, NY.
Synaptic transmission mediated by gap junctions: properties and plasticity
2.6. A TRIP TO THE SENSES: TRP CHANNELS IN SENSORY TRANSDUCTION
Chair: Rodolfo Madrid
18:00-18:20
2.6.1. Diana Bautista
Department of Mollecular & Cell Biology, UC Berkeley, USA.
TRPA1 mediates acute and chronic itch.
18:20-18:40
2.6.2. Tamara Rosenbaum
Instituto de Fisiología Celular, UNAM, México.
Greasing the gears of channel function: TRPV1 channels and lipids.
18:40-19:00
2.6.3. Karel Talavera
Dept. Of Mollecular and Cellular Medicine, KU Leuven, Belgium.
TRPV4, a molecular transducer involved in the epithelial barrier function.
19:00-19:20
2.6.4. Diego Restrepo
Department of Cell and Developmental Biology, Rocky Mountain Taste and Smell Center, University of Colorado, USA.
The Ca2+-activated TRPM5 channel mediates responses to pheromones in a subset of olfactory sensory neurons.
19:20-19:40
2.6.5. Juan Bacigalupo
Universidad de Chile, Chile.
Diacylglycerol activates the light-dependent channels, TRP and TRPL, in Drosophila photoreceptors.
19:40-20:00
2.6.6. Rodolfo Madrid
Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Chile.
The role of TRPM8 and Kv1 potassium channels in painful hypersensitivity to cold in response to axonal damage.
ROOM GRECO-DALÍ
2.7. STRATEGIES TO PROMOTE CNS HEALTH DURING HOMEOSTATIC
CONDITIONS AND AFTER NEUROLOGICAL DISORDERS
Chair: Michele Schultz Ramos de Andrade
18:00-18:30
2.7.1. Nibaldo C. Inestrosa
Centre for Aging and Regeneration (CARE Faculty of Biological Sciences) Catholic University of Chile, Chile.
Wnt signaling and synaptic plasticity in aging.
18:30-19:00
2.7.2. Michele Schultz
Universidade de Sao Paulo, Brazil.
Enhancing plasticity and functional recovery in the injured spinal cord.
19:00-19:30
2.7.3. Marilise Escobar Burger
Departamento de Fisiología e Farmacologia-Universidade Federal de Santa Maria (UFSM), RS Brazil.
Fatty acids and physical activity as neuroprotective agents in movement disorders.
19:30-20:00
2.7.4. Fernando Gomez-Pinilla
Dept. Integrative Biology and Physiology, and Neurosurgery, Univ.California Los Angeles, USA.
The impact of lifestyle in the CNS: from epigenetic to behavior.
ROOM LANZAROTE 1, 2
2.8. NEUROTRANSMITTER SIGNALING AND ELECTRICAL ACTIVITY
DURING NEURAL DEVELOPMENT
Chair: Eduardo Bouth Sequerra
18:00-18:30
2.8.1. Fernando Garcia de Mello
Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Brazil.
Neurochemical activity in the embryonic retina and its possible role in development.
18:30-19:00
2.8.2. Raúl E. Russo
Neurofisiología Celular y Molecular. Instituto de Investigaciones Biológicas Clemente Estable, Uruguay.
GABAergic signaling in a stem cell niche of the spinal cord.
19:00-19:30
2.8.3. Paola V. Plazas
Neurobiology Section and Center for Neural Circuits, Division of Biological Sciences,
Kavli Institute for Brain and Mind, UC San Diego, USA.
Electrical activity regulates Plexin A3-mediated axon pathfinding in developing zebrafish spinal motor neurons.
19:30-20:00
2.8.4. Eduardo B. Sequerra
Dept. of Physiology and Membrane Biology, University of California Davis, USA.
Interference with glutamate signaling induces neural tube defects:
Implications to antiepileptic drug action during neural tube formation.
2.9. MECHANISMS FOR AROUSAL AND ANTICIPATION OF FOOD
Chair: Carolina Escobar
18:00-18:30
2.9.1. Ralph Mistlberger
Simon Fraser University, Canada.
Circadian and non-circadian mechanisms of food anticipatory rhythms in nocturnal rodents.
18:30-19:00
2.9.2. Myrte Merkestein
Department of Physiology, Anatomy and Genetics, University of Oxford, United Kingdom.
The role of central ghrelin signalling in food anticipatory activity.
19:00-19:30
2.9.3. Fernando Torrealba
Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Chile.
Cortico-hypothalamic mechanisms in motivated arousal.
19:30-20:00
2.9.4. Carolina Escobar
Facultad de Medicina, Universidad Nacional Autónoma de México, México.
Interacting brain clocks produce arousal and anticipation for food intake.
ROOM DEL PRADO
20:00-21:00 LECTURE
L06. Marcelo Rubinstein
INGEBI-CONICET, and FCEyN. Universidad de Buenos Aires, Argentina.
Functional Dissection of Dopamine D2 Receptors by Conditional Mutagenesis
NOVEMBER 7
3.1. INTEGRATIVE NEUROPHYSIOLOGY OF HIGH ORDER BEHAVIORS
Chair: Hugo Merchant
09:00-09:24
3.1.1. Luis Lemus
Bimodal discrimination.
09:24-09:48
3.1.2. Yuriria Vazquez
Depto. de Neurociencias Cognitivas, Instituto de Fisiología Celular, UNAM, México.
Neural codes for perceptual detection in the primate somatosensory thalamus.
09:48-10:12
3.1.3. Valentin Dragoi
Dept. of Neurobiology and Anatomy, Univ. of Texas-Houston Medical School, USA.
Population coding in laminar cortical circuits.
10:12-10:36
3.1.4. Sidarta Ribeiro
Instituto do Cérebro, Universidade Federal do Rio Grande do Norte, RN Brazil.
Reverberation, storage and propagation of memories during sleep.
10:36-11:00
3.1.5. Hugo Merchant
Depto. Neurobiología Conductual y Cognitiva, Instituto de Neurobiología, UNAM, México. Interval tuning in the primate medial premotor cortex during different rhythmic tapping behavior.
ROOM GRECO-DALÍ
3.2. SYNAPTIC COTRANSMISSION AND TRANSMITTER SEGREGATION
Chair: Miguel A. Morales
09:00-09:30
3.2.1. Laura N. Borodinsky
Dept. Physiology & Membrane Biology, and Shriners Hospital for
Children Northern California, U. California Davis School of Medicine.
Activity-dependent neurotransmitter specification in the developing spinal cord:
Interplay between calcium signaling and morphogenetic proteins.
09:30-10:00
3.2.2. Miguel A. Morales
Deptarment of Physiology & Cell Biology, Biomedical Research Institute, Universidad Nacional Autónoma de México,
México. Segregation of transmitters: a plastic synaptic property of neurons.
10:00-10:30
3.2.3. Louis-Eric Trudeau
Université de Montréal, Canada.
Functional roles of vesicular glutamate transporters in dopamine neurons.
10:30-11:00
3.2.4. Rafael Gutiérrez
Departamento de Farmacobiología, Centro de Investigación y Estudios Avanzados del IPN, México.
Co-release of glutamate and GABA from the mossy fibers.
ROOM LANZAROTE 1, 2
3.3. PSYCHOPHYSIOLOGY AND THE DECLINE AND FALL OF COLD COGNITION
Chair: Eliane Volchan
09:00-09:24
3.3.1. Steven Hackley
Dept. of Psychological Sciences, Univ. of Missouri, USA.
Introductory remarks to “Psychophysiology”.
09:24-09:48
3.3.2. Steven Hackley
Dept. of Psychological Sciences, Univ. of Missouri, USA.
Deficits of anticipatory attention in Parkinson’s disease.
09:48-10:12
3.3.3. Yasunori Kotani
Tokyo Institute of Technology,Tokio, Japan.
Role of the right anterior insular cortex in anticipatory attention and emotion.
10:12-10:36
3.3.4. Maria Antonieta Bobes-Leon
Centro de Neurociencias de Cuba.
Overt and covert processing of emotion from identity in the brain
10:36-11:00
3.3.5. Eliane Volchan
Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Brazil.
Body and brain changes associated with invasion of peripersonnal space in PTSD
3.4. OLIGODENDROCYTE BIOLOGY IN DEVELOPMENT AND DISEASE
Chair: Penha C. Barradas
09:00-09:30
3.4.1. Juana M. Pasquini
Dept of Biological Chemistry and IQUIFIB. School of Pharmacy and Biochemestry,
University of Buenos Aires-CONICET, Argentina.
Galectin 3 drives oligodendroglial cell differentiation.
09:30-10:00
3.4.2. Luciana Nogaroli
Universidade Federal do Rio de Janeiro, Brazil.
Is LPA a regulator of oligodendrogenesis?
10:00-10:30
3.4.3. Babette Fuss
Virginia Commonwealth University, USA.
Autotaxin: a regulator of oligodendrocyte differentiation and myelination.
10:30-11:00
3.4.4. Penha Cristina Barradas
Depto. Farmacologia e Psicobiologia, IBRAG/UERJ Universidade do Estado do Rio de Janeiro, Brazil.
Oligodendroglial loss in a model of systemic perinatal hypoxiaischemia:
effects of blockade of NMDA receptors in PDGF-alfa receptor positive cells.
3.5. ETHICS IN NEUROSCIENCE: STATUS AND CHALLENGES (SYMPOSIUM IBRO)
Chair: Pedro Maldonado
09:00-09:30
3.5.1. Sarah Pallas, PhD.
Georgia State University, USA.
The role of ethics in experimental research with animals.”
09:30-10:00
3.5.2. Pedro Maldonado, Ph.D.
Faculty of Medicine, Universidad de Chile.
Bioethics and animal research in Latin America.
10:00-10:30
3.5.3. Joseph T. McCabe, Ph.D.
Department of Anatomy, Physiology, and Genetics, Uniformed Services University of the Health Sciences. USA.
Neuroethics: an agenda for neuroscience and society.
10:30-11:00
3.5.4. Ana Silva
Unidad Bases Neurales de la Conducta. Instituto de Investigaciones Biológicas Clemente Estable, Laboratorio de Neurociencias, Facultad de Ciencias, U de la R y Comisión Nacional Experimentación Animal MEC, Montevideo, Uruguay.
Animal models relevant to Latin America.
ROOM GOYA
3.6. STRESS ALONG THE LIFESPAN. NEUROCHEMICAL AND BEHAVIORAL
CONSEQUENCES (IBRO-ALUMNI SYMPOSIUM)
Chair: Marta Antonelli (Argentina)
09:00-09:30
3.6.1. Marta C. Antonelli
Instituto de Biologia Celular y Neurociencias. Facultad de Medicina. UBA. Buenos Aires. Argentina.
Long lasting neurodevelopmental effects of prenatal stress.
09:30-10:00
3.6.2. Paula Ayako Tiba
Centro de Matemática, Computação e Cognição.
Universidade Federal do ABC. Santo André, Brasil. Early life stress and its effects on sleep, behavior and neurochemistry.
10:00-10:30
3.6.3. Marquez,C (1, 2), Cordero, MI (2), Larsen, MH (2),
Groner AC (2), Magistretti PJ (2), Trono D (2), and Sandi C (2).
(1) Champalimaud Neuroscience Programme, Lisbon. Portugal.
(2) Ecole Politechnique Federale de Lausanne. Lausanne. Switzerland.
Peripuberty stress leads to abnormal aggression, altered amygdala and orbitofrontal
reactivity and increased prefrontal MAOA gene expression in adulthood.
10:30-11:00
3.6.4. Nicole L.Galvão Coelho
Department of Physiology, Universidade Federal do Rio Grande do Norte, Natal- RN, Brazil.
Cross-talk of hypothalamic-pituitary-adrenal (HPA) and hypothalamic-pituitary-gonadal
(HPG) axis during social stress in common marmosets (Callithrix jacchus).
ROOM DEL PRADO
13:00-14:00 LECTURE
L07. Alison S. Fleming
University of Toronto at Mississauga, Canada.
Effects of early life experience on the development of the central nervous system: role of maternal care
ROOM GOYA
14:00-15:00 SPECIAL LECTURE “CLEMENTE ESTABLE”
LO8.
Luis Barbeito
Instituto Pasteur, Montevideo, Uruguay.
Pathogenic role of phenotypically aberrant astrocytes in ALS
18:00-20:00 SYMPOSIA
3.7. FACTORS REGULATING NEUROGENESIS AND GLIOGENESIS IN THE CEREBRAL CORTEX
Chair: Cecilia Hedin Pereira
18:00-18:30
3.7.1. Adan Aguirre
Department of Pharmacological Science, State University of New York, New York, USA.
N-cadherin is activated in the adult neural stem cell niche and promotes
migration and recruitment of neural progenitor cells after demyelination.
18:30-19:00
3.7.2. Clarissa Schitine
CNC Lab of Brain Repair University of Coimbra Portugal and
Institute of Biophysics, Federal University Rio de Janeiro, Brazil.
Ampakine CX546 increases neuronal differentiation in postnatal subventricular zone cell cultures.
19:00-19:30
3.7.3. Ivan Velasco
Instituto de Fisiología Celular-Neurociencias, Universidad Nacional Autónoma de México.
Activin A promotes neuronal differentiation of cerebrocortical neural progenitor cells.
19:30-20:00
3.7.4. Cecilia Hedin Pereira
Instituto de Biofísica, Universidade Federal do Rio de Janeiro, Brazil.
Reelin as a regulator of neurogenesis and gliogenesis in cerebral cortex.
ROOM GRECO-DALÍ
3.8. AGING AND NEURODEGENERATION: FROM MOLECULAR ASPECTS TO THE CLINIC
Co-Chairs: Daniel Ortuño-Sahagún and Argelia E. Rojas-Mayorquín
18:00-18:05
3.8.1. Daniel Ortuño-Sahagún
Laboratorio de Desarrollo y Regeneración Neural, Instituto de Neurobiología,
Departamento de Biología Celular y Molecular, CUCBA, Universidad de Guadalajara.
Presentation and motif exposure. Aging and neurodegeneration: from molecular aspects to the clinic.
18:05-18:25
3.8.2. Luis Miguel Gutiérrez Robledo
Mexico.
Aging and health, a proposal for an action plan.
18:25-18:50
3.8.3. Dra. Mercè Pallàs
Department of Pharmacology.
Faculty of Pharmacy, University of Barcelona, Spain.
Sirtuin 1 modulation: the key or the lock in the ageing-gated neurodegeneration.
18:50-19:15
3.8.4. Verónica Palma
Centro FONDAP de Regulación del Genoma, Facultad de Ciencias, Universidad de Chile.
Sonic hedgehog and EGFR crosstalk: Parallels between brain neurogenesis and regulation of tumour growth.
19:15-19:40
3.8.5. Dario Acuña-Castroviejo
Centro de Investigación Biomédica, Parque tecnológico de Ciencias de la Salud, Universidad de Granada, Spain.
Role of melatonin in aging: clinical applications.
19:40-20:00
3.8.6. Rui Daniel Prediger
Departamento de Farmacologia, Universidade Federal de Santa Carina, Florianópolis, Brazil.
Brain in movement: physical exercise as a neuroprotective and disease-modifying agent of Parkinson’s disease.
ROOM LANZAROTE 1, 2
3.9. OLFACTORY SYSTEMS AND REPRODUCTIVE BEHAVIORS
Chair: Wendy Portillo
18:00-18:30
3.9.1 Rodrigo Suarez
Queensland Brain Institute. The University of Queensland Brisbane, Australia.
Neuroecology of the accessory olfactory system of placental mammals.
18:30-19:00
3.9.2 Raúl G. Paredes
Dpto de Neurobiología Conductual y Cognitiva, Instituto de Neurobiología, UNAM.
Role of the main and accessory olfactory bulbs in olfactory discrimination and sexual incentive motivation.
19:00-19:30
3.9.3 Ángel I. Melo
Laboratorio de Neuroendocrinología del Desarrollo, Centro de Investigación en Reproducción Animal,
CINVESTAV-Lab. Tlaxcala and Universidad Autónoma de Tlaxcala.
Chemical communication in rabbits: hormones and reproductive behaviors.
19:30-20:00
3.9.4 Rosalinda Guevara-Guzmán
Fac. de Medicina, UNAM.
Which is the role of the olfactory system in sexual behavior?
3.10. JUNIOR SYMPOSIUM: NEUROBIOLOGY OF FEAR MEMORY: MAINTENANCE VS. INHIBITION
Chair: Lucas de Oliveira Alvares
18:00-18:30
3.10.1. Fabrício do Monte
UPR-MS, Puerto Rico.
Midline thalamic nuclei in retrieval and maintenance of fear memory.
18:30-19:00
3.10.2 Fabrício Pamplona
D’Or Institute of Research and Education, Brazil.
(Fear) Re-learning through CB1cannabinoid receptors modulation.
19:00-19:30
3.10.3. Pedro Bekinschtein
Universidad de Buenos Aires.
Mechanisms of memory persistence: making memory last.
19:30-20:00
3.10.4.
Lucas de Oliveira Alvares
Universidade Federal do Rio Grande do Sul, Brazil.
Memory destabilization: exploring its biological role and clinical potential.
ROOM DEL PRADO
20:00-21:00 LECTURE
L09. Pablo E. Castillo
Dominick P. Purpura, Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY. USA.
Endocannabinoid-mediated plasticity: novel mechanisms and synaptic rules
NOVEMBER 8
4.1. MECHANISMS AND PHYSIOLOGICAL RELEVANCE OF CIRCADIAN RHYTHMS
Co-Chairs: Raúl Aguilar-Roblero and Mario Caba
09:00-09:30
4.1.1. María Fernanda Ceriani
Laboratorio de Genética del Comportamiento, Fundación Instituto Leloir, IIB-BA CONICET, Buenos Aires, Argentina.
Circadian period integrates network information through activation of the BMP signaling pathway.
09:30-10:00
4.1.2. Raúl Aguilar-Roblero
From the nucleus to the membrane: Ca2+ release from RyR signals time in SCN neurons.
10:00-10:30
4.1.3. John Fontenele Araujo
Departamento de Fisiologia - CB – UFRN, Brazil.
Understanding the circadian timing system of marmoset by desynchronization model.
10:30-11:00
4.1.4. Mario Caba
Centro de Investigaciones Biomedicas, Universidad Veracruzana. Xalapa, Ver., México.
The rabbit pup as a natural model of food anticipatory activity.
ROOM GRECO-DALÍ
4.2. SYNAPSE FUNCTION: INTRINSIC AND EXTRINSIC MODULATORS
Chair: Flávia Carvalho Alcantara Gomes
09:00-09:40
4.2.1. Vladimir Parpura
Deaprtment of Neurobiology, Center for Glial Biology in Medicine, Atomic Force Mricospocy and Nanotechnology
Laboratories, Civitan International Research Center, Evelyn F. McKnight Brain Institute, University of Alabama, US.
Tripartite synapse-astrocytic regulation of glutamate.
09:40-10:20
4.2.2. Cecilia Hidalgo
BNI and ICBM, Facultyn of Medicine, Universidad de Chile, Santiago de Chile.
Activation of Ryanodine Receptors/Calcium Release Channels Promotes Growth of Hippocampal Spines.
10:20-11:00
4.2.3. Flávia Carvalho Alcantara Gomes
Federal University of Rio de Janeiro, Brazil.
Astrocytes function and dysfunction: implications for synapse formation.
ROOM LANZAROTE 1, 2
4.3. NEURAL CONTROL OF CARDIORESPIRATORY FUNCTION
Chair: Fernando Peña
09:00-09:24
4.3.1 Consuelo Morgado
Centro de Investigaciones Cerebrales, Universidad Veracruzana, Mexico.
Respiratory rhythm generation: The whole is greater than the sum of the parts.
09:24-09:48
4.3.2. Fernando Peña
Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, UNAM, Mexico.
Glial and neuronal contributions to the reconfiguration of the respiratory network in hypoxia.
09:48-10:12
4.3.3. Jaime Eugenín
Universidad de Santiago, Chile.
Perturbation of the respiratory rhythm induced by prenatal nicotine exposure.
10:12-10:36
4.3.4. Jan Marino Ramirez
Center for Integrative Brain Research, Seatlle Children´s Research Institute, University of Washington, USA. From
Ball-and-Stick models to Clouds: new concepts in respiratory rhythm generation.
10:36-11:00
4.3.5. Davi José de Almeida Moares
Dept of Physiology, School of Medicine of Ribeirao Preto, Univ. Sao Paulo, Brazil.
Changes in electrophysiological profile of respiratory neurons cause sympathetic
overactivity in rats submitted to chronic intermittent hypoxia.
4.4. ROLES OF MICROGLIA IN DISEASE AND IN NORMAL DEVELOPMENT
Chair: Flavia Souza Lima
09:00-09:30
4.4.1. Monica J. Carson
University of California, Riverside, USA.
Microglial dependent modulation of synaptic maturation during post-natal development.
09:30-10:00
4.4.2. Fernando Pitossi
Fundacion Instituto Leloir, Argentina.
Functional role of neuroinflammation on Parkinson ‘s Disease etiology and progression.
10:00-10:30
4.4.3. João Ricardo Lacerda de Menezes
Lab de Neuroanatomia Celular, Instituto de Ciencis Biomedicas,
Centro de Ciencias da Saúde, UFRJ, Brazil
Distinct morphological features of microglia within the developing p
ostnatal subventricular zone/rostral migratory stream.
10:30-11:00
4.4.4. Flavia Regina Souza Lima
Universidade Federal do Rio de Janeiro, Rio do de Janeiro, Brazil.
Microglia-glioblastoma interaction: tumor proliferation and migration.
ROOM TENERIFE 1,2,3
4.5. JUNIOR SYMPOSIUM: ARTIFICIAL INTELLIGENCE IN THE CREATION OF
INTELLIGENT SYSTEMS FOR THE DIAGNOSTICS AND PRONOSTICS
OF CHRONIC AND NEURODEGENERATIVE DISEASES
Chair: Daniel Paredes
09:00-09:40
4.5.1. Alberto Hananel Baigorria
UGR-USAT, Peru.
Application of Neural Networks Models and Meshes of multivariate approach in Artificial Intelligence in the Diagnosis and Prognosis of Degenerative Diseases.
09:40-10:20
4.5.2. Santiago Paredes Ruiz
Universidad Nacional Mayor de San Marcos, Perú.
Definition of diagnostic and prognostic criteria in functional impairment
of personality development in childhood and adolescence: a clinical dilemma.
10:20-11:00
4.5.3.Daniel Angel Paredes
Universidad Peruana Cayetano Heredia, Perú.
Development of intelligent systems for the diagnosis and prognosis of neuropsychiatric disorders and degenerative
diseases.
ROOM DEL PRADO
13:00-14:00 LECTURE
L10. María Fernanda Ceriani
Instituto Leloir. IIB-BA CONICET. Buenos Aires, Argentina.
Circadian control of locomotor output: from structure to behavior
ROOM DEL PRADO
16:00-18:00 BUSINESS MEETING SOCIEDAD MEXICANA DE CIENCIAS FISIOLÓGICAS
4.6. ADVANCES IN PEPTIDE RESEARCH
Chair: Luis Aguilar
18:00-18:24
4.6.1. Rafael Coveñas
Instituto de Neurociencias de Castilla y León, España.
The peptidergic systems: basic and clinical aspects.
18:24-18:48
4.6.2. Luis Aguilar
Neuropeptides in the central auditory pathway.
18:48-19:12
4.6.3. Ewing Duque Díaz
Lab de Neurociencias, Universidad Pontificia Bolivariana-Montería, Colombia.
Neuropeptides in the human and monkey brainstem.
19:12-19:36
4.6.4. Inmaculada Cubero
Universidad de Almería, España.
The role of Orexins in binge-like ethanol drinking.
19:36-20:00
4.6.5. Luis Lerma
Structure and physiology of neuropeptides. What do we agree on?
ROOM GRECO-DALÍ
4.7. NEURONAL-GLIAL COMMUNICATION IN THE CNS: TRANSPORTERS
Chair: Ricardo AM Reis
18:00-18:30
4.7.1 Angelina Rodriguez
Facultad de Química, Universidad Autónoma de Querétaro, México.
Signaling through glutamate transporters in Bergmann glia cells.
18:30-19:00
4.7.2 Karin da Costa Calaza
Dept Neurobiologia, Universidade Federal Fluminense, Brazil.
Role of GABA transporters in the chick retina.
19:00-19:30
4.7.3. Arturo Ortega
Dept de Genética y Biología Molecular, Cinvestav-IPN, México.
Ontogeny of glial glutamine transporters.
19:30-20:00
4.7.4. Clarissa S Schitine
Inst Biofisica, Universidade Federal do Rio de Janeiro, Brazil.
Regulation of the GAT3 gabaergic transporter in avian Muller glia cells.
ROOM LANZAROTE 1, 2
4.8. HORMONES AND STRESS MODULATION OF HIPPOCAMPAL FUNCTION
Chair: Limei Zhang
18:00-18:30
4.8.1. Rafael Luján
Dpt Ciencias Medicas, Facultad de Medicina, Universidad de Castilla-La Mancha, Spain.
Structural and functional properties of hippocampus.
18:30-19:00
4.8.2. Zhenzhong Cui
Section on Neuroal Gene Expression, National Institute of Mental Health, Bethesda, USA.
Neuronal Connections of the Dorsal CA2 Area of the Mouse Hippocampus
19:00-19:30
4.8.3. Luz Torner
Centro de Investigaciones Biomédicas de Michoacán, Instituto Mexicano del Seguro Social, Morelia, Mexico.
Maternal separation and hippocampal neurogenesis at an early age: correlation with behavioral and
neuroendocrine disturbances in adulthood.
19:30-20:00
4.8.4. Limei Zhang
Departamento de Fisiología, Facultad de Medicina, Universidad Autónoma de México.
Synaptic innervation to rat hippocampus by vasopressin-immunopositive fibers from
the hypothalamic supraoptic and paraventricular nuclei.
4.9. NEURAL BASIS OF ATTENTIONAL PROCESSES
Chair: Mitchell Valdes-Sosa
18:00-18:30
4.9.1. Steven Hillyard
Department of Neurosciences, University of California, San Diego USA.
Tracking allocations of visual attention with Steady-State Visual Evoked Potentials.
18:30-19:00
4.9.2. Thalia Harmony Baillet
Unidad de Investigación en Neurodesarrollo y Departamento de Neurobiología
Conductual y Cognitiva, Instituto de Neurobiologia, UNAM, México.
Auditory attention in premature infants with periventricular leukomalacia.
19:00-19:30
4.9.3. Mitchell Valdes-Sosa
Centro de Neurociencias de Cuba, Cuba.
Neural basis of selective attention to global and local aspects of a visual scene.
19:30-20:00
4.9.4. Antigona Martinez.
Dept. Neurosciences, UC San Diego
Electrophysiological evidence for magnocellular processing deficits
in schizophrenia during feature selective attention.
ROOM DEL PRADO
20:00-21:00 LECTURE
L11. José María Delgado
Division of Neurosciences, Pablo de Olavide University, Sevilla, Spain.
Learning as a functional state: studies in wild type and transgenic mice
NOVEMBER 9
5.1. MULTIDISCIPLINARY APPROACH OF NEURODEGENERATIVE DISEASES
Chair: Luiz Roberto G. Britto
09:00-09:24
5.1.1. Luiz Roberto G. Britto
USP, Brazil.
Neurodegeneration and neuroprotection: lessons from animal models
09:24-09:48
5.1.2. Agustin Ibañez
INECO - Centros de estudios de la memoria y la conducta.
Action-verb processing in Parkinson´s disease: neural pathways for motor-language coupling.
09:48-10:12
5.1.3. Caroline Cristiano Real
USP, Brazil.
Exercise and neuroprotection in Parkinson’s disease.
10:12-10:36
5.1.4. Cecilia Cerqueira Café Mendes
USP, Brazil.
Peptidomic approaches in Parkinson’s disease.
10:36-11:00
5.1.5. Ana Francisca Barros Ferreira
USP, Brazil.
Mechanisms of cell death in Alzheimer’s disease.
ROOM GRECO-DALÍ
5.2. NEW DEVELOPMENTS IN SCHIZOPHRENIA RESEARCH
Chair: Elisa C. Dias
09:00-09:30
5.2.1. Elisa C. Dias
Nathan Kline Institute for Psychiatric Research, Orangeburg, New York, USA.
Sensory processing deficits in schizophrenia.
09:30-10:00
5.2.2. John F. Smiley
Nathan Kline Institute for Psychiatric Research, Orangeburg, New York, USA.
Cell selective changes in schizophrenia cerebral cortex.
10:00-10:30
5.2.3. Stevens Rehen
Laboratório Nacional de Células-Tronco Embrionárias, Instituto de Ciências Biomédicas, UFRJ, Brazil.
Elevated production of reactive oxygen species during neurogenesis of induced
pluripotent stem cells derived from a schizophrenic patient.
10:30-11:00
5.2.4. Pablo A. Gaspar
Clinical Hospital of the University of Chile.
Contributions of Functional Neuroimaging to understand the motion-processing deficits in schizophrenia.
ROOM LANZAROTE 1, 2
5.3. ROLE OF REACTIVE OXYGEN SPECIES IN THE PHYSIOLOGY AND
PATHOPHYSIOLOGY OF THE CNS
Chair: Marco Tulio Núñez
09:00-09:30
5.3.1. Cecilia Hidalgo
BNI, CEMC and ICBM, Facultad de Medicina, Universidad de Chile.
Role of redox sensitive RyR-mediated calcium release in synaptic plasticity.
09:30-10:00
5.3.2.
Andrea C. Paula-Lima
Faculty of Dentistry, Universidad de Chile, Santiago Chile.
Calcium and ROS in Alzheimer’s disease.
10:00-10:30
5.3.3. Joana C. D´avila
Oswaldo Cruz Foundation (FIOCRUZ), Rio de Janeiro,Brazil.
Oxidative stress and bioenergetic imbalance in the pathophysiology of septic encephalopathy.
10:30-11:00
5.3.4. Marco Tulio Núñez
Facultad de Ciencias, Universidad de Chile; Research Ring on
Oxidative Stress in the Nervous System, Santiago, Chile.
In vivo and in vitro reversion of midbrain dopaminergic neurons degeneration by iron chelators.
5.4. REPRODUCTION AND SEXUAL FUNCTION: ROLE OF STRESS AND DIFFERENT CONTEXTS
Chair: Monica Levy Andersen
09:00-09:30
5.4.1. Jorge Manzo
Centro de Investigaciones Cerebrales, Universidad Veracruzana, México.
Cerebellum and sexual behavior: What’s the relationship?
09:30-10:00
5.4.2. Monica L. Andersen
Dept Psicobiologia, Universidade Federal de Sao Paulo, Brazil.
Can sleep loss affect sexual behavior?
10:00-10:30
5.4.3. Tathiana Alvarenga
Universidade Federal de Sao Paulo, Brazil.
Sexual experience may modulate the sexual response.
10:30-11:00
5.4.4. Janete Anselmo-Franci
Faculdade de Odontologia de Ribeirão Preto, Universidade de São Paulo.
The effect of stress on female reproduction is always the same in different contexts?
NOTE: THE POSTERS ASSIGNED FOR THE DAY WILL BE LEFT ON DISPLAY UNTIL 15:00
ROOM DEL PRADO
13:00-15:00 DISCUSSION FORUM NEUROSCIENCES IN LATINAMERICA:
NEUROSCIENCE IN LATINAMERICA: WHERE ARE WE? WHERE SHOULD WE GO?
Co-Chairs:
Consuelo Morgado-Valle and Gabriela González-Mariscal, President of SMCF.
Carlos Belmonte, President of the International Brain Research Organization.
Ranulfo Romo, Instituto de Fisiologia Celular. UNAM
Gregory Quirk, School of Medicine, University of Puerto Rico
Rommy Von Bernhard Montgomery, President of the FALAN.
Carlos Beyer, Centro de Investigación en Reproducción Animal, CINVESTAV-Universida Autónoma de Tlaxcala, México.
ROOM DEL PRADO
20:00-24:00 CLOSING CEREMONY AND DINNER
LECTURES
L01
CONVERSION OF SENSORY SIGNALS INTO PERCEPTUAL DECISIONS
Ranulfo Romo
Instituto de Fisiología Celular, Universidad Nacional Autónoma de México and El Colegio Nacional, México
L02
BUILDING CORTICAL REPRESENTATIONS WITH EXPERIENCE:
INSIGHTS FROM VISUAL CORTEX
David Fitzpatrick
Max Planck Florida Institute, Jupiter Florida, USA
L03
86 BILLION BRAIN NEURONS: THE ADVANTAGES AND COSTS
OF THE REMARKABLE, BUT NOT EXTRAORDINARY, HUMAN BRAIN
Susana Herculano-Houzel
Universidade Federal do Rio de Janeiro, Brazil and Instituto Nacional de Neurociência
Translacional, São Paulo, Brazil
L04
USING SYSTEMS BIOLOGY TO GAIN INSIGHTS INTO THE GENETICS
AND EPIGENETIC MECHANISMS CONTROLLING MAMMALIAN PUBERTY
Sergio R. Ojeda
Division of Neuroscience, Oregon National Primate Research Center, Beaverton,
Oregon,USA
L05
SYNAPTIC TRANSMISSION MEDIATED BY GAP JUNCTIONS:
PROPERTIES AND PLASTICITY
ALBERTO PEREDA
Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine,
Bronx, New York, USA.
L06
FUNCTIONAL DISSECTION OF DOPAMINE D2 RECEPTORS
BY CONDITIONAL MUTAGENESIS
Marcelo Rubinstein
INGEBI-CONICET and FCEyN, Universidad de Buenos Aires, Argentina
L07
EFFECTS OF EARLY LIFE EXPERIENCE ON THE DEVELOPMENT
OF THE CENTRAL NERVOUS SYSTEM: ROLE OF MATERNAL CARE
Alison S. Fleming
University of Toronto at Mississauga, Canada
L08
PATHOGENIC ROLE OF PHENOTYPICALLY
ABERRANT ASTROCYTES IN ALS
Luis Barbeito
Institut Pasteur de Montevideo, Uruguay
L09
ENDOCANNABINOID-MEDIATED PLASTICITY:
NOVEL MECHANISMS AND SYNAPTIC RULES
Pablo E. Castillo
Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine,
Bronx, NY, USA.
L10
CIRCADIAN CONTROL OF LOCOMOTOR OUTPUT:
FROM STRUCTURE TO BEHAVIOR
María Fernanda Ceriani
Laboratorio de Genética del Comportamiento, Instituto Leloir, IIB-BA CONICET. Buenos
Aires, Argentina.
L11
LEARNING AS A FUNCTIONAL STATE OF THE BRAIN:
STUDIES IN WILD TYPE AND TRANSGENIC MICE
José María Delgado-Garcia
Division of Neurociences, Pablo de Olavide University, Seville, Spain
L01
CONVERSION OF SENSORY SIGNALS INTO PERCEPTUAL DECISIONS
Romo R. El Colegio Nacional and Universidad Nacional Autónoma de México, México.
L02
BUILDING CORTICAL REPRESENTATIONS WITH EXPERIENCE:
INSIGHTS FROM VISUAL CORTEX
David Fitzpatrick, Max Planck Florida Institute, Jupiter Florida.USA.
Most perceptual tasks require sequential steps to be carried out. This must be the case, for example,
when subjects discriminate the difference in frequency between two mechanical vibrations applied
sequentially to their fingertips. This perceptual task can be understood as a chain of neural operations:
encoding the two consecutive stimulus frequencies, maintaining the first stimulus in working memory,
comparing the second stimulus to the memory trace left by the first stimulus, and communicating
the result of the comparison to the motor apparatus. Where and how in the brain are these cognitive
operations executed? We addressed this problem by recording single neurons from several cortical
areas while trained monkeys executed the vibrotactile discrimination task. We observed that primary
somatosensory cortex (S1) drives higher cortical areas where past and current sensory information
are combined, such that a comparison of the two evolves into a decision motor report. Consistent
with this result, direct activation of the S1 can trigger quantifiable percepts in this task. These findings provide a fairly complete panorama of the neural dynamics that underlies the transformation of
sensory information into an action and emphasize the importance of studying multiple cortical areas
during the same behavioral task.
Early in postnatal development, as visual experience begins to influence neural activity, visual cortex
lacks the full complement of connections and the response selectivity that defines functional maturity. Recent studies emphasize that visually driven activity at this early stage is important for the
construction of cortical circuits, especially those representing stimulus motion. In ferret visual cortex,
at the time of eye-opening, cortical neurons are weakly tuned to the direction of stimulus motion and
they lack the columnar structure that characterizes the mature cortical representation. Under natural
conditions, both response selectivity and columnar structure for motion direction emerge during the
first week to 10 days after eye-opening, in a process that is dependent on visual experience. Under experimental conditions, exposure of visually naïve animals to a bidirectional motion “training_ stimulus
induces the rapid (10-12 hrs) emergence of direction columns. Changes in the response properties of
individual neurons that underlie the emergence of direction columns have been captured with in vivo
two-photon imaging of calcium indicators. Experience dramatically increases the direction selective
responses of individual neurons, and builds a coherent columnar structure from a weak spatial bias
that exists at the onset of training. The spatiotemporal properties of the motion training stimulus play
an instructive role in this process as unidirectional training results in a preponderance of neurons that
prefer the direction of the training stimulus.
L03
86 BILLION BRAIN NEURONS: THE ADVANTAGES AND COSTS OF THE
REMARKABLE, BUT NOT EXTRAORDINARY, HUMAN BRAIN
L04
USING SYSTEMS BIOLOGY TO GAIN INSIGHTS INTO THE GENETICS AND
EPIGENETIC MECHANISMS CONTROLLING MAMMALIAN PUBERTY
Herculano-Houzel S (1,2) , (1) Universidade Federal do Rio de Janeiro, Brazil; (2) Instituto Nacional de
Neurociência Translacional, São Paulo, Brazil.
Sergio R. Ojeda Division of Neuroscience, Oregon National Primate Research Center, Beaverton,
Oregon 97006,USA
Neuroscientists have become used to a number of “facts” about the human brain: it has 100 billion
neurons and 10-50 times more glial cells; it is the largest-than-expected for its body among primates
and mammals in general, and therefore the most cognitively able; it consumes an outstanding 20% of
the total body energy budget despite representing only 2% of body mass, because of an increased metabolic need of its neurons; it is endowed with an overdeveloped cerebral cortex, the largest compared
to brain size. These “facts” led to the widespread notion that the human brain is literally extraordinary:
an outlier, defying evolutionary rules that apply to other species, a uniqueness seemingly necessary to
justify the superior cognitive abilities of humans over mammals with even larger brains. These “facts”,
with deep implications for neurophysiology and evolutionary biology, are however not grounded on solid
evidence nor sound assumptions. Our recent development of a method that allows rapid and reliable
quantification of the numbers of cells that compose the whole brain has provided a means to verify
these “facts”. In this talk I will review this new evidence and argue that, with 86 billion neurons and
just as many non-neuronal cells, the human brain is a scaled-up primate brain in its cellular composition and metabolic cost, with a relatively enlarged cerebral cortex that does not have a relatively larger
number of brain neurons, yet is remarkable in its cognitive abilities and metabolism simply because of
its extremely large number of neurons. I will also argue that, because of metabolic limitations due to
the number of hours available for feeding on a raw diet, such an enormous number of neurons could
only be afforded in evolution with a shift to a cooked diet by our ancestors.
Puberty is a major developmental milestone set in motion by the interaction of genetic factors and
environmental cues of mostly metabolic and circadian nature. An increased pulsatile release of the
decapeptide gonadotropin releasing hormone (GnRH) from hypothalamic neurosecretory neurons is
required for both the initiation and progression of the pubertal process. This increase is brought about
by well-coordinated changes that occur in neuronal and glial networks associated to GnRH neurons. As
a result of these changes neuronal and glial stimulatory inputs to the GnRH neuronal network increase
and transsynaptic inhibitory influences diminish. While some of the major players controlling pubertal
GnRH secretion have been identified using gene-centric approaches, much less is known about the
system-wide control of the overall process. Because the pubertal activation of GnRH release involves
a diversity of cellular phenotypes, and a myriad of intracellular and cell-to-cell signaling molecules,
it appears that the overall process is controlled by a highly coordinated and interactive regulatory
system involving hundreds, if not thousands, of gene products. In this presentation we will discuss
emerging evidence suggesting that these genes are arranged as functionally connected networks organized in a hierarchical fashion, and that the integrative response of these networks to external inputs
is coordinated by epigenetic mechanisms. The concept will also be elaborated that the core of these
genetic networks is composed of transcriptional regulators that, by directing expression of downstream
subordinate genes, provide both stability and coordination to the cellular subsets involved in initiating
the pubertal process. Supported by NSF grant IOS 1121691.
L05
SYNAPTIC TRANSMISSION MEDIATED BY GAP JUNCTIONS:
PROPERTIES AND PLASTICITY
L06
FUNCTIONAL DISSECTION OF DOPAMINE D2 RECEPTORS BY
CONDITIONAL MUTAGENESIS
Alberto Pereda, Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine,
Bronx, New York, USA.
Marcelo Rubinstein, INGEBI-CONICET and FCEyN, Universidad de Buenos Aires, Argentina
While the study of plasticity of chemical synapses has long been an area of primary interest to neuroscientists, less is known about the properties and modifiability of gap junction-mediated electrical
synapses. In contrast with mammalian electrical synapses that generally have limited experimental
access, lower vertebrates have provided with advantageous experimental models in which basic properties of electrical transmission can be more easily study. This is the case of identifiable auditory afferents terminating on the teleost Mauthner cells. These endings are “mixed” (electrical and chemical)
synaptic contacts that offer the rare opportunity to correlate physiological properties with molecular
composition and specific ultrastructural features of individual synapses. Gap junctions at these model
synapses undergo activity-dependent potentiation and are mediated by fish homologs of connexin 36,
which is widely distributed across the mammalian brain. The talk will focus on the molecular mechanisms that underlie activitydependent changes in electrical transmission, in particular the role of
trafficking of gap junction channels and the identification of connexin-associated regulatory proteins.
We found that gap junction channels are continuously trafficked in and out of the membrane of these
contacts, suggesting that the strength of the electrical synapses at these terminals is sustained, at
least in part, by a fast turnover of gap junction channels. We also found that interactions involving
conserved regions of the carboxy-terminus of connexin 36 and its teleost homologs are required for
the surface expression of gap junction proteins. Thus, our data indicate that electrical synapses are
dynamic structures and that their channels are actively turned over, suggesting that regulated trafficking of connexons may contribute to modification of gap junctional conductance.
Dopamine (DA) participates in the control of locomotor activity, spatio-temporal organization of goaloriented behaviors and the reinforcing properties of natural rewards. Also, drugs acting on DA receptors
are often used in neurological and psychiatric disorders including Parkinson’s disease, schizophrenia,
ADHD and drug addiction. D2 receptors (D2Rs) are expressed postsynaptically in most DA target areas
and, in addition, in DA neurons where they act as autoreceptors. In vivo blockade or stimulation of D2R
subpopulations has been hampered by the fact that active compounds interact simultaneously with
the entire repertoire of D2Rs. To circumvent this difficulty, we created mutant mice selectively lacking
D2Rs by cell-specific conditional gene targeting. As a first example, mice carrying loxP sites flanking
Drd2 exon 2 (Drd2flox/flox) were crossed with mice expressing Cre from the dopamine transporter
gene (Dat+/IresCre). Analysis of compound Drd2flox/flox. Dat+/IresCre mice (autoD2RKO) showed a
total loss of Drd2 expression in midbrain dopaminergic neurons while retaining expression in forebrain
postsynaptic neurons and pituitary cells. Voltage clamp recordings showed that the D2-like agonist
quinpirole induced a slow hyperpolarizing current in midbrain DAergic neurons from Drd2flox/flox
mice but not in autoDrd2-/- mice. Similarly, the D2-like receptor antagonist sulpiride reduced evoked
inhibitory postsynaptic currents only in neurons from Drd2flox/flox mice. Fastscan cyclic voltammetry
in striatal slices and in vivo microdialysis studies demonstrated that DA release is highly increased
in autoD2RKO mice, and no DA uptake alterations. DA synthesis was elevated and insensitive to the
regulatory effects of quinpirole in the striatum of autoD2RKO mice. At the behavioral level autoD2RKO
mice displayed increased locomotor activity and supersensitivity to the motor effects of cocaine. Interestingly, autoD2RKO mice exhibited increased place preference for cocaine and enhanced motivation
for food reward. Thus, selective deletion of D2Rs proved to be a powerful tool to address the functional
role of specific D2R subpopulations.
L07
EFFECTS OF EARLY LIFE EXPERIENCE ON THE DEVELOPMENT OF THE
CENTRAL NERVOUS SYSTEM: ROLE OF MATERNAL CARE
L08
PATHOGENIC ROLE OF PHENOTYPICALLY
ABERRANT ASTROCYTES IN ALS
Alison S. Fleming, University of Toronto at Mississauga, Canada.
Barbeito L. Institut Pasteur de Montevideo, Uruguay.
What makes a mother want to mother? In most mammalian species, the female is not normally maternal until she herself gives birth. However, at the end of pregnancy and at birth the hormonal changes
that occur result in a shift in the mother’s attraction to young and attention to them. Among humans
as well, mothering motivation tends to increase after birth and is affected by a shift in mothers’ appraisal of babies, an enhanced emotional sensitivity and lability and a change in a number of executive
(cognitive) functions. The present talk will first discuss the role of hypothalamic, limbic, and cortical
systems within the brain in the regulation of mothering and associated behaviors. It will then describe
studies which show that variations in mothering behavior affect the brains of their daughters and, in
doing so, affects the maternal behavior of the next generation. HPLC and microdialysis studies indicate
that the pattern of extracellular DA release in response to pups seen in new mother rats is altered by
early experiences and maternal/social isolation. In fMRI studies in human mothers, differential BOLD
activation patterns to infant- as opposed to -noninfant stimuli occur in many of the same dopaminergic
and limbic system sites in the ‘maternal neural circuit’ and are also affected by experience. Taken together these studies suggest that there are similarities in the psychology and neurobiology of maternal
behavior in rat and human mothers.
Motor neuron loss and reactive astrocytosis are pathological hallmarks of Amyotrophic Lateral Sclerosis, a paralytic neurodegenerative disease that can be triggered by mutations in Cu,Zn-superoxide
dismutase-1 (SOD1). Dysfunctional astrocytes contribute to ALS pathogenesis, inducing motoneuron
damage and accelerating disease progression.However, it is unknown whether ALS progression is
associated to the appearance of a specific astrocytic phenotype with neurotoxic potential. We have
recently reported the isolation of astrocytes with aberrant phenotype (referred as AbAs) from primary
spinal cord cultures of symptomatic rats expressing the SOD1G93A mutation. Isolation was based on
AbA’s marked proliferative capacity and lack of replicative senescence, which allowed oligoclonal cell
expansion during over 1 year. AbAs displayed astrocytic markers including GFAP, S100_, glutamine
synthase and connexin 43, but lacked the GLT1glutamatetransporter and the glial progenitor marker
NG2 glycoprotein. Notably, AbAs secreted soluble factors that induced motoneuron death with a 10-fold
higher potency than neonatal SOD1G93Aastrocytes. AbA-like aberrant astrocytes expressing S100_
and connexin43 but lacking NG2 were identified nearby motoneurons, its number increasing sharply
after disease onset. Thus, AbAs appear as a yetunknown astrocyte population arising during ALS progression, with unprecedented proliferative and neurotoxic capacity, being potential cellular targets for
slowing ALS progression.
L09
ENDOCANNABINOID-MEDIATED PLASTICITY:
NOVEL MECHANISMS AND SYNAPTIC RULES
L10
CIRCADIAN CONTROL OF LOCOMOTOR OUTPUT:
FROM STRUCTURE TO BEHAVIOR
Castillo PE. Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine,
Bronx, NY, USA.
María Fernanda Ceriani- Laboratorio de Genética del Comportamiento. Instituto Leloir. IIB-BA CONICET.
Buenos Aires, Argentina.
Since the discovery of ∆9-THC as the main psychoactive ingredient of marijuana in the sixties, and
the cloning of cannabinoid receptors and subsequent identification of their endogenous ligands (also
known as endocannabinoids) in the nineties, our understanding of the molecular basis and functions
of the endocannabinoid signaling system has evolved considerably. Extensive research in the last 15
years has consolidated our view of endocannabinoids as powerful regulators of synaptic function
throughout the central nervous system. Their role as retrograde messengers suppressing transmitter
release, either in a transient or more consolidated manner, at both excitatory and inhibitory synapses,
is now well-established. There is also evidence that retrograde signaling may not be the only way by
which endocannabinoids control neural activity. Regardless the precise mechanism of action, it is
widely believed that by targeting synaptic function, endocannabinoids can regulate a wide range of
neural functions, including cognition, motor control, feeding behaviors and pain control. In this lecture,
Pablo Castillo will discuss recent discoveries on the major molecular and cellular mechanisms underlying endocannabinoid-mediated plasticity in the mammalian brain.
Circadian rhythms regulate physiology and behavior through the action of self-sustained transcriptional feedback loops of clock genes. In Drosophila, over 150 neurons in the fly brain are implicated in the
circadian regulation of restactivity cycles, but a small subset -so-called small ventral lateral neurons
(sLNvs)- are clearly crucial. Preservation of molecular oscillations within the sLNvs is key to command
rhythmic behavior under free running conditions. The sLNvs transmit this ¨time of day¨ information
releasing a neuropeptide known as pigment dispersing factor (PDF). Over the years a reasonably clear
picture of how the molecular clock is assembled within a cell has emerged; however, little is known
about how this molecular clock communicates with other clocks in the brain and the body to ensure
a coherent response to daily changes in the environment, which is the focus of our laboratory. In the
search for additional mechanisms employed by the central pacemaker neurons (sLNvs) to transmit
time of day information to the rest of the network we uncovered a novel circadian phenomenon involving extensive remodeling in the axonal terminals of the PDF circuit, which display higher complexity
during the day and significantly lower complexity at nighttime, both under daily cycles and constant
conditions (Fernandez et al. PLoS Biol. 2008). We then proposed that such circadian remodeling of
axonal terminals could imply synaptogenesis taking place on daily basis, and, as a consequence, determine a potential change in synaptic partners. The molecular mechanisms underlying this structural
plasticity will be discussed.
L11
LEARNING AS A FUNCTIONAL STATE OF THE BRAIN:
STUDIES IN WILD TYPE AND TRANSGENIC MICE
Delgado-Garcia JM, Division of Neurociences, Pablo de Olavide University, SevillE-41013, Spain
The complexity of brain functions can only be approached by the use of multidisciplinary and comparative approaches. The availability of genetically manipulated mammals (mice and rats for the moment)
and of sophisticated electrophysiological techniques, susceptible of being applied in alert behaving
animals during the acquisition of new motor and cognitive abilities, have largely facilitated this approach. Our group has studied for years the contribution of sensory, motor, premotor, hippocampal, and
prefrontal cortical circuits to non-associative, classical, and operant learning paradigms. For this, we
have recorded activity-dependent changes in strength in cortical and subcortical synapses during the
acquisition process. In addition, we have studied the contribution of many different neurotransmitters
and related receptors in selected transgenic animals, as well as using in vivo si-RNA injections and
pharmacogenetic procedures. The main output of our studies is that learning is the result of the activity
of wide cortical and subcortical circuits activating particular functional properties of involved synaptic
nodes and that brain functions during learning processes have to be studied during the acquisition
process, that is, at live.
SYMPOSIA
MONDAY NOVEMBER 5
1.1.1.
MÜLLER GLIA IN FOCUS
1.1.2.
NON-VISUAL PHOTORECEPTORS IN THE INNER RETINA
LAMAS M
Depto. de Farmacobiología. Centro de Investigación y de Estudios Avanzados, CINVESTAV.
GUIDO ME, DIAZ NM, MORERA LP, VERRA DM, CONTIN MA
CIQUIBIC-Dpto. Química Biológica, Fac. Cs. Químicas, Universidad Nacional de Córdoba-CONICET
Müller cells are radial glial that span the entire depth of the retina contacting all types of retinal
neurons and actively participating in the processing of visual information. Among the essential physiological functions of mature Müller glial cells, the observation that these cells retain the capacity to
dedifferentiate, proliferate and produce new neurons and glia, has brought into focus their potential to
constitute a promising target for therapeutic regeneration. We will discuss the ongoing efforts or our
laboratory to identify the genetic and epigenetic events underlying the dedifferentiation process that
drive the fully differentiated rat Müller cells to a “progenitor-like” stage. We will also present results
about the identification of intrinsic and extrinsic factors that control the proliferation and differentiation of postnatal Müllerderived progenitor cell and describe the experimental approaches developed to
fully characterize, in vivo, the regeneration potential of rat Müller cells. On the whole, we would like to
offer a “state of the art” in this exciting area of research that may lead to the unprecedented possibilty
of promoting retinal regeneration in mammals. This work was supported by CONACYT.
In the vertebrate retina, a new class of photoreceptor cells, the intrinsically photosensitive retinal ganglion cells (ipRGCs) has been recently described and implicated in the regulation of non-visual functions (pupillary light reflexes, synchronization of behavioral rhythms, etc.) (see Guido et al. 2010, for
review). RGCs express the non-visual photopigment melanopsin (Opn4) resembling ancient rabdomeric
photoreceptors. In the chicken retina, two Opn4 genes (Opn4x and Opn4m) have been reported. We
previously described non-visual light responses in GUCY1* (blind) birds mediated by the inner retina
(Valdez et al., 2009) and the presence of ipRGCs expressing both Opn4 proteins in the wild type (WT)
chicken retina which operates through a invertebrate-like photocascade (Contin et al., 2006, 2010).
Opn4m was found to be restricted exclusively to the GC layer whereas Opn4x was mainly expressed
in Prox1 (+) horizontal cells (HCs) by embryo day 15 (Verra et al., 2011). We have now developed
a novel method to separate and culture HCs (Morera et al., 2012) in order to study their potential
intrinsic photic responses. Therefore, bistable photopigments such Opn4 may use a novel visual cycle
for chromophore regeneration within the inner retina that relies upon distinct isomerase activities. We
investigated the expression of the photoisomerase RGR and assessed levels of retinal chromophores
(11-cis RAL and all-trans RAL) in the chicken inner retina in collaboration with A. Tsin laboratory (UTSA,
USA). Levels of 11-cis RAL were higher in the GC layer from light-adapted birds as compared with those
maintained in the dark. In addition, the GC layer differentially expressed RGR which colocalizes with
Muller cell markers. The different light-dark effects on retinoids and the differential expression of RGR
in the GC layer strongly suggest that a novel visual cycle takes place in the chicken inner retina to
support retinoid isomerization in ipRGCs or other photosensitive cells.
1.1.3.
PUPIL RESPONSES IN NEUROPATHIES AND MELANOPSIN
1.2.1
THE CROSSTALK BETWEEN THE CIRCADIAN AND IMMUNE SYSTEMS
Dora Fix Ventura1 , Ana Laura A. Moura1, Balázs V. Nagy1, Chiara La Morgia2, Solange R. Salomão3, Adriana
Berezovsky3, Carlos Filipe Chicani4, Valério Carelli2, Alfredo A. Sadun4 , Donald C. Hood5A,B. 1 Instituto de Psicologia, Universidade de São Paulo, Brasil; 2 Department of Neurological Sciences, University of Bologna, Italy; 3
Departamento de Oftalmologia, Universidade Federal de São Paulo, Brasil; 4 Doheny Eye Institute, Keck-USC School
of Medicine, LA, USA; 5A Psychology, B Ophthalmology, Columbia University, NY, USA
Erin E. Fortier1,2,3, Susan Westfall1,3, Julie Rooney2, Valérie Mongrain1,4,HuguesDardente1,4,
Argel Aguilar Valles 1,3, Shang Wan Liu1, Marie-Pierre Hardy2, Giamal N. Luheshi1,3,4, Nathalie
Labrecque2,5,6, Nicolas Cermakian1,3,4. 1 Douglas Mental Health University Institute, Montréal, QC,
H4H 1R3, CANADA 2Maisonneuve-Rosemont Hospital Research Centre, University of Montreal, Montréal, QC, H1T 2M4, CANADA. 3Department of Neurology and Neurosurgery, 4Department of Psychiatry,
McGill University, Montréal, QC, H3A 2T5, CANADA. 5Department of Medicine, 6Department of Microbiology and Immunology, University of Montréal, Montréal, QC, H3C 3J7, CANADA
The ganglion cells that express melanopsin respond directly to light incident in the retina and are
therefore called intrinsically photosensitive ganglion cells (ipRGC). These cells are thought to signal
the ambient light level and they are involved in the control of the circadian rhythm. In addition they
participate in the pupillary response to light. Optic neuropathies are generally characterized by the
loss of ganglion cells, and specifically in Leber’s Hereditary Optic Neuropathy (LHON) there is a sudden
and massive loss of ganglion cells due to a great wave of apoptosis. LHON is a genetic disease caused
by a mutation in the mitochondrial DNA. Our group is undertaking a large study in a giant pedigree of
patients with LHON, in Espírito Santo, Brazil, for the last 10 years. Post mortem histological analysis of
donor retinas of LHON patients confirmed the massive loss of ganglion cells, but showed a surprising
selective preservation of the ipRGCs. LHON patients also showed melatonin production in response
to a bright light presented during the night, suggesting preservation of this function. These findings
motivated our group to investigate the melanopsin component of the pupil response to light. Recent
work allowed the development of clinical protocols to study the melanopsin response in the pupillary
light reflex. The pupil response to light of LHON patients exposed to blue light (470 nm), that activates
melanopsin preferentially, was compared to that produced by red light (670 nm), outside the absorption band of this photopigment. The results showed that the sustained response to light, characteristic
of the ipRGC activity, was present. Its magnitude ranged from normal in some patients to somewhat
reduced in others, but there was no question that the ipRGCs were functional. These results confirm
the findings of selective preservation of ipRGCs and suggest that these cells form the main pathway
responsible for the pupillary photomotor response. Furthermore they explain the clinical observation
that, despite the massive ganglion cell loss, LHON patients preserve the pupillary photomotor reflex.
Many aspects of the immune system, including circulating cytokine levels as well as counts and function of various immune cell types, present circadian rhythms. We aimed to investigate the mechanisms
underlying the crosstalk between the circadian and immune systems. In a first study, we investigated
the circadian control of T cell response to antigen presentation. We showed that mouse lymph nodes
exhibit rhythmic clock gene expression. T cells from lymph nodes collectedover 24 h show a circadian
variation in proliferation after stimulation via the TCR, which is blunted in Clock gene mutant mice. The
tyrosine kinase ZAP70, which is just downstream of the TCR in the T cell activation pathway and crucial
for T cell function,exhibits rhythmic protein expression. Lastly, mice immunized with OVA peptideloaded dendritic cells in the day show a strongerspecific T cell response than mice immunized at night.
These data reveal circadian control of the Ag-specific immune response anda novel regulatory mode of
T cell proliferation, and may provide clues for more efficient vaccination strategies. To investigate the
other hand of the circadian-immune crosstalk, our second study addressed effects of inflammation on
the expression of clock genes. To this end, we induced inflammation in rats by injectionof turpentine
oil (TURP) and showed that this causes a time-dependent induction of interleukin(IL)-6 and has time-,
gene- and tissue-specific effects on clock gene expression. Co-treatment with anti-inflammatory agent
IL-1 receptor antagonist (IL-1Ra) did not alter the response of Per2 to TURP in liver, despite a reduced
induction of fever and IL-6 serum levels. Accordingly, IL- 6 treatment had no effect on clock gene
expression in HepG2 liver carcinoma cells.Altogether, inflammation causes significant time-dependent
changes in peripheral circadian clock gene expression, via a mechanism likely involving IL- 6- and
fever-independent mediators. Funding: Canadian Institutes of Health Research.
1.2.2
MELATONIN AND ITS INVOLVEMENT IN THE IMMUNE SYSTEM
1.2.3
THE HOST-PARASITE NEURO-IMMUNO-ENDOCRINE NETWORK
Regina P Markus – Institute of Bioscience, University of São Paulo, Brazil
Jorge Morales-Montor.
Departamento de Inmunología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México
Parasites are a fascinating example of adaptation due to their complex strategies of colonization and
invasion. They can exploit diverse mechanisms to alter host behavior that facilitates their establishment, growth, reproduction and in consequence, their transmission. Additionally, these organisms
play an important role in ecological interactions and ecosystem adjustment. In the host, the parasite
can alter the environment through the inflammatory response, causing either damage or apoptosis in
specific places or taking advantage of the neuroimmunoendocrine network of the host, managing a
hostile environment, to a facilitative one, conducive to their establishment, growth and reproduction
into an immunocompetitive host. In this symposium, I will present in some detail our extensive work on
the molecular changes in the central nervous, endocrine and immune system of the host in response
to helminth infection, as well as the role of these molecular changes in inducing behavioral changes
on the host, including aggressive, reproductive, learning and cognitive behaviors during the course of
infection. Also, a short review on the applications that these molecular changes may have in the drug
design against parasitic infections will be discussed.
The innate immune response is a rapid an efficient response against aggressionsof physical, chemical
and biological nature. It is mediated by a stereotyped transcription of genes that allows the migration of immune-competent cells to the site of lesion, and the production of substances that kills the
aggressor and removes cellular debris and strange particles.The terminus of the response is also an
active process, which leads to healing. The activation of the Immune-Pineal Axis is one of the regulatory
mechanisms that fine-tune this important process (1). Nocturnal melatonin inhibits the rolling and
adhesion of leukocytes to the endothelial layers avoiding the migration of cells to the tissues in healthy
animals. The activation of receptors that recognize pathogen-associated molecular patterns (PAMPs),
such as lipopolysaccharide (LPS) in the pineal gland induces nuclear translocation of nuclear factor
kappa B (NF-kB). In pinealocytes, NF-kB impairs the transcription of the gene that codifies the enzyme
that converts serotonin in N-acetylserotonin (the immediate precursor of melatonin). The reduction
in nocturnal circulating melatonin favors migration of leukocytes to the site of lesion. Recently, we
have shown that in the macrophage ambience NF-kB induces the synthesis of melatonin, turning on
the transcription of the enzyme serotonin-N-acetyltransferase. Local produced melatonin, by acting
through melatonin receptors potentiates phagocytic activity, improving the clearing of the ambience,
and in a mechanism independent of receptors, which requires much higher concentrations, reduces
the transcription of pro-inflammatory mediators and acts as a scavenger of free radicals, contributing
to the ending of the inflammatory response. A similar role is played by microglia in the central nervous
system. Looking back to the pineal gland, we showed that glucocorticoids, which increase during the
course of the inflammatory response due to activation of the hypothalamus-pituitary-adrenal axis
(HPA) blocks pineal NF-kB pathway, restoring nocturnal melatonin surge. The concept of the ImmunePineal Axis put together some controversial facts in the literature, regarding melatonin role in inflammatory responses, and disclose the cellular and molecular mechanisms responsible for pineal gland
participation in this complex and fine-tuning innate defense response. 1 - Markus RP, Ferreira ZS,
Fernandes PA, Cecon E. The immune-pineal axis: a shuttle between endocrine and paracrine melatonin
sources. Neuroimmunomodulation. 2007;14:126-133
1.2.4
OUR BIOLOGICAL CLOCK TUNES THE IMMUNE SYSTEM
1.3.1
NEURODEGENERATION MECHANISMS AND CELL CYCLE
Natali Guerrero-Vargas(1), Fernando Cazarez-Marquez(1), Joselyn Corona(1), Mara Guzman-Ruiz(1),
Roberto Salgado(1), Mari Carmen Basualdo(1), Carolina Escobar(2), Ruud M Buijs(1). Instituto de
Investigacioned Biomedicas and Depto Anatomia Fac Medicina Universidad Nacional Autonoma de
Mexico.
Antonio Camins (1), Felix Junyent (1), Carme Auladell (2), Aurelio Vazquez de la Torre (1), Maria Luisa
de Lemos (1), Ester Verdaguer (2) and Mercè Pallàs (1). (1)Universidad de Barcelona, Departamento
de Farmacologia y Quimica Terapeutica, Facultad de Farmacia (2) Universidad de Barcelona, Departamento de Biologia Celular, Facultad de Biologia.
Several studies have indicated the importance of time on the immune system, however the involvement
of our biological clock the suprachiasmatic nucleus has not been investigated. We examined after a
“moderate” immunological challenge using intraperitoneal or intravenous LPS, the activation of the
SCN, the temperature response and TNF-_ and IL-6 production. Animals challenged during the active
period (ZT14) showed an activation of the SCN, decreased core body temperature and high cytokine
production. During the day time (ZT2) the same immunological challenge did not activate the SCN notably beyond its normal day-time activity and resulted in a moderate temperature response and lower
cytokine production. We hypothesized that the day activity of the SCN reflected a higher inhibition of the
SCN of the immune system during the light period than during the night in nocturnal rodents. Ablation
of the SCN indeed resulted in a more severe response of the immune system to an LPS challenge. The
present results demonstrate the existence of a close interaction between the immune system and the
SCN; this interaction influences the intensity of the cytokine and temperature response. The increase of
the immune response after an SCN lesion suggests that the observed activation of the SCN after an LPS
challenge is aimed to curb the innate immune response. The less severe response during the day-time
which coincides with a high neuronal activity of the SCN suggests that indeed SCN activity is essential
to inhibit the immune response. The study was supported by Conacyt 79797 and PAPIIT 209711
There is no effective treatment for neurodegenerative disorders such as Alzheimer’s disease and
Parkinson’s disease. Thus, a major focus of neuroscience research is to examine the mechanisms
involved in neuronal loss in order to identify potential drug targets. Recent results indicate that DNA
damage and re-entry into the cell cycle may constitute a common pathway in apoptosis in neurological
diseases. The role of the cell cycle in such disorders is supported by data on the brain of patients who
showed an increase in cell-cycle protein expression. Indeed, studies performed in neuronal cell preparations indicate that oxidative stress could be the main mechanism responsible for cell cycle reentry.
DNA damage and repair after oxidative stress may activate the enzyme ataxia telangiectasia mutated,
which is a cell-cycle regulator. Once the cell cycle is activated, the increase in the expression of
transcription factor E2F-1 could induce neuronal apoptosis. Furthermore, the potential routes involved
in E2F-1 induced apoptosis could be p53- dependent or p53-independent. Under this E2F-1 hypothesis
of cell death, multiple mitochondria-dependent pathways may be activated, including caspase and
caspase-independent signaling cascades. Finally, given that cyclindependent kinase inhibitory drugs
have neuroprotective and anti-apoptotic effects in experimental models, their potential application for
the treatment of neurological disorders should be taken into account.
1.3.2
NEUROTOXICITY AND CONVULSIVE SUSCEPTIBILITY:
ASTROCYTE FUNCTION
(1,2)Dr. Carlos Beas-Zárate and (1)Mónca E. Ureña-Guerrero. (1)Deptarment of Molecular and Cellular
Biology, CUCBA, University of Guadalajara and (2)C.I.B.O., IMSS México.
A common phenomenon implicated in several neurodegenerative processes is known as excitotoxicity,
which is related with an uncontrolled increase in neuronal excitability mediated by amino acid neurotransmitters. Glutamate is the major excitatory amino acid neurotransmitter in the central nervous
system. Glutamate excitation is carried out through three ionotropic (NMDA-, AMPA-, and kainatereceptors) and eight metabotropic (mGluR1-8) general types of receptors. Neurotoxicity triggered by
glutamate has been mainly related with the over-activation of postsynaptic NMDA-receptors, this toxic
effect seems to be more significant during early development of the brain and is normally followed by
an inflammatory process. Results from our work group have shown that the exposure of neonate rats
to high doses of glutamate as monosodium salt (MSG) reduces neuronal density of both pyramidal
main neurons and GABAergic interneurons in the hippocampus and the cerebral cortex, which it has
been associated with a significant gliosis, release of proinflammatory cytokines and increments in the
Na+/Ca++ exchanger 3 (NCX3) in the astrocytes, particularly in the hippocampus during postnatal
development until adulthood. In addition, adult rats exposed at neonatal treatment with MSG seem
to be highly susceptible to convulsions induced by different convulsive drugs. However, preliminary
results suggesting that the reduced learning abilities of adult MSG-treated rats may be related with
a resistance to convulsive activity induced NMDA. Taken together these results with recent studies of
other authors, we discuss the participation of the astrocyte in a close relationship with neural cells as
determinant in the process of neuronal excitability regulation and damage and as a possible element to
promote the epileptogenesis. Member of the Group study of Neurosciences in Ibero-american network
supported by CYTED (610RT0405).
1.3.3
MOLECULAR MECHANISMS OF PHARMACORESISTANT EPILEPSY
Lazarrwoski A and CzornyJ L.
Near of 20–25% of the epileptic patients fails to achieve good control with the different antiepileptic
drugs (AEDs) treatments, developing refractory epilepsy (RE). Modifications of AEDs-targets expression produce a loss of sensibility of treatment, however it not explain the refractoriness to several
AEDs simultaneously administered. The activity of ABC-transporters (ABC-t) as P-glycopretein (P-gp),
multidrug-resistance-associated proteins and breast cancer resistant protein, was first related with
the multidrugresistant phenotype of cancer. Brain overexpression of ABC-t in patients with RE, suggesting an active efflux from brain as mechanism underling for this refractoriness. Both constitutive and
seizure-induced brain ABC-t overexpression on blood brain barrier and brain parenchyma cells, as astrocytes and neurons were described in clinical reports and experimental models of RE. Experimentally,
after induced seizures, a sequential early detection of P-pg in vessel-related cells and later in neurons
correlates with the progressive loss of protective effect of phenytoin. These dada suggests that refractoriness could depend with intensity and time-constancy of seizure-injury before that drug therapy get
the crisis control. Expression of ABC-t in excretory organs plays a central role in drugs elimination. An
increased liver clearance of the 99mTc-MIBI (a P-gp substrate) was detected in cases of RE surgically
treated, and suggests a simultaneous systemic and brain functional P-gp overexpression, that could
explain the refractory phenotype associated with persistent subtherapeutic levels of AEDs in plasma
as previously reported. P-gp neuronal expression is also related with a lower membrane potential
(Delta_0= _10 to –20mV) compared to normal physiological (Delta_0= –60 to -70 mV) playing
a potential epileptogenic role by decreasing the seizures thresholds. So, all these data indicates that
P-gp neuronal expression is related with phasmacorresistance as well as seizures susceptibility.
1.3.4
EPILEPTOGENICITY OF THE TEMPORAL
LOBE A DIGITAL EEG ANALYSIS APPROACH
1.3.5
THERAPEUTIC STRATEGIES TO HINDER
NEURODEGENERATION IN EPILEPSY
Morales Chacon Lilia
International Center of Neurological Restoration (CIREN)
ROCHA, L. PHARMACOBIOLOGY DEPT. CENTER FOR RESEARCH AND ADVANCED STUDIES.
Background: The assessment of the extent of the epileptogenic zone is a crucial objective during pre
and intrasurgical evaluation of intratactable temporal lobe epilepsy. In this study, we have showed the
associations between electrocorticography patterns and histological findings in patients with temporal
lobe epilepsy (TLE) and a dual pathology (mesial temporal sclerosis and mild focal cortical dysplasia
(FCD). Subjects and methods: A total of 27 patients with pharmacoresistant TLE were included in the
study, 20 of them with histologically confirmed hippocampal sclerosis (HS) associated with neocortical
temporal mild Palmini Type-I FCD subtypes and 7 with HS. Intraoperative electrocorticography (ECoG)
recordings were analysed for epileptiform discharge frequency and morphology. Associations between
histological,and electrocorticography pattern findings in these patients were analysed. Electroclinical
outcomes in these patients were also evaluated. Results: Neocortical areas with mild Palmini Type-I
FCD showed a significantly higher spike frequency (SF) recorded in the inferior temporal gyrus than
those neocortical areas in patients with HS. There was a tendency to higher spike frequency and lower
amplitude in neocortical areas with histopathologic subtype IB FCD in relation with IA during intraoperative ECoG. Post-SF excision and amplitude were significantly lower during neocortical post-excision
intraoperative ECoG than during neocortical preexcision recording. There was no difference found in
the clinical outcome between patients with and without FCD. Conclusions: Intraoperative electrocorticographic interictal spike frequency recorded in the neocortical inferior temporal gyrus may help to
characterize the histopathologic subtypes of mild Palmini Type-I FCD in patients with temporal lobe
epilepsy (TLE) and a dual pathology. Our data support the epileptogenicity of neocortical mild FCD in
TLE and assessments of ECoG patterns are relevant to determine the extent of the resection in these
patients which can influence the electroclinical outcome.
In spite of the high success rate of many antiepileptic drugs for epilepsy, a substantial number of
patients present cell damage and neurodegeneration. Different strategies have been used to reduce
or avoid the consequences of seizure activity. Brain stimulation such as Deep Brain Stimulation, Vagal
Nerve Stimulation and Transcraneal Magnetic Stimulation have gained considerable interest in the last
decade as alternative therapy for patients with medically refractory epilepsy. Research into the mechanism of action of the strategies for brain stimulation suggests a crucial role of different molecules
and channels such as Glutamate, Y-Aminobutyric Acid, adenosine, Brain-Derived Neurotrophic Factor,
calcium channels, sodium channels as well as extracellular potassium. In addition, brain stimulation
might also promote the neurogenesis in subjects with pharmacoresistant epilepsy in whom this process is declined. Other strategy to reduce neurodegeneration is the administration of substances with
neuroprotective effects. Studies carried out in our laboratory indicate that the systemic administration
of propylparaben immediately is able to reduce the neurodegeneration provoked by the pilocarpineinduced status epilepticus. Targeting the regulatory pathways in charge of the neurodegeneration
process will be discussed. Brain stimulation combined with drugs with neuroprotective effects may
represent an innovative approach to avoid neurodegeneration and epileptogenesis. Study supported
by CONACyT (project 98386).
1.4.1
SHAKER K+ CHANNELS (K+ CONDUCTION AND MG2+ BLOCKADE
IN A SHAKER KV-CHANNEL SINGLE POINT MUTANT HAVING AN
UNUSUALLY HIGH CONDUCTANCE)
Cristian Moscoso (1,2), Ariela Vergara-Jaque (4,5), Valeria Márquez-Miranda (5), Romina V. Sepúlveda
(6), Ignacio Valencia (3), Ignacio Díaz-Franulic (3), Fernando González-Nilo (1,6) and David Naranjo.
1) Centro Interdisciplinario de Neurociencias de Valparaíso. Pje. Harrington #278, Playa Ancha, Valparaíso 2360103, Chile. 2) Departamento de Neurociencia, U. de Valparaíso. Chile. 3) Doctorado en
Ciencias mención Neurociencia, U. Valparaíso, Valparaíso, Chile. 4) Doctorado en Ciencias Aplicadas,
U. de Talca, Talca, Chile. 5) Doctorado en Biotecnología, Facultad en Ciencias Biológicas, U. Andres
Bello, Santiago, Chile 6) Center for Bioinformatics and Integrative Biology, Facultad en Ciencias Biológicas, U. Andres Bello, Santiago, Chile.
Potassium channels exhibit a large diversity of single-channel conductances. Shaker is a low conductance K-channel in which Pro475_Asp, a single point mutation near the internal pore entrance,
promotes 6-8 fold higher unitary current (Sukhareva et al., 2003). To assess the mechanism for this
higher conductance, we measured Shaker-P475D singlechannel current in a wide range of symmetrical
K+ concentrations and voltages. Below 300 mM K+, current-to-voltage relations (i-V) showed inward
rectification that disappeared at 1000 mM K+. Single-channel conductance reached a maximum of
~190 pS at saturating [K+], a value 4-5 fold larger than that estimated for the native channel.
Intracellular Mg2+ blocked this variant with ~100-fold higher affinity. Near zero-voltage, blockade
was competitively antagonized by K+, however, at voltages >100 mV it was enhanced by K+. This
result is consistent with a lock-in effect in a single file diffusion regime of Mg2+ and K+ along the
pore. Molecular Dynamics simulations (MD) revealed higher K+ density in the pore, especially near
the Asp475 side chains as in the high conductance MthK bacterial channel. MD also showed that K+
ions bound distally can coexist with other K+ or Mg2+ in the cavity, supporting a lock-in mechanism.
The maximal K+ transport rate and higher occupancy could be due to a decrease in the electrostatic
energy profile for K+ throughout the pore, reducing the energy wells and barriers differentially, by
~0.7 and ~2 kT respectively.
1.4.3
POTASSIUM-DEPENDENT DYNAMICS OF THE PORE OF KV CHANNELS:
INACTIVATED AND NON-CONDUCTING NON-INACTIVATED STATES
Froylán Gómez-Lagunas, Elisa Carrillo & Imilla Arias-Olguin, Dept. Fisiología. Fac.Medicina. UNAM.
México DF.
In this talk, and as a result of our studies of the K+-dependent dynamics of the pore of Kv channels,
I will present the first characterization of the K+-dependent, slow-inactivation gating of Shab K channels. Shab inactivates from both open and closed states. Hence, we studied if inactivation could be of
the so called “U-type”. We found that with short depolarizing pulses the resulting “inactivation curve”
has indeed a pronounced U-shape, but as pulse duration increases, approaching the text-book, steadystate, conditions, the alleged “U-shape” vanishes. Shab inactivation is facilitated by external K+ and
TEA ions, and inhibited by the intracellular pore blocker quinidine. Based on these observations and
on our-own-data regarding the collapse of Gk in 0 K+ solutions, we state the novel hypothesis that:
in contrast to C-inactivation, Shab slow inactivation, and that of other Kv channels whose inactivation
is accelerated by K+, does not involve a significant narrowing of the extracellular entry of the pore.
1.4.2
COUPLING ANION PERMEATION TO VOLTAGE-DEPENDENT
GATING IN CLC CHLORIDE CHANNELS
Jorge Arreola(1),Jose A. De Santiago-Castillo(2), Jorge E. Sanchez-Rodriguez(3), Alejandra CastroChong(1), Ru-Chi Shieh(4), Pablo G. Nieto-Delgado(1), and Juan A. Contreras-Vite(1). (1) Universidad
Autonoma de San Luis Potosi, San Luis Potosi, Mexico; (2) Univ. Michoacana de San Nicolas de Hidalgo,
Morelia, Mexico; (3) University of Chicago, Chicago, USA; (4)Academia Sinica, Taipei, Taiwan;
The voltage-dependent gating mechanism of ClC chloride channels is not well understood. It has
been proposed that protonation of the so-called fast gate (formed by the side chain of a glutamic
acid protruding into the conduction pathway) by either extracellular or intracellular protons ([H+])
is responsible for voltage-dependent gating. However, in ClC-2—an inwardly rectifying ClC chloride
channel activated by hyperpolarizations—we have shown that voltagedependent activation results
from permeant anions interacting with the fast gate followed by stabilization of the open conformation
caused by extracellular H+. Our data show that in ClC-2 permeant anions trigger voltage-dependent
gating whilst impermeant anions are unable to do so. Furthermore, ClC-2 was gated by increasing [Cl-]i
in cells exposed to a [H+]e = 10-10 M, a proton concentration low enough that would not protonate
the fast gate. A quantitative analysis of our data showed that pore occupancy by permeant anions was
voltage dependent but the protonation reaction was not. Thus, both our data and model show that pore
occupancy by permeant Cl- is directly responsible for voltage-dependent gating in ClC-2. Supported by
CONACyT 79897.
1.4.4
STRUCTURE-FUNCTION RELATIONSHIP IN VOLTAGE DEPENDENT
SODIUM CHANNELS
Eduardo M. Salinas-Stefanon, Instituto de Fisiología, Univ. Autonoma de Puebla, Mexico
Voltage-gated sodium channels (VGSC) are multi-molecular protein complexes expressed in both excitable and nonexcitable cells. They are primarily formed by a pore-forming multi-spanning integral
membrane glycoprotein (_- subunit) that can be associated with one or more regulatory _-subunits.
The latter are single-span integral membrane proteins that modulate the sodium current (INa) and can
also function as cell adhesion molecules The sodium channels have several isoforms from Nav 1.1 to
Nav 1.9. When some mutations ocurred (on those channels), the physiological role may be altered
and they produced a diseases called chanelopathies. In addition to their physiological roles in cell
excitability and transmision, they are the site of action many toxins (like tetrodotoxin and saxitoxin)
and pharmacologic agents (like antiarrhythmic drugs, local anesthetics, antiepileptic drugs, and newly
developed analgesics). This symmposium will outline the structure, function, and biophysical properties of VGSC as well as their pharmacology and highlight some of the recent advances in this field,
using both, experimental and in silico approach in order to identify residues playing a key role in the
biophysics behavior of VGSC.
1.4.5
T-TYPE CALCIUM CHANNELS: FROM STRUCTURE TO FUNCTION
Lopez-Charcas O. (1), Sepulveda-Hirose R.K. (1), Arias J.M. (2), Rivera M. (1), and Gomora J.C. (1). (1)
Depto de Neuropatología Molecular, División de Neurociencias, Instituto de Fisiología Celular, UNAM.
México, DF. México; (2) Facultad de Estudios Superiores Iztacala, UNAM, Tlalnepantla, México.
Voltage-activated calcium channels (Cav) couple cell electrical activity to different intracellular signaling pathways by using Ca2+ as a mediator. Cav channels are divided in low-voltage activated (LVA)
and high-voltage activated (HVA) channels. Both of them are membrane proteins with several differences. HVA Ca2+ channels are composed of four subunits: alpha1, beta, alpha2delta and gamma;
they are activated by strong depolarizations, inactivate slowly and close very rapidly at negative potentials. On the other hand, LVA Ca2+ channels, also known as T-type or CaV3, seems to be formed
only by the alpha1 subunit; they are activated close to resting membrane potentials, inactivate fast
and close slowly after membrane’s repolarization. T-type Ca2+ channels were the last to be cloned
within the CaV family, since then the structure-function relationship of these channels have been the
priority of several research teams, including our own lab. Lately we have reported a novel structure
in the I-II loop of the alpha1 subunit of these channels that regulates gating activity. More recently
we have investigated the role of glycines and other aminoacids in the S6 segments of these channels
that might be functioning as the hinge glycines described for potassium channels (KV). Our results
indicate a quite different mechanism for the opening and closing of T-type channels. We have also
developed homology models of the T-type calcium channels proteins, which suggest they are not as
symmetrical as KV channels. This might explain in part the differences in the channel opening among
these channels. Our T-type homology models have been also useful determining the putative binding
sites of several T-type known antagonists, in particular, we have shown that the diuretic amiloride acts
selectively on CaV3.2 T-type channel through an extracellular binding site, while in CaV3.1 and CaV3.3
channels the amiloride mechanism of block includes extraand intracellular binding sites.
1.5.1
ENDOGENOUS NEUROPROTECTION AGAINST STROKE:
PRECONDITIONING, POSTCONDITIONING
AND REMOTE CONDITIONING
Cuomo O., Pignataro G., Sirabella R., Boscia F., Esposito E., Vinciguerra A., Di Renzo GF. Annunziato L.
(1)Division of Pharmacol., Department of Neuroscience, School of Medicine, Federico II University of
Naples, Italy.
Substantial evidence has established that a short sub-lethal brain ischemia applied before a prolonged harmful ischemic episode confers ischemic neuroprotection, a phenomenon named ischemic
preconditioning (Dirnagl et al, 2003; Gidday, 2006). However, ischemic preconditioning, though scientifically fascinating, is not clinically applicable since the harmful anoxic event is not predictable.
Recently, a hypothesis has been offered that modified reperfusion subsequent to a prolonged ischemic
episode may also confer ischemic neuroprotection, a phenomenon termed postconditioning (Burda
et al, 2006; Pignataro et al, 2006, 2008) The cation/Ca2+ plasma–membrane exchangers consisting of two branches, the K+-independent Na+–Ca2+ exchangers (NCXs) and the K+-dependent
Na+–Ca2+ exchangers (NCKXs), are plasmamembrane ionic transporters widely distributed in the
brain and involved in the control of Na+ and Ca2+ homeostasis and in the progression of stroke
damage (Pignataro et al., 2004, Cuomo et al., 2008, Molinaro et al., 2008). The objective of the present
study was to evaluate the role of the three isoforms of NCX, NCX1, NCX2 and NCX3 and of the mainly
neuronally expressed isoform of NCKX family, NCKX2, in preconditioning and postconditioning-induced
neuroprotection. Our results showed that both NCX1 and NCX3 expression increased in brain regions
protected by preconditioning and only NCX3 increased after postconditioning in a p-AKT-dependent
manner (Pignataro et al, 2011, Pignataro et al., 2012). On the other hand, NCKX2 expression increased
in temporoparietal cortex after preconditioning stimulus and both preconditioning and postconditioning prevented the dramatic NCKX2 drop occurring after cerebral ischemia in striatum. In support of
the relevant role of these exchanger isoforms during preconditioning and postconditioning, we showed
that their knocking down or knocking out partially reverted the preconditioning or postconditioninginduced neuroprotection. Collectively our results support the idea that the enhancement of expression
and activity of these exchangers might represent a reasonable strategy to reduce the infarct extension
after stroke.
1.5.2
MECHANISMS OF ETHANOL DEPENDENCE IN IMMATURE
AND MATURE ORGANOTYPIC HIPPOCAMPAL SLICE CULTURES
1.5.3
CHARACTERIZATION OF NEW NICOTINIC AGONISTS:
A POTENTIAL TREATMENT STRATEGY FOR PARKINSON’S DISEASE
Elisabetta Gerace, Elisa Landucci, Arianna Totti, Tania Scartabelli, Flavio Moroni, Guido Mannaioni &
Domenico E. Pellegrini-Giampietro. (1)Department of Preclinical and Clinical Pharmacology, University
of Florence, Viale Pieraccini 6, 50134, Italy
J.A. Abin-Carriquiry(1), Gustavo Costa, Jessika Urbanavicus, Giselle Prunell, Federico Dajas, Susan
Wonnacott(2), Margot Paulino & Bruce K. Cassels(3), (1)Department of Neurochemistry, Instituto de
Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay. (2) Department of Biology and
Biochemistry, University of Bath, UK. (3) Department of Chemistry, Faculty of Sciences, University of
Chile, Santiago, Chile
Chronic ethanol consumption causes persistent molecular alterations in brain cells and affects the
maturation of neuronal circuits by mechanisms that are not fully understood. We investigated the
mechanisms of ethanol dependence by exposing either immature (2 days in vitro) or mature (10 days
in vitro) rat organotypic hippocampal slice cultures to 100, 150 or 300 mM ethanol for 7 days, after
which ethanol was withdrawn for 24 h. Our results show that ethanol withdrawal led to a dose-dependent CA1 pyramidal cell injury in mature but not in immature slices. To comprehend the mechanisms
by which ethanol withdrawal induced cell death in mature neurons, we analyzed the expression levels
of presynaptic (vGlut1, vGlut2, CB1 receptor, synaptophysin) and postsynaptic (GluA1, homer 1b/c)
proteins in immature and mature organotypic slices treated with 150 mM ethanol for 7 days and 24
h after ethanol withdrawal. We observed no changes in the expression levels of vGlut1, vGlut2, CB1
receptor or homer 1b/c proteins neither in mature nor immature slices. On the other hand, we observed
a significant increase in GluA1 expression after ethanol withdrawal in mature slices, that may underlie
increased toxicity to glutamate, and a decrease in GluA1 and synaptophysin expression levels in immature slices, suggesting an impairment in synaptic transmission. To confirm the latter hypothesis,
whole cell voltage-clamp recordings from CA1 pyramidal cells of organotypic slices were performed: we
measured the frequency and the amplitude of sEPSCs 7 days after exposure to 150 mM ethanol and 24
h after ethanol withdrawal. Our results show a significant reduction in the frequency but not amplitude
of sEPSCs. These findings suggest that chronic ethanol treatment may promote abnormal synaptic
transmission in immature hippocampal neurons and that ethanol withdrawal leads to cell death of
mature CA1 pyramidal cells that may be important in neurodevelopmental and neurological disorders.
At present the most effective treatment of Parkinson’s disease is dopamine replacement therapy with
L-Dopa and/or dopamine agonists, in spite of the frequently arise of several side effects caused by
their chronic use. These drugs are particularly beneficial for improving motor deficits in Parkinson’s
disease. However they are unable to stop the neurodegenerative process; and their effectiveness diminishes with disease progression. Furthermore, these drugs are not able to improve the non-motor
symptoms linked to Parkinson’s disease, such as dementia, sleep deficits and depression. Hence, there
is a critical need to develop new pharmacological tools for Parkinson’s disease, ideally to prevent the
neurodegenerative process but also to provide better relief of the motor and non-motor symptoms.
Several epidemiological studies have identified tobacco smoking as the most significant environmental
protective factor for risk of developing Parkinson`s disease. Indeed, we have already shown that nicotine itself is able to significantly prevent the striatal dopaminergic loss in experimental Parkinson´s
disease, by mechanisms mediated by nicotinic acetylcholine receptors (nAChRs) stimulation. Moreover,
nicotine and nAChRs agonists have been identified as potential pharmacological tools able to reduce
L-Dopa induced dyskinesias and to improve several of the non-motor symptoms like dementia and
depressive symptoms in Parkinson’s disease. In this context, the finding of new nicotinic agonists
subtype-specific, with less secondary effects associated to the stimulation of the ganglionic nicotinic
receptors, could be a relevant step in the therapeutic of Parkinson’s disease. Among natural nicotinic
agonists, cytisine is an alkaloid present in many plant species of the Fabaceae or Leguminosae families
that has higher affinity and specificity for alpha4 beta2 nAChRs than nicotine. The aim of the present
work is to characterize in vitro, in vivo and in silico a series of cytisine derivatives as potential pharmacological tools for Parkinson’s disease treatment.
1.5.4
NEUROPLASTICITY IN BRAIN DISORDERS:
WHAT THE VISUAL CORTEX CAN TEACH US
1.6.1.
ON THE ROLE OF THE HIPPOCAMPUS IN
OBJECT RECOGNITION MEMORY
Rossi FM(1). (1)Facultad de Ciencias, UdelaR, and Institut Pasteur de Montevideo, Uruguay
CAMMAROTA M, Laboratory of Behavioral Neurobiology, Biomedical Research Institute – PUCRS, Porto
Alegre, Brazil.
The primary visual cortex (VC1) is a paradigmatic experimental model for the study of plasticity processes in the CNS. Here, the degree of plasticity is maximal during the critical period (CP) of development but declines dramatically in the adult. Recently, a few strategies for modulating the timing of the
CP and for reactivating plasticity in adults have been identified. Particularly relevant are non-invasive
treatments as the administration of fluoxetine and rearing in a sensory-motor enriched environment.
Both procedures have been shown to restore young levels of plasticity in adults and to recover visual
defects as amblyopia. However, despite decades of research, the cellular and molecular factors underlying these processes are largely unknown. In our laboratory we started a large-scale proteomic
approach for characterizing cortical plasticity mechanisms. The strategy consists in identifying
differences in the pattern of protein expression and in their post-translational modifications in the
mouse VC1 as a function of the plasticity level: high during development, low in adult, restored by experimental treatments (fluoxetine, enriched environment). In a first project we set up a bidimensional
gel differential electrophoresis with linear pI3-10 strips and SDS-PAGE on VC1 total protein extracts.
Preliminary results indicate that several proteins are modulated in the different models analyzed. In
a second project we focus on epigenetic processes known to regulate neuronal plasticity. We set up
an AUT/SDS 2D approach on VC1 acid extracted histones which allows separation of variants and
modified derivatives. Both studies are followed by mass spectrometry analysis for identification of
the modulated proteins and the histone posttranslational modifications. We believe this approach will
contribute to a better description of the molecular frameworkregulating plasticity in the VC1 which may
be also relevant for potential application in disorders with neurodevelopmental origin and in which
neuronal plasticity is affected (from autism to Rett’s syndrome)
1.6.2.
HIPPOCAMPO-CORTICAL DYNAMICS ACROSS THE SLEEP-WAKE CYCLE
Lopes-dos-Santos V, Tort A.B.L, Ribeiro S
Instituto do Cérebro, Universidade Federal do Rio Grande do Norte
Hebb postulated that new memories are encoded by neuronal assemblies that emerge during novel
experience through firing synchronization across brain regions, and reverberate thereafter. Despite its
popularity, this theory was never explicitly tested due to technological and methodological shortcomings. Research on mnemonic reverberation has focused on overtrained navigation tasks. Moreover,
statistical methods suited to disentangle cell assemblies from large neuronal populations and track
their activity as a whole were only recently developed. Breakthrough came from the demonstration
that the strength of assemblies recorded from the medial prefrontal cortex of rats performing a maze
task increases after animals learn a new navigation strategy, with significant reinforcement during
post-experience sleep. However, evidence for distributed assembly formation is yet to be obtained with
spike recordings from multiple brain sites, and without the overtraining confound intrinsic to maze
tasks. Here we investigate a more naturalistic paradigm in which rats freely explore objects they had
never encountered before. We found that assemblies composed of neurons simultaneously recorded
from two primary sensory neocortical areas and one hippocampal region become suddenly stronger
as exploration unfolds. These assemblies are coupled to hippocampal theta oscillations, and continue
to reverberate synchronously after object removal. During subsequent sleep, assemblies strengthened
during experience in the neocortex and hippocampus display increased synchronous activations. The
results provide direct evidence of Hebbian assemblies formed by theta rhythm in the hipocampocortical circuit.
After acquisition, information undergoes a protracted consolidation process that converts the initially
fragile trace into a disruption-resistant long-term memory (LTM). In addition, numerous studies indicate that every time they are retrieved, consolidated LTMs are rendered again vulnerable to disruption
and, to persist, must go through a stabilization process referred to as reconsolidation. Both, consolidation and reconsolidation require gene expression and the synthesis of new proteins in areas of the
brain relevant to memory. During my talk, I will present and discuss experimental evidence concerning
the molecular basis and the behavioral consequences of consolidation and reconsolidation of object
recognition memory, a type of declarative memory conferring the ability to discriminate between novel
and familiar entities.
1.6.3.
MODELING TEMPORAL LOBE EPILEPSY IN THE HIPPOCAMPUS:
FROM BEHAVIOR TO NEUROPLASTICITY
Garcia-Cairasco, N. Univ. of Sao Paulo, Ribeirao Preto, Brazil
Epilepsies are neurological alterations, convulsive or not, usually associated with neuronal loss, hyperexcitability and hypersynchronisms. Temporal Lobe Epilepsy (TLE) is one of the most frequent types
of seizures in patients and, in spite of historical and contemporary clinical and basic sciences efforts,
there is still a lack of consensus on the potential causes and brain circuits involved, and the cellular an
molecular mechanism of their expression. Using the clinical data as the target for studies and modeling, either in animals or with computational methods, our laboratory and its associated collaborators
have advanced in an integrated study of neuronal epileptogenic networks associated to the clinical and
cellular expression of TLE. In the current presentation we will discuss behavioral aspects of clinical
and experimental TLE, their cellular and molecular correlates and implicit neuroplasticity phenomena,
ending with “in silico” modeling and its predictions. The latter close the loop, after coming back to the
original questions posed by patients and experimental animals, where new hypothesis can be tested.
The resulting data can be used for further modeling. Financial support from Brazilian Research Foundations: FAPESP, FAPESP-Cinapce, PROEX-CAPES, CNPq, FAEPA.
1.7.1
AYAHUASCA AND THE HUMAN BRAIN
Riba, J.
Instituto de Investigación Biomédica Sant Pau de Barcelona
Ayahuasca is a unique Amazonian psychotropic plant preparation containing the psychedelic indole
N,Ndimethyltryptamine and monoamine oxidase-inhibiting alkaloids that render it orally active. In recent years ayahuasca use has spread to countries around the world, where individuals use it in ritual
and lay contexts. Ayahuasca was studied in a series of clinical and field studies aiming at assessing its
general pharmacology, mechanism of action on the human brain and long-term effects. These studies
have shown that ayahuasca induces a transient modified state of awareness during which thought
processes, perception and emotion are intensely modified. Subjective effects are accompanied by
characteristic neuroendocrine and neurophysiological changes and increases in blood flow in prefrontal and temporal regions of the brain. The assessment of long-term users did not find evidence of
neuropsychological impairment derived of its chronic use.
1.7.2
FUNCTIONAL MAGNETIC RESONANCE IMAGING AND AYAHUASCA:
STUDIES ON MENTAL IMAGERY AND INTERNAL ATTENTION
Araujo, D.
Instituto do Cérebro, Universidade Federal do Rio Grande do Norte
The hallucinogenic brew Ayahuasca, a rich source of serotonergic agonists and reuptake inhibitors,
has been used for ages by Amazonian populations during religious ceremonies. Among all perceptual
changes induced by Ayahuasca, changes in the visual system and internal attention are remarkable.
Therefore, this presentation will aim at presenting results from studies conducted by our group, which
used functional magnetic resonance imaging to better understand some neurophysiological aspects of
these two perceptual changes induced by Ayahuasca.
1.7.3
IN VIVO STUDIES OF RADIOLABELED N,
N-DIMETHYLTRYPTAMINE AND TRYP-TAMINE AS MARKERS OF
THE INDOLIC HYPERMETHYLATION: RELATIONSHIP WITH HUMAN
PERCEPTION ALTERATIONS IN PSYCHIATRIC PATHOLOGIES
1.7.4
IBOGAINE IN THE TREATMENT OF DRUG ADDICTION:
AN OBSERVATIONAL STUDY IN BRAZIL
Vitale A.A, Pomilio A.B, Cañellas C.O, Macareno J, and Ciprian-Ollivier J
In this talk Dr. Schenberg will present results from a preliminary study about an ongoing treatment for
drug abuse and dependence using the psychedelic substance Ibogaine. The work is legally conducted
in Brazil, where 165 patients were already treated combining psychotherapy before and after ibogaine
sessions conducted in a hospital by a general physician. The presentation will cover a brief history
about ibogaine and it’s source plant and the discovery of its potential to treat drug abuse and dependence, as well as the possible risks involved. Results form clinical data and qualitative interviews with
a subsample of the patients will be shown and discussed.
Single photon emission computed tomography (SPECT)/gamma-camera studies were carried out with
N,Ndimethyltryptamine (DMT) in comparison with serotonin and tryptamine in rabbits. The indoleamines were labeled with Iodine-131 under the same conditions. Iodine-131 was chosen in order to
perform long-lasting in vivo studies since this radioisotope decays with a half life of 8.06 days. Brain,
heart, liver, kidneys and bladder were the regions of interest (ROIs). Brain uptake, plasma clearance,
and renal excretion were assessed. Afterwards, these biochemical markers were studied in psychotic
patients compared to controls, e.g., dosage of platelet monoamine oxidase (MAO) and serum amine
oxidase (AO), transmethylation activity, and dosage of the urinary N,N-dimethylindolealkylamines, bufotenine and N,N-dimethyltryptamine (DMT). Neuropsychological tests were simultaneously performed
for evaluating psychometric parameters in the same subjects under study.
Schenberg E, Silveira D.X, Chaves B.R, Comis M.A.C, and Canan C.
Universidade Federal de São Paulo (UNIFESP)
1.8.1
PREFRONTAL REGULATION OF FEAR AND VIGILANCE
Sotres-Bayon F and Quirk Gregory J.
University of Puerto Rico
Retrieval of fear-related memories is often more complex than the initial acquisition of these memories, because retrieval involves selection of the appropriate memory based on temporal and contextual
factors. In conditioned fear, the prefrontal cortex (PFC) plays a key role in the retrieval of both fear
and extinction memories. The prelimbic PFC receives direct input from hippocampal, amygdala, and
thalamic sources. Combining pharmacological inactivation with unit recording, we show that amygdala drives conditioned responses in PL neurons, whereas the ventral hippocampus inhibits them, via
activation of local inhibitory interneurons. The dorsomedial thalamus becomes recruited into the conditioned fear circuit between 8 and 24 h after training, and is critical for retrieval and maintenance of
fear memories, likely via projections to PL and the amygdala. Understanding the relationships between
the thalamus, prefrontal cortex, hippocampus, and amygdala during retrieval of fear can ultimately
explain the extinction and maintenance of fear memory.
1.8.3
INFLUENCE OF STRESS ON FEAR MEMORY RECONSOLIDATION
Molina VA, Martijena ID, IFEC-CONICET, Departamento de Farmacología, Facultad de Ciencias Químicas,
Universidad Nacional de Córdoba, Argentina.
It is well recognized that stressful experiences promote robust emotional memories, which are well
remembered. The amygdaloid complex, principally the basolateral complex (BLA), plays a pivotal role in
fear memory and in the modulation of stress-induced emotional responses. A large number of reports
have revealed that GABAergic interneurons provide a powerful inhibitory control of the activity of projecting glutamatergic neurons in the BLA. Indeed, a reduced GABAergic control in the BLA is essential
for the stress-induced influence on the emergence of associative fear memory and on the generation of
long-term potentiation (LTP) in BLA neurons. The extracellular signal-regulated kinase (ERK) subfamily
of the mitogen-activated protein kinase (MAPK) signaling pathway in the BLA plays a central role in the
consolidation process and synaptic plasticity. In support of the view that stress facilitates long-term
fear memory, stressed animals exhibited a phospho-ERK2 (pERK2) increase in the BLA, suggesting the
involvement of this mechanism in the promoting influence of threatening stimuli on the consolidation
fear memory. Moreover, the occurrence of reactivation-induced lability is prevented when fear memory
is encoded under intense stressful conditions since the memory trace remains immune to disruption
after recall in previously stressed animals. Thus, the underlying mechanism in retrieval-induced instability seems not to be functional in memories formed under stress. All these findings are indicative that
stress influences both the consolidation and reconsolidation fear memory processes. Thus, it seems
reasonable to propose that the emotional state generated by an environmental challenge critically
modulates the formation and maintenance of long-term fear memory.
1.8.2
MECHANISMS OF RETRIEVAL AND UPDATING
OF RECOGNITION MEMORY
Federico Bermudez-Rattoni
UNAM, DF, Mexico
Reconsolidation theory posits that upon retrieval, stored memory is destabilized and requires a protein
synthesisdependent process to be retained in long-term storage. During my talk I will present some
evidences to test whether explicit retrieval is indispensable to trigger memory reconsolidation in two
different learning tasks; a declarative memory model of object recognition task and non-declarative
taste aversion memory task. We injected muscimol in the perirhinal cortex or NBQX in the amygdala
to block memory retrieval of object recognition and taste aversion memories respectively, and the
protein synthesis inhibitor anisomycin to impede memory reconsolidation. In both cases we found that
protein synthesis inhibition impaired memory reconsolidation in absence of retrieval. Therefore, stored
memory undergoes reconsolidation even though memory is not recalled. These results provide evidence
of molecular dissociation between retrieval and activation of memory.
1.8.4
PERIODICALLY REACTIVATED CONTEXT MEMORY RETAINS
ITS PRECISION AND DEPENDENCE ON THE HIPPOCAMPUS
Alvares L de O (1), Einarsson EÖ (2), Santana F (1), Crestani AP (1), Haubrich J (1), Cassini LF (1),
Nader K (2), Quillfeldt JA (2). (1)Laboratório de Psicobiologia e Neurocomputação, Departamento de
Biofísica, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil;
(2) Department of Psychology, McGill University, Montreal, Canada
Hippocampus is hypothesized to play a temporary role in the retrieval of contextual memories. Similarly, previous studies have reported that the expression of context memories becomes more generalized
as memory ages. We report, first, that contextual fear memory expression changes from being sensitive
to dorsal hippocampus inactivation by muscimol at 2 days post-conditioning, to insensitive at 28 days,
and second, that over the same period, rats lose their ability to discriminate between a novel and
conditioned context. Furthermore, we show that repeated brief memory reactivation sessions are able
to prevent memory from becoming both hippocampus-independent and generalized.
1.9.1
CONNEXIN 36 IN PANCREATIC BETA CELLS:
NEW FUNCTIONAL ROLES.
1.9.2
MIXED ELECTRICAL-CHEMICAL SYNAPSE
BETWEEN PRINCIPAL CELLS IN THE HIPPOCAMPUS
E. Martha Pérez Armendariz and Cristina Coronel Cruz Laboratorio de sinapsis eléctricas. Departamento
de Medicina Experimental, Facultad de Medicina, UNAM. México D.F., 04510.
GUTIERREZ, R. Departamento de Farmacobiología, Centro de Investigación y Estudios Avanzados del IPN.
Glucose induced electrical activity in beta cells (B) is critical for the precise regulation of insulin
secretion and glucose serum levels. In the mouse, glucose induces rhythmic bursts of Ca2+ and K+
action potentials that occur simultaneously and in phase in most B cells within an islet and which
are temporally correlated with pulses of insulin secretion. Thus, islet pancreatic B cells represent an
interesting cell model for studying the functional role of gap junctions in excitability of mammalian
cells. Previous studies from our group have shown that most freshly isolated pairs of pancreatic B
cells are electrically coupled as well as that they abundantly expressed Cx36 both in vivo and in vitro.
Moreover, using double voltage clamped freshly dissociated pairs of B cells; we have demonstrated
that junctional currents are formed by single channel events with a unitary conductance and voltage
dependence similar to those recorded in cells transfected with Cx36. Therefore, we have proposed that
electrical coupling through Cx36 gap junction channels is the main mechanism that synchronizes the
electrical and functional activity within most B cells of a single islet induced by glucose. In agreement
with this hypothesis, damped and asynchronous fluctuations of intracellular calcium oscillations as
well as alterations in the insulin secretion have been found by others in Cx36 deficient pancreatic
islet B cells. Recently, we have characterized the ontogeny of the major connexins expressed in the
pancreas and found that Cx36, but not Cx26 or Cx32, is specifically expressed in pancreatic B cells
as early as this cell type form cell aggregates during embryonic life. In addition, we have found that
Cx36 transcript increases in an age dependent manner during fetal and newborn stages in parallel
with this gap junction protein expression in B cells. These findings indicate new functional roles for
Cx36 in pancreatic B cells which will be discussed. Research funded by grants from DGAPA-IN231011,
and CONACYT-127658.
1.9.3
DENDRITIC ELECTRICAL COUPLING DETERMINES
THE AMPLITUDE OF CHEMICAL SYNAPTIC POTENTIALS
Francisco F. De-Miguel Instituto de Fisiología Celular-Neurociencias, UNAM. Mexico, D.F., México.
We have studied how electrical coupling between dendrites regulates the amplitude of synaptic potentials in response to chemical transmitters and expand the effective dendritic field of the neurons
by regulating the leak of synaptic currents from one neuron to another. Our experiments were made
in pairs of Retzius neurons of the leech, which are coupled by a non-rectifying electrical synapse. In
addition, both neurons produce synaptic potentials that can be recorded from both somata in response
to transmitter release from a common presynaptic input. By combining electrophysiological recordings,
morphological reconstructions of the pair of neurons and mathematical modeling we showed first,
that presynaptic inputs to both neurons are established in the coupled dendrites, at about 7 microns
from the electrical synapses. Excitatory synaptic potentials appear synchronously in both neurons with
quantal amplitude variations. The amplitude of the unitary synaptic potentials is inversely proportional
to the coupling coefficient of the pair of neurons. In addition, upon transmission failures onto one neuron, it is possible to detect the synaptic potential arriving from the coupled neuron, with its amplitude
being directly proportional to the coupling ratio of the neurons. Synaptic potentials produced in both
neurons are summed as they arrive at the primary axon, and this summation extends the decay time
of the synaptic potentials, thus favoring temporal summation. Altogether our data show that dendritic
electrical coupling expands the integrative capabilities of the coupled neurons.
Morphological and electrophysiological studies have shown that interneurons and pyramidal cells establish electrical communication with other neurons of the same type through gap junctions located
in their dendrites, axons or somata. The granule cell axons, the mossy fibers (MF), establish gap junctions and, therefore, electrical communication among them. That granule cells express gap junctional
proteins in their axons suggests the possibility that their terminals express them as well. If this were to
be the case, mixed electrical-chemical communication could be supported, as MF terminals normally
use glutamate for fast communication with their target cells. I will provide electrophysiological and
anatomical evidence consistent with this hypothesis. MF activation produced fast spikelets followed
by excitatory postsynaptic potentials in pyramidal cells (PCs), which, unlike the spikelets, underwent
frequency potentiation and were strongly depressed by activation of metabotropicglutamate receptors, as expected from transmission of MF origin. The spikelets, which persisted during blockade of
chemical transmission, were potentiated by dopamine and suppressed by the gap junction blocker
carbenoxolone(1). Pyramidal cells and mossy fibers present dye coupling and EM shows the presence of gap junction-like structures, along with neurotransmitter vesicles in the synaptic region(2).
Mixed electrical and glutamatergic communication between granule cells and some PCs in CA3 may
ensure the activation of sets of PCs, bypassing the strong action of concurrent feed-forward inhibition
that granule cells activate. Importantly, MF-to-PC electrical coupling may allow bidirectional, possibly
graded communication that can be faster than chemical synapses and subject to different forms of
modulation. 1. Vivar, C., Traub , R.D., Gutiérrez, R. Eur. J. Neurosci. Eur. J. Neurosci. 35: 76–82, 2012.
2. Hamzei-Sichani, F., Davidson, K.G.V., Yasumura, T., Janssen, W.G.M., Wearne, S.L., Hof, P.R., Traub,
R.D., Gutiérrez, R., Ottersen, O.P., Rash, J.E. Frontiers in Neuroanatomy 6, Art. 13, 1-26, 2012.
1.9.4
HEMICHANNELS EXPRESSED BY GLIAL CELLS AS MOLECULAR
TARGETS TO PREVENT CELL DEGENERATION UNDER
NEUROINFLAMMATORY CONDITION
Juan C Saez and Juan A. Orellana
Pontificia Universidad Catolica de Chile
Inflammation contributes to neurodegeneration in diverse pathological conditions including stroke,
diabetes, and Alzheimer’s disease. This inflammatory response includes activation of microglia and
astrocytes. We studied the role of microglia treated with amyloid-_ peptide (A_) on hemichannel activity of astrocytes subjected to hypoxia in high glucose. Reoxygenation after 3 h hypoxia in high glucose
induced transient astroglial permeabilization via Cx43 hemichannels and reduction in intercellular
communication via Cx43 cell-cell channels. Both responses were greater and lasted longer in astrocytes previously exposed for 24 h to conditioned medium by A_-treated microglia (CM-A_). The effects
of CM-A_ were mimicked by TNF-_ and IL-1_ and were abrogated by neutralizing TNF-_ with soluble
receptor and IL-1_ and with a receptor antagonist, respectively. Astrocytes under basal conditions protected neurons against hypoxia, but the exposure to CM-A_ made them toxic to neurons subjected to
a sub-lethal hypoxia/reoxygenation episode, revealing the additive nature of these insults. Astrocytes
exposed to CM-A_ induced permeabilization of cortical neurons through activation of neuronal pannexin1 (Panx1) hemichannels by ATP and glutamate released through astroglial Cx43 hemichannels.
The inhibition of NMDA or P2X receptors partially reduced the activation of neuronal Panx1 hemichannels and neuronal mortality, but simultaneous inhibition of both receptors completely prevented the
neurotoxic response. Therefore, we suggest that responses to ATP and glutamate converge in activation
of neuronal Panx1 hemichannels. In hippocampal slices the application of A_ for 3 h induced neuronal
death that was prevented by inhibition of astroglia or neuronal hemichannels. Thus, we propose that
blocking hemichannels expressed by astrocytes and/or neurons in the inflamed nervous system could
be an alternative strategy to reduce neuronal loss in various pathological states including Alzheimer’s
disease, diabetes and ischemia. Partial funds came from Anillo ACT71 project.
1.9.5
IS SYNDROMIC DEAFNESS A HEMICHANNEL DISEASE?
MARTÍNEZ AD, GARCIA IE, CERIANI R, JARA O, MARIPILLÁN J. Centro Interdisciplinario de Neurociencias
de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile.
Gap junction channels (GJCs) and hemichannels (HCs) are major pathways for intercellular signaling.
GJCs and HCs are made of a family of homologous proteins named connexins (Cxs). Mutations in
the gene encoding Cx26 account for a large proportion of genetic deafness. These can lead to nonsyndromic or syndromic disease, respectively. In syndomic deafness the hearing loss is associated with
abnormal epidermal keratinisation. How these different clinical phenotypes arise remains unclear. We
have study and characterized the effect of several syndromic and nonsyndromic mutations in Cx26
targeting its N-termini (NT) and first transmembrane domain and using HeLa cells as exogenous expression system. All Cx26 mutants associated with non-syndromic deafness presented impairments in the
function of GJCs and HCs, which parallel the severity of the disease. But for syndromic Cx26 mutant the
situation was less clear. Some Cx26 mutants associated with syndromic deafness were associated with
gain in HC activity and in some cases were also associated with cell death, consistent with the notion
that syndromic deafness is an HC disease. However, we found that other syndromic mutations targeting
the NT domain of Cx26 produced HCs that were indistinguishable from the wild type Cx26 HCs, but produce loss of GJC formation and function. This finding raises doubts about the HC disease hypothesis for
syndromic deafness. However, we found that when these syndromic mutants were co-expressed with
Cx43 (a connexin that normally does not hetero-oligomerize with wild type Cx26) a gain in HC activity
is observed. Therefore, we are studied these heteromeric HCs made by the association of syndromic
Cx26 mutants and Cx43. Since Cx43 is co-expressed with Cx26 in the skin the mechanism by which
Cx26 mutants induce deafness may differ from the mechanism that induces skin disease. (Financed
by Millennium Institute-CINV, FONDECYT-1090573 and Anillo grants ACT-71 and ID-10224 to ADM)
1.10.2
EXTRAPITUITARY GROWTH HORMONE: GH IN IMMUNE SYSTEM
LUNA M.(1), RODRÍGUEZ-MÉNDEZ, AJ.(1,2) LUNA-ACOSTA JL.(1), CARRANZA M.(1), HARVEY S.(3), AND
ARÁMBURO C.(1). (1) Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología,
Universidad Nacional Autónoma de México,(2) Departamento de Investigación Biomédica, Facultad de
Medicina, Universidad Autónoma de Querétaro, 76230 Querétaro, México, (3) Department of Physiology, University of Alberta, Edmonton, Alberta, T6G 2H7, Canada.
GH has many effects on the immune system. Previously, our group described evidence about its participation in B cell differentiation and maturation in bursa of Fabricius (BF). We have shown that GH is
produced in the BF and suggest that it may act as an autocrine and/or paracrine modulator. The time
course of mRNA and GH expression in the BF suggests that GH may be involved in development and involution of the BF, since GH is known to be present mainly in B lymphocytes and epithelial cells. In addition, as GH is anti-apoptotic in other tissues, we assessed the possibility that GH promotes cell survival
in the BF. This work was focused on determining the mechanism by which GH can inhibit apoptosis of
B cells and if the PI3K/Akt pathway is activated. Bursal cultur es were treated with different GH concentrations (0.1-100nM). The results showed that 10nM GH treatment significantly increased viability
(± 16.7±0.67%) compared with the control. Caspase-3 activity decreased to 40±20% in these
cultures. Akt phosphorylation and Bcl2 expression were increased with 10nM GH. When a PI3K/Akt
pathway inhibitor (10 _M wortmannin) was added, it blocked GH effects. Together, these data indicated that GH antiapoptotic effects are mediated by PI3K/Akt. Supported by PAPIIT-DGAPA, UNAM
(IN208812) and CONACYT, México (118353, 178335), and technical assistants (Nydia Hernández and
Gerardo Courtois).
1.10.1
GROWTH HORMONE: NEWS FROM THE
PAST AND STORIES WITH A FUTURE
*BARRERA SALDAÑA H.A., RODRÍGUEZ SÁNCHEZ I.P., PÉREZ MAYA A.A., PÉREZ IBAVE D.C. Departamento
de Bioquímica y Medicina Molecular. Facultad de Medicina de la Universidad Autónoma de Nuevo León.
Monterrey, N.L. México. *[email protected]
The human growth hormone (GH) locus (17q24.2) consists of one pituitary gene (hGH-N) and four placental genes [hCSH-A and-B that code for a mature identical chorionic somatomammotropin hormone
(CSH), the hGH-V which encodes a variant of GH that is postulated to replace GH-N during pregnancy,
and the putative pseudogen hCSH-L] NEWS FROM THE PAST. Sequencing of GH loci in bacterial artificial
chromosomes of primates has allowed us to determine the loci’s composition and organization. Our
findings confirm a single gene in prosimians, more than half a dozen GH genes (including pseudogenes) in NWM, six GH/CSHS genes in OWM, and between five and six GH/CSHs genes in great apes.
Intergenic regions expanded and differentiated to control differential expression of the new members.
Interestingly, we discover that the CSHs genes render four different hormones in the gorilla, two in the
chimpanzee, to only one in humans. STORIES WITH A FUTURE. It is now clear that the GH locus is active
in tissues other than pituitary gland and placenta. GH has been detected in the retina of birds, rodents
and man. From human ocular tissues from cadavers and surgical procedures, we extracted RNA and
subjected it to reverse transcription coupled to polymerase chain reaction conventional (RT-PCR) and
quantitative (RT-qPCR) to study expression of the genes from the hGH locus, GH receptor (GHR) and
transcription factor Pit-1. We found GHN and GHR gene expression in the human retina, of GHN in the
choroid and the trabecular meshwork, and of GHR in the choroid, lens, and conjunctiva. Expression of
the placental genes of the locus and of the transcription factor Pit-1 gene was not found in the retina.
Thus it is proposed that the mechanisms regulating ocular GH expression are different from those in
the pituitary gland and placenta. BIBLIOGRAPHY: 1. Harper, M.E. et al. (1982). Am J Hum Genet. 34(2):
p. 227-34. 2. Barrera-Saldaña, H.A. et al. (1983). J Biol Chem. 258(6): p. 3787-93. 3. Chen, E.Y., et
al. (1989). Genomics. 4(4): p. 479-497. 4. Pérez-Maya, A.A. et al. (2012). Mamm Genome 23: p.
387–398 5. Harvey, S. et al. (2009). Neurosci Lett. 455(3): p. 199-202. 6. Sanders, E.J. et al. (2009).
Mol Vis. 15: p. 920-6.
1.10.3
EXTRAPITUITARY GROWTH HORMONE (GH):
GH IN THE NERVOUS SYSTEM
HARVEY S(1), LUNA M(2), ARAMBURO C(2), (1) Dept. of Physiology, University of Alberta, Edmonton,
Canada and (2)Department of Cellular and Molecular Neurobiology, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, México.
Although growth hormone (GH) is traditionally viewed as a pituitary endocrine, it is also expressed in
the central and peripheral nervous systems, where it is thought to act as an autocrine or paracrine
regulator. Using the chick as an experimental model, GH immunoreactivity (IR) is present throughout
the embryonic brain before the end of the first trimester of incubation (embryonic day (ED) of the 21d
incubation period) and before the ontogenetic appearance of pituitary somatotrophs (at approximately
ED 15) and the presence of GH in peripheral plasma (at ED 17). Following hatch, GH-IR is widespread
in perikarya and fiber tracts and particularly intense in the hypothalamus and cerebellum. In the brain,
GH-IR can be detected as a 25 kDa moiety by Western blotting, as in the pituitary gland. GH-IR is also
abundant in spinal nerves, the spinal cord, and in peripheral nerves. This immunoreactivity reflects the
expression of the GH gene, which is homologous to that expressed in the pituitary. Within the nervous
system, GH receptor (GHR) gene expression occurs and radioligand GH-binding sites are present on the
plasma membrane of neural tissues, which are thus likely to be endocrine, autocrine or paracrine sites
of GH action, as indicated by the expression of a specific GH response gene (GHRG). The neural retina
is a major site of GH gene expression and GH is present throughout the visual system of the chick,
although predominately as 15 kDa and 16 kDa moieties. Within the neural retina, GH has neuroprotective actions that promote the survival of retinal ganglion cells (RGCs) during developmental waves
of apoptosis. The functional importance of retinal GH in RGC survival is shown by the increased RGC
death following the immunoneutralization of endogenous retinal GH and after the siRNA knockdown of
endogenous retinal GH expression. GH is thus a neurotrophin.
1.10.4
EXTRAPITUITARY GROWTH HORMONE:
GH IN THE REPRODUCTIVE SYSTEM
ARÁMBURO C.(1). MARTÍNEZ-MORENO CG.(1), AHUMADA-SOLORZANO SM.(1), CARRANZA M.(1), HARVEY
S.(2), AND LUNA M.(1), (1) Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, (2) Department of Physiology, University of Alberta,
Edmonton, Alberta, T6G 2H7, Canada.
It is known that GH plays a role in the control of both female and male reproductive tract development.
Acting as an endocrine, paracrine and/or autocrine regulator, GH influences proliferation, differentiation and function of reproductive tissues. We studied GH mRNA and GH protein local expression in both
the chicken testis and in ovary, and found it is distributed mainly in germinal and Leydig cells, and
in follicular granulosa cells (GC), respectively. GH immunoreactivity was located in the cytoplasm and
within the nucleus. We also found co-localization of GH receptor (GHR) in the same locations. Locally
expressed GH was found to be heterogeneous, with a 17 kDa variant being predominant. Both testicular
and follicular cells in primary cultures were able to synthesize and release GH to the culture medium.
Addition of GH (0.1, 1.0, 10 nM) in the media stimulated progesterone production in cultured GCs in a
dose-dependent manner (1.5, 2.9, 5.4 times, respectively). This effect was mediated by regulating the
expression of cytochrome P450cc mRNA. GH (10 and 1 nM) also stimulated cell proliferation in both
testicular cell (70%) and GC cultures (78%) as determined by 3H-thymidine incorporation, respectively. GH immune-neutralization inhibited these effects. Data suggest local GH may have important autocrine/paracrine effects. Supported by PAPIIT-DGAPA, UNAM (IN208812) and CONACYT, México (118353,
178335), and technical assistants (Nydia Hernández, Ma. Lourdes Palma and Gerardo Courtois).
SYMPOSIA
TUESDAY NOVEMBER 6
2.1.1
CIRCUIT MECHANISMS UNDERLYING PATHOLOGICAL
OSCILLATIONS IN ANIMAL MODELS OF PARKINSON’S DISEASE
2.1.2
INVESTIGATING THE ROLE OF STRIATAL SUBCIRCUITS IN THE
PERFORMANCE OF ACTION SEQUENCES USING OPTOGENETICS
Murer MG, University of Buenos Aires School of Medicine, Department of Physiology and Biophysics,
Buenos Aires, Argentina.
Tecuapetla F(1), Xin J(2), Lima S(1), Costa R(1). (1) Champalimaud Centre for the Unknown, Lisbon,
Portugal. (2) The Salk Institute for Biological Studies.
The symptoms of Parkinson’s disease have been related to pathological oscillations in basal ganglia
circuits. These oscillations involve large populations of neurons and are synchronized across basal
ganglia strutures and with cortical oscillations. We have shown that spontaneous activity in the thalamo-cortical network drives robust plateau depolarizations (up states) in “medium spiny” projection
neurons of the striatum. In a rat model of Parkinson’s disease, up states reach a more depolarized
potential and medium spiny neurons show increased firing, which depends on the tonic stimulation
of NMDA receptors. This striatal hyperactivity is translated into abnormal patterns of synchronization
between the globus pallidus and frontal cortex. Both striatal hyperactivity and globus pallidus oscillations are relatively insensitive to D2 dopamine receptor agonists, but can be induced by genetic
manipulations reducing D2 receptors in the brain. We propose a mechanism through which the lack of
D2 receptor stimulation together with the tonic activation of NMDA receptors in the striatum allows the
establishment of a fixed route of information flow in the cortico–striato-pallidal network, which may
reduce the efficacy of dopamine replacement therapy in advanced stages of the disease.
The basal ganglia have been implicated in the control of action, particularly in the initiation of actions
sequences. The striatum, the main input to the basal ganglia is composed of two projection pathways,
the striatonigral and the striatopallidal projections. In this study we investigated the role of these pathways in the initiation and performance of self-paced action sequences by manipulating their activity
using optogenetics. We trained mice in a task in which animals have to press 8 times to get a reward,
which results in the development of stereotypical sequences. We used channelrhodopsin 2 (ChR2) or
Archerhodopsin (ArchT) to manipulate the firing of the striatal neurons optically while the animals
perform the task. The specificity of the ChR2 driven spikes in the striatonigral and striatopallidal
pathways was obtained by striatal injections of adeno-associated virus with Credependent ChR2-EYFP
expression into D1-Cre, D2-Cre (expressing Cre recombinase in D1 or D2 dopamine receptors expressing neurons, respectively). Our data shows that activation of specific neostriatal subcircuits either
before or after sequence initiation affects different aspects of action sequence execution like sequence
initiation, sequence length, and sequence termination. Supported by: European Research Council Grant
243393 (ERC), Fundação para a Ciência e a Tecnologia (FCT), Consejo Nacional de Ciencia y Tecnologia
(CONACyT).
2.1.3
DYNAMIC RECONFIGURATION OF NEURAL NETWORKS:
TOWARDS THE UNDERSTANDING OF COMPOSITIONAL
PROPERTIES IN BIOLOGICAL SYSTEMS
2.1.4
NOT ONLY REWARD: DOPAMINE NEURONS CODE SUBJECTIVE
PERCEPTUAL EXPERIENCE AND UNCERTAINTY OF DECISIONS
CARRILLO-REID L. Northwestern University, Feinberg School of Medicine, Dept. of Physiology, Chicago,
USA.
Compositionality refers to the ability of any system to build complex representations from basic elements and a specific set of rules. Indeed, we continually deal with composite structures such as
language, motor sequences or action planning. However, the neuronal substrate and the synaptic
dynamics that support the formation of composed patterns of activity have been difficult to examine
experimentally in living neural networks. With the use of optical and electrophysiological approaches
we described that striatal cell assemblies allow the composition of complex patterns of activity. The
activation of the cholinergic system enables striatal cell assemblies with properties that have been
posited for recurrent neural networks with memory storage capabilities allowing repeated sequences
of activity to compose habits. On the other hand, the selective activation of dopaminergic receptors
revealed receptor-specific configurations of striatal cell assemblies: D1 receptor activation generates closed trajectories with high recurrence favoring the selection of specific sequences; whereas
D2 receptor activation discloses a manifold of reverberating cycles with low recurrence outlining the
potential configurations of the network for a future selection. Remarkably, in the absence of dopamine
the compositional capabilities of cell assemblies are disrupted by the generation of dominant states
that engaged most of the striatal circuitry explaining some pathological states. The demonstration of
sequential activity patterns that can be dynamically modulated by neurotransmitters provides a bridge
between cellular and systems studies that could generate a novel interpretation of functional aspects
of basal ganglia circuitry.
Victor de Lafuente(1), Ranulfo Romo(2), (1) Instituto de Neurobiologia, UNAM, Querétaro, QRO. México.
(2) Instituto de Fisiología Celular, UNAM, D.F., México.
Midbrain dopamine (DA) neurons respond to sensory stimuli associated with future rewards. When
reward is delivered probabilistically, DA neurons reflect this uncertainty by increasing their firing rates
in a period between the sensory cue and reward delivery time. Probability of reward, however, has been
externally conveyed by visual cues, and it is not known whether DA neurons would signal uncertainty
arising internally. Here we show that DA neurons code the uncertainty associated with a perceptual
judgment about the presence or absence of a vibrotactile stimulus. We observed that uncertainty
strongly modulates the activity elicited by a go cue instructing a monkey subject to communicate its
decision. That is, the same go cue generates different DA responses depending on the uncertainty level
of a judgment made a few seconds before the go instruction. Easily detected supra-threshold stimuli
elicit small DA responses, indicating that future reward will not be a surprising event. In contrast, the
absence of a sensory stimulus generates large DA responses associated with uncertainty: was the
stimulus truly absent, or did a low amplitude vibration go undetected? Our results thus uncover neuronal activity signaling that, in a detection task, the absence of evidence is not evidence of absence.
In addition, the responses of DA neurons to the stimulus itself increase with vibration amplitude,
but only when monkeys correctly detect its presence. This suggests that DA activity is not related to
actual intensity but rather to perceived intensity. Therefore, besides their well known role in reward
prediction, DA neurons code subjective sensory experience and uncertainty arising internally from
perceptual decisions.
2.1.5
MGLUR MODULATION OF CALCIUM-PERMEABLE
AMPAR-MEDIATED SYNAPTIC PLASTICITY IN THE NUCLEUS
ACCUMBENS FOLLOWING PROLONGED WITHDRAWAL
FROM COCAINE SELF-ADMINISTRATION
Kuei Y. Tseng, MD, PhD. Department of Cellular and Molecular Pharmacology, The Chicago Medical
School at Rosalind Franklin University, North Chicago, IL USA
AMPARs lacking the GluA2 subunit are Ca2+-permeable (CP-AMPARs) and exhibit higher conductance than GluA2- containing, Ca2+-impermeable AMPARs (CI-AMPARs). In the nucleus accumbens
(NAc), a critical region for drug addiction, CI-AMPARs predominate in drug-naive adult rats. During
prolonged withdrawal from extended access cocaine self-administration, CP-AMPARs accumulate in
the NAc during withdrawal and mediate the expression of “incubated” cocaine craving. Thus, removing
CP-AMPARs is expected to decrease NAc responsiveness to excitatory inputs, which in turn could potentially reduce craving. Towards this goal, we began assessing the role of group I mGluR activation in the
regulation of CP-AMPARs from NAc synapses. Whole-cell patch-clamp recordings f NAc medium spiny
neurons (MSNs) were conducted in brain slices from adult rats after extended access cocaine or saline
self-administration (6 h/day for 10 days) followed by >45 days of withdrawal. We found that bath
application of the group I mGluR agonist DHPG (50μM, 10min) rapidly eliminates the CP-AMPAR component of excitatory transmission in the NAc of cocaine-exposed rats, an effect that is accompanied by
facilitation of CI-AMPAR-mediated excitatory transmission. Both effects are dependent on mGluR1 and
postsynaptic PKC activation. In saline controls, however, DHPG does not appear to change postsynaptic
AMPAR function but instead attenuates NAc glutamatergic transmission through a pathway requiring
mGluR5 activation and a CB1R-dependent presynaptic mechanism. Together, these results indicate
that a different form of mGluR-dependent synaptic regulation emerges in the NAc following prolonged
withdrawal from extended access cocaine self-administration. Of translational value, our study suggests a novel perspective on the use of group I mGluR-based drugs that could be exploited to reduce
cocaine craving, and ultimately to treat cocaine addiction.
2.2.2
OPPOSED DRIVING FORCES: SEX AND
AGGRESSION DURING LACTATION
FERREIRA ANNABEL
Sección Fisiología y Nutrición, Facultad de Ciencias, Universidad de la Republica
One of the most dramatic alterations that occur during motherhood in the rat is the appearance of
high levels of aggression towards intruders in the nest cage. Maternal aggression depends on maternal
state, the nest and the pups. Therefore, we hypothesized that variations in maternal motivation are
directly associated with changes in maternal aggression. We showed that low licking lactating females
which have lower maternal motivation than high licking females, also showed less levels of maternal
aggression. Sensitized females (ovariectomized females rendered maternal through a close contact
with the pups, that have a lower maternal motivation than lactating dams), also exhibit deficits in
maternal aggression. These deficits were overridden by demanding pups (pups that remained separated from their mothers for 12 hours and have an increase demand of maternal care). These results
suggest that maternal aggression is directly associated with maternal motivation, probably associated
to activation of the DA system, and is modulated by pups, that may increase the aversive value of the
male. However, the rat has a postpartum estrus, during which she is sexual and maternally motivated.
To explore if a male can be attractive and aversive, at the same time, we evaluated the responses of
dams in postpartum oestrus (PPO) to a sexually active male introduced into their home cage containing
the pups.
2.2.1
RABBIT MATERNAL BEHAVIOR AS A MODEL OF A
SPECIFIC HORMONE-RELATED MOTIVATION
GONZALEZ-MARISCAL G. Centro de Investigación en Reproducción Animal, CINVESTAV-Universidad
Autónoma de Tlaxcala .
The onset of maternal motivation in rabbits involves a change in the valence of pup odors. The interpretation of scents derived from the litter and/or the nest changes across pregnancy from “uninteresting”
or “aversive” to attractive. More sniffings are displayed towards a box containing nest material +
pups than towards one containing “neutral” material. These differences are significant from midpregnancy onwards, indicating that factors present during gestation promote changes in the valence of
pup odors. Across lactation maternal motivation consists of a single, daily nursing bout per day, lasting
around 3 min. The maintenance of this pattern, that includes behavioral (crouching over the litter),
neuroendocrine (release of oxytocin and prolactin), and physiological (milk delivery) components relies
heavily on the type of suckling stimulation provided by the litter. Nursing less than four pups provokes:
alterations in the circadian display of nursing and longer times inside the maternal nest box. The offset
of maternal motivation allows weaning of the litter and the initiation of a new reproductive cycle.
This process occurs only if rabbits are concurrently pregnant and lactating, a finding suggesting that
factors associated with gestation are essential to turn off maternal motivation. Progesterone administration to rabbits that are only lactating promotes an early decline in milk output but does not modify
maternal behavior. In summary, the onset, maintenance, and decline of rabbit maternal motivation
relies on complex interactions between sensory and endocrine factors we are only beginning to unveil.
2.2.3
NEUROENDOCRINE AND BEHAVIORAL EFFECTS OF NEONATAL STRESS
LUCION AB. Departamento de Fisiologia, Instituto de Ciências Básicas da Saúde (ICBS), Universidade
Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil.
Early life stress has been related, among other factors, to emotional and behavioral disorders later in
life. Children exposed to aversive environments are at risk to develop psychopathologies. The understanding of the mechanisms that have altered in the infants as a consequence of the environmental
intervention seems crucial to unravel the development of the subject. Neonatal handling has been
used experimentally with rodents in order to analyze the long-lasting effects of environmental intervention on the mother–infant relationship. The neonatal handling involves brief, but repeated, maternal
separations and experimental handling, which is an useful tool to unravel mechanisms to explain
those changes. We showed alterations in the structure of maternal behavior. Thus, the disruption in
mother-infant relationship induces acute and long-lasting behavioral, neuroendocrine and morphological changes. Although several studies have extensively described the long-lasting effects of early
life stress, the knowledge on the neuroendocrine mechanisms that have induced those changes is
limited. The effects of handling on the stress system have been well described, but changes in the
neuroendocrine basis for reproduction have been poorly addressed. In female rats, we showed that the
handling procedure decreases ovulation, sexual behavior and changes central e peripheral hormone
physiology. That intervention may also reduce the number of neurons in crucial areas for reproduction
(Locus Coeruleus, medial preoptic area, and PVN). The repeated mother–infant disruption imposed
by the handling procedure “lesioned” those structures. We also investigated the effects of neonatal
handling on social behaviors in pups, juveniles, and adults. Handling reduces social interactions in all
those periods. Although the responsiveness of the hypothalamic–pituitary–adrenal axis to stressors is
reduced in the neonatal period, environmental interventions may impact behavioral and biochemical
mechanisms relevant to the animal at that early age. Support: CNPq, CAPES, FAPERGS, FAPESP
2.2.4
HORMONES AND SEXUAL REWARD
2.2.5
MOTIVATIONAL ASPECTS OF SEXUAL SATIETY IN MALES AND FEMALES
Paredes R.G (1). (1) Instituto de Neurobiología, Universidad Nacional Autónoma de México
FERNANDEZ-GUASTI A. Centro de Investigación y Estudios Avanzados, Departamento de Farmacobiología, México D.F., México
There is an extensive literature in which the rewarding effects of drugs have been investigated. However, little attention has been devoted to study the possible role of hormones in reward states. One
of the methods most frequently used to study reward or positive affective states is the conditioned
place preference (CPP) paradigm. Using this methodology only a few hormones have been studied to
determine their possible contribution to reward states. These hormones include: oxytocin, cholecystokinin, ghrelin, melatonin, substance p, corticosteroids, testosterone (T), estradiol (E) and progesterone
(P). The appropriate expression of sexual behavior depends on adequate hormone levels which are
essential for sex to be rewarding. Females require both E and P in order to develop a reward state after
mating. Moreover, this reward state is induced with different doses of these hormones. In males, both
intact and recently castrated males developed CPP after a sexual interaction. The ability to control
or pace the sexual interaction is crucial in both sexes to develop a reward state after mating. In
females, we have shown that CPP after paced mating is blocked by the systemic injection of naloxone
or after infusion of this opioid antagonist into the medial preoptic area, the medial amygdala or the
ventromedial nucleus of the hypothalamus suggesting that these areas are part of a circuit important
for the reward state induce by paced mating in females. We have recently showed that paced mating
in both males and females increases the number of new neurons in the olfactory bulbs as evaluated
by the mitotic marker 5´-Bromo-2´-deoxyuridine (Brdu). Taken together these results suggest that
adequate hormone levels are crucial for sex to be rewarding and mating can induced plastic changes
in brain function. Undoubtedly, more research is needed to elucidate the possible rewarding effects of
hormones. Supported by CONACyT 167101 and DGAPA IN200512.
Sexual satiety is defined as the inhibition of sexual behaviour that occurs after repeated ejaculations.
This inhibitory process is regulated by various factors including motivation. A male rat may be considered sexually satiated but if presented with a different female with which it has copulated to satiety, it
reinitiates sexual activity (Coolidge effect). The “biological meaning” of copulation during the Coolidge
effect may be, rather than an increase in reproductive diversity, to impede that other males fertilize a
sexually receptive female. To directly measure the motivational state of a male at different intervals
after sexual satiety we tested their preference for another male or an estrous female and found that
immediately after and 24-48h post sexual satiety there is a drastic decrease in the preference for the
female that coincided with a maximal sexual behaviour inhibition. Thereafter both processes recovered
parallelly. We also analyzed if in the female rat there is also a behavioural process similar to sexual satiety and Coolidge effect classically described for the male. Females in natural proestrus were allowed
to copulate with the same male for 90 min, thereafter a new sexually active male –unknown for the
female- was presented and another 90 minutes of constant copulation were allowed.These procedures
were undertaken in two conditions: female paced mating (where the female regulates the copulation
timing) and male paced mating. In addition to lordosis we measured proceptivity which reflects the female motivation to copulate. Interestingly we observed that under both conditions (female’s or male’s
paced mating) the hops/darts were drastically and linearly reduced after continuous copulation. However a Coolidge effect was observed in this parameter only when the female regulates the copulation
timing. Regarding ear wiggling, we found that when the male regulates mating this behaviour linearly
and drastically reduces after repeated mating; however, when the female regulates copulation it does
not change. Lordosis behaviour was unaltered regardless of the condition (male’s or female’s paced
mating) along the 180 min of repeated copulation. These data indicate that in the female there is a
process of sexual satiety and Coolidge effect mainly reflected on motivational aspects.
2.3.1
NEURON-GLIA INTERACTIONS IN NEUROMETABOLIC DISEASES
2.3.2
ASTROCYTE-MEDIATED NEUROTOXICITY
OLIVERA-BRAVO S(1), ISASI E (1), SARLABÓS MN (1), FERNÁNDEZ A (2), ROSILLO JC (2), CASANOVA G (3),
BARBEITO L (4), (1) Cell and Molecular Neurobiology, IIBCE, Montevideo, Uruguay; (2) Cell and Molecular
Neurophysiology, IIBCE, Comparative Neuroanatomy Unit Associated to the School of Sciences, UDELAR,
Montevideo, Uruguay; (3) Unit of Transmitted Electron Microscopy, School of Sciences, UDELAR, Montevideo, Uruguay; (4) Institut Pasteur Montevideo, Montevideo, Uruguay.
Patricia Cassina
Facultad de Medicina, Uruguay
In neurometabolic diseases the functional coupling among neurons and glial cells is altered. Astrocytes, the major population of brain glial cells, play a central role in the regulation of this neurometabolic coupling by contributing to the activity-dependent fuelling of neuronal energy demands associated with synaptic transmission. However, astrocyte roles in the pathogenesis of organic acidemias,
a type of early childhood neurometabolic/neurodegenerative diseases, are poorly known. We have
previously shown that instead of neurons, astrocytes are the main cellular target of the metabolites
accumulated in glutaric acidemia I (GAI), an organic acidemia characterized by striatal and cortical
neurodegeneration accompanied by central diffuse white matter alterations. Once exposed to GA metabolites, astrocytes increased their proliferation rate and suffer mitochondrial dysfunction that lately
evolve to significant striatal neurotoxicity, both in vivo and in vitro. Interestingly, GAI metabolites did
not show direct neurotoxicity suggesting that neurodegeneration reported in GAI are mainly mediated
by astrocyte dysfunction. Accordingly, iron porphyrins that abbrogated astrocyte response to GAI metabolites offer significant neuroprotection. Our recent results show that astrocyte dysfunction caused
by GAI metabolites also participates in the disease characteristic myelin disturbances by causing
oligodendrocyte cytotoxicity evidenced by delayed maturation, altered trafficking of myelin associated
proteins and significant ER stress. All together, our data indicate that focusing on astrocytes, a key
element in the neuron-glia interactions, could potentially lead to a better understanding of neurometabolic diseases and to design novel therapeutic strategies.
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder characterized by motor neuron
degeneration resulting in paralysis and eventual death. Growing evidence indicate that mitochondrial
dysfunction and oxidative stress contribute to motor neuron degeneration in ALS. We have previously
shown that the expression of SOD1G93A in astrocytes leads to mitochondrial dysfunction linked to an
inflammatory astrocytic phenotype that promotes the death of neighboring motor neurons. Importantly,
these deleterious effects were prevented by the mitochondri-targeted therapeutics either antioxidant
ubiquinone covalently coupled to a triphenylphosphonium cation (MitoQ) or mitochondria modulator
dichloroacetate (DCA) suggesting that defective mitochondrial respiration in SOD1G93A astrocytes was
associated to neurotoxicity. Trials with both drugs in ALS mice led to a significant increase in hind-limb
strength and lifespan. Our results support a role for astrocytes in disease progression and the potential
pharmacological utility of mitochondria-targeted therapeutics in ALS treatment.
2.3.3
EFFECT OF PERIPHERAL INFLAMMATION ON
AN INFLAMMATORY MODEL OF DEMYELINATION
2.3.4
AGE-DEPENDENT CHANGES ON THE ACTIVATION OF MICROGLIA:
UNDERSTANDING CYTOTOXICITY IN NEURODEGENERATIVE DISEASES
Ferrari, CC. Murta, V, Pitossi, F
Fundacion Instituto Leloir
Rommy von Bernhardi, Juan Tichauer, Francisca Cornejo, Gigliola Ramírez. Dpt. Neurology, School of
Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile.
Multiple sclerosis is a chronic inflammatory disease characterized by demyelination and remyelination
events. Etiology of the disease is still not clear and therapeutic interventions fail in reducing disability
or influencing the disease progression. Pro-inflammatory cytokine Interleukin-1beta (IL-1) is associated with a spectrum of neuroinflammatory processes in neurodegenerative diseases. We previously
studied that the chronic expression of IL-1 in the striatum, induced neutrophil infiltration, micro and
astroglial activation and reversible demyelination. On the other hand, our lab and others recently
demonstrated that a peripheral proinflammatory stimulus can exacerbate the damage produced by
central stimulus in both Parkinson’s and prion disease models. However, few studies analyze the effect
of peripheral infections in demyelinating diseases. The aim of this project is to analyze the effect of a
peripheral inflammation on an ongoing inflammatory damage in the striatum. We used and adenovector expressing IL-1 (AdIL-1) to induce chronic expression in the striatum. Animals previously injected in
the striatum with the AdIL-1, were injected endovenously with a pro-inflammatory stimuli 30 days after
central stimulus. Animals injected with AdIL-1/AdIL-1 exhibited an exacerbation of both inflammatory
and demyelinating response compared to AdIL-1/Adbgal. Animals AdIL-1/Adbgal exhibited a similar
response to that observed in non-peripherally injected animals. Astroglia and microglia response were
in accordance with the inflammatory response. In summary, pro-inflammatory stimuli exacerbate both
inflammatory and demyelinating events. This response is accompanied by microglia and astroglia
activation, and therefore increases the ongoing nervous tissue damage. Our data model provides data
evidenced by the chronic expression of a unique proinflammatory cytokine, which allowed us to dissect the effect of this cytokine or its downstream components as major mediators of demyelination in
chronic inflammatory and demyelinating diseases and analyse the effect of peripheral inflammation
on central damage.
Aging is the main risk factor for neurodegenerative diseases such as Alzheimer‘s disease (AD) and several others, all of which share an increased neuroinflammation and glial activation. Many age-related
changes affecting the brain contribute to functional decline and increased frailty, increasing neuronal
vulnerability, and contributing to the pathogenesis of neurodegeneration. Here, we assess how aging
and inflammatory environment modulate microglia phenotype and reactivity. In previous reports, we
have shown that microglial cytotoxicity was modulated through the secretion of TGFß-1 by astrocytes
and hippocampal cells. However, although in aging TGFß-1 is increased, glia appear to be increasingly
activated. To approach this apparent contradiction, we developed a culture system for normal adult
microglia, and we assessed changes of TGFß-1-Smad3 signaling during aging and its effect on the
modulation of microglial cell function: NO secretion, ROS production and phagocytosis, in culture.
We found that Smad3 increased in the hippocampus in response to inflammatory stimuli in young,
but not in adult mice. NO secretion was only induced in microglia from young mice exposed to LPS,
effect that was potentiated by inflammatory preconditioning, whereas induction of ROS predominated
in adult mice. TGFß-1 modulated LPS dependent induction of NO and ROS production by a mechanism
that was partially dependent on Smad3 pathway and was impaired by inflammatory preconditioning.
Phagocytosis was induced by inflammation and TGFß-1 only in microglia from young mice. The modulatory effect of TGFß-1 was prevented by Smad3 inhibition. Data support our idea that microglial cells’
phenotype and function change with aging, inducing cytotoxicity in contrast to neuroprotection, and
could contribute to the onset of neurodegenerative changes. They also suggest that TGFß-1-Smad3
pathway is important for the activation pattern of microglia, and it appears to be impaired in aging,
being in position of potentiating cytotoxicity and microglia-mediated neurodegeneration. Support: Fondecyt1090353 and NIHR03-TW008019.
2.5.1
NOVEL ADENOSINE-BASED THERAPEUTIC STRATEGIES
TO MANAGE BRAIN DYSFUNCTION AND DAMAGE UPON EPILEPSY
2.5.3
ADENOSINE-DOPAMINE RECEPTOR-RECEPTOR
HETEROMERIZATION AND PARKISON’S DISEASE
CUNHA RA(1,2), (1)CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Portugal (2)
Faculty of Medicine, University of Coimbra, Portugal
CIRUELA F
Universitat de Bacelona
Adenosine is a neuromodulator acting through inhibitory A1 receptors (A1R) and facilitatory A2A receptors (A2AR), controlling neuronal firing and synaptic plasticity, respectively. A1R also constitute a
hurdle, whereas A2AR activation exacerbates brain damage, a concept now tested in epilepsy. Preconditioning male adult rats with 2hrs of restraint stress enhanced after 24 hours a 21-28% increase of
A1R hippocampal density. Previous restraint stress also decreased by 64-73% kainate-induced hippocampal lesion (FluoroJade-labelling, n=4), an effect abrogated by the A1R antagonist DPCPX (1 mg/
kg, ip, n=4). In contrast, blocking A2AR pharmacologically (with SCH58261 0.05 mg/kg, ip) or genetically (A2AR knockout) afforded a robust and sustained (1 up to 7 days) hippocampal protection against
kainate (10 mg/kg, ip)-induced neurotoxicity (cresyl violet or FluoroJade staining), astrogliosis (GFAP
staining) and microgliosis (CD11b or tomato lectin staining). Kainate exposure enhanced density and
gain of function of presynaptic A2ARs, which results from a localized translation of A2AR mRNA located
in nerve terminals. Accordingly, selectively deleting A2AR in forebrain neurons (CAM-kinase II-driven
deletion of A2AR) attenuated kainate-induced neuronal damage. However, A2AR were also up-regulated
in microglia, where A2AR control the autocrine BDNF-mediated proliferation of microglia and the release of pro-inflammatory cytokines, which we observed to bolster glutamate-induced neurotoxicity in
an A2AR-dependent manner; this paves the way to also involve the control of neuro-inflammation as an
ancillary mechanism associated with A2AR-mediated neuroprotection. Finally, we observed that A2AR
blockade efficiently controlled synaptic sprouting upon eTLE, in accordance with our observations that
A2AR control synaptogenesis as well as neuronal migration during development. These results rebut
the concept of adenosine as anti-epileptic agent, while showing the need to combine prophylactic
strategies bolstering of A1R with the therapeutic blockade of A2AR to prevent epileptic activity and
ensuing brain damage. (Supported by FCT)
The molecular interaction between adenosine and dopamine receptors within oligomeric complexes
has been postulated to play a pivotal role in the adenosine-dopamine interplay in the central nervous
system, both in normal and pathological conditions (i.e. Parkinson’s disease). While the determinants
of Parkinson’s disease are still unknown, it is well-established that a gradual and progressive loss
of dopaminergic neurons of the substantia nigra occurs, and that it leads to a glutamatergic and
adenosinergic neurotransmission imbalance. As a result, this neurotransmitter deregulation affects
the functions controlled by the basal ganglia, namely motor activity control, motor learning and some
forms of associative and visual learning. Attempts to discover new medications have operated under the assumption that GPCRs are monomers and that a specific drug activates one single receptor
coupled to one single signal transduction mechanism. We proposed a new paradigm considering adenosine-dopamine receptor-receptor oligomers as a drug target in Parkinson’s disease, thus the understanding of the pharmacology of these oligomers will help to design combined therapies or heteromertailored drugs in the future. This work was supported by grants SAF2011-24779 and Consolider-Ingenio
CSD2008-00005 from Ministerio de Ciencia e Innovación and ICREA Academia-2010 from the Catalan
Institution for Research and Advanced Studies.
2.5.4
NEUROPROTECTIVE STRATEGIES TO MANAGE MOTOR
AND NON-MOTOR SYMPTOMS IN PARKINSON’S DISEASE
PREDIGER RD(1)
(1)Departamento de Farmacologia, Universidade Federal de Santa Catarina, Florianópolis, Brazil
Parkinson’s disease (PD) is the second most common neurodegenerative disorder affecting approximately 1% of the population older than 60 years. Classically, PD is considered to be a motor system
disease and its diagnosis is based on the presence of a set of cardinal motor signs that are consequence of a pronounced death of dopaminergic neurons in the substantia nigra pars compacta
(SNc). Nowadays there is considerable evidence showing that non-dopaminergic degeneration also
occurs in other brain areas which seems to be responsible for the deficits in olfactory, emotional and
memory functions that precede the classical motor symptoms in PD. Dopamine-replacement therapy
has dominated the treatment of PD and although the currently approved antiparkinsonian agents offer
effective relief of the motor deficits, they have not been found to alleviate the non-motor features as
well as the underlying dopaminergic neuron degeneration and thus drug efficacy is gradually lost.
We have recently proposed a new experimental model of PD consisting of a single intranasal (i.n.)
administration of the proneurotoxin 1-methyl-4- phenyl-1,2,3,6-tetrahydropyridine (MPTP) in rodents.
Our findings demonstrated that rats and mice treated intranasally with MPTP suffer impairments in
olfactory, cognitive, emotional and motor functions conceivably analogous to those observed during
different stages of PD. Such infusion causes time-dependent loss of tyrosine hydroxylase in the olfactory bulb and SNc, resulting in significant dopamine depletion in different brain areas. We have also
identified some pathogenic mechanisms possibly involved in the neurodegeneration induced by i.n.
administration of MPTP including mitochondrial dysfunction, oxidative stress, activation of apoptotic
cell death mechanisms and glutamatergic excitotoxicity. The present presentation attempts to discuss
recent findings from our group indicating the potential of neuroprotective agents (e.g., agmatine, caffeine and atorvastin) to manage motor and non-motor symptoms of Parkinson’s disease. Financial
support: CNPq, FAPESC, CAPES-COFECUB.
2.6.1
TRPA1 MEDIATES ACUTE AND CHRONIC ITCH
Diana Bautista, Sarah Wilson, Kristin Gerhold
Department of Molecular & Cell Biology, UC Berkeley, Berkeley, CA 94720 USA.
Pruritus, or itch, is associated with many inflammatory conditions including insect bites, atopic dermatitis and psoriasis. Acute itch serves an important protective function by warning against harmful
agents in the environment such as insects, toxic plants or other irritants. In contrast, pruritus can also
be a debilitating condition that accompanies numerous skin, systemic, and nervous system disorders.
Approximately 15% of primary afferent Cfibers are activated by endogenous itch-producing compounds
released by non-neuronal cells in the skin (Ikoma et. al., 2006; Davidson & Giesler, 2010). While many
itch pathways involve histamine signaling, there are clearly other key neural pathways as most pathophysiological itch conditions are insensitive to antihistamine treatment and novel therapeutic targets
have yet to be identified (Ikoma et. al., 2006; Davidson & Giesler, 2010). Members of the Mas-Related G
Protein coupled Receptor (Mrgpr) family have emerged as key mediators of histamine-independent itch.
Mast cells secrete a variety of peptides that activate MrgprC11 to evoke itch. Likewise, MrgprA3 is activated by the antimalaria drug, chloroquine, which causes antihistamine-insensitive intolerable itch.
We now show that MrgprA3 and MrgprC11 couple to TRPA1 in heterologous systems and sensory neurons, providing a molecular mechanism of Mrgpr-evoked excitation. TRPA1-deficient neurons display
clear signaling deficits in response to chloroquine and the MrgprC11 pruritogen, BAM 8-22. Indeed, our
data definitively show that TRPA1 is the primary contributor to MrgprA3 and MrgprC11- evoked itch, as
animals lacking this channel show a huge reduction in chloroquine and BAM 8-22 sensitive neurons.
This is also matched by a profound alteration in behavior, such that TRPA1-deficient mice display no
scratching following chloroquine or BAM 8- 22 injection. Likewise, we also show that TRPA1 is essential for itchevoked scratching behaviors in an experimental dry-skin mouse model of chronic itch.
Thus TRPA1 may define a new signaling pathway that mediates histamine-independent, chronic itch.
2.6.2
GREASING THE GEARS OF CHANNEL FUNCTION:
TRPV1 CHANNELS AND LIPIDS
2.6.3
TRPV4, A MOLECULAR TRANSDUCER INVOLVED
IN THE EPITHELIAL BARRIER FUNCTION
Rosenbaum T(1), Picazo-Juárez G(1), Llorente I(1), Morales-Lázaro, S (1), Escalante-Alcalde D (1) and
Islas LD (2). (1) Instituto de Fisiología Celular, UNAM, Mexico. (2) Facultad de Medicina, UNAM, Mexico.
Yeranddy A. Alpizar(1), Pieter Uvin(1,2), Brett Bonnen(1), Katrien Luyts(3), Vanessa De Vooght(3),
Thomas Voets(1), Dirk DeRidder(2), Benoit Nemery(3), Pieter Hoet(3), Karel Talavera(1). (1) Dept. of
Molecular and cellular Medicine, KU Leuven, Belgium. (2) Dept. of Development and Regeneration, KU
Leuven, Belgium. (3) Dept. of Public Health, KU Leuven, Belgium.
For the last two decades there has been growing evidence that the bioactive phospholipid, lysophosphatidic acid (LPA), activates primary nociceptors resulting in neuropathic pain. The TRPV1 ion channel
is expressed in primary afferent nociceptors and is activated by physical and chemical stimuli. We have
shown that LPA produces acute painlike behaviors in normal mice, which are substantially reduced
in Trpv1 null- mice. Our data also demonstrate that LPA activates TRPV1 through a novel mechanism
that is independent of G protein-coupled receptors, contrary to what has been widely shown for other
ion channels, by directly interacting with the C-terminus of the channel. We conclude that TRPV1 is
a direct molecular target of the pain-producing molecule LPA (levels of which are increased during
tissue injury) and this constitutes the first example of LPA binding directly to an ion channel to acutely
regulate its function. Moreover, we have also investigated the role of cholesterol on TRPV1 function. In
contrast to LPA, cholesterol inhibits capsaicin- and temperature- activated TRPV1 currents. Previous
studies had suggested that cholesterol regulates TRPV1 activity by affecting trafficking processes.
Nonetheless, we found that in excised membrane patches, cholesterol interacted with the channel
through a recognition amino acid consensus (CRAC) motive, which we localized to the S5 helix of the
channel. Interestingly, we also found that two human TRPV1 variants, with different amino acids in the
CRAC sequence, had different responses to cholesterol.
TRPV4 is a Ca2+-permeable non-selective cation channel belonging to the vanilloid subfamily of Transient Receptor Potential proteins. This channel has a rather ubiquitous expression in epithelial cells
(skin, airways, endothelium and urothelium) and it is activated by a wide variety of physical and chemical stimuli, including heat, arachidonic acid metabolites, endocannabinoids and synthetic _-phorbol
derivatives..We have recently found that activation of TRPV4 by different irritant chemical species of
natural origin induces changes in the functional properties of the urinary bladder and airways. Cystometry experiments show that acute intravesical application of these compounds induces immediate
increases of the rate of bladder voiding in wild type but not in Trpv4 knockout (KO) mice. On the other
hand, challenge of the airways with these TRPV4 agonists induced strong ventilatory responses and
infiltration of macrophages and neutrophiles that were potentiated in Trpv4 KO mice. Acute stimulation
of TRPV4 in monolayer cultures of human bronchial epithelial cells induced a rapid increase of the
transepithelial electrical resistance, which is suggestive of an increase in the barrier function. In these
cells, stimulation of TRPV4 was followed by a release of nitric oxide, indicating that activation of this
channel can also trigger para- and/or exocrine signaling cascades directly regulating airway resistance
and permeability. These data point to important roles of TRPV4 at the level of epithelial cells where this
channel supports mechanisms of flushing and barrier tightening upon exposure to toxic compounds.
2.6.4
THE CA2+- ACTIVATED TRPM5 CHANNEL MEDIATES RESPONSES
TO PHEROMONES IN A SUBSET OF OLFACTORY SENSORY NEURONS
2.6.5
DIACYLGLYCEROL ACTIVATES THE LIGHT-DEPENDENT CHANNELS,
TRP AND TRPL, IN DROSOPHILA PHOTORECEPTORS
Diego Restrepo1, Fabián López2, Ricardo Delgado2, Roberto López1 and Juan Bacigalupo2 1Department of Cell and Developmental Biology, Rocky Mountain Taste and Smell Center, University of Colorado
Anschutz Medical Campus 2Department of Biology, University of Chile.
Bacigalupo J(1), Delgado R(1), Muñoz Y(1), Roth A(1), Peña H(2). (1) Universidad de Chile, Chile; (2)
Universidad Técnica Federico Santa María, Chile.
TRPM5 appears to be involved in transduction for pheromones in the main olfactory epithelium (Lin et.
al. PNAS 104:2471, 2007) but the mechanism is unknown. In this study we recorded putative pheromone and general odor responses of olfactory sensory neurons (OSNs) expressing or not expressing
TRPM5. We find that under loose patch OSNs expressing GFP in TRPM5-GFP mice (TRPM5-GFP+ OSNs)
respond to pheromones but not to odorants and that TPPO, a selective inhibitor of TRPM5, suppresses
the response. Moreover, OSNs that did not express GFP (TRPM5-GFP- OSNs) responded to odors and
pheromones, and responses were not inhibited by TPPO. In TRPM5-GFP+ OSNs pheromones, but not
odorants, elicited increases in intraciliary Ca2+ ([Ca2+]i) mediated by Ca2+ entry. In contrast in
TRPM5-GFP- OSNs both odors and pheromones elicited increases in [Ca2+]i. In complementary loose
patch experiments OSNs were stimulated with pheromones in Ringer’s without Ca2+. The response
is over twice that in the control condition and not inhibited by TPPO. Moreover, blockers of adenilyl
cyclase III and cAMP-gated channels (CNG) suppressed the response to pheromones. This result is
consistent with stimulusinduced CNG channel current mediating the responses in both TRPM5-GFP+
and – OSNs. Finally, immunohistochemical experiments show that CNG is expressed in the cilia of
TRPM5-GFP+ and - OSNs while the Ca2+-activated Cl- channel ANO2 is not expressed in TRPM5GFP+ OSNs. Our data indicate that OSNs expressing TRPM5 respond to pheromones by opening of CNG
channels that stimulate opening of TRPM5 channels through increases in [Ca2+]i.
.2.6.6
THE ROLE OF TRPM8 AND KV1 POTASSIUM CHANNELS IN PAINFUL
HYPERSENSITIVITY TO COLD IN RESPONSE TO AXONAL DAMAGE
MADRID R(1), RESTREPO C(1,2), UGARTE G(1), PIÑA R(1,3), HARDY P(1), GÓMEZ-SÁNCHEZ J(4)& PERTUSA M(1). (1)Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago
de Chile, 9160000 Santiago,Chile; (2)Escuela de Postgrado, Facultad de Medicina, Universidad de
Chile, 8380453 Santiago, Chile; (3)Departamento de Biología, Facultad de Ciencias, Universidad de
Chile, 7800003 Santiago, Chile and (4) Instituto de Neurociencias de Alicante, Universidad Miguel
Hernández-CSIC, 03550 San Juan de Alicante, Spain.
Transient receptor potential melastatin 8 (TRPM8), a calcium-permeable cation channel activated by cold,
voltage, and cooling compounds such as menthol, is the main molecular entity responsible for detection
of cold temperatures in the somatosensory system. TRPM8 is expressed in a subpopulation of primary
sensory neurons from trigeminal and dorsal root ganglia that respond to temperature reductions. These
cold-sensitive thermoreceptor neurons (CSNs) display a wide range of temperature thresholds in response
to temperature reductions, and can be separated in lowand high-threshold CSNs, the latest ones involved
in signaling cold-induced discomfort and pain. The temperature sensitivity of both low- and high-threshold
CSNs is determined, in a large extent, by the relative expression of the excitatory TRPM8 channels and
Shaker-like Kv1.1-1.2 potassium channels, the molecular counterpart of IKD, with antagonistic effects on
neuronal excitability. IKD is a potassium current that acts as an excitability break, that tunes the sensitivity
CSNs into the innocuous and noxious range of cold temperatures and prevents non-specific responses to
cold in neurons of other sensory modalities. Painful hypersensitivity to cold is a common sensory alteration that can be induced by axonal damage of primary sensory neurons of the somatosensory system.
An increase in TRPM8 expression has been linked to the development and maintenance of painful cold
hypersensitivity after injury of peripheral somatosensory nerves, although there are evidences that suggest
that this pathological condition is not necessarily correlated with significant variations in the expression
of this channel. In this symposium we show new evidences supporting the idea that an unbalance in the
functional expression levels of cold-sensitive TRPM8 channels and IKD current has an important role influencing the thermosensitivity of primary sensory neurons in response to axonal damage, contributing to
the development and maintenance of painful sensitivity to innocuous cold after peripheral neuronal injury.
Supported by FONDECYT1100983(RM)-3110128(MP)and PIA-CONICYT(RM,MP,GU).
TRP and TRPL are the light-dependent channels of Drosophila photoreceptors. These channels reside
in the rhabdomere, a narrow ensemble of microvilli flanking the elongated photoreceptor cell bodies.
These Ca2+-permeable channels are the targets of phototransduction, a process mediated by a phospholipase C signaling cascade, specifically its lipid branch. It is currently debated whether the PLC
substrate, PIP2, its products Diacylglycerol (DAG) and H+, or the DAG metabolites polyunsaturated
fatty acids (PUFAs), are directly responsible for TRP/TRPL activation. We addressed this problem, the
most relevant unanswered question in Drosophila phototransduction, by two different approaches. We
did single-channel measurements in rhabdomeric inside-out excised patches, where we tested the
aforementioned possible activators. We found that these isolated membranes retained their phototransduction protein constituents, allowing us to perform ‘pipette biochemistry’ on patches from wild
type and mutant flies. With the help of pharmacological inhibitors, we obtained strong support for DAG
as the principal channels activator. In a parallel study, we used high resolution hybrid mass spectrography to determine, in a novel rhabdomeric membrane preparation, if light changed DAG and PUFAs levels
in the rhabdomere. We characterized the rhabdomeric lipid profiles of dark and light-adapted flies, and
found that light only increased DAG, but did not alter PUFAs. Our data indicate that DAG is the most
likely if not the only channel activator in Drosophila photoreceptors. Support: FONDECYT 1100730 and
MIDEPLAN ICM-P05-001-F CONICYT Scholarship 22110957.
2.7.1
WNT SIGNALING AND SYNAPTIC PLASTICITY IN AGING
INESTROSA NC. entre for Aging and Regeneration (CARE, Faculty of Biological Sciences, Catholic University of Chile, Santiago, Chile, e-mail: [email protected]
The role of Wnt signaling pathway during synaptic development has been well established. In the adult
brain, different components of Wnt signaling are expressed, but little is known about its role in mature
synapses. Emerging in vitro studies implicate Wnt signaling in synaptic plasticity. Also, activation of
Wnt signaling protects against amyloid- (A )- induced synaptic impairment. Herein we will report
that in vivo activation of Wnt signaling improves episodic memory and enhances long-term potentiation (LTP) in adult wild-type and transgenic APP/PS1 mice, a model of Alzheimer’s disease (AD). These
findings indicated that Wnt signaling modulates cognitive function in the adult brain. Moreover, the
activation of Wnt signaling rescues memory loss and improves synaptic dysfunction in APP/PS1 mice.
More recent studies, showed that treatment of old transgenic (APP/PS1) mice with inhibitors of glycogen synthase kinase-3_ (GSK-3_), recovers spatial memory, synaptic function, LTP and attenuates
inflammatory and oxidative damage triggered by A_ oligomers, however, we do not found effects in the
levels of A_ aggregates, but observed a clear reduction in tau phosphorylation. Interestingly, incubations with a labdane diterpene in vitro generate an increase in field excitatory postsynaptic potentials
in CA1 hippocampal slices and inhibits long-term depression (LTD). Our results suggest that activation
of Wnt signaling is a promising target for AD therapy. Supported by CONICYT- PFB N° 12/2007 and
Fondecyt N° 1120156.
2.7.2
ENHANCING PLASTICITY AND FUNCTIONAL
RECOVERY IN THE INJURED SPINAL CORD
2.7.3
FATTY ACIDS AND PHYSICAL ACTIVITY AS
NEUROPROTECTIVE AGENTS IN MOVEMENT DISORDERS
Schultz M.Universidade de São Paulo, São Paulo, Brazil; University of California, Los Angeles, USA.
Burger, M.E.(1); Teixeira, A.M.(2); Trevizol, F.(2); Barcelos, R.C.S.(2); Emanuelli, T.(3)
(1) Departamento de Fisiologia e Farmacacologia-Universidade Federal de Santa Maria (UFSM), RSBrazil. (2) Programa de Pós Graduação em Farmacologia-UFSM, RS Brazil. (3) Departamento de Tecnologia dos Alimentos-UFSM, RS-Brazil
Many approaches have been tested aiming to understand how to enhance plasticity and functional
recovery after spinal cord injury (SCI). Some of these approaches aim to enhance the endogenous
potential of central nervous system (CNS) in promoting regeneration and functional reestablishment.
Non-pharmacological interventions based in dietary compounds lead to molecular changes and improvement of functional recovery after SCI. It has been shown that the docosahexaenoic acid (DHA),
a polyunsaturated fatty acid, and the curcumin (cur), a poly-phenolic compound, have effects on CNS
lesions. Cur attenuates inflammation while DHA is involved in cellular maintenance. Cur and DHA have
antioxidant properties and can ameliorate the effects of injuries over sensorimotor behavior through
plasticity. We will demonstrate the effects of DHA and/or curcumin intake on sensorimotor behavior
and plasticity of rats submitted to a low thoracic hemisection. Rats fed with curcumin and/or DHA
after hemisection had a better sensorimotor recovery. These findings are in line with changes found
in plasticity mediated by brain derived neurotrophic factor (BDNF) and synapsin-3. The interaction
between the metabolism of DHA and cur reduces lipid peroxidation and damage caused by oxidative
stress. The fatty acids profile in spinal cord was influenced by diets containing DHA and cur. Lumbar
DHA levels were increased in rats fed the diets supplemented with DHA, which could lead behavioral
improvement since DHA promotes cellular homeostasis. Therefore, DHA and/or Cur can be considered
as dietary treatments after spinal cord injuries. Supported by Conselho Nacional de Pesquisa (CNPq),
Brazil; NIH ROI NS 056413; NIH ROI NS 050465.
Dietary fatty acids (FA) play a key role in brain membrane phospholipids, and can modify it plasticity
and fluidity, acting in the development of cognitive and neuropsychiatric disorders. Healthy habits
include balanced diet and physical activity, which has regularly been described as a form of rehabilitation or prevention of CNS diseases. We evaluated the influence of the exercise on haloperidol-induced
oxidative damage. Exercise prevented the development of orofacial dyskinesia (OD) and locomotor
damage antipsychotic-induced. Catalase activity (CAT) was recovered in subcortical region, preventing
cortical and subcortical lipid peroxidation (LP). Also in subcortical area, a positive correlation between
LP and OD was observed, concurrent with a negative correlation between CAT and OD. While these data
reinforce the involvement of oxidative stress (OS) in the development of movement disorders, physical
exercise increased the dopamine transporter activity, thereby helping to reduce striatal levels of this
neurotransmitter, often elevated by the antipsychotic (Teixeira et al., 2011). In the following study,
weaned rats were supplemented with different FA (soybean oil-SO, rich in polyunsaturated FA; lard-L,
rich in saturated FA; and hydrogenated vegetable fat-HVF, rich in trans FA) and daily exercised for three
months. Biochemical evaluations performed after 15 months showed higher incorporation of trans FA
in brain of HVFsupplemented group. Behavioral assessments showed that HVF increased OD, which was
intensified by exercise in both HVF and L groups. Locomotion was reduced in these groups and was
not modified by exercise. CAT activity was reduced in L and HVF, but it was increased by exercise in the
latter one. The different FA did not alter striatal Na+K+- ATPase activity, which was increased by
exercise in L and SO groups. Trans FA brain incorporation may be related to motor impairments mainly
observed in HVF group, while the absent of this incorporation in SO group can be related to best motor
performance and enzymatic activities (Teixeira et al., 2012). Taken together, our data suggest that a
reduced intake of saturated and trans FA allied to physical activity, can prevent the development of
neurological and neuropsychiatric disorders.
2.7.4
THE IMPACT OF LIFESTYLE IN THE CNS:
FROM EPIGENETIC TO BEHAVIOR
2.8.1
NEUROCHEMICAL ACTIVITY IN THE EMBRYONIC
RETINA AND ITS POSSIBLE ROLE IN DEVELOPMENT
Fernando Gomez-Pinilla
Dept. Integrative Biology and Physiology, and Neurosurgery, Univ. California Los Angeles, Los Angeles,
CA, USA.
I will discuss how nutrients and exercise influence cognition and emotions, and how these capacities can be used to counteract neurological disorders. Specific diets and exercise routines influence
molecular systems that facilitate synaptic transmission, improve cognitive abilities, and make the CNS
more resistant to damage. In particular, omega- 3 fatty acids are crucial for brain development and
reduce vulnerability to psychiatric and neurological disorders. Conversely, the presence of saturated
fats and sugars can harm the brain. Our research indicates that the action of nutritional factors and
exercise is displayed at the level of processes involved in control of energy homeostasis, and control of
epigenetic regulation of genes important for neuronal signaling such as BDNF. We have also found that
because of their lipid composition, neuronal plasma membranes are targets for the action of diets,
with implications for the transmission of information across cells. From a practical point of view, it is
crucial that the actions of dietary factors are complementary. For example, the curry spice curcumin
complements the action of omega-3 fatty acids, and exercise interacts with the effects of the diet. Exercise can counteract some of the consequences of unhealthy diets or boost the effects of healthy diets.
Diets rich in omega 3-fatty acids or curcumin can counteract the effects of brain trauma as tested
in animals; however, diets rich in saturated fats and sugar do the opposite. In summary, I will convey
the concept that management of diet and exercise is an excellent and non-invasive strategy to support
brain function, reduce mood disorders, and maintain cognitive function across several conditions and
ages. Based on the outstanding safety profiles of diet and exercise interventions, information derived
from animal studies can be readily translatable into human treatment (supported by NIH/NINDS).
de Mello FG,Santos LE,Fleming RL,Stutz B and Gardino PF. Instituto de Biofísica Carlos Chagas Filho,
Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ Brasil.
Neurochemical activity is detected in the developing nervous system. In the retina, at the early stages
of development, neurotransmitter and neuropeptide signaling is a common event occurring before
synapse formation or even before all neurons of the tissue are fully mature. In the present study we
will focus on the role of dopamine and PACAP signaling during avian retina development. Both agents
influence plastic changes in amacrine cells phenotype as well as on their neurite extension. While
PACAP can promote an increased number of dopaminergic cells and the extension of their neurites,
dopamine itself negatively influence the growth of neurites of these neurons. Moreover, we show that
during avian retina development an alternative source of dopamine is transiently observed in the tissue, before maturation of dopaminergic amacrine cells. Supported by: CAPES, CNPq, Faperj, INNT-INCT.
2.8.2
GABAERGIC SIGNALING IN A STEM CELL
NICHE OF THE SPINAL CORD
2.8.3
ELECTRICAL ACTIVITY REGULATES PLEXIN A3-MEDIATED AXON
PATHFINDING IN DEVELOPING ZEBRAFISH SPINAL MOTONEURONS
Russo RE
Neurofisiología Celular y Molecular. Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
Paola V. Plazas and Nicholas C. Spitzer. Neurobiology Section and Center for Neural Circuits, Division of
Biological Sciences, Kavli Institute for Brain and Mind, UC San Diego, La Jolla, California, USA.
The behavior of both progenitors and neuroblasts within adult neurogenic niches must be regulated to
maintain the functional stability of the host circuit. GABA plays a major role in this kind of regulation
in the brain, but little is known about GABAergic signaling in neurogenic niches of the spinal cord. The
region that surrounds the central canal (CC) is a stem cell niche immersed within already functional
circuits, where two sources of GABA occur: GABAergic terminals and CC-contacting neurons. GABA
depolarized brain lipid binding protein (BLBP) positive progenitors via GAT3 transporters and/or GABAA
receptors. In CC-contacting neurons, GABAA receptor activation generated responses ranging from
excitation to inhibition. This functional heterogeneity appeared to originate from a predominance of
the Na+-K+-Cl- co-transporter NKCC1 over the K+-Cl- KCC2 co-transporter. In both progenitors and
immature neurons, GABA induced an increase in intracellular Ca2+ that required extracellular Ca2+
and was blocked by the selective GABAA receptor antagonist gabazine. Our study shows that GABAergic
signaling around the CC shares fundamental properties with those in the embryo and adult neurogenic
niches, suggesting that GABA may be part of the mechanisms regulating the production and integration
of neurons within operational spinal circuits in the turtle.
2.8.4
INTERFERENCE WITH GLUTAMATE SIGNALING INDUCES NEURAL
TUBE DEFECTS: IMPLICATIONS TO ANTIEPILEPTIC DRUG ACTION
DURING NEURAL TUBE FORMATION
Sequerra EB(1,2), Borodinsky LN(1,2). (1) Dept. of Physiology and Membrane Biology, University of
California Davis. (2) Shriners Hospital for Children Northern California
Failure of neural tube closure leads to malformations known as neural tube defects (NTDs). Offspring
of epileptic women exhibit higher incidence of NTDs due to the use of antiepileptic drugs (AEDs) during
pregnancy. The mechanisms through which these drugs induce NTDs remain unclear. We hypothesize
that neurotransmitter signaling is present at neural plate stages and is important for neural tube
formation. AEDs induce NTDs by impairing embryonic neurotransmitter signaling. Immunostaining and
calcium imaging experiments reveal that glutamate is expressed throughout the neural plate and its
cells are responsive to glutamate and NMDA. The AED valproic acid (VPA) inhibits these responses. We
then investigated whether NMDA receptor-mediated signaling influences neural tube formation by incubating early neural plate stage embryos with the NMDA receptor antagonist, D-AP5 until neural tube
closure was completed in control siblings. D-AP5 increases the incidence of NTDs in a dose-dependent
manner. In parallel, knocking down the NMDA receptor subunit NR1 inhibits the responsiveness of
neural plate cells to NMDA and induces open neural tube phenotype. Inhibiting NMDA receptors, or
its expression, increases the number of phospho-histone H3-expressing neural plate cells, suggesting
that glutamate signaling regulates cell proliferation during neural tube formation. Interestingly, the
induction of NTDs by VPA is accompanied by increases in BrdU incorporation, in PCNA-labeled and total
number of neural plate cells, suggesting that VPA is interfering with the normal cell cycle progression.
These findings suggest that glutamate signaling regulates cell cycle exit during neural tube formation
and AEDs may interfere with this action.
One of the puzzles in neurosciences is how neuronal circuits are formed during the development of the
nervous system. While the role of genetic programs in this process is well understood, evidence for
a role of electrical activity is quite limited. In zebrafish embryos, each spinal hemisegment contains
3 primary motorneurons (PMN), named CaP, MiP and RoP, and ~30 secondary motorneurons (SMN).
We simultaneously characterized PMN axon outgrowth and Ca2+ activity during pathfinding behavior
in transgenic Hb9:Gal4/UAS:GCaMP3 embryos. Between 17 hr (PMN axonogenesis) and 24 hr post
fertilization, PMN display two types of spontaneous Ca2+ transients: waves and spikes. Ca2+ waves
are generated in both PMN and SMN, with similar durations and frequencies. In contrast, only PMN
exhibit specific patterns of Ca2+ spiking activity at different developmental stages. Suppression of
Ca2+ spiking activity by stochastic expression of inward rectifier K+ channels (hKir) in single PMN
led to errors in MiP and RoP axon pathfinding. Errors comprise aberrant branching in 30% of MiPs
and intraspinal pathfinding mistakes in 26% of RoPs. Misguided RoP axons either extend towards the
endogenous exit point but bypass it or orient away from it. Axon trajectories of hKirexpressing PMN
were restored to normal when the activity of nearby cells was also suppressed; suggesting that an
activity-based competition rule is a key regulator of PMN axon pathfinding. The guidance receptor
PlexinA3 plays a major role in PMN axon pathfinding. Coinjections of PlexinA3 morpholino (MO) with
hKir cDNA induced a synergistic effect in the incidence of pathfinding errors compared with embryos
injected either with PlexinA3 MO alone or hKir cDNA alone. Moreover, whole mount in situ hybridizations
showed that PlexinA3 expression is not regulated by activity. Our results provide an in vivo demonstration of the role of spontaneous electrical activity in axon pathfinding, modulating PlexinA3 signal
transduction pathway.
2.9.1
CIRCADIAN AND NON-CIRCADIAN MECHANISMS OF FOOD
ANTICIPATORY RHYTHMS IN NOCTURNAL RODENTS
Ralph Mistlberger. Simon Fraser University, Canada
Animals can be said to occupy a temporal niche, defined as nocturnal, diurnal or crepuscular (dawndusk) based on the timing of voluntary locomotor activity relative to the daily light-dark (LD) cycle. The
preferred temporal niche is assumed to be determined by a LD-entrainable circadian pacemaker in
the suprachiasmatic nucleus (SCN). However, if food is restricted to a particular time of day or night,
activity rhythms come under control of an alternate timing mechanism that can generate a daily rhythm
of food anticipatory activity. Based on the formal properties of food anticipatory rhythms, including
the persistence of these rhythms in SCN-ablated rats and mice, the timing mechanism has been conceptualized as a food-entrainable circadian oscillator (FEO) separate from the light-entrainable SCN.
Rats and mice can also anticipate two daily meals, at inter-meal intervals of 5h or more. We have
conducted behavioral experiments to determine whether anticipation of two daily meals represents
entrainment of two separate FEOs, entrainment of one FEO that can be consulted at multiple phases,
or a combination of circadian and shortinterval timers measuring intervals between meals or between
LD cues and meals. The empirical results are compatible with a dual-FEO model, and can be simulated
quantitatively using two coupled phase-only FEOs. Light can modulate the level of food anticipatory activity, but does not appear to be involved in its timing. We are currently seeking evidence for a dual-FEO
model by quantifying circadian rhythms of clock gene expression in peripheral tissues (stomach and
adrenal gland) using RT-PCR, and in the brain using in situ hybridization. In rats anticipating two daily
meals, peripheral tissues, and associated hormones (plasma ghrelin and corticosterone, respectively)
exhibit only unimodal circadian rhythms. Analysis of clock gene expression in the brain is in progress.
2.9.2
THE ROLE OF CENTRAL GHRELIN SIGNALING
IN FOOD ANTICIPATORY ACTIVITY
2.9.3
CORTICO-HYPOTHALAMIC MECHANISMS
IN MOTIVATED AROUSAL
M. Merkestein1*, G. van der Plasse1,2, M.A. van Gestel1, M.C.M. Luijendijk1, M.A.D. Brans1, M. van
der Roest3, H.M.G. Westenberg2, A.B. Mulder3, R.A.H. Adan1. 1 Rudolf Magnus Institute of Neuroscience, Department of Neuroscience and Pharmacology, University Medical Centre Utrecht, Utrecht, the
Netherlands. 2 Rudolf Magnus Institute of Neuroscience, Department of Psychiatry, Utrecht University
Medical Centre, Utrecht, the Netherlands. 3 Department of Anatomy and Neurosciences-NCA, VU University Medical center, Amsterdam, the Netherlands. * Current address: Department of Physiology,
Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
Fernando Torrealba. Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago,
Chile
Food anticipatory activity (FAA) is characterized as increased locomotor behaviour in response to impending food availability. This behaviour is observed in rats that are maintained on a time-restricted
feeding schedule or when limited availability of food is cued. Studies which used the neuronal activation marker Fos or which lesioned brain areas indicated that the ventromedial and dorsomedial
hypothalamus (VMH and DMH) might be implicated in FAA. In addition, levels of the orexigenic hormone
ghrelin rise in anticipation of a meal and, growth hormone secretagogue receptor 1a (GHS-R1a), the
ghrelin receptor, knockout mice display attenuated FAA. Therefore, we set out to explore the role of
ghrelin signaling in the VMH/DMH area in FAA. Using in vivo electrophysiology, neuronal responses
were recorded in awake, behaving rats in the VMH/DMH area. Rats had limited access to food which
was signaled by a light cue. In addition, rats received peripheral injections of leptin and ghrelin. The
neuronal population as a whole responded significantly to both the light cue and ghrelin administration by increasing neuronal activity. Taking into account only the neurons that responded significantly
to both ghrelin and cue, a strong positive correlation was found between these responses. In another
experiment, GHS-R1a was specifically knocked down in either the VMH or the DMH. GHS-R1a knockdown
in the VMH decreased the onset of FAA, whereas knockdown in the DMH attenuated both onset and
amplitude of FAA. These experiments suggest that there is a neuronal population within the DMH/VMH
that responds in a highly correlated way to both ghrelin and a food signaling cue. In addition, local
reduction of ghrelin signaling within the DMH and VMH resulted in impaired FAA. Altogether, these
studies imply a role for ghrelin signaling within the DMH and VMH in FAA.
2.9.4
INTERACTING BRAIN CLOCKS PRODUCE AROUSAL
AND ANTICIPATION FOR FOOD INTAKE
Escobar C (1), Salgado R (2), Rodriguez K (1), Blancas Vázquez AS (1), García SD (1), Palomares DM (1),
Angeles-Castellanos M (1), Buijs RM (2). (1)Fac. de Medicina, (2) Instituto de InvestigacionesBiomédicas, Universidad Nacional Autónoma de México.
Food is a potent time signal for the circadian system and has shown to entrain and override temporal
signals transmitted by the biological clock, the suprachiasmatic nucleus, which adjusts mainly to the
daily light/dark (LD) alternation. Organisms mostly ingest food in their active period and this permits
a correct coordination between the LD and the food elicited time signals with the circadian system.
Under conditions when feeding opportunities are shifted to the usual resting/sleep phase, the potent
entraining force of food, shifts circadian fluctuations in several tissues, organs, and brain structures
toward meal time, resulting a desynchrony within the body and between the organism and the external
LD cycle. The daily scheduled access to a palatable snack exerts similar changes specifically to brain
areas involved in motivation and reward responses. This review describes the phenomenology of food
entrainment and entrainment by a palatable snack. It suggests how scheduled feeding can lead to food
addiction and how shifted feeding schedules toward the sleep phase can result in altered ingestive
behavior, obesity and disturbed metabolic responses.
Supported by PAPIIT IN-203907 and CONACyT 82462
Brain histamine may affect a variety of different behavioral and physiological functions; however, its
role in promoting wakefulness has overshadowed its other important functions. Here, we review evidence indicating that brain histamine plays a central role in motivation and emphasize its differential
involvement in the appetitive and consummatory phases of motivated behaviors. We discuss the role
of the cortical input from the infralimbic area that controls histaminergic neurons of the tuberomamillary nucleus of the hypothalamus, which determines the distinct role of these neurons in appetitive
behavior. In particular we show evidence indicating that histamine neurons are important in behavioral
arousal and in the modulation of effort to obtain rewards. Moreover, we review evidence supporting the
dysfunction of histaminergic neurons and the cortical input of histamine in regulating specific forms
of decreased motivation (apathy).
SYMPOSIA
WEDNESDAY NOVEMBER 7
3.1.1
BIMODAL DISCRIMINATION
Lemus L(1), Romo R(1), (1) Instituto de Fisiología Celular, UNAM, DF, México
Behavior is based on decisions arrived from the neural coding of current, and stored sensory information. But, are there as many decisions signals as different sensory modalities? In order to solve this
question, two monkeys were trained to discriminate a pair of train pulses either auditory, tactile or
both. Crucial to the task, is that information about tactile and auditory stimuli was coded in the flutter
frequency given by the number of pulses per second in each stimulus. In this manner, tactile and auditory stimuli could be discriminated interchangeably. We found a hierarchical evolution of the sensory
signal, starting in primary sensory cortices and converging in premotor cortices of the frontal lobe. At
these final stages, single neurons activity carried single modality information and, surprisingly, some
neurons also vary their firing rates as a function of sensory, memory and decision processes for both
sensory modalities. We propose that these prefrontal neurons are dedicated to process behaviorally
relevant information, regardless of the sensory modality.
3.1.3
POPULATION CODING IN LAMINAR CORTICAL CIRCUITS
Valentin Dragoi. Dept. of Neurobiology and Anatomy, Univ. of Texas-Houston Medical School, Houston,
TX, USA
Despite the fact that strong trial–to–trial correlated variability in response strength has been reported in many cortical areas, recent evidence suggests that neuronal correlations are much lower
than previously thought. However, the responses of cortical neurons are known to depend on their
network environment, which changes as a function of cortical layer. We used multi–contact laminar
probes to revisit the issue of correlated variability in primary visual (V1) cortical circuits. We found
that correlations between neurons depend strongly on the local network context – whereas neurons in
the input (granular) layer of V1 showed virtually no correlated variability, neurons in the output layers
(supragranular and infragranular) exhibited strong noise correlations. The laminar dependence of spike
count correlations is consistent with recurrent models in which neurons in the granular layer receive
intracortical inputs mainly from nearby cells, whereas neurons in supragranular and infragranular
layers receive inputs over larger cortical distances. Contrary to expectation that the output cortical
layers encode stimulus information most accurately, we found that the input network encodes more
information and offers superior discrimination performance compared to the output networks.
3.1.2
NEURAL CODES FOR PERCEPTUAL DETECTION
IN THE PRIMATE SOMATOSENSORY THALAMUS
Vázquez Y(1), Zainos A(1), Alvarez M(1), Salinas E(2) and Romo R(1,3), (1) Depto. De Neurociencias
Cognitivas, Instituto de Fisiología Celular, UNAM, México D.F., México; (2) Department of Neurobiology
and Anatomy, Wake Forest University School of Medicine, Winston-Salem, North Carolina, U.S.A. and (3)
Colegio Nacional, México, D.F., Mexico.
The contribution of the sensory thalamus to perception and decision making is a problem not yet
entirely solved in neuroscience. We addressed this by recording single neurons in the ventral posterolateral (VPL) nucleus of the somatosensory thalamus, while trained monkeys judged the presence or
absence of a vibro-tactile stimulus applied to their fingertip. We found that neurons in the VPL nucleus
modulate their firing rate as a function of the stimulus amplitude. These modulations accounted for the
monkeys’ psychophysical performance. We also found that the VPL activity did not predict the animals’
decision reports. Moreover, the neural sensitivity to changes in the stimulus amplitude was similar
comparing a behavioral context where monkeys were required to detect the stimulus and report their
decision, to a control condition where they passively received the stimuli and no report was required.
These results suggest that the somatosensory thalamus is exclusively related to encoding the sensory
inputs and providing a neural copy to the primary somatosensory cortex for further processing associated with the cognitive components of the detection task used here.
3.1.4
REVERBERATION, STORAGE AND PROPAGATION
OF MEMORIES DURING SLEEP
RIBEIRO, S. Instituto do Cérebro, Universidade Federal do Rio Grande do. Norte, Brazil
Episodic and spatial memories require the hippocampus during acquisition but progressively engage
the neocortex over time. This talk will present electrophysiological and molecular evidence that the
interplay between slow-wave sleep (SWS) and rapid-eye-movement sleep (REM) propagates recent
synaptic changes from the hippocampus to the neocortex. During post-novelty SWS, neocortical firing
rates remain elevated while hippocampal firing rates quickly return to basal levels. Likewise, postnovelty REM triggers immediate-early gene expression that recurs in the neocortex for hours after the
stimulus, but fades away in the hippocampus after a single post-novelty REM episode. Altogether the
data indicate that hippocampo-neocortical activation during waking is ensued during sleep by multiple
waves of neocortical – but not hippocampal - plasticity.
3.1.5
INTERVAL TUNING IN THE PRIMATE MEDIAL PREMOTOR
CORTEX DURING DIFFERENT RHYTHMIC TAPPING BEHAVIORS
Merchant H(1), Pérez O(1), Zarco W(1), and Gámez J(1). (1) Dpto. de Neurobiología Conductual y Cognitiva, Instituto de Neurobiología, UNAM, Querétaro, Querétaro, México.
The precise quantification of time during motor performance is critical for many complex behaviors
including musical performance; however, its neural underpinnings are unknown. We found that neurons
in the medial premotor areas (MPC) of behaving monkeys are tuned to both the duration of produced
intervals and the ordinal structure of rhythmic tapping tasks. The same population of neurons is able
to multiplex a wide range of durations in the range of hundreds of milliseconds with the order of the
executed interval in a sequence of temporalized movements. In addition, we found that interval-tuned
neurons in MPC showed similar preferred intervals across tapping behaviors that varied in the number
of produced intervals and the modality used to drive temporal processing. Our results also revealed
a gain mechanism for the encoding of the total number of produced intervals in a sequence, where
the discharge rate in the preferred interval of tuned cells increases for larger numbers of produced
intervals. These data suggest that MPC uses interval tuning as an abstract signal to represent temporal
processing in a variety of behavioral contexts where time is explicitly quantified.
3.2.1
ACTIVITY-DEPENDENT NEUROTRANSMITTER SPECIFICATION
IN THE DEVELOPING SPINAL CORD: INTERPLAY BETWEEN
CALCIUM SIGNALING AND MORPHOGENETIC PROTEINS
Yesser H. Belgacem, Immani Swapna, Laura N. Borodinsky, Dept. of Physiology & Membrane Biology,
University of California Davis School of Medicine & Shriners Hospital for Children Northern California,
Sacramento, CA, USA.
Neurotransmitter specification is crucial for the functional participation of developing neurons in the
emerging neural circuits. Whether the embryonic specification of neural progenitor cells predetermines
the identity of neurotransmitter to be expressed in neurons remains unclear. Sonic hedgehog (Shh)
and bone morphogenetic proteins (BMPs) orchestrate the patterning of embryonic tissues and are
essential for nervous system development. Concurrently, embryonic electrical activity is important
for proliferation, migration and differentiation of neurons. Here we demonstrate the novel interplay
between morphogenetic protein signaling and calcium dynamics in the developing spinal cord. Calcium
imaging of embryonic Xenopus spinal cord shows that Shh acutely increases calcium spike activity
through activation of the Shh coreceptor Smoothened (Smo) in neurons. Smo recruits a heterotrimeric
guanosine triphosphate binding protein-dependent pathway and engages calcium release from stores
and calcium influx. The dynamics of this signaling are manifested in synchronous calcium spikes
and inositol triphosphate transients apparent at the neuronal primary cilium. In contrast, BMP decreases electrical activity by enhancing p38 MAPK-mediated negative modulation of voltage-gated
sodium channels. The interaction between morphogenetic proteins and electrical activity modulates
neurotransmitter phenotype specification in spinal neurons. These findings identify an unexpected
interplay that is critical for decoding the morphogen gradient in an activity-dependent manner during
spinal neuron differentiation.
3.2.2
SEGREGATION OF TRANSMITTERS:
A PLASTIC SYNAPTIC PROPERTY OF NEURONS.
3.2.3
FUNCTIONAL ROLES OF VESICULAR GLUTAMATE
TRANSPORTERS IN DOPAMINE NEURONS
Morales MA, Cifuentes F, Vega A. Department of Physiology & Cell Biology, Biomedical Research Institute, Universidad Nacional Autónoma de México
TRUDEAU LE, FORTIN GM, GIGUERE N. Université de Montréal
It has been generally accepted that neurons store and release the same set of transmitters at all
their synaptic processes. However, evidence of the last two decades that show axon endings of single
neurons storing and releasing different transmitters disagree with this assumption, and give support
to the hypothesis that neurons can segregate their transmitters to different synapses. Accordingly, we
have shown that sympathetic neurons segregate classic transmitters, acetylcholine (ACh) and norepinephrine (NE), and co-transmitters (neuropeptides). Considering that sympathetic neurons can switch
their phenotype either in culture or in vivo, we could expect that neurons were able to sort transmitters
to separate varicosities according to their synaptic requirements. We have explored segregation of
transmitters and its possible plasticity in sympathetic neurons using two experimental approaches.
First, in ganglionic neurons co-cultured with cardiac myocytes we investigated segregation and its potential modulation by ciliary neurotrofic factor (CNTF) or endogenous factors produced in longer times
in culture. Secondly, we studied whether segregation in preganglionic sympathetic neurons can be
modified in vivo by changing ganglionic NGF content by axotomy of ganglionic neurons. We have found
that co-cultured sympathetic ganglionic neurons segregate NE from neuropeptide Y (NPY)-containing
varicosities and cholinergic puncta. CNTF and culture-produced factors modify segregation demonstrating the potential plasticity of this neuronal property. Transection of postganglionic axons reduces
NGF ganglionic content and increases segregation of ACh from met-enkephalin (mENK)-containing varicosities. Restoration of ganglionic NGF by exogenous administration of this neurotrophin prevents the
changes. We conclude that sympathetic neurons have the capability to segregate its neurotransmitters
to separated varicosities and also that this phenomenon is plastic and responds to the environment
requirements. (Supported by CONACYT, México Grant # 128332.
Studies of dopamine neurons in culture revealed in 1998 that these cells have the potential to release
glutamate as a second classical neurotransmitter. Until quite recently, this observation was viewed by
many as an intriguing culture artifact. However, following our discovery in 2004 that a subset of rodent
dopamine neurons expresses the type 2 vesicular glutamate transporter (VGLUT2), a flurry of reports
have examined further this phenomenon and it now seems clear that a subset of dopamine neurons
in vivo, mainly those of central regions of the VTA, possess a dual dopamine-glutamate cophenotype.
This presentation will summarize the results of recent investigations aiming to better understand how
and why dopamine neurons express VGLUT2 and release glutamate from some of their axon terminals.
3.2.4
CO-RELEASE OF GLUTAMATE AND GABA FROM THE MOSSY FIBERS
3.3.1
INTRODUCTORY REMARKS TO “PSYCHOPHYSIOLOGY”
GUTIERREZ, R. Departamento de Farmacobiología, Centro de Investigación y Estudios Avanzados del IPN.
HACKLEY SA, Dept. of Psychological Sciences. Univ. of Missouri, Columbia, Missouri, U.S.A.
We and other laboratories have provided immunohistochemical, molecular biological and electrophysiological evidence that the glutamatergic granule cells of the dentate gyrus can transiently express a
GABAergic phenotype during development and, in the adult, after a sustained period of hyperexcitability (1). Electrophysiological recordings on hippocampal slices obtained under these conditions
have shown that stimulation of the mossy fibers (MFs) provokes simultaneous monosynaptic GABAA
and glutamate receptor-mediated responses in their target cells, which have the pharmacological and
physiological characteristics of MF neurotransmission. This evidence, although strongly supporting the
hypothesis that MFs co-release glutamate and GABA, is indirect, as the extracellular stimulation used
in slice experiments could activate fibers other than MFs. I will show the evidence of a double, glutamatergic/GABAergic phenotype of the granule cells. Indeed, the selective stimulation of single, identified MF boutons (MFBs) of developing rats produced synaptic currents mediated by either glutamate
receptors only or by both glutamate and GABAA receptors. By contrast, stimulation of MFBs of adult
rats produced exclusively glutamate receptor-mediated responses. All responses evoked by stimulation
of MFBs underwent strong frequency-dependent potentiation and were depressed by the activation
of presynaptic metabotropic glutamate receptors. On the other hand, synaptic responses evoked by
stimulation of interneuronal boutons located on the soma or on the basal dendrites of the same pyramidal cells were exclusively mediated by GABAA receptors, underwent frequency-dependent depression
and were unaffected by mGluR agonists (2). We demonstrate that the simultaneous glutamatergic and
GABAergic responses evoked by MF stimulation in pyramidal cells of CA3 during development have
a common origin in the giant MFBs (1) Gutiérrez, R. The dual glutamatergic-GABAergic phenotype of
the hippocampal granule cells. Trends in Neurosci. 28: 297-303, 2005. (2) Beltrán, J. Gutiérrez, R. J.
Physiol., 2012, DOI: 10.1113/jphysiol.2012.236372.
Although psychophysiology was among the first branches of neuroscience to embrace the cognitive
revolution, its connections to affective neuroscience, especially the autonomic nervous system, have
always been strong. The research presented in this symposium highlight the value of the integrative
tradition associated cognitive and affective research by psychophysiologists.
3.3.2
DEFICITS OF ANTICIPATORY ATTENTION IN PARKINSON’S DISEASE
3.3.3
ROLE OF THE RIGHT ANTERIOR INSULAR
CORTEX IN ANTICIPATORY ATTENTION AND EMOTION
Hackley SA, Department of Psychological Sciences. University of Missouri, Columbia, Missouri, U.S.A.
Data from behavioral, neuroimaging, and surface electrophysiology studies will be presented to elucidate the specific deficits of attention found in Parkinson’s Disease. Whereas arousal mechanisms
appear normal, visual working memory and reward anticipation are impaired. Subcortical and cortical
mechanisms will be examined, with special emphasis on the pre-supplementary motor area (pre-SMA)
and right anterior insula. The intricate linkage of motivational and cognitive deficits supports the view
that “hot hedonics” and “cold cognition” approaches should be combined to achieve a more complete
understanding of this brain disorder.
Kotani Y(1), Ohgami Y(1), Arai J(2), Kiryu(3), & Inoue Y(4). (1)Tokyo Institute of Technology, Tokyo,
Japan; (2)Daikin Industries, Osaka, Japan; (3)The University of Tokyo, Tokyo, Japan; (4)Kitasato University, Kanagawa, Japan.
Objectives:Recent neuroimaging studies have hypothesized that the right anterior insular cortex
modulates attention systems in the human brain. Intriguingly, a number of studies using event-related
potentials (ERP) have also suggested the importance of the insular cortex for anticipatory attention
process (Brunia et al, 2011). In the present study, we employed a time estimation task that has been
conventionally employed in the ERP studies, and the brain activations were evaluated using eventrelated fMRI and psychophysiological interaction (PPI) method to examine the effective connectivity of
the right anterior insular cortex in the anticipatory attention process. Participants and Methods: Participants were twenty-eight healthy adults (16 females and 12 males). They performed a time estimation task with the Feedback and Control conditions during fMRI acquisition. In the Feedback condition,
a feedback stimulus about task performance was presented three seconds after a button press while
the feedback stimulus was omitted in the Control condition. Results: The PPI analysis on brain activations during participants anticipating the occurrence of a feedback stimulus revealed that the right
anterior insular cortex has greater effective connectivity with the anterior cingulate cortex (ACC) during
the Feedback condition compared to the Control condition. In addition, the PPI analyses on the ACC
and other regions revealed a network involving the ACC, the fusiform gyrus, the middle frontal gyrus,
and the inferior parietal lobule. Conclusions: The present results suggest that the ACC acts as a hub
of anticipatory attention process connecting to the fusiform gyrus, the inferior parietal lobule, and the
middle frontal gyrus. In addition, the PPI analyses revealed that the ACC activity was modulated by the
right anterior insula. Taken these into account, the right anterior insula could control the anticipatory
attention system by modulating the ACC activities.
3.3.5
BODY AND BRAIN CHANGES ASSOCIATED WITH INVASION
OF PERIPERSONNAL SPACE IN PTSD
VOLCHAN E(1), ROCHA-REGO V(1), PEREIRA M(2), OLIVEIRA L(2),MENDLOWICZ M(3), MARQUES-PORTELLA
C(4), FISZMAN A(4), and FIGUEIRA I(4). (1) Universidade Federal do Rio de Janeiro. (2)Univ. Fed. Fluminense, Niteroi
Urban violence is an important and pervasive cause of human suffering. Violent events, such as armed
robbery, are very frequent in certain cities, and these episodes increase the risk of posttraumatic
stress disorder (PTSD). Assaultive trauma is characterized by forceful invasion of the peripersonal
space, which is defined as a margin of safety around the body. The invasion of this margin of safety is
often experienced as a threat to an individual’s psychological or biological integrity and may lead to
that individual’s intense discomfort and anxiety. Neurobiology studies have suggested that the premotor cortex incorporates both a representation of peripersonal space and certain aspects of defensive
motor functions. The experimental studies presented here provided evidence that life-threatening
urban violence events are a major trigger for defensive motor reactions in humans. Investigating structural brain alteration in PTSD victims of urban violence we found that, compared with traumatized
controls, PTSD patients presented reduced gray matter volume in the ventral premotor cortex. This
may be associated with a disruption in the dynamical modulation of the safe space around the body in
those patients. Tonic immobility, characterized by profound motor inhibition, is elicited under inescapable threat in many species. To fully support the existence of tonic immobility in humans, participants
exposed to violent crime listened to the script of their autobiographical trauma while biological correlates were recorded. Reports of script-induced immobility were associated with restricted area of body
sway and were correlated with accelerated heart rate and diminished heart rate variability, implying
that tonic immobility is preserved in humans as an involuntary defensive strategy. Immobility reports
seemed more evident in PTSD than in controls, suggesting that, in some patients, tonic immobility
may be elicited during re-experiencing episodes in daily life. This study provided a measure of tonic
immobility, a peritraumatic reaction for which cumulative clinical evidence had linked to the severity
of the most disruptive sequelae of trauma exposure– PTSD.
3.4.1
GALECTIN 3 DRIVES OLIGODENDROGLIAL CELL DIFFERENTIATION
(1)Pasquini LA, (1)Millet V, (1)Hoyos H, (*)Rabinovich G and (1)Pasquini JM. (1)Dept of Biological
Chemistry and IQUIFIB. School of Pharmacy and Biochemistry, UBA-CONICET.(*)Laboratory of Immunopathology, IBYME/CONICET.
Galectins control critical pathophysiological processes, including the progression and resolution of
central nervous system (CNS) inflammation. In spite of considerable progress in dissecting their role
within lymphoid organs, their functions within the CNS remain elusive. Here, we investigated the role
of galectin–glycan interactions in the control of oligodendrocyte (OLG) differentiation, myelin integrity
and function. Both galectin-1 and -3 were abundant in astrocytes and microglia. Although galectin-1
was abundant in immature but not in differentiated OLGs, galectin-3 was upregulated during OLG
differentiation. Biochemical analysis revealed increased activity of metalloproteinases responsible
for cleaving galectin-3 during OLG differentiation and modulating its biological activity. Exposure to
galectin-3 promoted OLG differentiation in a doseand carbohydrate-dependent fashion consistent with
the ‘glycosylation signature’ of immature versus differentiated OLG. Accordingly, conditioned media
from galectin-3-expressing, but not galectin-3-deficient (Lgals3-/-) microglia, successfully promoted
OLG differentiation. Supporting these findings, morphometric analysis showed a significant decrease
in the frequency of myelinated axons, myelin turns (lamellae) and g-ratio in the corpus callosum and
striatum of Lgals3 -/- compared with wildtype (WT) mice. Moreover, the myelin structure was loosely
wrapped around the axons and less smooth in Lgals3-/- mice versus WT mice. Finally, commitment
toward the oligodendroglial fate was favored in neurospheres isolated from WT but not Lgals3-/- mice.
Hence, glial-derived galectin-3, but not galectin-1, promotes OLG differentiation, thus contributing to
myelin integrity and function with critical implications in the recovery of inflammatory demyelinating
disorders. Protective role of galectin-3 during cuprizone demyelination will be also shown
3.4.2
LYSOPHOSPHATIDIC ACID EFFECTS ON EARLY
POSTNATAL SUBVENTRICULAR ZONE PROGENITORS
3.4.3
AUTOTAXIN: A REGULATOR OF OLIGODENDROCYTE
DIFFERENTIATION AND MYELINATION
Nogaroli, L. Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de
Janeiro, Brazil.
Fuss Babette. Virginia Commonwealth University
In the central nervous system (CNS) most of the cortical oligodendrocytes are derived primarily postnatally from neural progenitors present within the subventricular zone (SVZ). Once generated, oligodendrocyte progenitors (pOLGs) migrate radially out of the SVZ into the overlying cortical parenchyma
differentiating into mature oligodendrocytes. The molecular mechanisms regulating OLG specification
and pOLG migration in the mammalian forebrain are currently poorly understood. At the time-point
when OLGs are generated in the SVZ, Phosphodiesterase-I_/Autotaxin (PD-I_/ATX) is expressed by
choroid plexus epithelial cells and is presented in the cerebrospinal fluid, surrounding the gliogenic
niche. PD-I_/ATX is the main source of the signaling lipid lysophosphatidic acid (LPA), which is involved in several biological effects in the CNS. We hypothesize that LPA is one of the factors regulating
proliferation and migration of pOLG in the SVZ. Real-time PCR shows that all known LPA receptors
are expressed in SVZ, striatum and cerebral cortex in different levels. In SVZ there is a prevalence of
LPA1 and LPA6 followed by LPA4. Using in vitro and in vivo approaches we show that glial migration
is significantly altered while proliferation is not largely affected by LPA administration. LPA promotes
increasing of glial progenitors in the white matter and the marginal zone/ layer I and may regulate not
only radial but also tangential migration of glial progenitors in the white matter. Thus, our data so far
support our initial hypothesis that choroid plexus-derived PDI_/ ATX is one of the factors regulating
pOLG migration in the mammalian forebrain. LPA primarily stimulates the generation and migration of
neuronal progenitor cells during embryonic development, while during postnatal development it mainly
affects the migration of glial cells. This apparent functional dichotomy needs to be taken into account
when considering LPA as a therapeutic target for stimulating repair of the CNS.
During development, oligodendrocytes, the myelinating cells of the vertebrate central nervous systems
(CNS), are generated from neural progenitor cells that are located within distinct regions of the neuroepithelium. More specifically, within the developing spinal cord and hindbrain ventrally located progenitor cells that are characterized by the expression of the transcription factor olig2 give temporally
rise to first motor neurons and then oligodendrocyte progenitors. Once oligodendrocyte progenitors are
specified they undergo a lineage progression during which bipolar oligodendrocyte progenitor cells
give rise to cells with a complex (highly branched) and extended process network that then transition
into mature oligodendrocytes generating the myelin sheath. The regulation of both the initial temporal
neuron-glial switch as well as the progression through the oligodendrocyte lineage have been found
complex and little is known about the extrinsic factors regulating them. Our studies identified autotaxin
(Atx), also known as Enpp2, phosphodiesterase-I_/Atx or lysoPLD, as an extracellular factor promoting
the maturation of differentiating oligodendrocytes via an autocrine mechanism. This functional role
of Atx was found to be mediated by its modulator of oligodendrocyte remodeling and focal adhesion
organization (MORFO) domain. More recently and via the use of the zebrafish as an in vivo model
system, we found that Atx is expressed by cells of the cephalic floor plate during a time period when
ventrally-derived oligodendrocyte progenitors arise in the developing hindbrain. Knock-down of Atx
expression resulted in a delay and/or inhibition of the timely appearance of oligodendrocyte progenitors and subsequent developmental stages of the oligodendrocyte lineage. Thus, our studies suggest
that Atx does not only function as an autocrine factor promoting the maturation of differentiating
oligodendrocytes but also as a paracrine factor regulating the progression of olig2-positive progenitor
cells into lineage committed oligodendrocyte progenitors.
3.4.4
OLIGODENDROGLIAL LOSS IN A MODEL OF SYSTEMIC PERINATAL
HYPOXIAIS-CHEMIA: EFFECTS OF BLOCKADE OF NMDA RECEPTORS
IN PDGF-ALFA RECEPTOR POSITIVE CELLS
Barradas, P.C.(1), Savignon, T.(1,2), Costa, A.P.(1), Tenorio, F.(1), Manhães, A.C (3). (1)Depto. Farmacologia e Psicobiologia, IBRAG/UERJ, Rio de Janeiro, Brasil; (2)FIOCRUZ, Rio de Janeiro, Brasil; Depto.
Ciências Fisiológicas, IBRAG/UERJ, Rio de Janeiro, Brasil.
Maturation of oligodendroglia and maintenance of myelin occur in the context of a diverse extracellular
environment, which may vary not only during development but in particular under pathological conditions. Glutamatergic excitotoxicity is associated to hypoxic-ischemic (HI) damages and oligodendroglia
is vulnerable to neonatal HI insults. We used a modified model of prenatal systemic HI in rats to
investigate the effects of an antagonist of NMDA receptors in oligodendroglial development. Rats in the
18th gestation day were anesthetized and the four uterine arteries were clamped for 45 minutes (H
group). SHAM controls (S group) had no arteries clamped. From P1-P5, half of the animals received a
peritoneal injection of saline (HS or SS groups) or MK801 (HM or SM groups), 0.3mg/Kg. Frozen sections
of cerebellum were immunostained for PDGFR_ or CNPase. The number of PDGFR_+ cells in the deep
white matter (WM) in HS/HM animals at P9 was significantly lower than in SS/SM. At P23, the number
of PDGFR_+ cells in HM was higher when compared with all groups, indicating that the treatment
might have rescued oligodendroglial progenitors. CNPase immunohistochemistry showed an intense
staining pattern in SS and SM animals. At P9, CNPase+ fibers and cells were observed in more distal
positions in the folia of SS and SM than in HS animals. The immunoreactivity to CNPase was altered in
the WM of HS animals at P23, indicating that HS animals suffered a great loss also in mature CNPase+
oligodendroglia, whereas HM presented a pattern very similar to SS/SM animals. Our results showed
that HI decreases oligodendroglial differentiation in cerebellum by reducing the number of progenitors.
Furthermore, oligodendroglial progenitors could be rescued by using an antagonist of NMDA receptor.
Our findings reinforce the notion that this model could be used in devising new therapeutic strategies
for HI insults.
3.5.2
BIOETHICS AND ANIMAL RESEARCH IN LATIN AMERICA:
STATUS AND CHALLENGES
MALDONADO P; Universidad de Chile, Fisiologia y Biofisica, Instituto de Ciencias Biomédicas, Santiago,
Chile.
Neuroscience research in Latin America as seen a large resurgence in the last 20 years. Many new
laboratories and institutes devoted to this field has been created in many countries such as Argentina,
Brazil , and Chile. Nonetheless, laws and regulations that govern neuroscience research has advanced
at a slower pace. The diversity of realities, and compliance with rules and regulations differ substantially within the region and even within the same country. Here I present a summary of the status
of bioethics and animal research and indicate our challenges, which include more compliance with
international regulations and homogenisation of ethical practices.
3.5.3
NEUROETHICS: AN AGENDA FOR NEUROSCIENCE AND SOCIETY
3.5.4
ANIMAL MODELS RELEVANT TO LATIN AMERICA
McCABE, JT. Uniformed Services University of the Health Sciences
SILVA A (1,2,3). (1) Unidad Bases Neurales de la Conducta, Instituto de Investigaciones Biológicas
“Clemente Estable”. (2) Laboratorio de Neurociencias, Fac. De Ciencias, UdelaR. (3) Comisión Nacional
Experimentación MEC. Uruguay.
Scientists currently recognize that as members of society we exist in a shared culture. Scientific research provides advancement of knowledge about the mechanisms underlying the physical world, but
is also seen by the general public and the majority of scientists as contributing to societal benefit
through technological developments for the improvement of better living conditions and health. Among
the shared consensus that scientists must consider are the consequences of advancements and technological applications. An area of special concern to neuroscientists and the general public is the
application of new findings and technologies that affect brain function. While advances for the cure or
treatment of acute and chronic brain disorders is a benefit to society, manipulations that alter brain
function have a personal and societal impact relating to perceptions of controlling the personal “me”
by changes in thinking patterns and behaviors. In this review, a history of the recognition of ethical
considerations in scientific research will be discussed, followed by attention to particular recent implications of neuroscience research advancements and treatments. The shared consensus of scientists,
their patients, and the need for societal engagement is considered in light of historical events and
future challenges in neuroscience research and development.
The rich native fauna of Latin America is filled with current and potential model systems whose study is
important to encourage. First, because all protective policies should arise from a profound knowledge
of natural biodiversity. Second, because many of these wild species may constitute advantageous
model systems to test hypotheses from neuroethological, ecological, and evolutionary perspectives.
However, ethical considerations when conducting animal research on native animals impose additional
challenges. Animal collection and field research require to pay special attention to the conservation status of the studied species and to putative environmental interferences. On the other hand,
several laws and rules that apply to traditional laboratory animals cannot be usually instrumented
in wild animals. Therefore, researchers have to spend time and efforts to adapt guidelines on several
issues (sanitary, feeding, anaesthethic, end-point, etc), based on their privileged knowledge of the
natural history of their study species. As examples, I will focus on the long-lasting studies developed
in two groups of native teleosts in Uruguay: freshwater weakly electric fish (Order Gymnotiformes) and
annual killyfish that inhabit temporary ponds (Genus Austrolebias, Family Rivulidae, Order Cyprinodontiformes). Regarding species-specific needs, researchers shall commit to guarantee the ultimate
aim of animal welfare by generating ad hoc guidelines and adapting accordingly their experimental
procedures.
3.6.1
LONG LASTING NEURODEVELOPMENTAL
EFFECTS OF PRENATAL STRESS
3.6.2
EARLY LIFE STRESS AND ITS EFFECTS ON SLEEP, B
EHAVIOR AND NEUROCHEMISTRY
ANTONELLI MC. Instituto de Biologia Celular y Neurociencias “Prof. Dr. E. De Robertis”. Facultad de
Medicina. UBA. Buenos Aires. ARGENTINA.
Tiba PA (1) and Suchecki D (2). (1) Centro de Matemática, Computação e Cognição, Universidade
Federal do ABC, Santo André, Brazil. (2) Departamento de Psicobiologia, Universidade Federal de São
Paulo, São Paulo, Brazil
In recent years, there has been increasing awareness that various forms of pathological behaviours in
humans may be the outcome of an interaction between genetic factors and the prenatal and postnatal
environments. The vulnerability to develop neurological disorders are associated with a reduced adaptive capacity to an stressor and disturbances in DA and Glu neurotransmission contribute to neurochemical mechanisms underlying these disorders. We investigated the effects of prenatal stress on expression of DA and Glu receptors in offsprings of dams subjected to restrain stress during the last week
of gestation. DA receptors increased in limbic areas of the adult brain whereas Glu receptors increased
both in limbic and motor areas. Adoption at birth was used to change the postnatal environment and
the complex pattern of receptor changes obtained reflects the high vulnerability of DA and Glu systems
to variations both in prenatal and in postnatal environment. Behavioral studies have also been carried
out and adult offsprings of rats stressed during pregnancy (S) exhibited higher levels of anxiety than
control rats (C). In contrast, offsprings of control mothers but raised by rats stressed during pregnancy
(S/C) showed similar levels of anxiety to stressed groups S/S and S. Levels of anxiety were also similar
among C/S, C/C and C groups. The anxiety levels show direct correlation with benzodiazepine receptors
exhibiting a decrease in the number of [3H]flunitrazepam, benzodiazepine receptors (BDZ) binding
sites in amygdala and hippocampus. These findings suggest that adult prenatally stressed rats suffer
modifications in the GABA/BDZ receptor complex, that are associated to an ansiogenic behavior in the
adult life. However, changes in the postnatal environment such as adoption by control mothers can
block this ansiogenic behavior. We also performed morphological studies to evaluate astrocytes and
dendritic arborization in frontal cortex, striatum and hippocampus of the prenatally stressed adult rat
brain. Morphological studies revealed that PS offspring present a significant reduction in the dendritic
arborization of mesencephalic structures suggesting that normal connectivity between areas might be
impaired. Taking into consideration our results and those of the literature, we speculate that changes
exerted on the limbic system by prenatal insults might be associate with behavioural disorders or
neuropsychiatric pathologies with adolescent or young adult onset
Exposure of humans and animals to stressful events early in life leads to significant and often permanent behavioural, neuroendocrine and central alterations. Thus, early adverse experiences represent
risk factors for the development of anxiety and mood disorders. The increased secretion of corticosterone during an essentially anabolic developmental period is often investigated by separation of the
neonate from its mother for periods ranging from 3 to 24 h. In a series of studies, we showed altered
sleep pattern, behavior and central neurotransmission as consequences of this early adversity, and
corticosterone does not seem to play the central role in many cases.
3.6.3
PERIPUBERTY STRESS LEADS TO ABNORMAL AGGRESSION, ALTERED
AMYGDALA AND ORBITOFRONTAL REACTIVITY AND INCREASED
PREFRONTAL MAOA GENE EXPRESSION IN ADULTHOOD
3.6.4
CROSS-TALK OF HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AND
HYPOTHALAMIC-PITUITARY-ADRENAL (HPG) AXIS DURING SOCIAL
STRESS IN COMMON MARMOSETS (CALLITHRIX JACCHUS)
Marquez C (1,2), (1) Champalimaud Neuroscience Programme. Lisbon, Portugal. (2) Ecole Politechnique Federale de Lausanne. Lausanne, Switzerland.
GALVÃO-COELHO NL (1), SHIRAMIZU VKM (2), GALVÃO ACM (3), SILVA LMP (4), SOUSA MBC (1). (1) Department of Physiology, Federal University of the Rio Grande do Norte -UFRN. (2) Graduate Program in
Psychobiology-UFRN 3 Undergraduate Curse of Biological Sciences- UFRN. 4 Undergraduate Curse of
Pharmaceutical Sciences- UFRN.
Although adverse early life experiences have been found to increase lifetime risk of developing violent
behaviors, the neurobiological mechanisms underlying these long term effects remain unclear. We
present a novel animal model for pathological aggression induced by early stress with face, construct
and predictive validity. We show that male rats submitted to fear induction experiences during the peripubertal period exhibit high and sustained rates of increased aggression at adulthood, even against
unthreatening individuals, and increased testosterone/corticosterone ratio. They also exhibit hyperactivity in the amygdala under both basal conditions (evaluated by 2-deoxy-glucose autoradiography) and
after a resident intruder test (evaluated by c-Fos immunohistochemistry), and hypoactivation of the
medial orbitofrontal cortex after the social challenge. Alterations in the connectivity between the orbitofrontal cortex and the amygdala were linked to the aggressive phenotype. Increased and sustained
expression levels of the MAOA gene were found in the prefrontal cortex but not in the amygdala of
peripubertally stressed animals. They were accompanied by increased activatory acetylation of histone
H3, but not H4, at the promoter of the MAOA gene. Treatment with a MAOA inhibitor during adulthood
reversed the early trauma induced antisocial behaviors. Beyond the characterization and validation
of the model, we present novel data highlighting changes in the serotonergic system in the prefrontal
cortex and pointing at epigenetic activatory control of the MAOA gene in the establishment of the
link between peripubertal stress and later pathological aggression. Our data emphasize the impact of
biological factors triggered by peripubertal adverse experiences on the emergence of violent behaviors.
Psychiatric pathologies as depression and posttraumatic stress disorder are correlated with chronic
stress response. Our group use a non-human primate animal model, Callithrix jacchus, to determine
a cross-talk response of hypothalamic-pituitary-adrenal (HPA) and hypothalamic-pituitary-gonadal
(HPG) axis using two paradigms of social stress to induce depression in non-human primates (social
isolation: SS1, and dispute of rank position: SS2). Isossexual no-related dyads of adults males (n=6)
and females (n=6) C. jacchus remained in baseline phase (BP) for 28 days, with their feces for
hormonal measurement were colected in alternate days. After these animals were isolated in a new
similar cage (SS1) for seven days, and later they were reunited (SS2) at baseline cage for seven more
days. Males and females increased cortisol levels at SS1 and only females increased androgens levels
at SS2. It was also observed significant positive correlation between these hormones for males and
females. These results indicate that a interaction between HPA and HPG in the stress response to
social challenges in common marmosets and that activation depends on the sex of the animal and of
the nature of stressors as observed for other mammals, including humans. These findings might be
reflecting physiological adjustments in order to cope with stress situation.
3.7.1
N-CADHERIN IS ACTIVATED IN THE ADULT NEURAL STEM CELL
NICHE AND PROMOTES MIGRATION AND RECRUITMENT OF
NEURAL PROGENITOR CELLS AFTER DEMYELINATION
Aguirre A (1), and Klingener M (1). (1) SUNY at Stony Brook University, Department of Pharmacological
Science, Stony Brook, New York 11794, USA.
Cellular microenvironments, regulate stem cell size and their development, as well as function in
maintaining tissue homeostasis. As such there is a great interest to further characterize the niche as
well as to understand how it controls stem cell behavior during normal and pathological conditions.
The adult subventricular zone niche (SVZniche) is the largest reservoir of neural stem cells (NSCs) in the
adult brain and instructs NSCs to proliferate, migrate and differentiate. While signaling pathways in the
adult SVZ-niche remains fairly well understood, the pathways activated following injury and resulting
outcomes are less clear. It was thought that the adult mammalian central nervous system (CNS) has
very limited capabilities for endogenous cell replacement and circuit repair, both of which are essential
to achieve significant functional recovery following injury. Furthermore, progress in developmental
neurobiology and stem cell biology has expanded expectations for cell-base therapeutic approaches to
neurological diseases. Accordingly, is now well accepted that the brain maintains ongoing self-repair
potential supported by endogenous neural stem cells that reside in the SVZ-Niche. Our study here
demonstrated that during demyelination of subcortical white matter (SCWM), activation and expansion
of the NPC population was observed in the in the SVZ-niche. Protemic analysis from the SVZ-niche of
demyeinated mice demonstrated that signaling pathways that play pivotal roles in stem cell biology,
including cell adhesion, migration and angiogenesis were upregulated in the SVZ-niche during the peak
of demyelination, and those were back to control levels during the regeneration process. Furtermore,
gain- and loss- of- function approaches demonstrated that Ncadherin signaling enhanced SVZ NPC
migration to demyelinated lesions. Our data demonstrated that regulation of adhesion proteins can be
targeted to enhance cell recruitment and remyelination from the pool of endogenous SVZ NPCs in the
adult brain, following brain injury.
3.7.2
AMPAKINE CX546 INCREASES NEURONAL DIFFERENTIATION IN
POSNATAL SUBVENTRICULAR ZONE CELL CULTURES
Schitine, C(1,2), Xapelli, S(1), Agasse, A(1), Sarda-Arroyo L(1), Silva, AP(3), Reis,RAM(2), Mello, FG (2)
and Malva, JO(3). (1)CNC Lab of Brain Repair University of Coimbra, Portugal, (2)Institute of Biophysics
Federal University Rio de Janeiro, Brazil and (3) Institute of Biomedical Research on Light and Image
(IBILI), Faculty of Medicine, University of Coimbra, Coimbra, Portugal.
Ampakines are chemical compounds known to modulate the properties of ionotropic a-amino-3-hydroxyl-5-methyl-4- isoxazolepropionate (AMPA)-subtype glutamate receptors. The functional effects
attributed to ampakines involve plasticity and the increase in synaptic efficiency of neuronal circuits,
a process that may be intimately associated with differentiation of newborn neurons. The subventricular zone (SVZ) is the main neurogenic niche of the brain, containing neural stem cells with brain
repair potential. Accordingly, the identification of new pharmaceutical compounds with neurogenesisenhancing properties is important as a tool to promote neuronal replacement based on the use of SVZ
cells. The purpose of the present paper is to examine the possible proneurogenic effects of ampakine
CX546 in cell cultures derived from the SVZ of early postnatal mice. We observed that CX546 (50 lm)
treatment triggered an increase in proliferation, evaluated by BrdU incorporation assay, in the neuroblast lineage. Moreover, by using a cell viability assay (TUNEL) we found that, in contrast to AMPA,
CX546 did not cause cell death. Also, both AMPA and CX546 stimulated neuronal differentiation as
evaluated morphologically through neuronal nuclear protein (NeuN) immunocytochemistry and functionally by single-cell calcium imaging. Accordingly, short exposure to CX546 increased axonogenesis,
as determined by the number and length of tau-positive axons co-labelled for the phosphorylated form
of SAPK _ JNK (P-JNK), and dendritogenesis (MAP2-positive neurites). Altogether, this study shows that
ampakine CX546 promotes neurogenesis in SVZ cell cultures and thereby may have potential for future
stem cell-based therapies.
3.7.3
ACTIVIN A PROMOTES NEURONAL DIFFERENTIATION
OF CEREBROCORTICAL NEURAL PROGENITOR CELLS
3.7.4
REELIN AS A REGULATOR OF NEUROGENESIS
AND GLIOGENESIS IN CEREBRAL CORTEX
Rodríguez-Martínez G.(1), Molina-Hernández A.(1) and Velasco I.(1), (1) Instituto de Fisiología CelularNeurociencias, Universidad Nacional Autónoma de México, México D.F., México.
HEDIN-PEREIRA, C, Instituto de Biofísica Carlos Chagas Filho/Universidade Federal do Rio de Janeiro
Activin A is a protein that participates principally in reproductive functions. In the adult brain, Activin
is neuroprotective, but its role in brain development is still elusive. We studied if Activin A influences
proliferation, differentiation or survival in rat cerebrocortical neural progenitor cells (NPC). After stimulation of NPC with Activin A, phosphorylation and nuclear translocation of Smad 2/3 were induced. In
proliferating NPC, Activin produced a significant decrease in cell area and also a discrete increase
in the number of neurons in the presence of the mitogen Fibroblast Growth Factor 2. The percentages of cells incorporating BrdU, or positive for the undifferentiated NPC markers Nestin and Sox2
were unchanged after incubation with Activin. In differentiating conditions, continuous treatment with
Activin A significantly increased the number of neurons without affecting astroglial differentiation nor
apoptotic death. In cells cultured by extended periods, Activin treatment produced further increases
in the proportion of neurons, excluding premature cell cycle exit. In clonal assays, Activin significantly
increased neuronal numbers per colony, supporting an instructive role. Activin-induced neurogenesis was dependent on activation of its receptors, since incubation with the type I receptor inhibitor
SB431542 or the ligand-trap Follistatin prevented neuronal differentiation. Interestingly, SB431542 or
Follistatin by themselves abolished neurogenesis and increased astrogliogenesis, to a similar extent
to that induced by Bone Morphogenetic Protein (BMP)4. Co-incubation of these Activin inhibitors with
the BMP antagonist Dorsomorphin restored neuronal and astrocytic differentiation to control levels.
Our results show an instructive neuronal effect of Activin A in cortical NPC in vitro, pointing out to a
relevant role of this cytokine in the specification of NPC towards a neuronal phenotype.
Reelin is an extracellular matrix glycoprotein present in dorsal and ventral telencephalon during development. It has been proposed that reelin produced by Cajal-Retzius neurons provides in the cortical
marginal zone produce a stop signal for neurons that migrate radially from the cortical VZ via receptors
VLDL and ApoER2 promotingphosphorylation of adaptor protein Dab1. GABAergic neurons from medial
ganglionic eminence (MGE) migrate tangentially to the cerebral cortex (Cx) via a reelin rich pathway in
the MZ. In our work we investigate a role for reelin as a regulator of GABAergic neuronal migration. We
studied the migratory response of MGE neurons to reelin as well as two other telecephalic regions, the
cortical hem (CH) and the lateral olfactory tract region (LOT), both rich in reelin producing cells and
GABAergic neurons. We found that reelin+ cells do not express any of the reelin receptors or intracellular Dab1 in all the regions studied. However, GABAergic neurons from all regions expressed VLDLR,
ApoER2, _3 and ß1 integrins as well as Dab1. To address the role of reelin in GABAergic neuronal migration we used the transwell assay and studied the behavior of the telencephalic regions to a medium
conditioned by HEK293T transfected with full length reelin vector (MC-reelin) as compared to control
medium conditioned by HEK293T (MCHEK). We found that GABAergic cells migrate significantly more to
the reelin containing compartment. Nestin positive and GABA/nestin cells show an even more dramatic
increase. We have also shown by the expression of Ki67 that cells significantly increased proliferation when in MC-reelin. CR-50 antibody reverted, the effect, significantly decreasing the migration of
total, GABA, nestin positive or GABA/nestin cells showing that these effects are specific to reelin. We
conclude that reelin provides an attraction signal for MGE, CH and LOT GABAergic cells and increases
proliferation in the developing telencephalon.
3.8.1
PRESENTATION AND MOTIF EXPOSURE. AGING AND
NEURODEGENERATION: FROM MOLECULAR ASPECTS TO THE CLINIC
ORTUÑO-SAHAGÚN D(1), and ROJAS-MAYORQUÍN A.E(2). (1)Laboratorio de Desarrollo y Regeneración
Neural, Instituto de Neurobiología, Departamento de Biología Celular y Molecular, CUCBA, Universidad
de Guadalajara; (2)Departamento de Investigación Básica, Instituto Nacional de Geriatría (INGER),
México D.F., México.
There has been a substantial increase in life expectancy and therefore a gradual aging of the population. From the health and socio-economic point of view, this phenomenon suggests the need to implement strategies that enable aging with greater assurance of health and wellness. The most common
health problems associated with aging are the cardiovascular and neurodegenerative processes. The
study of the aging process, focusing in particular on neurodegeneration is of great scientific and
social relevance. The research objectives are ambitious and multidisciplinary y. For example, to define
molecular markers for senescence which are necessary to implement strategies to prevent pathologies and to determine possible therapeutic interventions or lifestyle, allowing the healthy aging of
the population. Within this general framework fits this symposium on neurodegeneration and aging.
Through the different talks, we shall review neurodegenerative diseases during aging at several levels.
From molecular aspects, with particular emphasis in some specific proteins, as sirtuins and melatonin,
as neuroprotective molecules, and the crosstalk between Sonic hedgehog and EGFR, as an example of
parallelism between neurogenesis and cancer. In addition, an approach to epigenetic factors, such
as the acetylome regulation on aging, or physical exercise as a neuroprotective factor in Parkinson’s
disease. Finally, we will consider the advances in Biomedicine and Gerontotechnology during aging and
the clinical aspects associated, as for example the strategies to intervene or prevent cellular dysfunction during aging and in neuropathology, trying to improve the life quality. Symposium supported by
IBRO-LARC FALAN, SMCF, Universidad de Guadalajara, Universitat de Barcelona.
3.8.2
AGING AND HEALTH, A PROPOSAL FOR AN ACTION PLAN
GUTIERREZ-ROBLEDO LM (1)KERSHENOBICH STALNIKOWIKZ D (2). (1) Director General, Instituto Nacional
de Geriatría (2) Presidente, Academia Nacional de Medicina de México.
Population dynamics determine a marked increase in the absolute numbers and proportion of older
adults in the Mexican society. If aging does not necessarily mean being ill, old age is frequently compounded with several chronic and degenerative ailments that have a negative impact on healthy life
expectancy and quality of life. Besides these facts, Mexico is a diverse country where profound social
inequality still prevails and tends to deepen. At the same time it is a rapidly ageing society. Thus,
individuals 60 years and older in Mexico, represent a very peculiar population that has survived the
profound demographic, social, economic and epidemiological changes that we have endured during
the past century and yet today. A wide array of social determinants interacts to determine the health
and the aging profile of our population. Neurodegenerative disorders are particularly prevalent in this
context and their association with social disadvantage particularly for Alzheimer’s disease is clear cut
and widely recognized. This and other challenges related with non-communicable disorders have received less attention than they would deserve. The National Institute of Geriatrics mission statement is
to promote our population’s healthy and active aging throughout knowledge production, enhancement,
dissemination and translation into common knowledge and public policies. That is why, following an
initiative led by the National Academy of Medicine, and together with the National University of Mexico,
we have developed an Action Plan on Aging and Health aiming to deal with the challenge of NCD and
their negative consequences on health related quality of life. The aim of this work is to present the
current status of the epidemiology of aging in Mexico as it relates to these disorders, with particular
emphasis on neurodegenerative illnesses and consequently, the action plan being proposed as an
answer to this challenge in the nearby future.
3.8.3
SIRTUIN 1 MODULATION: THE KEY OR THE LOCK
IN THE AGEING-GATED NEURODEGENERATION
3.8.4
SONIC HEDGEHOG AND EGFR CROSSTALK : PARALLELS BETWEEN
BRAIN NEUROGENESIS AND REGULATION OF TUMOR GROWTH
PALLÀS M, DEL VALLE J, CAMINS A, PORQUET D. Department of Pharmacology. Faculty of Pharmacy.
University of Barcelona. Spain.
MILLA LA(1), WAINWRIGHT BJ(2) and PALMA V(1). (1) Centro FONDAP de Regulación del Genoma, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile; (2) Institute for Molecular Bioscience, University of Queensland, Australia.
The sirtuins have intrigued workers in various fields of aging medicine, ranging from oncologist to
gerontologist, because of early links and subsequent findings of Sir2/SIRT1 as a longevity factor in
multiple model organisms. Sirtuin 1 is a NAD-dependent deacetylase that not only deacetylates histone
but also downregulates the tumor suppressor p53, the forkhead transcription factor Foxo3a and other
mammalian forkhead factors, NFkB, or PGC- 1alfa. Neurodegenerative diseases have experienced a
significant increase in prevalence in recent decades due to the increase in life expectancy in the
population, being Alzheimer’s disease the most common of these diseases. Among the features of the
brains of Alzheimer’s patients include the presence of abnormally hyperphosphorylated tau protein in
the cytoplasm forming neurofibrillary tangles and plaques of beta amyloid peptide in the extracellular
space. Sirtuin 1 is also responsible for increasing the activity of ADAM-10 favoring in this way the
non-amyloidogenic processing of Amyloid precursor protein (APP). Sirtuin 1 activity can be increased
by caloric restriction, exercise, or by molecules as resveratrol. Then, an increasing number of studies
deal to determine if the modulation of sirtuin 1 could be a successful strategy to prevent neurodegeneration associated to deleterious effects of senescence in central nervous system, mainly focusing
on Alzheimer’s disease. We administered resveratrol to a model of senescence, SAMP8, described as
a good model of early Alzheimer’s disease, showing deficits in memory and learning. An increase in
halflife of 33% in SAMP8 mice treated with resveratrol was found. Also it was found that resveratrol
ameliorates memory, meanwhile an increase in sirtuin 1 expression, a diminution in amyloid clusters
and in tau phosphorylation occurred in brain of SAMP8 mice fed with resveratrol. Then, in the SAMP8
model resveratrol acts as a neuroprotective agent, with beneficial effects on cognition, and reinforces
the role of siruin 1 as a key for treating neurodegenerative illness, as Alzheimer’s disease.
The canonical Shh/Gli pathway plays multiples roles during Central Nervous System (CNS) development.
In order to address the molecular repertoire of Shh target genes, we have recently described new
transcriptional targets in response to Shh pathway alterations. Among them, we were able to identify
Neogenin1, a death dependence receptor, as a new direct Shh downstream mediator in neural precursor proliferation. Since appropriate Shh signaling is required for cerebellar growth and alterations
cause Shh-driven Medulloblastoma (MB) we have studied Shh/Neogenin1 interaction in the context
of cerebellar development and cancer. We demonstrate that the Shh pathway regulates Neogenin1
expression in mouse models that recapitulate the Shh- MB subtype after introducing activating mutations in the Shh pathway with Granule Neuron Precursors (GNP)-specific expression. Canonical Shh
pathway directly regulates the neo1 gene, acting through an upstream sequence in its promoter, both
in vitro and in vivo in the GNPs. We provide evidence that Neogenin1 is necessary for the progression of
the cell cycle in a human MB cell line, since a loss of function of Neogenin1 arrests cells in the G2/M
phase. Taken together, these results highlight Neogenin1 as a new target in the molecular response of
the Shh MB subgroup, and as a possible prognostic marker for this type of cancer. I will discuss the
general implications of these resul results in the context of neurogenesis and cancer. Grant Sponsors:
FONDECYT 1110237, FONDAP 15090007.
3.8.5
ROLE OF MELATONIN IN AGING: CLINICAL APPLICATIONS
ACUÑA-CASTROVIEJO D, LÓPEZ-RÁMIREZ A, ESCAMES G. Centro de Investigación Biomédica, Parque Tecnológico de Ciencias de la Salud, Universidad de Granada
Melatonin was initially identified as a compound produced by the pineal gland and related to the chronobiotic control of the organism. Melatonin, however, is produced also by most of the organs and tissues of
the body, and it is considered now as the major endogenous antioxidant. Recently, it was reported the antiinflammatory actions of melatonin, and the mitochondria as the main intracellular target of the hormone.
These three properties of melatonin, i.e., chronobiotic, antioxidant, and anti-inflammatory, led to study its
efficacy in a series of diseases coursing with oxidative stress and inflammation, with or without circadian
rhythms disruption. That is the case of Parkinson’s disease (PD), an age-related neurodegenerative illness
with not treatment to date. Independently of its origin, genetic or sporadic, PD courses with mitochondrial
dysfunction, hyperoxidative status and inflammation. Thus, we considered it worthwhile to examine the
beneficial effects of melatonin administration in a mouse model of PD. B6;129S4- Nos1tm1Plh/J (nNOS-/-)
mice and their wild-type controls B6129SF2/J (nNOS+/+), and B6.129P2-Nos2tm1Lau mice (iNOS-/-)
and their wild-type controls C57 _ Bl _ 6mice (iNOS+/+), were injected with MPTP (15 mg/kg bw) to
induce PD. Melatonin was administered at the time of MPT (10 mg/kg bw), and the animals were sacrificed
24 hours later. Mitochondrial respiration and bioenergetics, mtDNA expression and OXPHOS complexes
content, mitochondrial biogenesis, and mitochondrial oxidative stress and inflammatory status, were assessed. Moreover, iNOS and Nnos involvement in the pathophysiology of PD was also evaluated. Finally,
locomotor activity of control and PD mice was recorded during the night. Our results show that 24 hr after
MPTP mice were seriously impaired, with a decreased mtDNA levels and citrate synthase activity, suggesting a loss of the mitochondrial biogenesis ability, and a reduction in the OXPHOS complexes content,
loss in mitochondrial respiration, and in ATP production, suggesting an impairment of the bioenergetic
capacity. The expression of iNOS and its mitochondrial isoform, i-mtNOS, increased significantly, enhancing
the intramitochondrial levels of NO responsible for the irreversible inhibition of the OXPHOS complexes.
These mice had a significant impairment of their motility. Melatonin administration was able to prevent all
these manifestations of PD, restoring the mitochondrial function and the normal locomotor activity of the
mice. The results support the efficacy of melatonin against molecular and phenotypic impairments in PD.
Supported in part by grants P07-CTS-03135 P10-CTS-5784, and CTS-101.
3.8.6
BRAIN IN MOVEMENT: PHYSICAL EXERCISE AS A NEUROPROTECTIVE
AND DISEASE-MODIFYING AGENT OF PARKINSON’S DISEASE
PREDIGER RD(1), AGUIAR JR. AS (1,2), (1) Departamento de Farmacologia, Universidade Federal de
Santa Catarina, Florianópolis, Brazil; (2) Departamento de Bioquímica, Universidade Federal de Santa
Catarina, Florianópolis, Brazil.
Parkinson’s disease (PD) is the most prevalent motor neurodegenerative disease, with higher incidence
in the elderly population. Some important features of this disease, such as its progressive nature, the
presence of non-motor symptoms that largely do not respond to antiparkinsonian drugs, and the efficacy loss and the emergence of serious side effects after chronic treatment with dopaminergic drugs
represent major challenges to clinical and academic communities. In the last two decades, an increasing number of clinical and experimental studies have indicated the potential of physical exercise as a
palliative or adjuvant agent in PD. The present presentation attempts to discuss recent findings from
our group indicating that the prevention of mitochondrial dysfunction and oxidative stress are potential mechanisms associated to the exercise-induced neuroprotective effects. Moreover, the treadmill
exercise during 6 weeks attenuated the motor impairments induced by intra-striatal administration
of 6-OHDA and cognitive dysfunction induced by intranasal administration of MPTP. Furthermore, voluntary exercise for 14 days in running wheels reduced the severity of L-DOPA-induced dyskinesias in
hemiparkinsonian mice. These benefits were accompanied by significant neuroplastic changes in the
striatum of exercised animals including the increase in the number and sensitivity of dopamine D2
receptors, as well as decreasing dopamine turnover. Exercise also prevented striatal modification in the
glutamatergic neurotransmission and intracellular signaling potentially involved in the development of
L-DOPA-induced dyskinesias. Altogether, the current findings support the potential of physical exercise
as a disease-modifying agent of PD, being able to alleviate motor and cognitive symptoms in animals
submitted to experimental models of PD, and to reduce the severity of L-DOPA-induced dyskinesias.
Financial support: CNPq, FAPESC, CAPES-COFECUB.
3.8.7
ACETYLOME AND SIRTUINS: FROM EPIGENOME REGULATION
TO PROTEOME SIGNALLING ON AGING
3.9.1
NEUROECOLOGY OF THE ACCESSORY OLFACTORY
SYSTEM OF PLACENTAL MAMMALS
SANCHÉZ-ALEGRíA K, RIVERA-PÉREZ JA, MICHÁN S. Instituto Nacional de Geriatría, Mexico.
Rodrigo Suárez. Queensland Brain Institute, The University of Queensland, Brisbane, Australia.
Sirtuins regulate lysine acetylation levels, a modification originally identified in histones, which has
long been known to critically regulate many diverse cellular processes by controlling the epigenome
and global gene expression. Memory and synaptic plasticity are the brain functions most vulnerable
to decline with aging and transcriptional deregulation mediated by sirtuins is one of the mechanisms
associated with those events. At the level of proteins, acetylation of lysine residues also plays an
important role as potential regulator of aging and age-related diseases. An extensive variety of proteins
dynamically post-translationally regulated by acetylation have been discovered, collectively comprising
“the acetylome”. Loss of acetylome homeostasis may drive changes in protein activity, localization and
stability, thus leading to the deterioration that accompanies aging and age-related diseases. Factors
that regulate the acetylome, such as class I and II histone deacetylases (HDACs), sirtuins, and histone
acetyl transferases (HATs), also mediate the age-associated deterioration of various biological functions, including cognitive decline, cancer and neurodegeneration. Although several proteins have been
identified as targets for sirtuins, HDACs and HATs, it is know very little about the global acetylation
pattern of the proteome in young versus old states, or in pathological versus healthy longevity. We are
investigating the dynamic regulation of the acetylome in different models of postmitotic aging and
cell survival in order to determine acetylation marks that may contribute to healthy aging, or to the
development of an age-associated neuropathology
The sense of olfaction has played an important role in the evolution of mammals. While odorants
related to a wide range of ecological contexts are processed by the main olfactory system, scents
involved in social and sexual interactions –traditionally known as pheromones- involve the action of
the accessory olfactory system. Two populations of sensory neurons located in the vomeronasal organ
send projections that end at two distinct regions of the accessory olfactory bulb (AOB). These segregated pathways have been proposed to sense different sets of molecules and to be involved in opposing
behavioural contexts. Here I will present comparative data on the anatomy of vomeronasal projections
to suggest that both phylogenetic associations and ecological differences across species can explain
the diversity of these neuronal structures in rodents. I will also propose an evolutionary scenario for
species from a larger range of mammalian lineages that relates male-female communication systems
with events of partial and total deterioration of vomeronasal projections.
3.9.2
ROLE OF THE MAIN AND ACCESSORY OLFACTORY BULBS IN
OLFACTORY DISCRIMINATION AND SEXUAL INCENTIVE MOTIVATION
3.9.3
CHEMICAL COMMUNICATION IN RABBITS:
HORMONES AND REPRODUCTIVE BEHAVIORS
Renteria R (1), Sandoval I (1), and Paredes R.G (1). Dpto. de Neurobiología Conductual y Cognitiva.
Instituto de Neurobiología, UNAM, Querétaro, México.
Ángel I. Melo (1). (1)Lab. de Neuroendocrinogía del Desarrollo, Centro de Investigación en Reproducción Animal, CINVESTAV-Lab. Tlaxcala, Universidad Autónoma de Tlaxcala, Ixtacuixtla, Tlax., México.
It was originally postulated that the main olfactory system (MOS) detected volatileodors mostly generated from food or prey, whereas the accessory olfactory system (AOS) detected large-molecular-weight
nonvolatile odors that influence reproductive behaviors and neuroendocrine function. However, several
lines of research indicate that this subdivision is not as clear as originally conceived. It appears
that these two systems play interacting roles in mediating social responses to chemical signals from
conspecifics in a variety of species. To further asses this functional interaction sexually experience
male rats receive bilateral electrolytic lesions of the main or accessory olfactory bulbs and evaluated
in different tasks in which olfaction plays an important role. Males were tested with receptive females
and those that ejaculated in 3 tests were included in the experiment. Then, they were tested in an
olfactory discrimination test to determine if they could discriminate between odors from the urine of
sexually experienced males or estrous females. In a separate test, they were tested for their ability to
discriminate between banana and mint odors. They were also tested for sexual incentive motivation,
that is, the approach behavior of male rats to either a sexually receptive female or a sexually active
male in a test where the subjects can smell, hear, and see the stimulus animal but prevents their
physical interaction. These tests were performed before and after the lesions. None of the behaviors
was affected indicating that the main and olfactory bulbs receive information from volatile and non
volatile odors further suggesting that they are functionally connected. Technical assistance Francisco
Camacho. Supported by CONACYT 167101 and DGAPA IN200512
Rabbits, as many mammals that live in community, use several olfactory signals in order to regulate
a variety of biological functions as organize, to maintain a territory and hierarchy, and reproduction
(mating, maternal behavior, and nursing). Olfactory cues are produced in skin glands (submandibular,
Harder’s, lachrymal, preputial, anal, and mammary gland-nipple complex). Rabbits transmit olfactory
cues by active behaviors (chin-marking, urination, defecation), or passively (mammary pheromone
emission and inguinal secretions). For example, chin-marking behavior or chinning consists in rubbing
the chin on solid objects present in the environment. This behavior in males has been reported as a
form of territorial marking and an attachment of sexual behavior. In female rabbits, chinning has been
proposed to be part of the estrous cycle; the frequency is high during estrus and low during pregnancy
and lactation. In both sexes mating and chinning are regulated by sex steroids: gonadectomy abolishes
both behaviors in males and females, systemic administration of estradiol benzoate (EB) to females or
testosterone propionate (TP) to males restores both behaviors. Recently it has been reported that EB
implants into the ventromedial hypothalamus (VMH) or medial preoptic area (MPOA) stimulated chinning in females, and most of them showed lordosis. In males, chinning, but not sexual behavior, was
stimulated by TP implants into MPOA or Diagonal band of Broca. Another interesting example of olfactory signals and reproduction in rabbits is the emission of the “mammary pheromone”. These olfactory
signals, emanating from the belly of lactating, and also pregnant females, trigger in the pups a stereotyped behavior that guide them toward the maternal nipples and allowed them to suckle. Although the
origin of these signals remains to be determined, it has been identified in milk as 2-methyl-but-2-enal,
and its emission is regulated by estradiol, progesterone and prolactin. In conclusion, the above evidence suggests that rabbits produce olfactory signals that are involved in the specific reproductive
process, and are regulated by sex steroids.
3.9.4
WHICH IS THE ROLE OF THE OLFACTORY
SYSTEM IN SEXUAL BEHAVIOR?
3.10.1
MIDLINE THALAMIC NUCLEI IN RETRIEVAL
AND MAINTENANCE OF FEAR MEMORY
Guevara-Guzmán R . Facultad de Medicina, Universidad Nacional Autónoma de México
Fabricio do Monte. UPR-MS, Puerto Rico
The perception of odors is special by its close association with memories and with emotions and moods.
This could explain why we usually remember odors as well, mainly if they come from our close partner “our
lover”. There is no doubt that sense of smell has an important role in our interpersonal communication.
Sexual reflex and sexually related behavior are also influenced by olfactory signals, although more so in
lower mammals than in humans. In a previous paper we have demonstrated that mechanical stimulation
of the vagina and cervix produce morphological and electrophysiological changes in the olfactory bulb
(OB), a clear increase of the mitral cells activity in estrus female rats and a decrease it in diestrus animals.
We have also reported that vagino cervical stimulation (VCS) induced changes in the OB may be partly
mediated via the vagus nerve and the nucleus of the solitary tract since the OB responds to electrical
stimulation of the vagus and the nucleus of the solitary tract to VCS. However, the pelvic and hypogastric
nerves may be involved as well since they are also activated by VCS. There has been a long history of interest and controversy concerning the effect of hormones on the nasal epithelium. In women, a range of nasal
symptoms has been described in association with hormonal changes occurring during the reproductive
cycle. Observations include the appearance or increase in nasal complaints, such as congestion or rhinitis,
among women taking contraceptive pill and during pregnancy. We have found a significant correlation
between the cytological characteristics of the nasal and vaginal smears and stage of the menstrual cycle,
with cornified cells predominating during the follicular phase and rounded or spindle-shaped epithelial
cells predominating during the luteal phase. It was interested to find that cornified cells predominated
in the nasal smears from the postmenopausal women and the prepubertal girls at all time tested. On the
other hand we have also investigated whether olfactory detection threshold is correlated with phase of the
menstrual cycle. We found that thresholds differed significantly across the cycle and were lowest during
the ovulatory and highest during the menstrual phase. Thresholds for all control groups were higher than
for the cycling women during the ovulatory phase. There is no doubt that olfactory threshold is related
to phase of the menstrual cycle. All of these data support the important role of the olfactory system in
reproductive behavior. Grants: Conacyt: 24784, 152613 and Papiit 216907.
Interest in the neural circuit mediating the expression of conditioned fear memories has exponentially
increased in the last decade. The prelimbic (PL) subregion of the medial prefrontal cortex and the
amygdala are essential structures for retrieval of a conditioned fear memory (Sotres-Bayon & Quirk,
2010), but few studies have investigated the inputs to these areas. The dorsal part of the midline
thalamus (dMT) has reciprocal connections with PL (Vertes, 2006) and also projects to the basal and
central nucleus of the amygdala (Vertes & Hoover, 2008). We have recently found that pharmacological
inactivation of dMT impaired the retrieval of older (> 24 h), but not recent fear memories (< 6 h),
suggesting a time-dependent recruitment of dMT into the fear circuit (Padilla-Coreano et al, 2012).
Using immunohistochemical and optogenetic tools we now demonstrate that recent fear memories
require a circuit which involves PL and amygdala in absence of dMT, whereas remote memories require
all three structures (PL, amygdala and dMT). This new evidence supports the idea that fear behavior is
constant with time, but the circuits mediating the behavior are not.
3.10.2
(FEAR) RE-LEARNING THROUGH CB1
CANNABINOID RECEPTORS MODULATION
3.10.4
MEMORY DESTABILIZATION:
EXPLORING ITS BIOLOGICAL ROLE AND CLINICAL POTENTIAL
PAMPLONA, F.A. D’Or Institute of Research and Education
Lucas de Oliveira Alvares. Universidade Federal do Rio Grande do Sul
The seminal work of Marsicano et al (2002), currently with almost 1000 citations has ignited the
research field of endocannabinoids and fear memory extinction. Since then, many groups established
the implication of this neurotransmission system in fear extinction, but also in other similar processes
of re-relearning involving behavioral flexibility and use of previously-acquired information. Administration of cannabinoid agonists (exogenous, phyto and endogenous cannabinoids) can facilitate this
process, whereas endogenous ligands are not always physiologically involved. In this talk, we want to
summarize our view of these last 10 years of the research field and communicate new evidence that
the role of CB1 cannabinoid receptors activation may be broader than expected, underlying memory
update in general, even when it means increasing intensity of the conditioned response. With these
eyes, long-term extinction might be interpreted as an inclusion of new information into a given memory
engram rather than suppression of a behavioral response. Also, it reveals how naive is the overall
assumption/belief that cannabinoids necessarily impair learning.
Retrieval can induce some memories to undergo a stabilization period, called reconsolidation. The
result of this plastic state is that memory can be changed after the destabilization induced by reactivation, requiring a reconsolidation process in order to persist. The mechanism of reconsolidation has
been extensively studied. However, the destabilization induced by reactivation of a previously consolidated memory is less known. In the present study, we addressed the question: how are the mechanisms
that cause a memory to be transformed from a fixed consolidated state, to a labile one? We found that
exposure time, novelty, D-cicloserine and NR2B hippocampal activation are required in some boundary condition in order to undergo memory destabilization/reconsolidation. A better comprehension of
how memory becomes labile is critical because targeting reconsolidation of traumatic memories has
been proposed for many psychopathology treatments. We took advantage of these results to create
a protocol where subjects were able to impair strong aversive memories in a post-traumatic stress
disorder model in rats.
SYMPOSIA
THURSDAY NOVEMBER 8
4.1.1
CIRCADIAN PERIOD INTEGRATES NETWORK INFORMATI
ON THROUGH ACTIVATION OF THE BMP SIGNALING PATHWAY
4.1.4
THE RABBIT PUP AS A NATURAL MODEL
OF FOOD ANTICIPATORY ACTIVITY
Beckwith EJ, Gorostiza EA,Berni J,Rezával C and Ceriani MF, Laboratorio de Genética del Comportamiento, Fundación Instituto Leloir, IIB-BA CONICET, Buenos Aires, Argentina.
Caba M, Meza E, Moreno ML and Guzman A. Centro de Investigaciones Biomédicas, Universidad Veracruzana, A.P. 114, Xalapa, Ver., México.
Living organisms use biological clocks to maintain internal temporal order and anticipate daily environmental changes. Clocks employ self-sustained biochemical oscillators expressing at molecular,
physiological and behavioral levels. In Drosophila, 150 neurons are implicated in circadian regulation
of locomotor behavior; the small ventral lateral neurons (sLNvs) are clearly crucial. They express and
release the neuropeptide Pigment Dispersing Factor (PDF) and set the period of locomotor behavior
under free running conditions. To identify components involved in transmitting information relevant to
network synchronization a screen was carried out through deregulation of gene expression in PDF+
cells. As a result a strain that causes period lengthening of daily activity rhythms was singled out
affecting schnurri (shn), a nuclear component of the BMP signalling pathway. During development this
pathway acts as a retrograde signal to define synaptic properties according stage-specific requirements. shn overexpression in the PDF circuit is necessary and sufficient to generate a 25.5h period
of locomotor behavior, while downregulation of shn levels resulted in deconsolidated activity rhythms.
Strikingly, adultspecific activation of BMP signalling in PDF+ cells is sufficient for period lengthening.
To gain insight into the molecular mechanism PERIOD (PER) subcellular localization was analyzed. As
predicted from the behavioral phenotype, PER nuclear entry was delayed upon shn overexpression, suggesting that pathway activation leads to downregulation of PER protein levels; in support of this possibility concomitant overexpression of PER (and CLOCK) rescued the long period phenotype. Additional
experiments including transcriptional reporter lines supported the notion that shn overexpression (i.e.,
pathway activation) results in reduced CLOCK levels. We propose that controlled activation of the BMP
pathway through the postsynaptic release of specific ligands is required to fine-tune circadian period
in the adult brain. Thus, adult circadian period would integrate both, the pace of the cell autonomous
molecular clock and information derived by other circadian relevant clusters to ensure coherence in
the network.
When food is restricted during certain hours of the day, subjects develop food anticipatory activity
(FAA) a phenomenon that is commonly studied with experimental manipulations in adult rodents. The
most salient events during FAA are an increase in locomotor behavior and in hormone corticosterone
levels before food presentation. Our laboratory and others have demonstrated that rabbit pups show
characteristics similar to FAA, but in contrast to adult rodents, without excessive manipulations. Rabbit pups are exposed to a natural restricted schedule as they ingest food, in this case milk, just once
a day, for a few minutes, with circadian periodicity. The aim of present contribution is to present an
overview of the current evidence from our laboratory that supports the proposal of the rabbit pup as
a natural model of FAA. But also will present recent data about neural areas involved in FAA, which
had not been considered before in other species. The doe certainly nurse their pups once a day with
circadian periodicity, but in order to study this phenomenon in detail we usually schedule nursing either during the day or the night. Regardless of the hour, nursing synchronizes locomotor behavior, corticosterone, free fatty acids and several hypothalamic and brainstem nuclei. Then in mother-deprived
pups, artificially fed through an intragastric cannula, we demonstrated that indeed food is the main
synchronizing signal. Finally we discovered that the Organum vasculosum of lamina terminalis and the
median preoptic nucleus not only synchronizes to this daily event but even more, anticipates nursing
timing schedule. This pattern is similar to that of the orexin cells in the lateral hypothalamic area and
considering their connections and involvement in arousal we propose that these two areas, together
with the orexin cells, perhaps are key areas involved in arousal, which leads to FAA.
4.2.1
TRIPARTITE SYNAPSE-ASTROCYTIC REGULATION OF GLUTAMATE
4.2.2
ACTIVATION OF RYANODINE RECEPTORS/CALCIUM RELEASE
CHANNELS PROMOTES GROWTH OF HIPPOCAMPAL SPINES
PARPURA V (1)(2), (1)Department of Neurobiology, Center for Glial Biology in Medicine, Atomic Force
Microscopy & Nanotechnology Laboratories, Civitan International Research Center, Evelyn F. McKnight
Brain Institute, University of Alabama, Birmingham, AL 35294, USA. (2) Department of Biotechnology,
University or Rijeka, 51000 Rijeka, Croatia.
Astrocytes are an integral element of the tripartite synapse. These cells release the excitatory transmitter glutamate which modulates synaptic transmission in nearby neurons. Astrocytic glutamate release
can occur through Ca2+- dependent exocytosis, which can operate under physiological conditions.
The intercellular Ca2+ necessary for this glutamate release comes from two sources. The majority
originates from the endoplasmic reticulum internal store, but entry of external Ca2+ is also involved.
Transient receptor potential (TRP) proteins, which form channels that are activated by depletion of
internal Ca2+ stores to allow Ca2+ entry from the extracellular space, mediate the entry of external
Ca2+ in glutamate release from astrocytes. Ca2+ can also enter the cytosol from the extracellular space by the reverse mode operation of the plasma membrane sodium calcium exchanger (NCX).
Additionally, cellular Ca2+ dynamics are regulated by mitochondria which are able to accumulate
Ca2+ via Ca2+ uniporter and to release Ca2+ through the mitochondrial Na+/Ca2+ exchanger
as well as transient openings of the mitochondrial permeability transition pore. Vesicular glutamate
transporters (VGLUTs) are responsible for vesicular glutamate storage and exocytotic glutamate release
from astrocytes. Over-expression of individual isoforms of VGLUTs in solitary astrocytes shows that
VGLUT-3, but not VGLUT-1 and -2, enhances glutamate release from astrocytes without affecting their
intracellular Ca2+ increase. Inhibition of glutamine synthetase activity by L-methionine sulfoximine
in astrocytes, which raises cytoplasmic glutamate levels greatly increase the exocytotic glutamate
release. Taken together, VGLUTs and cytoplasmic glutamate levels in astrocytes regulate exocytotic
release from these cells.
ADASME T(1), PAULA-LIMA AC(2)and HIDALGO C(3). (1)CEMC, F. Medicine, Universidad de Chile, Santiago, Chile; (2) Faculty of Dentistry, Universidad de Chile, Santiago, Chile; (3) BNI and ICBM, Faculty of
Medicine, Universidad de Chile, Santiago, Chile.
Dendritic spines, which are the sites of most excitatory synaptic inputs, undergo rapid morphological
changes in response to neuronal activity. The signaling cascades triggered in dendritic spines by neuronal activity promote spine remodeling and play a key role in the integration and storage of neuronal
information. Previous reports indicate that brain-derived neurotrophic factor (BDNF) - a neurotrophin
implicated in synaptic plasticity, learning and memory – and caffeine promote hippocampal spine
remodeling. We explored here if the spine remodeling induced by BDNF requires calcium signals generated by activation of Ryanodine Receptors (RyR), which together with InsP3 receptors are the two main
types of intracellular calcium release channels that mediate calcium release from the endoplasmic reticulum. To this aim, we loaded primary rat hippocampal cultures with calcein and followed changes in
spine morphology by confocal microscopy of live neurons. We found that BDNF addition induced rapid
changes in spine morphology, as evidenced by the growth of existing spines and the emergence of new
ones. We also confirmed that activation of RyR channels with caffeine, which acts as a RyR agonist,
induced hippocampal spine remodeling. The spine remodeling induced by BDNF or caffeine required
functional RyR channels since they were abolished by pharmacological RyR inhibition. Our previous
results indicate that the antioxidant N-acetylcysteine (NAC) abolishes RyR-mediated calcium release
in neuronal cells. Here, we report that NAC addition also abolished the spine remodeling induced by
BDNF or caffeine. Of the three RyR isoforms present in adult rat hippocampus, the spine remodeling
induced by BDNF required functional RyR2 channels, since selective RyR2 knock-down abolished the
spine morphology changes induced by BDNF. We propose that redox-sensitive RyR2-mediated calcium
signals are an integral part of the signaling cascades underlying BDNF-induced hippocampal synaptic
plasticity. Supported by FONDECYT (11110322-1100052-3120093), CONICYT (79090021), FONDECYTFONDAP (1501006), MILLENNIUM BNI (P-09-015F).
4.2.3
ASTROCYTES FUNCTION AND DYSFUNCTION:
IMPLICATIONS FOR SYNAPSE FORMATION
4.3.1
RESPIRATORY RHYTHM GENERATION:
THE WHOLE IS GREATER THAN THE SUM OF THE PARTS
Flávia Carvalho Alcantara Gomes. Federal University of Rio de Janeiro
MORGADO-VALLE C(1), BELTRAN-PARRAZAL L(1), TOLEDO-CARDENAS R(1), MANZO J(1)
(1)Universidad Veracruzana, Centro de Investigaciones Cerebrales.
Astrocytes are components of brain development and pathology that actively control synapse formation and function. Synaptic dysfunctions may lead to several neurodevelopmental disorders, including
autism, schizophrenia, epilepsy and others. Thus, understanding the mechanism by which synapses
are formed, specified and maintained is a key step, not only for understanding human cognitive advantages, but to design therapeutic approaches to repair the injured human nervous system. Here, we will
discuss recent advances on the signaling pathways that control radial glia differentiation, astrocyte
generation, and glia effect on synapse formation.
Breathing is a continuous behavior in mammals essential for life and one of the few mammalian
behaviors that can be studied in vivo in intact awake, anesthetized or decerebrate mammals and in
highly reduced in vitro and in situ preparations. The preBötzinger Complex (preBötC) is a small medullary nucleus that plays an essential role in normal breathing and is widely accepted to contain the
kernel of inspiratory rhythm generation. In the last 20 years, substantial advances in understanding
respiratory rhythmogenesis have arisen from in vitro studies; however the underlying mechanisms
remain unknown. Multiple mechanisms, parts and components described in vitro once considered as
“necessary and sufficient” have been tested and proven not to be so. NK1 receptor, h or A current,
voltage-dependent or -independent pacemaker neurons, persistent sodium or CAN current, dendritic
Ca2+, metabotropic glutamate receptors, IP3 receptor? Can the whole exist without a single part? Is
the respiratory rhythm an emerging property?
4.3.2
GLIAL AND NEURONAL CONTRIBUTIONS TO THE RECONFIGURATION
OF THE RESPIRATORY NETWORK IN HYPOXIA
4.3.3
PERTURBATION OF THE RESPIRATORY RHYTHM INDUCED BY
PRENATAL NICOTINE EXPOSURE
Peña-Ortega F(1). (1)Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, UNAM, Campus Juriquilla, México
EUGENIN JL. Universidad de Santiago de Chile
Breathing is generated and controlled by brainstem neuronal networks. Exquisite interactions among
intrinsic and synaptic properties are involved in the generation of different respiratory rhythms. However, the specific contributions of such network properties may change under different physiological
and pathological conditions, such as hypoxia. The respiratory hypoxic response is biphasic, an initial
increase in respiratory frequency is followed by a secondary depression during which gasping emerges.
Gasping is the last resort respiratory rhythm, that is produced by a reconfiguration of the respiratory rhythm generator (the preBötzinger complex). Such reconfiguration includes changes in synaptic
and intrinsic properties generated by hypoxia itself, and by different neuromodulators released during
hypoxia, either from neurons or from glial cells. Here, I am going to review how hypoxia alters the
respiratory networks to generate gasping, focusing on the changes in neural synaptic and intrinsic
properties as well as the role of some neuromodulators, and of glial cells, in the plastic process that
leads to the generation of gasping activity.
Breathing is a mammalian motor behaviour that emerges early in fetal life and continues relentlessly
from birth up to death. However, the generation of the respiratory rhythm can fail leading to catastrophic conditions such as Sudden Infant Death Syndrome (SIDS). Maternal cigarette smoking appears
as a major risk factor in epidemiological studies of SIDS. Then, nicotine, the main neuroteratogen
and addictive substance of cigarette smoke, appears as a good candidate for being the agent linking maternal smoking habit with SIDS. We have found in CF1 mice that nicotine (60 mg Kg-1 day-1)
administered subcutaneously from gestational days 5-7 to early postnatal life causes hypoventilation and reduced responses to hypercapnia in postnatal days 0 to 5 (P0-P5). Even more, prenatal
nicotine reduces respiratory central chemoreception in brainstem slices and in “en bloc” brainstem
/ spinal cord preparations from P0- P3 nicotine exposed mice. Reduction in central chemoreception
was associated to irregular respiratory rhythm, hypoactivity of caudal raphe neurons, and a reduced
serotonergic innervation of the ventral respiratory column. These results indicate that prenatal nicotine
exposure can modify the respiratory rhythm pattern generator and impair central chemoreception during the early postnatal life. Consequently, breathing becomes highly vulnerable, failing in responding
to chemosensory demands as likely occurs in SIDS.
4.3.4
FROM BALL-AND-STICK MODELS TO CLOUDS:
NEW CONCEPTS IN RESPIRATORY RHYTHM GENERATION
Jan-Marino Ramirez, Michael Carroll, Tatiana Malaschenko, Alfredo Garcia III, Atsushi Doi
Center for Integrative Brain Brain Research, Seattle Children’s Research Institute, University of Washington, Seattle, WA, USA
4.3.5
CHANGES IN ELECTROPHYSIOLOGICAL PROFILE OF RESPIRATORY
NEURONS CAUSE SYMPATHETIC OVERACTIVITY IN RATS SUBMITTED
TO CHRONIC INTERMITTENT HYPOXIA
Davi J.A. Moraes, Daniel B. Zoccal and Benedito H. Machado. Dept. of Physiology, School of Medicine of
Ribeirao Preto, USP, 14049-900, Ribeirao Preto, SP, Brazil.
The respiratory network located within the pre-Bötzinger complex is critical for breathing. When lesioned in whole animals, breathing ceases, when isolated in transverse brainstem slices, respiratory
rhythmic activity persists. Most models of respiratory rhythm generation propose synaptic interactions
between concrete classes of respiratory neurons. These neurons include inspiratory, expiratory and
postinspiratory neurons dependent on their rhythmic activation with specific respiratory phases. Here
we used extracellular multiarray recordings and intracellular recordings to characterize the discharge
pattern of respiratory neurons in the preBöetzinger complex. Our recordings fail to identify concrete
classes of respiratory neurons. Rather we find a gradient of neuronal discharge patterns that ranges
from inspiratory to expiratory neurons. We also find a gradient with regard to the neurons’ intrinsic
membrane properties that ranges from pacemaker to non-pacemaker neurons, with neurons exhibiting
various degrees of weak to strong pacemaker properties. When embedded in the network, individual
neurons showed a high onset variability. Neurons can lead some cycles but follow the onset of other
cycles. Our computer modeling of these properties reveal that the respiratory network is sparsely connected and assembled stachastically in a cycle-by-cycle manner. Thus, from the point of the respiratory
network every breath is a new breath that is lead and followed by different sets of neurons. This more
flexible description of respiratory rhythm generation is conceptually a major departure from current
ball-and-stick models that assume concrete classes of respiratory neurons that are fully connected
and generate a rhythm with very little onset variability.
We hypothesized that hypertension following chronic intermittent hypoxia (CIH) exposure is, at least
in part, dependent on alterations in the respiratory network and its interaction with the sympathetic
nervous system. With simultaneous recordings of respiratory and sympathetic nerves, intracellular and
whole cell path-clamp of respiratory and pre-sympathetic neurons of ventrolateral medulla, we evaluated the mechanisms underlining CIH-induced hypertension in juvenile rats. In CIH rats, the decrease
in the frequency discharge of post-inspiratory (post-I) neurons reduced the post-I activity of cervical
vagus nerve. The overactivities of augmenting expiratory and pre-inspiratory (pre-I) neurons increased
the late-E abdominal and pre-I hypoglossal nerves activities. Due to these changes, the frequency
discharge of pre-sympathetic neurons and thoracic sympathetic activity were enhanced by an increase
in the excitatory post-synaptic potentials and currents, which were time-locked with AbN late-E activity. However, CIH produced changes in the input resistance and excitability, independent of synaptic
transmission, only in the pre-I and post-I neurons. These changes were accompanied by increase in the
inward riluzole-sensitive persistent sodium current and in the 4-aminopyridine-sensitive component
of transient outward potassium current in the CIH pre-I and post-I neurons, respectively. These data
describe novel mechanisms underlying sympathetic overactivity and hypertension, which critically depend on changes of ionic currents of medullary respiratory neurons and excessive excitatory drive to
pre-sympathetic neurons in CIH rats. Financial Support: FAPESP, CAPES and CNPQ.
4.4.1
MICROGLIAL DEPENDENT MODULATION OF SYNAPTIC
MATURATION DURING POST-NATAL DEVELOPMENT
4.4.2
FUNCTIONAL ROLE OF NEUROINFLAMMATION ON
PARKINSON’S DISEASE ETIOLOGY AND PROGRESSION
Deirdre S. Davis, Slawomir Sloniowski, Yoshinori Otani, Devin K Binder, Iryna M. Ethell, Monica J Carson.
University of California Riverside
Fernando Pitossi, Fundacion Instituto Leloir, Buenos Aires, Argentina.
Infancy and early childhood are periods characterized by recurring bouts of systemic inflammation in
part due to first exposures to pathogens in the home, day care and school. Overt neurologic consequences are not observed in the vast majority of individuals. However, epidemiological studies suggest
linkages exist between the onset and/or exacerbation of neurodevelopmental neurologic disorders and
various pre-, neo- and post-natal inflammatory events. As yet, little is known about the consequences
and developmental regulation of CNS responses to common systemic inflammatory events or their
potential for dysregulation by environmental factors including alcohol. Here, using flow cytometric
and immunohistochemical methodologies, we characterize astrocyte, CNS-resident microglia and CNSinfiltrating macrophage activation states in response to systemic immune challenge during critical
postnatal periods of brain development and hippocampal synaptogenesis. In brief, we find that that
glia and macrophages not only regulate synaptic maturation during normal development but also in
response to routine inflammatory insults. Using overexpression and knock-out approaches, we specifically find that TREM2 dependent microglial functions modulate the ratio of excitatory to inhibitory
synapses quantified histologically not only in response to bouts of systemic inflammation but even
during normal unmanipulated CNS development. Drug induced seizure approaches confirm that these
histologic changes result in functional differences in synaptic maturation. Finally, we find that the
extent of glial regulation of synaptic maturation is developmentally regulated.
One patho-physiological feature consistently found in animal models and PD patients is robust microglial activation. However, microglia activation could mediate neurodegenerative or neuroprotective effects depending on the array of molecules associated with this activation and the molecular
and cellular context in which they act. As a consequence, microglial activation remains an unreliable
therapeutic target in PD treatment. We believe that identifying parameters that could determine a
univocal role of microglial activation on neuronal cell death in the substantia nigra (SN), the main
region affected in PD, is crucial to define new therapeutic targets against PD and select PD patients
to be enrolled in anti-PD trials based on immunomodulation. We have found that microglial cells in
the degenerating SN are “primed”. Microglial cells can be shifted to a proinflammatory state by, not
only central, but also sub toxic levels of systemic inflammation. This shift can dramatically exacerbate
on-going neurodegeneration in the SN leading to increased and earlier motor symptoms, via Interleukin- 1beta (IL-1) overproduction. In addition, we have observed that sustained but not acute expression
of IL-1 or Tumor necrosis factor-alpha (TNF) in the SN leads to dopaminergic neuronal demise, motor
symptoms and microglial activation. TNF effects are dose-dependent since, using a combination of
knock-in mice, adenoviral vectors and the CRE/lox system we could demonstrate that low levels of TNF
can be neuroprotective for nigral neurons, while higher levels could be detrimental. In conclusion, we
have identified parameters that determine a given effect of pro-inflammatory cytokines on neuronal
viability, paving the way to test new hypothesis, study the effects of immunomodulatory treatments,
and identify downstream effector molecules on these newly generated models of PD.
4.4.3
DISTINCT MORPHOLOGICAL FEATURES OF MICROGLIA
WITHIN THE DEVELOPING POSTNATAL SUBVENTRICULAR
ZONE/ROSTRAL MIGRATORY STREAM
Xavier ALR (1,2), Moura P(1), Teixeira L(1), Lima FRS(3), de Menezes JRL(1), Nedergaard M(2). (1) Lab. De
Neuroanatomia Celular, Instituto de Ciências Biomédicas, Centro de Ciências da Saúde – Universidade
Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ – Brasil. (2) Lab. De Morfogênese Celular; Instituto de
Ciências Biomédicas, Centro de Ciências da Saúde – Universidade Federal do Rio de Janeiro (UFRJ), Rio de
Janeiro, RJ – Brasil. (3) Division of Glia Disease and Therapeutics, Center for Translational Neuromedicine,
Department of Neurosurgery, University of Rochester Medical School, Rochester, NY - EUA.
Microglia comprises the innate immune cells of the central nervous system (CNS) that interacts with
neural cells under pathological conditions, but also contributes to CNS homeostasis. This study sought
to characterize microglia ontogeny within the subventricular zone (SVZ), the major postnatal neurogenic
niche, where interneuron precursors are generated and migrate through the rostral migratory stream (RMS)
towards the olfactory bulb. Swiss and transgenic mice expressing the enhanced green fluorescent protein
(eGFP) under the chemokine receptor CX3CR1 promoter at postnatal ages P0, P7, P14 and P60 (n=3 for
each age and lineage) were used. Sections were stained for glial and neuronal markers: BLBP, GFAP, CD68,
F4/80, Iba1, TREM2, NG2, DCX and IB4. Cell proliferation was analysed with intraperitoneal injections (i.p.)
of bromodeoxyuridine (BrdU; 100mg/kg). IB4+ cells were sorted using Streptavidin conjugated magnetic
beads (Miltenyi Biotec) and analyzed for glial and neuronal markers as described above. Microglia is a
distinct population within the SVZ/RMS, displaying typical amoeboid morphology during neonatal periods, but at later stages the immature/migratory morphology differs from cortical ramified cells. Analysis
with phenotypic markers revealed a clear heterogeneity among the microglial population of the SVZ/RMS.
Microglia appose to BLBP+/GFAP+ processes, indicating that they could establish cellular/molecular
interactions with SVZ stem cell lineage. Neuroblasts do not seem to be phagocytized along the SVZ/RMS, as
we do not observe colocalization of CX3CR1-eGFP+/TREM2+ with DCX+/BrdU+. In contrast, phagocytic activity occurs at glomerular layer, where neurons are continuously replaced in adult rodents. There,
CX3CR1-eGFP+/TREM2+ activated microglia are closely related to neurons. Together our data indicate
that resident microglia of the SVZ are regionally distin ct, displaying low phagocytic activity and shows a
surprising phenotypic heterogeneity. Financial Support: CNPq; CAPES-PSDE; IBNet,
4.4.4
MICROGLIA-GLIOBLASTOMA INTERACTION:
TUMOR PROLIFERATION AND MIGRATION
Fonseca ACC, Romão L, Amaral RF, Assad Kahn S, Martins S, Marcondes de Souza J, Moura Netoa V and
LIMA FRS Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
Microglial activation is a key event in the progression and infiltration of tumors. We have previously
demonstrated that the co-chaperone Stress Inducible Protein 1 (STI1), a Cellular Prion Protein (PrPC)
ligand, promotes glioblastoma (GBM) proliferation. In the present study, we examined the influence of
microglial STI1 in the growth and invasion of the human glioblastoma cell line GBM95. We demonstrated that soluble factors secreted by microglia into the culture medium (microglia conditioned medium;
MG CM) caused a two-fold increase in the proliferation of GBM95 cells. This effect was reversed when
STI1 was removed from the MG CM. In this context, we have shown that microglial cells synthesize
and secrete STI1. Interestingly, no difference was observed in proliferation rates when GBM cells were
maintained in MG CM or MG CM containing an anti-PrPC neutralizing antibody. Moreover, rec STI1 and
rec STI1_230–245, which lack the PrPC binding site, both promoted similar levels of GBM95 proliferation. In the migration assays, MG CM favored the migration of GBM95 cells, but migration failed when
STI1 was removed from the MG CM. We detected metalloproteinase 9 (MMP-9) activity in the MG CM,
and when cultured microglia were treated with an anti-STI1 antibody, MMP-9 activity decreased. Our
results suggest that STI1 is secreted by microglia and favors tumor growth and invasion through the
participation of MMP-9 in a PrPC-independent manner.
4.5.1
APLICATION OF NEURAL NETWORKS MODELS AND MESHES
OF MULTIVARIATE APPROACH IN ARTIFICIAL INTELLIGENCE
IN THE DIAGNOSIS AND PROGNOSIS OF DEGENERATIVE DISEASES
4.5.2
DEFINITION OF DIAGNOSTIC AND PROGNOSTIC CRITERIA IN
FUNCTIONAL IMPAIRMENT OF PERSONALITY DEVELOPMENT
IN CHILDHOOD AND ADOLESCENCE: A CLINICAL DILEMMA
Alberto Hananel Baigorria. UGR-USAT, Peru.
PAREDES-RUIZ SC. Universidad Nacional Mayor de San Marcos, Lima, Perú.
The aim of this work is to present the mathematical aplication of layers of Neural Networks Models
who can be combined in the formulation of Meshes of multivariate approach in the Diagnosis and
Prognosis of Degenerative Diseases. For this objective it is necesary to detail concrete models in
Artificial Intelligence like Neural Networks and Fuzzy Expert Systems focussing in the way to connect
some algorithms of the Approximation Theory for interpolation and reconstruction of a live structure.
Some of these models are concerned with the Finite Element Method in an approach for passing exact
to applied mathematics. With the results of this numerical method it is possible to have an holistic
vision of the patient for a better diagnosis and prognosis of a degenerative disease as a second hand
technique with a trascendency of Ethical Neurosciences which is presented with concrete results in the
mandible of a patient and his movements of oclussion.
The research analyzes which are the most significant clinical criteria that must be considered in
both the diagnosis and prognosis of children and adolescents with attention deficit and hyperactivity
disorder. Traditionally this analysis is done considering the extent to which clinical symptoms are
presented characteristic of the disorder or syndrome. But this analysis is not significant for prognosis
because it does not consider the characteristics of the development process, in which the role of
the “social mind” or the acquisition of cultural tools plays a major role in reducing the margin of
the deficit and the randomness of development. The factors that we consider to be integrated in the
clinical analysis of diagnosis and prognosis are primarily functional characteristics of the family and
secondly functional characteristics of the formal education. These are the factors that would determine
that the primary disorder generates secondary formative difficulties, such as disturbance of behavioral
or learning difficulties, with which the characteristics of executive deficits would complete its altered
cycle, becoming deficit of executive brain functions in problems of social behavior or personality disorders. This research follows a methodology retrospective on analysis of cases of individuals with attention deficit disorder and hyperactivity, clinically tested, and is exposed the role in both the diagnosis
and prognosis, not only specific components primary deficit, but also the role and characteristics of
the family and school system in which the analyzed individual develops.
4.5.3
DEVELOPMENT OF INTELLIGENT SYSTEMS FOR THE
DIAGNOSIS AND PROGNOSIS OF NEUROPSYCHIATRIC
DISORDERS AND DEGENERATIVE DISEASES
PAREDES-RUIZ DA. Universidad Peruana Cayetano Heredia, Lima, Perú.
4.6.3
NEUROPEPTIDES IN THE HUMAN AND MONKEY BRAINSTEM
Ewing Duque(1) and Rafael Coveñas(2). (1) Lab. de Neurociencias, Univ. Pontificia Bolivariana-Montería, Colombia (2)Laboratorio de Neuroanatomía de los Sistemas Peptidergicos, Instituto de Neurociencias de Castilla y León (INCYL), Salamanca, España.
Expert systems must express the principles of modeling entities. When they are applied to the diagnosis
of a disease depend on a priori concepts proposed for such disease, which in order to achieve a predictive capability should reconsider as a way to validation. For this work we started from previous studies
identifying determining factors for a degenerative joint disease. Degenerative diseases have important
features as to be progressive, evolutionary, multi determined, multi determinant, irreducible. By their
effects we find that they share principles with neuropsychiatric diseases. Having as axis on this research generate an intelligent diagnostic tool, we develop in this research an ontological analysis of
the degenerative and neuropsychiatric diseases as an entity. We conclude that 1) it is essential in every
disease temporal analysis, retrospective and prospective, 2) we enhance the prognostic significance
as temporary approach to a disease, 3) it is important to approach the point of irreducibility of the determinants, limit point selection process of criteria for a disease, 4) each factor in diagnosis/prognosis
is associated with other “cooperating” systems, 5) it must generate schemes of partial relationships
between systems of factors which may be represented by Partial Differential Equations(PDE), 6) finite
element methods are a very good alternative in solving PDEs, 7) the determinants of neuropsychiatric
diseases are related in fuzzy approaches, 8) the model must be able to represent the temporal relationship between systems “cooperating”, 9) the fuzzy mathematics can successfully integrate determining
factors, 10) the system for diagnostic /prognostic will be improved with the addition of each new case
as expert system, and 11) the system should aim ultimately to simplicity.
By using an immunocytochemical technique, we have studied the distribution of immunoreactive fibres and cell bodies containing twelve neuropeptides (alpha-neo-endorphin, neurokinin A, neurokinin
B, neurotensin, somatostatin-28 (1- 12), methionine-enkephalin, methionine-enkephalin-Arg6-Gly7Leu8, leucine-enkephalin, beta-endorphin, adrenocorticotropic hormone, substance P, calcitonin genrelated peptide) in the human and monkey (Macaca fascicularis and Saimiri sciureus) brainstem.
Immunoreactive cell bodies containing neuropeptides were observed in both human and monkey in the
periaqueductal gray matter, the interpeduncular nucleus, the spinal trigeminal nucleus, the reticular
formation of the pons and in the superior colliculus. Immunoreactive fibres containing neuropeptides
were widespread distributed throughout the human and monkey brainstem. We found a high or moderate density of inmunorective fibres in the periaqueductal gray matter, the reticular formation of the
medulla oblongata, the inferior colliculus and in the spinal trigeminal nucleus. A low density of fibres
containing neuropeptides was observed in many nuclei of the mesencephalon, pons and medulla oblongata. The widespread distribution of neuropeptides in the human and monkey brainstem suggests
that they can be involved in many physiological functions (cardiovascular and respiratory mechanisms,
nociception...), acting as neurotransmitters and/or neuromodulators.
4.7.1
SIGNALING THROUGH GLUTAMATE TRANSPORTERS
IN BERGMANN GLIA CELLS
4.7.2
ROLE OF GABA TRANSPORTERS IN THE CHICK RETINA
Rodriguez A(1) and Ortega A(2). (1)Facultad de Química, Universidad Autónoma de Querétaro, Querétaro, Mexico, (2)Dept de Genética y Biología Molecular, Cinvestav-IPN, México DF, Mexico.
Glutamate, the major excitatory amino acid, activates a wide variety of signal transduction cascades.
Synaptic plasticity requires an activity-dependent differential protein expression. Glutamate receptors (ionotropic as well as metabotropic) are involved in long-term synaptic changes, although recent
findings suggest that Na+-dependent glutamate transporters, responsible of the removal of this excitatory neurotransmitter from the synaptic cleft, also participate in glutamate-dependent signaling.
Transporter proteins are present in neurons and glia cells although the bulk (aprox. 80%) of glutamate
uptake occurs in the glial compartment. Within the cerebellum, Bergmann glia cells completely ensheat
glutamatergic synapses and participate in the recycling of glutamate through the well-established
glutamate/glutamine shuttle. In this context, we decided to investigate a plausible role of Bergmann
glia glutamate transporters as signaling entities. To this end, primary cultures of chick cerebellar Bergmann glia cells were exposed to D-aspartate and other transporter ligands and the pattern of serine
2448 phosphorylation of the master regulator of protein synthesis, namely the mammalian target of
rapamycin (mTOR), determined. A time and dose-dependent increase in mTOR phosphorylation was
detected. The signaling cascade included Ca2+influx, activation of the phosphatidylinositol 3- kinase
and protein kinase B. Furthermore, transporter signaling resulted also in an increase in Activator
Protein-1 (AP-1) binding to DNA and the up-regulation of the transcription of an AP-1 driven gene
construct. These results will be discussed in terms of a novel glial mediator of the glutamate effects at
the translational and transcriptional levels.
Karin C Calaza, Dept Neurobiologia, Universidade Federal Fluminense, Niteroi, Brazil
We have shown that glutamate promotes GABA release through ionotropic receptors and metabotropic receptors in the chick retinal cells. The release of GABA is greatly mediated by the reversal of
GABA-transporter 1 (GAT-1). We also found that nitric oxide (NO) can modulates GABA release through
this mechanism. Specific inhibition of neuronal nitric oxide synthase (nNOS) reduced the number of
GABA+ amacrine cells and cells in the ganglion cell layer (GCL) by 33% and 41%, respectively. A
GABA transporter inhibitor (NO-711) blocked this effect. L-arginine (100 μM), the precursor of NO, induced increases of 62% and 34% in the number of GABA+ amacrine cells and GCL cells, respectively,
in a nNOS-, PKG- and GAT-1- dependent way. We conclude that basal NO production and moderate NO
production (possibly induced by L-arginine; 100μM) inhibit basal GABA release from amacrine cells
and GCL cells. However, NMDA or L-arginine (1mM) induces a NO-dependent increase in GABA release
in GCL cells, possibly by stimulating higher NO production. GATs can also regulate GABA availability in
pathological conditions. It is known that hyperglycemia could induce neuronal death. This study aimed
to analyze the effects of different concentrations of glucose on morphological features and GABAergic
system of the retina. Ex vivo chick retinas were kept under continuous perfusion with 95%O2/5%CO2
in physiological medium containing different glucose concentrations (in mM): 0, 5.6 and 35 for 30
minutes. Hypoglycemia promoted loss of GABA content (50%) from amacrine cells in the inner nuclear
layer (INL) and GCL and its processes. This effect was due to GABA release since it could be blocked by
GAT-1 inhibitor (NO-711). We concluded that glycemic oscillations modulate GABA availability possible
through regulation of GATs expression.
4.7.3
ONTOGENY OF GLIAL GLUTAMINE TRANSPORTERS
Ortega A(1) and Rodriguez A(2). 1Dept de Genética y Biología Molecular, Cinvestav-IPN, México DF,
Mexico. 2Facultad de Química, Universidad Autónoma de Querétaro, Querétaro, México,
Glutamate is the main excitatory neurotransmitter in the vertebrate brain. Once released, its extracellular levels are tightly regulated through the action of a family of sodium-dependent glutamate/aspartate transporters profusely expressed in glial cells. Once internalized into the glial compartment, it is
metabolized by glutamine synthetase to glutamine (Gln). This neutral, non-essential amino acid is the
precursor Glu and GABA, that is transported by different transmembranal proteins. The solute sodium
amino acid transporters (SNATs) are key molecules in the recycling of the mentioned transmitters. It
has been generally accepted that the bi-directionally acting systems N(SNAT3/SNAT5) are expressed in
astrocytes, whereas neurons are enriched in Glutamine uptake promoting transporters SNAT2. Using
the well-established model of cultured cerebellar Bergmann glia cells, in this work, we sought to
characterize the functional coupling of glutamate uptake and glutamine release. Our results will be
discussed in terms of the continuous dialogue of Bergmann glia cells with the synapses surrounded
by them.
4.8.1
STRUCTURAL AND FUNCTIONAL PROPERTIES OF HIPPOCAMPUS
Rafael Luján, Dpt. Ciencias Medicas, Facultad de Medicina, Universidad de Castilla-La Mancha, España
The hippocampus is a major component of the brains of all mammals that plays important roles in
learning and memory. The efficiency of synaptic transmission at any given synapse is constantly changing in response to a variety of factors, and these changes play a central role in the function of the hippocampus in normal and pathological conditions. One important way by which synaptic transmission
can be modulated is by changing electrical excitability. The action of neurotransmitter receptors and
ion channels on the surface of hippocampal neurons are crucial for this process. The identification of
the subcellular components in which neurotransmitter receptors and ion channels are operative and
their density at the different compartments is essential to understand the molecular mechanisms
underlying the involvement of these channels in hippocampal functions and dysfunctions. Excitatory
synapses on CA1 spines contain three types of glutamate receptors: NMDA, AMPA and metabotropic
glutamate (mGlu) receptors. NMDA receptors mediate a slow synaptic current blocked in a voltagedependent manner by Mg2+ and occupy a disklike space near the centre of the PSD. AMPA receptors
mediate a fast synaptic current and are distributed more evenly along the PSD. mGlu receptors mediate
a slow synaptic current, modulate the action of NMDA and AMPA receptors and are localised outside
the PSDs. Excitatory synapses on CA1 spines, also contain small conductance Ca2+-activated K+
(SK) channels, which modulate neurotransmission and contribute to synaptic plasticity through their
coupling to NMDA receptors, as well as GABAB receptors, which hyperpolarise the membrane of spines
and are located both at PSDs and at the extrasynaptic plasma membrane. All these signalling molecules play a crucial role in the correct function of excitatory neurotransmission in the hippocampus
and their alteration is involved in pathological conditions like epilepsy and Alzheimer’s disease Support
Contributed By: MICINN (BFU-2009-08404 and CSD2008-00005),
4.7.4
REGULATION OF THE GAT3 GABAERGIC
TRANSPORTER IN AVIAN MULLER GLIA CELLS
Schitine CS(1), Ornelas I(2), Calaza KC(2), Gardino PF(1), Reis RAM(1) and de Mello FG(1). (1) Inst
Biofisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil. (2) Dept Neurobiologia, Universidade Federal Fluminense, Niteroi, Brazil
GABA (gamma-amino butyric acid) is a major inhibitory transmitter in the central nervous system and
its action is ended through specific membrane transporters (GAT) found in neurons and glial cells. We
have previously described that GAT-3 is a major GABA transporter that operates in avian Müller cells
in culture in a Na+ and Cl- dependent manner. It is action is inhibited by b-alanine, but not by NNC711, a neuronal GAT-1 blocker. To evaluate the influence of neurons on glia GAT-3, conditioned media
prepared from retinal neurons was assayed and decreased GABA uptake suggesting that secreted
molecules from neurons could modulate GAT-3 function. Glutamate decreases [3H]- GABA uptake in
purified glia cells in culture up to 50%. This effect is mimicked by kainate (0.05-0.3 mM) or N-methyl
D-Aspartate (NMDA 0.1-1mM), but not by the metabotropic group I glutamate receptor agonist 3,5
dihydroxyphenylglycine (DHPG 0.05-0.1 mM). GABA uptake decrease is reversible and inhibited by
ionotropic glutamategic receptors antagonists (5 μM MK-801 and 70 μM DNQX). Treatment of purified
cultures with 0.01-2 μM phorbol myristate acetate (PMA), a protein kinase C (PKC) activator, reduced
in a dose dependent concentration (IC50 approx 0.6 μM) [3H]-GABA uptake by 40 ± 6%. GAT-3 is
present from embryonic day 5 (E5) retina increasing up to the end of embryonic development and posthatch avian retina. All GAT-3 is detected in neuronal layers (ganglion cell and interplexiform) and no
immunoreactivity is found in Müller cells. However, upon intra-vitreous injection of 50 nmoles kainate
on adult chick eye, an upregulation of GAT3 in Müller glia cells is shown 72h later. Indeed, purified
cultured Müller cells expressed discrete GAT-3 on its surface. This suggests a regulatory neuron-glia
signaling on GABA uptake.
4.8.2
NEURONAL CONNECTIONS OF CA2 AREA
OF THE MOUSE HIPPOCAMPUS
Zhenzhong Cui (1), Charles R. Gerfen (2), and W. Scott Young, 3rd (1).1. Section on Neural Gene Expression and 2. Laboratory of Systems Neuroscience, National Institute of Mental Health, National
Institutes of Health, Department of Health and Human Services, Bethesda, Maryland 20892.
The CA2 area is an important, although relatively unexplored, component of the hippocampus. Our
tracer studies provided a comprehensive analysis of CA2 connections in mice. Using adeno-associated
viruses that express fluorescent proteins, we found, for the first-time, vasopressinergic projections
from the paraventricular nuclei (PVN) to CA2, and projections from CA2 to the supramammillary nuclei (SUM). As expected, we observed CA2 afferent projections from neurons in ipsilateral entorhinal
cortical layer II as well as from bilateral dorsal CA2 and CA3 using retrograde tracers. Additionally,
we saw CA2 neuronal input from medial septal nuclei, vertical and horizontal limbs of the nucleus of
diagonal band of Broca (VDB and HDB), supramammillary nuclei and median raphe nucleus. Dorsal CA2
injections of adeno-associated virus expressing green fluorescent protein revealed axonal projections
primarily to dorsal CA1, CA2 and CA3 bilaterally. These results are consistent with recent observations
that dorsal CA2 forms disynaptic connections with entorhinal cortex to influence dynamic memory
processing. Mouse dorsal CA2 neurons send projections to septal nuclei,VDB,HDB and SUM. Novel connections from the PVN and to the SUM suggest important regulatory roles for CA2 in mediating social
and emotional input for memory processing. At the mean time, method of viral injection into dorsal
CA2 was developed, rescued expression of vasopressin 1b receptor at CA2 regions on 1b knockout mice
were tested. The results indicated that the vasopressin 1b receptor rescue expression could restore the
aggressive behavior in mice. Experiment of injecting cre expressing lenti-virus at CA2 region on floxed
NR1 mice have shown that NMDA receptor knockout at CA2 neurons reduced the aggressive behaviors.
These studies, together with recently published CA2 studies, indicated hippocampal CA2 neurons play
important roles for the memory processing at hippocampus and contribute to the social and emotional
functional of the hippocampus.
4.8.3
MATERNAL SEPARATION AND HIPPOCAMPAL NEUROGENESIS
AT AN EARLY AGE: CORRELATION WITH BEHAVIORAL AND
NEUROENDOCRINE DISTURBANCES IN ADULTHOOD
4.8.4
SYNAPTIC INNERVATION TO RAT HIPPOCAMPUS BY
VASOPRESSIN-IMMUNOPOSITIVE FIBERS FROM THE
HYPOTHALAMIC SUPRAOPTIC AND PARAVENTRICULAR NUCLEI
Naima Lajud, Ma Angélica Roque, Luz Torner. Centro de Investigaciones Biomedicas de Michoacán,
Instituto Mexicano del Seguro Social
Limei Zhang, Vito. S. Hernández. Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico.
Exposure to adverse experiences early in life has profound effects on brain development and maturation, and altersthe expression of several behaviors. To test whether hippocampal ontogeny is affected
by early exposure to stress, we evaluated the effects of periodic maternal separation on neural precursor cell survival within the hippocampus at postnatal day (PN) 15, and correlated them with HPA axis
responsiveness and depressive -like behavior in adulthood. Maternally Separated (MS; 3hr/day from
PN1-14) or animal facility reared (AFR). Sprague Dawley rat pups were injected with Bromodeoxyuridine
(BrdU, 50mg/kg, ip) at PN5, and were perfused at PN15. Additional litters were used to analyze basal
and stress - induced corticosterone (Cort) concentrations at PN3, PN12 and PN70, or to screen their
behavior in the forced swimming test. Analyses along the sagital plane revealed significant decreases
in the number and density of BrdU+ cells that survived at PN15 in the dentate gyrus after MS. Double
immunostaining against BrdU and Doblecortin (BrdU / Dcx) or NeuN (BrdU / NeuN), markers of immature and mature neurons respectively, showed a decreased density of doublecortin (DCX) positive BrdUlabeled cells of MS pups. No differences were found on basal or stress-induced Cort concentrations
between SM and AFR pups at PN3 and PN12. However adult (PN70) MS male rats showed a deregulation
of the HPA axis. Additionally MS male adults displayed a more passive coping strategy in the Forced
Swimming test. We conclude that early life stress induces a decrease on neurogenesis within the hippocampus with an early onset, affecting its ontogeny and contributing to deregulate the HPA axis and
to induce a depressive - like behavior in adulthood.
The neuropeptide arginine vasopressin (AVP) exerts a modulatory role on hippocampal excitability
through vasopressin V1A and V1B receptors. However, the origin and mode of termination of the AVP
innervation of the hippocampus remains unknown. We have used light and electron microscopy to trace
the origin, distribution and synaptic relationships of AVP-immunopositive fibres and nerve terminals
in the rat hippocampus. Immunopositive fibres were present in all areas (CA1-dentate gyrus) of the
whole septo-temporal extent of the hippocampus; they had the highest density in the CA2 region,
strongly increasing in density towards the ventral hippocampus. Two types of fibres were identified,
both establishing synaptic junctions. Type A had large varicosities packed with immunopositive large
granulated peptidergic vesicles and few small clear vesicles forming type I synaptic junctions with
pyramidal neuron dendrites, dendritic spines and with axonal spines. Type B had smaller varicosities
containing mostly small clear vesicles and only few large granulated vesicles and established type II
synaptic junctions mainly with interneuron dendrites. The AVP-positive axons in stratum oriens appeared to follow and contact mGluR1a-immunopositive interneuron dendrites. Fluorogold injection into
the hippocampus revealed retrogradely labelled AVP-positive somata in hypothalamic supraoptic and
paraventricular nuclei. Hypothalamo-hippocampal AVP-positive axons entered the hippocampus mostly
through a ventral route, also innervating the amygdala and to a lesser extent through the dorsal fimbria
fornix, in continuation of the septal AVP innervation. Thus, it appears the AVP containing neurons of
the magnocellular hypothalamic nuclei serve as important sources for hippocampal AVP innervation,
although the AVP-expressing neurons located in amygdala and bed nucleus of the stria terminalis
reported previously may also contribute.
4.8.5
STRUCTURAL AND FUNCTIONAL PROPERTIES OF THE HIPPOCAMPUS
4.9.1
TRACKING ALLOCATIONS OF VISUAL ATTENTION
WITH STEADY-STATE VISUAL EVOKED POTENTIALS
Rafael Luján. Dpt. Ciencias Medicas, Facultad de Medicina, Universidad de Castilla-La Mancha
Hillyard S. Department of Neurosciences University of California San Diego
The hippocampus is a major component of the brains of all mammals that plays important roles in
learning and memory. The efficiency of synaptic transmission at any given synapse is constantly changing in response to a variety of factors, and these changes play a central role in the function of the hippocampus in normal and pathological conditions. One important way by which synaptic transmission
can be modulated is by changing electrical excitability. The action of neurotransmitter receptors and
ion channels on the surface of hippocampal neurons are crucial for this process. The identification of
the subcellular components in which neurotransmitter receptors and ion channels are operative and
their density at the different compartments is essential to understand the molecular mechanisms
underlying the involvement of these channels in hippocampal functions and dysfunctions. Excitatory
synapses on CA1 spines contain three types of glutamate receptors: NMDA, AMPA and metabotropic
glutamate (mGlu) receptors. NMDA receptors mediate a slow synaptic current blocked in a voltagedependent manner by Mg2+ and occupy a disklike space near the centre of the PSD. AMPA receptors
mediate a fast synaptic current and are distributed more evenly along the PSD. mGlu receptors mediate
a slow synaptic current, modulate the action of NMDA and AMPA receptors and are localised outside
the PSDs. Excitatory synapses on CA1 spines, also contain small conductance Ca2+-activated K+
(SK) channels, which modulate neurotransmission and contribute to synaptic plasticity through their
coupling to NMDA receptors, as well as GABAB receptors, which hyperpolarise the membrane of spines
and are located both at PSDs and at the extrasynaptic plasma membrane. All these signalling molecules play a crucial role in the correct function of excitatory neurotransmission in the hippocampus
and their alteration is involved in pathological conditions like epilepsy and Alzheimer’s disease. Support Contributed By: MICINN (BFU-2009-08404 and CSD2008-00005).
A regularly flickering stimulus between 6 and 30 Hz typically elicits a steady-state visual evoked potential (SSVEP), which is a frequency-tagged neural oscillation in the visual cortex that has the same
fundamental frequency as the driving stimulus. The amplitude of the SSVEP is generally enhanced when
the driving stimulus is attended. Allocations of attention among two or more concurrently presented
stimuli may be assessed by flickering each stimulus at a different rate and recording the separate
frequency-tagged SSVEPs. Using this method, it has been shown that the “spotlight” of spatial attention may be divided into separate regions of space, and that several hundred ms are required to shift
attention from one location to another. Evidence from SSVEP recordings have also shown that attention
may be directed to items of one color that are interspersed among items of a different color, and that
paying attention to a color feature at one location results in a global enhancement of that feature
throughout the visual field. Selective attention to one of two overlapping objects (rotating dot surfaces)
can also be tracked using SSVEPs.
4.9.2
AUDITORY ATTENTION IN PREMATURE INFANTS
WITH PERIVENTRICULAR LEUKOMALACIA
4.9.3
NEURAL BASIS OF SELECTIVE ATTENTION TO GLOBAL
AND LOCAL ASPECTS OF A VISUAL SCENE
Gutiérrez-Hernández CC,Harmony T, Avecilla-Ramírez GGN, Calderón-Carrillo M and Carlier-Torres M.
Unidad de Investigación en Neurodesarrollo, Departamento de Neurobiología Conductual y Cognitiva,
Instituto de Neurobiología, Universidad Nacional Autónoma de México, Qro., Querétaro.
Valdes Sosa, M. Centro de Neurociencias de Cuba
Due to medical advances, there is an increased survival rate in children who are born preterm. The
most important brain abnormalities in premature infants are denoted by the term periventricular leukomalacia (PVL) which refers to white and gray matter lesions. Long term cognitive deficits have been
increasingly recognized as a major adverse outcome in PVL, and it has been reported that school-aged
children, who were born preterm, are at risk for attention difficulties possibly leading to a diagnosis
of ADHD. Our goal is the development of early methods for the detection and treatment of problems in
the regulation of attention. Behavioral (Bayley, and one created by us) and electrophysiological studies
were performed in 3 groups of children: 1) Healthy infants at term and 2 groups of preterm infants
with PVL showing attention deficits, one with and another without a behavioral treatment developed by
our group. Evaluations were made at 3 and 8 months old. ERPs to tones in 2 different paradigms were
obtained: 1) Series of 4 stimuli, 3 were repetitions of the same tone and the last one may be different
with a probability of 20% and 2) an oddball paradigm 80/20%. At 3 months no differences between
preterm groups were observed, although they showed differences compared with healthy infants. At 8
months the group treated showed higher amplitudes of the ERPs. Preterm treated infants showed significant improvement in behavioral tests at 8 months. The data suggest that early behavioral treatment
may advance attention deficits in preterm infants with PVL. Further follow up of these children will
be necessary to determine if they showed a future ADHD diagnosis. Acknowledgements: Support was
provided by PAPIIT-DGAPA IN220110 project, Programa de Doctorado en Psicología UNAM and CONACYT
164971. We want to acknowledge Dr. Héctor Barragán, engineer Héctor Belmont and David Avila.
4.9.4
ELECTROPHYSIOLOGICAL EVIDENCE FOR MAGNOCELLULAR
PROCESSING DEFICITS IN SCHIZOPHRENIA DURING
FEATURE SELECTIVE ATTENTION
Martinez A, Gaspar Pablo A. , Steven A. Hillyard, Daniel C. Javitt. Nathan Kline Institute for Psychiatric
Research Schizophrenia Research Division New York
Schizophrenia is associated with cognitive dysfunction that includes impairments in visual attention. The underlying physiological bases of these deficits remain poorly understood. In recent years,
deficits in early visual processing, primarily along the magnocellular/dorsal visual pathways, have
been increasingly documented and there is mounting evidence that these deficits impact higher order
perceptual functions including attention. The studies presented here test the hypothesis that deficits
in the early stages of sensory/perceptual encoding of visual information contribute, at least in part,
to attentional impairments in schizophrenia. In particular, we investigated whether schizophrenia
patients show deficits in attending selectively to visual stimuli that are processed via the magnocellular/dorsal stream pathways. Sinusoidal gratings of low and high spatial frequency were presented
to preferentially stimulate the magnoand parvocellular visual pathways, respectively. Schizophrenia
patients and healthy control subjects were required to pay attention selectively on separate runs to
either the low or high SF gratings, which were presented in randomized sequences. Event-related brain
potentials (ERPs) were recorded from 168 scalp sites to all stimuli. It was found that schizophrenia
patients were generally impaired at detecting target stimuli of low spatial frequency and that ERP
amplitudes to stimuli of low SF were diminished, both for the early sensory-evoked components and
for the attend minus unattend difference component (the Selection Negativity). These findings support
the hypothesis that deficits at the initial stages of sensory/perceptual encoding of visual information
within the magnocellular/dorsal stream may contribute to higher-order deficits in selectively focusing
attention on magnocellular-biased stimuli.
Attention can be paid to different hierarchical levels within a visual scene, ranging from more globalto
more local aspects. Attention to these levels has been traditionally studied with compound figures
(e.g. global letters built up from local letters) in which both levels are presented at once. Using rapid
serial object transformation (RSOT,Valdes-Sosa et al, 2005),one can independently control the timing
of presentation for the global and localfacets of the same compound figure. This allows measurement
of the duration of between-level attention shifts. Local to global shifts take much more time than
local to global in neuro-typical observers, a relationship that appears to be reversed in some cases
of autism. Using RSOT one can also record event related potentials (ERPs) that have been selectively
triggered by the onset of either the local or the global levels of the figure. Sustained attention to one
level enhances the amplitude of early negative (with latency about 200 ms) components in the ERPs
elicited by presentation of that level, relative to when attention is directed at the other level. The
effects are earlier for attention to the global level. These components present a scalp distribution
with an occipito-temporal maximum. Functional resonance imaging with the same paradigm shows
that shifting attention between levels modulates activity in visual extra-striate areas. These findings
indicate that attention to different hierarchical levels within a visual scene implicate a reconfiguration
of early visual processes, with enhancement or suppression of neural representations corresponding
to distinct aspects of the same visual object.
SYMPOSIA
FRIDAY NOVEMBER 9
5.2.1
SENSORY PROCESSING DEFICITS IN SCHIZOPHRENIA
5.2.2
CELL-SELECTIVE CHANGES IN SCHIZOPHRENIA CEREBRAL CORTEX
Dias EC, Bickel S, Javitt DC, Nathan Kline Inst. for Psych. Res, Orangeburg,NY, USA
Smiley J.F (1), Haxhija L (1), Bleiwas C (1), Dwork, A.J (2), (1) Nathan Kline Institute for Psychiatric
Research, Orangeburg, New York, USA; (2) New York Psychiatric Institute, New York, New York, USA
Deficits of higher cognitive processing have been documented extensively in schizophrenia. More
recently, deficits at the level of primary sensory function have been also documented, such as impaired initial sensory processing within auditory and visual streams. Nevertheless, contributions of
early sensory-level deficits to impairments in higher cortical processing have been investigated only
to a limited degree. This study investigated the interrelationship between sensory and cognitive level
deficits in schizophrenia, using variations of the “AX” type continuous performance task (AX-CPT)
combined with high density event-related potentials (ERP). AX-CPT is among the most widely used
paradigms for investigating neural mechanisms of cognitive dysfunction in schizophrenia. Deficits
in AX-CPT performance appear to reflect primarily a failure to utilize the informational content of the
cue stimulus to disambiguate response to the subsequent target letter. A major unanswered question
is the degree to which impaired performance reflects impaired encoding of cue-related information
vs. impaired retention of this information across delay. ERP were obtained from 27 individuals with
schizophrenia and 15 healthy comparison subjects in 3 versions of the AX-CPT that varied based upon
stimulus probabilities and global prepotencies. The sensory potentials P1 and N1 indexed early stages
of visual response, whereas N2, P3 and CNV to cue and N2 and P3 to probe indexed subsequent stages.
The study demonstrated impaired activation within both sensory and higher order brain regions in
schizophrenia during the AX-CPT, with impaired processing of both cue and probe related information.
Significant impairments were observed in task versions that required encoding of both inhibitory and
facilitatory response sets. Overall, these findings demonstrate significant impairment in processing
visual stimuli in the AX-CPT, and support generalized models of cognitive dysfunction with distributed
disturbances across both sensory and cognitive brain regions in schizophrenia.
Schizophrenia has been associated with decreased gray matter volume in the cerebral cortex, with
most pronounce changes in frontal and temporal areas, including auditory regions of the superior temporal gyrus. Reduced gray matter volume predicts cellular atrophy or decreased cell number, but the
cell-specificity of the changes is poorly defined. We have undertaken a series of studies in post-mortem
brains to investigate the detailed anatomy and cellular composition of the auditory cerebral cortex in
schizophrenia. Our studies of neuron density, number and size have not revealed consistent changes,
suggesting that the basic neuronal organization of the cerebral cortex is not grossly altered. Additionally, we and others have investigated gene expression changes associated with schizophrenia auditory cortex, and found evidence of increased antioxidant enzymes, suggesting that altered oxidative
metabolism may contributed to disrupted function and synaptic plasticity in schizophrenia. Because
both microglia and astroglia are closely associated with changes in oxidative stress, we are currently
evaluating whether schizophrenia is associated with changes in the density and size of these glia subtypes. Subjects with major depression are being used as a psychiatric comparison group to determine
the disease specificity of the findings. Astroglia and microglia are thought to be directly involved in
neurotransmission and synaptic plasticity, and anatomical changes in these cells may provide insights
into the neuropathology of psychiatric diseases and potential sites of pharmacological intervention.
5.2.3
ELEVATED PRODUCTION OF REACTIVE OXYGEN SPECIES DURING
NEUROGENESIS OF INDUCED PLURIPOTENT STEM CELLS
DERIVED FROM A SCHIZOPHRENIC PATIENT
5.2.4
CONTRIBUTIONS OF FUNCTIONAL NEUROIMAGING
TO UNDERSTAND THE MOTION-PROCESSING
DEFICITS IN SCHIZOPHRENIA
Bruna da Silveira Paulsen(1), Renata de Moraes Maciel(1), Antonio Galina(2), Mariana, Souza da Silveira(3), Cleide dos
Santos Souza(1), Hannah Drummond(1), Ernesto Nascimento Pozzatto(1), Hamilton Silva Junior(1), Leonardo Chicaybam(4),
Raffael Massuda(5), Pedro Setti-Perdigão(9), Martin Boamino(4), Paulo Silva Belmonte-de-Abreu(5), Newton Gonçalves
Castro(9), Helena Brentani(6,7,8), Stevens Rehen(1). (1)Laboratório Nacional de Células–Tronco Embrionárias, Instituto de
Ciências Biomédicas, UFRJ, Rio de Janeiro, RJ, 21941-913, Brazil; (2)Laboratório de Bioenergética e Fisiologia Mitocondrial,
Instituto de Bioquímica Médica, UFRJ, Rio de Janeiro, RJ, 21941-590, Brazil; (3)Laboratório de Neurogênese, Instituto de
Biofisica Carlos Chagas Filho, UFRJ, Rio de Janeiro, RJ, 21941-902, Brazil; (4)Divisão de Medicina Experimental, Instituto
Nacional de Câncer, Rio de Janeiro, RJ, 20231-050, Brazil; (5)Departamento de Psiquiatria, Faculdade de Medicina, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, 90035-003, Brazil; (6)Departamento de Psiquiatria,Faculdade de
Medicina, Universidade de São Paulo, São Paulo, SP, 05403-010, Brazil; (7)Instituto Nacional de Psiquiatria do Desenvolvimento, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, 05403-010, Brazil; (8)Laboratório de Investigação
Médica, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, 05403-010, Brazil; (9) Laboratório de Farmacologia Molecular, Instituto de Ciências Biomédicas, UFRJ, Rio de Janeiro, RJ, 21941-902, Brazil.
Gaspar PA(1),Martinez A(2),Javitt DC (2). (1) Clinical Hospital of the University of Chile, Santiago, Chile;
(2) The Nathan Kline Institute for Psychiatric Research, New York, USA.
Oxidative unbalance, either by an impairment of antioxidant defenses or by an intensified production of reactive oxygen species (ROS), is increasingly related to risk factors of neurodevelopmental disorders such as
schizophrenia. Identifying the role of ROS in neurogenesis as well as tackling oxidative stress and its disturbances in schizophrenic patients may provide an interesting opportunity for the treatment and also prevention
of schizophrenia. Human induced pluripotent stem cells (hiPSCs) emerged as a novel platform for the study
of cellular and molecular aspects of schizophrenia, complementing other experimental models, with exclusive
advantages such as the recapitulation of human neurodevelopment. Here we describe that neural cells, derived from hiPSCs generated from skin fibroblasts of a schizophrenic patient, presented a 2-fold increase in
extra-mitochondrial oxygen consumption as well as elevated levels of ROS, when compared to controls. This
difference in ROS levels was reverted by the mood stabilizer valproic acid. Our model shows evidence that
metabolic changes occurring during neurogenesis are associated with schizophrenia, which might not only
contribute to the onset of the disease but also represent an important target for treatment.
Several studies have shown that motion processing is significantly impaired in schizophrenia (SZ).
Although the alterations in the multimodal brain areas have been well documented, less attention has
been focused on how early motion processing areas are implied in these deficits. To study the extension of the motion deficits on the visual cortical pathway we used a 3T-FMRI device while subjects
performed two motion tasks. As we expected, we found a widespread alteration in the visual pathway,
such as the fusiform gyrus, MT area, STG and Prefrontal cortex, during the perception of implicit – and
real - motion compared with no-motion conditions. Here we show a large extension of the brain areas
implicated in the motion deficits observed in schizophrenia including early motion processing brain
areas. These results support the idea that motion processing deficits observed in this disease not only
requires the integrity of the high-order, multimodal- brain areas, but also the normal processing of
sensory visual pathway.
5.3.1
ROLE OF REDOX SENSITIVE RYR-MEDIATED
CALCIUM RELEASE IN SYNAPTIC PLASTICITY
HIDALGO, C, BNI, CEMC and ICBM, F. Medicina, Universidad de Chile, Santiago, Chile.
5.3.2
CALCIUM AND ROS IN ALZHEIMER’S DISEASE
PAULA-LIMA AC(1), SANMARTIN(2) CD(2), ADASME T(2)., and HIDALGO C(2), (1) Faculty of Dentistry, (2)
Faculty of Medicine, Universidad de Chile, Santiago, Chile.
Neuronal electrical activity increases intracellular calcium concentration and the generation of reactive oxygen species. In hippocampal CA1 neurons the activity-dependent increase in postsynaptic
calcium concentration originates calcium signals that play a central role in hippocampal synaptic
plasticity (LTP and LTD) and underlie spatial memory formation and consolidation. These postsynaptic
calcium signals originate from calcium entry through Nmethyl- D-aspartate receptors (NMDAR); via
calcium-induced calcium release these initial signals stimulate calcium release through the intracellular ryanodine receptor (RyR) channels present in the endoplasmic reticulum. We have found that
exogenous addition of hydrogen peroxide to primary hippocampal neurons increases RyR oxidation
via Sglutathionylation of RyR cysteines and stimulates RyR-mediated calcium release. The resulting
calcium signals stimulate ERK and CREB phosphorylation, cfos mRNA levels and NF-kB- dependent
transcription; RyR inhibition prevented these effects. Of note, high-frequency stimulation (HFS) of primary hippocampal cultures stimulates hydrogen peroxide generation by the NOX2 isoform of NADPH
oxidase, which in turn stimulates RyR-mediated calcium release and the ensuing signaling cascades
described above, and increase type-2 RyR protein content. Additionally, we have found that the antioxidant N-acetyl-cysteine inhibits NOX2-dependent hydrogen peroxide generation as well as RyR-mediated
Ca2+ release and prevents the increase in RyR2 protein content and the stimulation of NF-kB induced
by HFS. Moreover, pharmacological inhibition of RyR function prevented LTP induction by theta burst
stimulation of hippocampal slices (CA3 to CA1). Based on these results, we propose that calcium
signals generated jointly as a result of RyR stimulation by calcium and ROS are central elements of
the signaling cascades that underlie hippocampal synaptic plasticity. Financial Support: FONDECYT
(1100052), FONDECYT-FONDAP (1501006), MILLENNIUM BNI (P-09-015F).
Increasing evidence indicates that the memory loss characteristic of Alzheimer’s disease results from
the extensive synaptic dysfunction promoted by amyloid-_ peptide oligomers (A_Os). We have reported
previously that non-lethal concentrations of A_Os generate persistent and redox-sensitive Ca2+signals in primary hippocampal neurons, which arise from Ca2+ entry through N-methyl-D-aspartate
receptors (NMDAR) and subsequent amplification by Ca2+ release through the intracellular ryanodine
receptor (RyR) channels present in the endoplasmic reticulum (ER). The persistent Ca2+ signals
invoked by A_Os decrease RyR2 mRNA and protein levels, prevent the spine remodeling invoked by
brain-derived neurotrophic factor (BDNF), and provoke mitochondrial network fragmentation. Previous
reports indicate that activation of intracellular Ca2+ release channels generates hot spots of high
[Ca2+] at the interface between ER and mitochondria, which trigger mitochondrial Ca2+ uptake and
reactive oxygen species (ROS) generation. Consequently, in this work we aimed to test if RyR-mediated
Ca2+-signals generated by A_Os stimulate mitochondrial Ca2+-uptake and ROS production in
primary hippocampal neurons. We have found that A_Os promote mitochondrial Ca2+ uptake and
stimulate mitochondrial superoxide and H2O2 production; selective RyR inhibition prevents mitochondrial Ca2+-uptake but not the increased superoxide production induced by A_Os. Additionally, we
have found that the antioxidant N-acetyl-cysteine inhibits RyR-mediated Ca2+ release and prevents
the mitochondrial fragmentation induced by A_Os. Taken together, our results indicate that A_Os
- by sequentially stimulating MDARmediated Ca2+-influx and redox-sensitive RyR-mediated Ca2+release - cause defects in neuronal mitochondrial dynamics and spine remodeling. These abnormal
responses presumably contribute to the impaired hippocampal synaptic plasticity produced by A_Os.
Financial Support: FONDECYT (11110322-1100052-31320093), CONICYT (79090021), FONDECYTFONDAP (1501006), MILLENNIUM BNI (P-09-015F).
5.3.3
OXIDATIVE STRESS AND BIOENERGETIC IMBALANCE
IN THE PATHOPHYSIOLOGY OF SEPTIC ENCEPHALOPATHY
5.3.4
IN VIVO AND IN VITRO REVERSION OF MIDBRAIN DOPAMINERGIC
NEURONS DEGENERATION BY IRON CHELATORS
D’AVILA JC (1); RODRIGUES RS (2,3); OLIVEIRA MF (3); MORTON KA (4); CASTRO-FARIA-NETO HC (1); BOZZA
FA (1,2). (1) Oswaldo Cruz Foundation (FIOCRUZ), Rio de Janeiro, Brazil; (2) D’Or Institute for Research
and Education (IDOR), Rio de Janeiro, Brazil; (3) Federal University of Rio de Janeiro (UFRJ), Rio de
Janeiro, Brazil; (4) Dept. of Radiology, University of Utah School of Medicine, Utah, U.S.A.
NÚÑEZ MT, PÉREZ P, AGUIRRE P, MENA N, GONZÁLEZ C. Biology Department, Faculty of Sciences, Universidad de Chile and Research Ring on Oxidative Stress in the Nervous System, Santiago, Chile.
Sepsis is the systemic inflammatory response to an infection and may evolve to multiple organ dysfunctions. Septic encephalopathy is a frequent complication in severe sepsis but its pathogenesis and
mechanisms are not fully understood. Oxygen supply and utilization are critical for organ function,
specially for the brain, a tissue extremely dependent on oxygen and glucose. Disturbances in oxygen
utilization are common in sepsis and a number of mitochondrial dysfunctions have been described in
different tissues in septic animals as well as in septic patients. Our group described mitochondrial
dysfunctions in the brain during experimental sepsis. We believe that a metabolic imbalance can be
associated to the pathophysiology of septic encephalopathy. I this study systemic inflammation was
induced by either endotoxemia or polymicrobial sepsis as models of experimental sepsis. Mice with
polymicrobial sepsis present hypoglycemia, hyperlactatemia and long-term cognitive impairment. We
observed a rapid increase in the uptake of fluorescent glucose analog 2-deoxy-2-[(7-nitro-2,1,3- benzoxadiazol-4-yl)amino]-D-glucose (NBDG) in brain slices from septic mice in vitro. A similar increase
in brain glucose uptake was observed in vivo in endotoxemic rats using Positron Emission Tomography
(PET) with [18F]Fluorodeoxyglucose (FDG) and autoradiography with 2-deoxy-14C-glucose. Remarkably,
the increase in glucose uptake started 2h after LPS injection, earlier than in other organs. The brains
of mice with experimental sepsis presented neuroinflammation, mitochondrial dysfunctions and oxidative stress, but mitochondria isolated from septic brains generated less ROS in vitro. This led us
to investigate the role of NADPH oxidase, an enzyme induced during innate immune response, as a
potential source of reactive oxygen species in experimental sepsis. We are observing a new metabolic
phenotype in response to systemic inflammation, characterized by a rapid increase in glucose uptake
and mitochondrial dysfunctions that may be secondary to inflammation and hypoxia.
Inflammatory conditions, oxidative damage and iron accumulation are characteristics of neurodegenerative diseases such as Alzheimer (AD), Parkinson (PD) and amyotrophic lateral sclerosis (ALS). In particular, PD is characterized by iron accumulation-associated death of SNpc neurons. In this work, we
tested the putative neuritogenic capacity of the iron chelators deferoxamine (DFO), deferiprone (DFP)
and dipyridyl (DPD), determined after treatment of cultured mesencephalic dopaminergic neurons
with the neurodegenerative drug MPP+, the active metabolite of MPTP (1- methyl-4-phenyl-1,2,3,6tetrahydropyridine). We also tested the regeneration of the nigra-striatum fibers in mice after MPTP
intoxication. We found that the three chelators presented potent neuritogenic activity as determined
by tyrosine hydroxylase (TH) labeling. Moreover, chelator treatments regenerated synaptic activity as
determined by synaptophisin labeling. M30 is a brain blood barrier (BBB)-permeable bifunctional iron
chelator with neuroprotective activity in experimental models of AD, PD and ALS. Here, we evaluated
the putative neuroregenerative capacity of M30 in the recovery of the dendritic tree of mice intoxicated
with MPTP. We found that M30, given orally for 14 days after MPTP treatment, induced the recovery
of fibers in the nigro-striatal axis as determined by TH labeling. We conclude that BBB-permeant iron
chelators are possible therapeutic agents for the treatment of PD, AD and other neurodegenerative
diseases. This work was supported by FONDECYT grant 1100599 and grant from the Programa de
Investigación Asociativa from CONICYT, Chile.
5.4.1
CEREBELLUM AND SEXUAL BEHAVIOR: WHAT’S THE RELATIONSHIP?
5.4.2
CAN SLEEP LOSS AFFECT SEXUAL BEHAVIOR?
MANZO J. Centro de Investigaciones Cerebrales and Facultad de Medicina, Universidad Veracruzana,
Xalapa, Ver., México
ANDERSEN ML, ALVARENGA TA AND TUFIK S. Universidade Federal de Sao Paulo, Sao Paulo, Brazil; Dept.
Psicobiologia
The highly stereotyped organization of neurons and circuits at the cerebellar cortex seems to have just
one aim: the control of Purkinje neurons that constitute the only output of the cerebellum. In turn, the
purpose of this output is the control of fine movements and the regulation of time in the execution of
such movements. In a behavioral context, the sexual behavior is a complex of postures and movements
that have been under study for a long time. However, a topic poorly studied is the relationship of the
cerebellum as a foundation neural center for the control of sexual movements. By analyzing the cerebellum of male rats during non-contact stimulation or the execution of consecutive ejaculations, we
showed that the cerebellum has a biphasic response by activating granule cells in response to sensory
stimulation, and inhibiting them following behavioral execution. Also, we showed that the cerebellum
is involved in the learning ofthe skills needed for appropriate behavioral displays during copulation.
Thus, in addition to all the brain nuclei that classically have been related to copulation, the role of the
cerebellum for the appropriate execution of sexual behavior is significant. Furthermore, the relationship of sexual behavior and cerebellum seem to be an appropriate model to study the cerebellar basis
of motor learning. The learning and execution of sexual behavior have also an impact on the level of
androgen receptors expressed by shallow Purkinje neurons, suggesting that the cerebellum has also an
endocrine role during sexual behavior.
Reduced amount of sleep has become prevalent in modern society and can lead to various functional
effects. These impairments significantly impact the endocrine system, and cause changes in sexual
behavior, which can affect reproductive function. In sleep research using rodents, it is common to use
an experimental model called paradoxical sleep deprivation (PSD). This model is based on a platform
technique and involves numerous awakenings, which predominantly affect the paradoxical stage of
sleep. Hence, the PSD model mimics sleep fragmentation due to repeated awakenings, a useful tool in
investigating the effects of sleep loss on sleep patterns. Interestingly, PSD induces a marked increase
in the frequency of spontaneous genital reflexes (erection and ejaculation) in rats. Although erection
and ejaculation are representatives of fundamental behavior towards sexual engagement, these two responses do not define sexual behavior per se. In order to comprehensively assess sexual behavior, one
must scrutinize other motivational behaviors expressed as performance in the number of mounts, intromissions and ejaculation. For instance, PSD reduced sexual performance in male rats, as evidenced
by an increase in latency of intromission initiation and a reduction in the number of intromissions
when compared to a control group. These findings indicate that PSD interferes with several regulatory
mechanisms of male sexual behavior. In addition to altering sexual behavior, PSD has also been found
to influence sex hormones. Our group has reported that PSD decreased testosterone and estradiol concentrations as well as increased those of progesterone and glucocorticoids. With strong evidence from
numerous studies, sleep deprivation has been shown to promote behavioral and hormonal alterations,
leading to marked changes in sexual behavior.
POSTERS
MONDAY NOVEMBER 5
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Addiction
Anatomy and Comparative Neuroanatomy
Behavior: Learning and Memory
Behavior: Sexual and Maternal
Biological Rhythms and Sleep
Cardiovascular Physiology
Circuits, Synapses and Plasticity
Clinical
Cognitive Functions
Damage, Regeneration, Neuroprotection and Recovery
Development
Educational
Endocrinology, Neuroendocrinology, Neuroimmunology
Epilepsy
Gene and Protein Expression
Ion Channels and Biophysics
Metabolism, Nutrition and Food
Methods, Novel Technologies, Models
Muscle
Neurodegenerative and Psychiatric Disorders
Pharmacology
Receptors
Sensory Systems
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MO001
CONSEQUENCES OF CHRONIC MATERNAL SEPARATION
AND ALCOHOL INTAKE ON ADOLESCENT RATS
ODEON MM(1), ANDREU M(2), YAMAUCHI L(2), GROSMAN M(2), ACOSTA GB(1), (1)
Institute of Pharmacological Research (ININFA), National Research Council of Argentina (CONICET)-Univ. of Buenos Aires;(2) Laboratorio Bioquímica Médica SRL Buenos
Aires, Argentina.
MO002
LOCOMOTOR SENSITIZATION PROPERTY OF COCA-PASTE
SEIZED SAMPLES: INVOLVEMENT OF COCAINE AND
CAFFEINE AS ITS MAIN COMPONENTS
PRIETO JP(1), MEIKLE MN(1), LÓPEZ-HILL X(1), GALVALISI M(1), URBANAVICIUS J(1),
ABÍN-CARRIQUIRY JA(2), and SCORZA C(1), (1)Laboratory of Cell Biology and (2) Department of Neurochemistry, IIBCE, Montevideo, Uruguay.
Adverse events early in life have been linked with a maladaptive stress response in
adulthood that can predispose individuals to psychiatric and physiological disorders when they become adults. Glutamate (Glu) in the central nervous system (CNS)
may contribute to the prevention of excitotoxic neurodegeneration. Extracellular Glu
concentrations are regulated by glia cells and neuronal transporters proteins. We
evaluated the consequences of chronic early life manipulations on alcohol intake
and glutamate transporters (GluT) on adolescent rats. In chronic maternal separation (CMS), the pups were separated from their mothers and exposed to cold stress
for 1 h during 20 days. Then animals were exposed to a voluntary ethanol intake
for 7 days. We measured Glu uptake using time course and kinetic parameters on
synaptosomes isolated from frontal cortex (FC) and hippocampus (Hic). Along with
immunoblotting we showed detectable levels of the transporters subtypes: EAAC1
and GLT-1 in different treatments. Besides, we evaluated the plasmatic levels of
corticosterone, catecholamines and transaminases. These results suggest that an
exposure to CMS increases the alcohol intake, modify GluT activity and affect the
hormones in hypothalamicpituitaryadrenal (HPA) axis, which could be relevant to
the function of GluT in the adult rat brain. Again, the importance of early experience
on the drug cosumption and GluT functioning becomes evident.
Coca-paste (CP) is a drug of abuse widely consumed throughout South America above
all in vulnerable populations. It contains cocaine (base) and impurities since it is an
intermediate product of the cocaine alkaloid extraction process from coca leaves. CP
is adulterated when it reaches the consumers. Because of its great abuse liability, it is
extremely important understand the factors involved in it. We have previously demonstrated that cocaine and caffeine (adulterant) are the main components which underlie
the acute stimulant effect of CP seized samples; however their roles after a CP repeated
administration have not been studied so far. Locomotor sensitization (LS) is a useful behavioral paradigm involved in the development and persistence of addiction. Similarly
to what was determined for acute treatment, the involvement of cocaine and caffeine in
the CPinduced LS was also investigated. LS was assessed in male rats over 5 days after
CP injection at an equivalent dose of 10 mg/kg of cocaine or vehicle in comparison with
that induced by cocaine (10 mg/kg). In other series of experiments, LS was evaluated
during 3 days of cocaine treatment or the co-administration of cocaine plus caffeine
(injected at the same proportions usually found in CP seized samples). For both experiments, after 5 withdrawal days a challenge with each treatment was done. Locomotor
activity was automatically measured in an Open Field test by Ethovision video-tracking
software. CP induced sensitization and it was similar to cocaine. Moreover, although
a 3 days cocaine treatment was not enough to elicit the expression of sensitization, a
specific combination of cocaine plus caffeine was. These results demonstrated the role
of cocaine in CP-induced LS but additionally highlight the contribution of caffeine in
the expression of LS since the adulteration with caffeine could be able to accelerate the
multiple neuroadaptations implicated in addictive-related behavior.
MO003
TOLUENE EFFECTS IN PSYCHOTIC-RELATED BEHAVIORS
AND BRAIN DOPAMINE CONCENTRATIONS IN RATS
MO004
BLOCKADE OF NITRIC OXIDE SYNTHESIS IN THE DORSAL RAPHE NUCLEUS
ATTENUATES ETHANOLINDUCED EFFECTS OF ABSTINENCE
RIVERA-GARCÍA MT (1), LÓPEZ-RUBALCAVA C(1), CRUZ SL(1), Departamento de Farmacobiología, Cinvestav Sur, IPN, México, DF.
GONZAGA; NA¹; TIRAPELLI, CR²; PADOVAN, CM³
¹Dept. of Pharmacology, Faculty of Medicine of Ribeirao Preto - FMRP-USP, ²Dept. of
Psychiatric Nursing and Human Sciences School of Nursing of Ribeirão Preto - EERPUSP. ³ Dept. of Psychology, Faculty of Philosophy, Sciences and Letters of Ribeirão
Preto - FFCLRP-USP, Sao Paulo, Brazil.
Toluene-based products are intentionally misused by inhalation for recreational purposes.
It has been described that high toluene concentrations can produce illusions and hallucinations; however, the mechanism involved in these effects is not well understood.Toluene has
a complex mechanism of action, which includes non-competitive NMDA receptor antagonism
in the CNS. Toluene also increases brain dopamine levels, but concentration-dependent studies in specific brain regions involved in hallucinations are still lacking. It is well know that
several NMDA receptor antagonists can induce positive and negative symptoms of schizophrenia, which is the most common form of psychosis. On the other hand, the dopaminergic
hypothesis of schizophrenia supposes that abnormalities in this system are involved in the
genesis of this disorder. The main objective of this work was twofold: a) to evaluate if toluene
could increase dopamine concentration in the brain prefrontal cortex, striatum and hippocampus; and b) to analyze if toluene inhalation could alter performance in social interaction
and prepulse inhibition tests. For this purpose, independent groups of male Wistar rats were
exposed to toluene (500-8000 ppm) for 15 min, in a static exposure chamber. Immediately
after completing exposure time, rats’ brains were removed and dopamine levels were measured by high-performance liquid chromatography (HPLC). Our results show that toluene
increases dopamine levels in prefrontal cortex and striatum, but not in hippocampus. For
behavioral evaluations, independent groups of animals were exposed to toluene (500-8000
ppm) for 30 min and social interaction or startle response to an auditory stimulus were registered. Our results indicate that toluene decreases social interaction and prepulse-induced
inhibition in a concentration-dependent manner. In conclusion, toluene induces behaviors
that are considered similar to the positive and negative symptoms of schizophrenia. These
effects are probably related with alteration in dopaminergic neurotransmission.
Chronic consumption of ethanol (EtOH) and abstinence to it has been associated to
disorders such as anxiety and depression. Nitric Oxide (NO) has been implicated in
the behavioural effects of abstinence to ethanol. Non-specific blockade of Nitric Oxide Synthetase (NOS) or in the Dorsal Raphe Nucleus (DRN) attenuated these effects.
Thus, the aim of this study was to investigate if nNOS is involved in the anxiogenic
effects induced by abstinence to chronic ethanol evaluated using the Elevated Plus
Maze (EPM) Test. Male Wistar rats with guided cannulas aimed at the DRN received
an injection of NPLA (nNOS inhibitor, 1, 3 or 10 nmoles/0,2μl) or saline (0,2μl) in
order to determine a non-effective dosage of this drug on basal levels of anxiety. Five
minutes later were tested in the EPM. Data showed that while 3 nmoles increased
exploratory activity in the EPM, 1 or 10 nmoles did not. On a second protocol rats
were submitted to water or ethanol chronic (21 days) or acute (1 day) treatment. 48
hours after discontinuation of ethanol consumption, rats received an intracerebral
treatment with NPLA (nNOS inhibitor, 10nmoles/0,2μl) or saline (0,2μl) and five
minutes later rats were tested in the EPM. The results showed that NPLA treatment attenuated abstinence-induced decrease in open arms exploration in chronic
ethanol-treated rats, as revealed by a slight increase in the number of entries, but
not time spent, in the open arms. No behavioural changes were detected after abstinence to acute treatment with ethanol. Although further experiments are necessary to increase the number of animals per group, it seems that anxiogenic effects
induced by abstinence to chronic ethanol involve increases in NO formation through
activation of the neuronial isoform of NOS. CAPES, CNPq e FAPESP.
Mo005
MILD AND SEVERE PERINATAL ASPHYXIA INDUCE
OPPOSITE EFFECTS ON COCAINE SENSITIZATION IN ADULT RATS
GALEANO P(1), BLANCO-CALVO E(2,3), BISAGNO V(4), ROMERO JI(1), HOLUBIEC MI(1), SARACENO GE(1),
LUQUE-ROJAS MJ(2), RODRÍGUEZ DE FONSECA F(3), and CAPANI F(1), (1)Instituto de Investigaciones
“Prof. Dr. Alberto C. Taquini”, Facultad de Medicina, UBA-CONICET, Buenos Aires, Argentina. (2)Departamento de Psicobiología y Metodología de las Ciencias del Comportamiento, Facultad de Psicología,
Universidad de Málaga, Málaga, Spain. (3)Laboratorio de Medicina Regenerativa, Fundación IMABIS,
Málaga, Spain. (4)Instituto de Investigaciones Farmacológicas (ININFA), UBA-CONICET, Buenos Aires,
Argentina.
Perinatal asphyxia (PA) is an obstetric complication that has been associated with an increased risk
to develop dopamine-related disorders, such as attention deficit hyperactivity disorder (ADHD) and
schizophrenia. Dysregulation of dopaminergic transmission is one of the long-lasting consequences
of PA in the central nervous system. Since the dopaminergic system plays a major role in addiction
processes, we hypothesized that PA could be associated with an increased vulnerability to psychostimulant addiction, particularly cocaine addiction. In the present work, we studied the behavioral
sensitization to cocaine in adult rats that had undergone 15 min (mild) or 19 min (severe) of birth asphyxia. In addition, changes in the expression of tyrosine hydroxylase (TH) in the dorsal striatum were
measured. Experimental subjects consisted of rats born vaginally (CTL), by caesarean section (C+),
or by caesarean section followed by 15 min (PA15) or 19 min (PA19) of asphyxia. At three months of
age, cocaine-induced behavioral sensitization was evaluated and TH levels in the dorsal striatum were
determined by Western Blot analysis. During five consecutive days, all groups increased their locomotor activity in response to daily cocaine injections (15 mg/kg) (conditioning phase). Seven days later,
CTL and C+ rats displayed a robust locomotor sensitization to an acute priming dose of cocaine (7.5
mg/kg). However, the acute priming injection of cocaine elicited an attenuated sensitized response in
PA19 rats, while PA15 rats displayed an exacerbated sensitized response. Expression of TH in dorsal
striatum was significantly higher in PA15 rats compared to all other groups. These results demonstrate
that birth asphyxia induces opposite effects on behavioral sensitization to cocaine depending on its
severity. In addition, this data suggest that the increased TH levels in the dorsal striatum of PA15 rats
could be associated with the displayed hypersensitized response. Supported by CONICET, University of
Buenos Aires and grant PCI-A/023328/09.
MO006
MC4-R SIGNALING IN THE NUCLEUS ACCUMBENS MODULATES ETHANOL
PALATABILITY. INFUSION OF A SELECTIVE MC4-R AGONIST INTO THE
NUCLEUS ACCUMBENS ALTERS ETHANOL PALATABILITY IN RATS
Lerma-Cabrera JM(1), Carvajal F(1), Chotro G(2), Gaztañaga M (2), Navarro M(3),
Thiele TE(3) and Cubero I(1). (1)Depto. de Neurociencia y Ciencias de la Salud, Univ.
de Almería, Almería, España; (2)Depto. de Procesos Psicológicos Básicos y su Desarrollo, Universidad del País Vasco, Guipúzcoa, España and (3) Dept. of Psychology,
University of North Carolina at Chapel Hill, North Caroline, United States.
The Melanocortin (MC) system is one of the crucial neuropeptidergic systems modulating energy balance. The role of endogenous MC and MC4-R signalling within the
hypothalamus in the control of homeostatic aspects of feeding, food selection and
body weight is well established. Recently, it has been proposed that MC signaling
regulates nonhomeostatic aspects of feeding within limbic circuits. The central MC
plays a key role in ethanol consumption. Our previous studies have shown that NAc/
VTA-infusion, but not on lateral hypothalamus, of a selective MC4-R agonist decreases ethanol consumption. We assessed whether MC4-R signaling in the nucleus
accumbens (NAc) alter normal ingestive hedonic and/or aversive responses to ethanol in rats as measured by a taste reactivity test. Adult male Sprague-Dawley rats
received 24-h, unlimited access to ethanol (6% w/v) for 1 month. Then, rats were
given bilateral NAc-infusion of the selective MC4-R agonist cyclo (NH-CH2-CH2-COHis-D-Phe-Arg-Trp-Glu)-NH2 (0, 0.75 or 1.5 μg/0.5μl/site) and following 30 min,
the animals received 1 ml of ethanol solution (6% w/v) for 1 minute in which aversive and hedonic behaviours were recorded. We report here that NAc-administration
of a selective MC4-R agonist decreased total duration of hedonic reactions and
significantly increased aversive reactions relative to responses in saline-infused
animals. Present data support that MC signaling within the NAc may contribute
to ethanol consumption by modulating non-homeostatic aspects (palatability) of
intake.
MO007
EFFECT OF RIGHT HEMIOVARIECTOMY IN MORPHOLOGY
OF CA1 AND CA3 NEURONS
MO008
EVIDENCE FOR THE INVOLVEMENT OF SARA IN NEURONAL POLARIZATION AND CORTICAL LAYER LAMINATION
Bravo-Durán DA, Silva-Gómez AB
Lab. Neurofisiología experimental, Escuela de Biología, BUAP, Puebla, Mexico
MESTRES IVAN(1), ARIAS CRISTINA(1), SUNG CHING-HWA(2), CACERES ALFREDO(1) and CONDE CECILIA(1),
(1) Instituto Mercedes y Martin Ferreyra (INIMEC CONICET). Cordoba, Argentina. (2) Cornell Medical
College, NYC,U.S.A.
Recent evidence of hemiovariectomized rats suggest that sensorial innervation have an important role
in the biosynthesis of steroids which is different between ovaries. On the other hand, estradiol produce
changes in the size of dendritic trees of hypothalamic nuclei and also have an important activity in
pyramidal cells of hippocampus, because a depletion of estradiol after an ovariectomy promote a
decrease in spine density. The aim of the present study was evaluate the neuronal morphology of
righ and left hippocampus after a right hemiovariectomy. Twelve adult female rats of CIIZ-V strain
(180±20g) with at least three regular estrous cycle monitored by cytological examination of daily
vaginal smears were used. All rats were housed in light-dark cycle (12:12 h) with access to food
and water ad libitum. Six rats were anesthetized; laparotomized and right ovary was extirped. After
hemiovariectomy, the estrous cycle was monitored and after presenting three consecutive 4-d cycles,
the animals were sacrificed. The six remaining rats were used with sham surgical treatment. The brains
were collected and processed by Golgi-Cox method. Twenty neurons of right hippocampus (CA1=10,
CA3=10) and twenty of left hippocampus were drawn with camera lucida. Total dendritic length and
dendritic spine density was calculated. Right hemiovariectomy causes in both left hemisphere and in
the right hemisphere a decrease in apical and basolateral dendritic length of CA1 and CA3 neurons.
With regard to dendritic spines all the trees analyzed, except apical dendritic tree of CA3 neurons of
right hippocampus, showed a decrease in spine dendritic density. These results support previous data
about neural connections between ovaries and the central nervous system (SNC). Considering that ovaries have different connections with SNC we are analyzing results related with left hemiovariectomy too.
SARA (Smad anchor for receptor activation) localizes to early endosomes (EE) where it regulates their
morphology and function. We now show that in cultured rat hippocampal pyramidal neurons SARA overexpression generates unusual large EE and reduces neurite outgrowth. By contrast, SARA suppression
with short hairpin (sh) RNAi gave rise to a large rab11 positive compartment, as well as long axons
with large growth cones. In situ electroporation of mouse embryonic brains also suggests a pivotal role
for SARA in neuronal development. Three days after electroporation, control Hc-Red neurons started
migration through the cortical plate showing proper pia-directed orientation. By contrast, neurons expressing Hc-Red-sh-SARA failed to migrate as expected, acquiring a horizontal orientation. Quantitative
analysis reveals that 90% of these neurons lack vertical orientation, being tilted with angles ranging
from 0 to 45 degrees. A similar analysis at a later time point after electroporation (5 days) revealed
that SARA-suppressed neurons remained in deep cortical layers, and failed to reach superficial ones.
3D cell reconstructions showed that while control neurons extend appropriately polarized leading and
trailing edges, Hc-Redsh- SARA expressing cells exhibit a single longer and curved leading process but
lack a typical trailing extension; besides, many of them are completely inverted. Together, our results
suggest a major contribution of SARA to key aspects of neuronal development, including migration,
polarized growth and neurite formation. It is likely that some of these functions could be related with
a role of SARA as a regulator of endosomal trafficking. Supported by ANPCyT and CONICET to AC and CC
MOO009
HOW MANY NEURONS CAN YOU AFFORD? METABOLIC LIMITATIONS
IMPOSE TRADE-OFF BETWEEN NUMBER OF BRAIN NEURONS AND
BODY SIZE IN HUMAN AND NON-HUMAN PRIMATE EVOLUTION
MO010
EFFECTS OF MRNA SYNTHESIS INHIBITION IN THE DORSAL
HIPPOCAMPUS ON MEMORY CONSOLIDATION OF ENHANCED
INHIBITORY AVOIDANCE
Fonseca-Azevedo K(1), Herculano-Houzel S(1), (1) Federal University of Rio de Janeiro, Rio de Janeiro,
Brazil.
Torres-García ME, Medina AC, Quirarte GL, Prado-Alcalá RA Departamento de Neurobiología Conductual
y Cognitiva, Instituto de Neurobiología, UNAM, Querétaro, México.
The human brain is outstanding in its number of neurons, which is close to 3 times larger than in
gorillas and orangutans. But we are not outstanding primates in body size: gorillas can grow to be 3
times larger than humans.
Here we examine the possibility that brain and body mass expansion in primate evolution have been
subjected to metabolic constraints. Both larger bodies and larger brains require more energy for their
maintenance, the first varying with body mass raised to an exponent of 0.75, the latter varying linearly
at an average cost of 6x10-9 kcal per neuron. Here we estimate how caloric intake scales with body
mass (MBD) and use this estimate to calculate how many hours of feeding on raw foods would be
required to afford increasing both MBD and the number of brain neurons (NBN). Using a model scaling
energetic intake and expenditure with increasing MBD and NBN, we demonstrate that feeding exclusively on a raw diet makes metabolism a limiting factor in primate evolution. Thus, larger NBN come at
a cost of either longer feeding times, smaller MBD, or a combination of both. For instance, a primate
that fed the maximum of 12 hours/day could afford a brain of at most 139 billion neurons, but in that
case it could weigh no more than 68 kg; if it fed 10 hours/day, it could afford a brain of no more than
81 billion neurons, but a body no larger than 33 kg. It is interesting to consider that the expansion in
the NBN in human evolution may have been afforded by the advent of cooking, which both increases
their caloric yield and decreases the amount of time required for feeding. Without cooking, primate
body mass and number of brain neurons seem to be severely constrained.
Memory consolidation is the process by which newly learned information is stabilized into long-term
memory. The finding that interference with transcription in cerebral structures that are involved in
memory consolidation, such as the dorsal hippocampus (DH), produces memory deficiencies, has led
to the suggestion that this process requires de novo mRNA synthesis. On the other hand, it has been
demonstrated over-training protects against the amnesic effects of several treatments that interfere
with cerebral activity, including protein synthesis inhibitors. The objective of the present work was
to determine whether enhanced inhibitory avoidance (IA) training also has a protective effect in rats
treated with the mRNA synthesis blocker 5,6-dichloro-1-”beta” -d-ribofuranosyl benzimidazole (DRB)
in the DH. Independent groups of rats were trained in IA using two different intensities of foot-shock
(1.0 and 2. 0mA). DRB (80 ng/0.5 μL) or its vehicle, dimetil sulfoxide (DMSO), was administered
bilaterally 15 min before the training session. Forty-eight hours later, their retention latencies were
measured. Our results showed that pre-training DRB administration produced amnesia in the 1.0 group
while no alterations in memory consolidation were produced the group that had been trained with 2.0
mA. These data suggest that in an enhanced learning of an IA training (high footshock group) mRNA
synthesis is not required for memory consolidation at least in DH. We thank Norma Serafin, Angel
Mendez, Leonor Casanova, Lourdes Ayala, and Martín Garcia for their important contributions to this
work. Supported by CONACYT (Grant 128259) and PAPIIT (IN201712).
MO011
DEVELOPMENT OF A NOVEL TASTE-DISCRIMINATION
TASK TO STUDY GUSTATORY WORKING MEMORY
MO012
CHRONIC EXPOSURE TO MERCURY CHLORIDE FOR 60 DAYS CAUSES
OBJECT RECOGNITION AND AVERSIVE MEMORIES DEFICITS IN RATS
Miguel A. Villavicencio, Isaac O. Perez & R. Gutierrez, CINVESTAV-IPN, Laboratory of Neurobiology of
Appetite; Department of Pharmacology, Mexico.
ALVES N(1), BARROS WM(1), MENEZES J(1), BORGES S(1), RIZZETTI D(1), WIGGERS GA(1), PEÇANHA FM(1),
VASSALO D(2), MELLO-CARPES PB(1), (1) Grupo de Pesquisa em Fisiologia, Federal University of Pampa,
Uruguaiana, RS, Brazil; (2) Universidade Federal, do Espírito Santo.
The neural correlate of somatosensory, spatial and visual working memory has been extensively studied
in rodents and non-human primates. However, no behavioral model to study gustatory working memory
(GWM) in rodents has been reported. Here, we exploited the natural rhythmic licking behavior of the
rats to design a novel Gustatory Delay-Match to Sample (GDMS) task, in which to solve it, rats would
necessarily evoke a GWM trace. In this paradigm, rats are required to lick an empty sipper (dry licks) in
a central-port from where they receive in sequence two gustatory cues (T1 and then T2; e.g., a drop of
umami or NaCl), separated between each other by 3 to 7 interleaved dry licks. In each trial, rats need to
use the memory trace left by the first tastant (T1), compare it against the second tastant (T2), and then
to obtain 3 drops of sucrose reward, rats need to respond to the right-port if T1 and T2 were the same
(Match trials) or to the left-port if they were different (Non-match trials), the rewarding port was counterbalanced between rats. After 3 weeks of training most rats acquired a proficiency of >85% correct
trials and a discriminative index (d’) >3. This result demonstrated for the first time that rats can use
a GWM trace evoked by a single 20 μL drop of a tastant and then make decisions in a goal-directed
manner to obtain a reward. We found that rat’s GWM was resistant to the variability of licking and the
different number of randomly interleaved empty licks between T1 and T2. In contrast, GWM was gradually impaired in a time-dependent manner, most notably when rats hold T1 in memory for more than 1
s. In summary, our task is ideal to evaluate the neural correlates of gustatory working memory in rats.
The exposure to mercuric chloride (HgCl2) can cause significant neurologic consequences, besides
its toxics effects in Nervous System. This work aims analyze the effects of chronic exposure to HgCl2
on recognition and aversive memories. 20 male Wistar rats were divided into 2 groups treated for 60
days: control (im, saline 0,9%) and HgCl2 (1st dose 4,4 μg/kg and subsequent 0,07 μg/kg/day). After
treatment the animals were tested in Object Recognition (OR) and Inhibitory Avoidance (IA) behavioral
paradigms. For OR test, animals are training in a open field with two different objects (A and B) for
exploration during 5 min; 24 hours after, in the tested, they had a familiar object (A) and a new (C).
During each session was recorded the exploration time of each object. For IA test, animals were training putting them in a platform inside a box which floor was made by an electrifiable grid, measuring
the latency time to step down. The results of OR were analyzed by Student’s t test for mean of a sample
(theoretical average 50%) and of IA by Wilcoxon and Mann-Witney. To control we used Elevated Plus
Maze and Open Field, to verify the anxiety, locomotor and exploratory activity. We verify that the rats
treated with mercury explored equally the two objects in the test session, while the control rats explored significantly more time the new object (the control group spent 62.33±4,9% of total exploration time and the HgCl2 group 53.7±7.9% exploring the object C), indicating that only the control rats
recognized this object as new. In IA test all animals can learn; the step down latency increased when
we compare training x test in control (3.93±0.81; 300±28.06) and treated animals (5.91±0.92;
49.28±46.53), but we found differences between test latencies (P=0.0327). Treatment with HgCl2
affects the recognition and aversive memory consolidation.
MO013
COMPARISON OF THE EXPRESSION OF TWO IMMEDIATE EARLY GENE
PROTEINS, FOSB AND FOS IN THE RAT HIPPOCAMPAL FORMATION
AFTER TRAINING OR OVERTRAINING OF A SPATIAL MEMORY TASK
MO014
CHRONIC CONSUMPTION EFFECTS OF SWEET TASTES WITH
DIFFERENT CALORIC CONTENT ON TASTE PREFERENCE AND
AVERSIVE TASTE RE-LEARNING
LAMPREA MR(1), TRONCOSO J(2), LAMPREA N(3), CERON-GONZÁLEZ J(1),MÚNERA A(4), GARCIA-BECERRA,
AM(5), ORTEGA S(1). (1)Univ. Nacional de Colombia, Dept. of Psychology; (2) Univ. Nacional de Colombia, Dept. of Biology; (3) Univ. Nacional de Colombia, Neuroscience MSc. Program; (4) Univ. Nacional de
Colombia, Dept. of Physiology and (5)Univ. de la Sabana, Dep. of Psychology.
MIRANDA MI(1), and FREGOSO-URRUTIA DJ(1), (1)Dpto. de Neurobiología Conductual y Cognitiva, Instituto de Neurobiología, UNAM, Querétaro, Querétaro, México.
In previous experiments, we observed differential effect of acute stress or corticosterone on the recovery of a spatial memory task in rats trained or overtrained. The trained animals showed impairments
in the recovery while the overtrained rats showed no effect or better recovery. These effects suggest
a different pattern of cellular activation in the hippocampal formation during each type of training.
Inducible transcription factors (ITFs) are activity dependant proteins that regulate protein production.
One member of the activator protein-1 family of ITFs, c-Fos, has been extensively used as an indicator
of synaptic activation in the nervous system after learning and memory tasks. Since different ITFs
have different levels of constitutive expression and time courses of expression, determining the time
course of ITF expression following training or overtraining could be useful in understand the role of the
hippocampus in the differential effects of stress described above. This study investigated the Fos and
FosB immunoreactivity in three regions of hippocampal formation [CA1, CA3 and dentate gyrus (DG)]
of male Wistar rats exposed to training (one session of eight trials) or overtraining (two sessions of
eight trials) with or without a reactivation trial 24-h later. The patterns of FosB and Fos expression were
compared between the sections taken from the same animals. Quantitative immunohistochemistry
revealed a significant increase in the number of Fos-positive neurons in CA1 in animals trained without
reactivation and in CA3 in animals overtrained with or without reactivation. Significant increase in
FosB-positive neurons was observed in CA1 and CA3 after both types of learning without reactivation
and in DG in groups exposed to reactivation after training or overtraining. Taken together, the present
results suggest that FosB expression is co-involved with Fos in the neural activation during training and
overtraining and this activity is dependent of the reactivation of the task.
The preference for sweet tasting foods has been well established as they are associated with a positive
hedonic value and quick source of energy, and have different effects over the brain chemistry. As a result, palatability (e.g., hedonic value) is a crucial factor in guiding food choice and amount consumed.
Consequently, the sweet preference may lead to an excessive consumption with severe health cost,
suggesting that the consumption reduction by re-learning the new negative consequences is altered
after chronic consumption of caloric and sweet flavored foods. Also, it has been suggested that the
preference for sweeter foods does not depend only on the sweet taste but also on its nutritional value;
however, a significant increase in the consumption of sweeteners, e.g. saccharin, which have no caloric
value, has been extensively reported. Therefore regardless of the evidence, there is still little information about the food hedonic value impact, after chronic consumption, in learning and taste recognition
memory. Thus, the main goal of this study was to determine the preference differences of sweet tastes
with different caloric content (sucrose or saccharin), during chronic consumption (14 days) on adult
rats (270-310 gr) and evaluate the impact on taste relearning after aversive ingestion consequences
by conditioning taste aversion (CTA) and aversive extinction. The results demonstrated that chronic
consumption of 10% sucrose solution, as the only liquid available, induces a gradual but significant
increase in the liquid consumed daily and, although the animals ate less solid food, they showed a
significant increase in body weight. In contrast, 0.1% saccharin chronic consumption did not induce
any significant increase in liquid consumption, solid food consumption or body weight. Furthermore,
both chronic groups showed a strong latent inhibition of CTA for the same taste. Additionally, rats that
chronically consumed sucrose showed a faster extinction than rats that consumed saccharin. These
findings suggest that the caloric content of sweet tastes plays a role in the development of sweet food
preferences and differentially affects the re-learning aversive experience related to the same taste
stimulus through associative learning processes.
MO015
ENDOGENOUS MEMORY MODULATION
DURING RECONSOLIDATION PROCESSES
MO016
HOW CAN A TRAUMATIC MEMORY BE ATTENUATED? EXPLORING THE
NEUROBIOLOGY OF MEMORY DESTABILIZATION
Sierra RO(1), Cassini LF(1), de Oliveira Alvares L(1), Santana F(1), Crestani AP(1), Duran JM(1), Boos
FZ(1), Haubrich J(1), Dutra FD(1), Zanona QK(1) and Quillfeldt JA(1). Laboratório de Psicobiologia e
Neurocomputação, Departamento de Biofísica, Instituto de Biociências, Universidade Federal do Rio
Grande do Sul.
De Oliveira Alvares L, Crestani AP, Booz FZ, Dutra FD,Santana F, Haubrich J, Cassini LF,Sierra RO, Quillfeldt JA. Laboratório de Psicobiologia e Neurocomputação, Departamento de Biofísica, Instituto de
Biociências, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9500, Prédio 43422,
room 208, CEP 91.501-970, Porto Alegre, RS, Brasil.
Introduction: After retrieval, some memories enter into a labile state. To persist it must undergo another process, called reconsolidation. One functional role of memory reconsolidation is update existing
memories. Particular endogenous states concomitant with the reconsolidation could influence the
storage and future expression of memory. Here, we explored whether an endogenous process activated
during a natural/physiological experience can update the memory content. Method: Experiment 1:
Male Wistar rats were conditioned in Contextual fear conditioning on day 1. Twenty four hours later,
they were divided in two groups (with or without 24h water deprivation) and reexposed to the same
context (reactivation) for 3min on day 3. Two test sessions were performed: in the test 1 on day 4,
animals were conducted without water deprivation, and in the test 2 on day 5, animals under water
deprivation during reactivation were retested under the same conditions. Additional two experiments
were conducted to evaluate the water deprivation effects. Experiment 2: 30 min before reactivation,
animals were injected with Nimodipine (16mg/kg; S.C.) or vehicle. Experiment 3: Losartan (200μM),
PD 123319 (200μM) or vehicle were injected immediately after reactivation in dorsal hippocampus.
Results Animals under water deprivation during reactivation expressed less freezing responses than
animals without water deprivation in test 1. In test 2 no difference was verified. This response was abolished with nimodipine administration before reactivation. In the same way, the AT1 antagonist Losartan
reversed the water deprivation effects on reactivated memory. Conclusions: The water deprivation state
during reconsolidation changes pre existing endogenous information and turns a notdepending state
memory on a dependent one. Our experiments showed that this response was mediated by updating
memory content during reconsolidation. Water deprivation effects are associated with AT1 receptor
in dorsal hippocampus. In conclusion our result showed that memory can be modulated by natural/
physiological experiences that change the neurohumoral information during memory reconsolidation.
Retrieval can induce some memories to undergo a stabilization period, called reconsolidation. The
result of this plastic state is that memory can be changed after the destabilization induced by reactivation, requiring a reconsolidation process in order to persist. The mechanism of reconsolidation has
been extensively studied. However, the destabilization induced by reactivation of a previously consolidated memory is less known. In the present study, we addressed the question: how are the mechanisms
that cause a memory to be transformed from a fixed consolidated state, to a labile one? We found that
exposure time, novelty, D-cicloserine and NR2B hippocampal activation are required in some boundary
condition in order to undergo memory destabilization/reconsolidation in contextual fear conditioning
task. A better comprehension of how memory becomes labile is critical because targeting reconsolidation of traumatic memories has been proposed for many psychopathology treatments. We took advantage of these results to create a protocol where subjects were able to impair strong aversive memories
and its related commorbities in a post-traumatic stress disorder model in rats.
MO017
CONTRIBUTION OF RYANODINE RECEPTORS
ON RECOGNITION MEMORY AND AGING
Arias-Cavieres A(1), Adasme T (3), Hidalgo MC (3), and Muñoz P (2), (1) Programa de Doctorado en
Ciencias Mención Neurociencia, Universidad de Valparaíso, Valparaíso, Chile, (2) Centro Interdisciplinario de Neurociencias, Universidad de Valparaíso, Valparaíso, Chile, (3) CEMC & BNI, Facultad de
Medicina, Universidad de Chile, Santiago, Chile.
A progressive cognitive decline in recognition memory (RM) – defined as the ability to remember a previously presented object - takes place during aging. The hippocampus and perirhinal cortex (PrhC) are
considered anatomical substrates for RM. Recent evidence supports an important role of the ryanodine
receptor/calcium release channels (RyR) in hippocampal-dependent memory; however, the participation of RyR in other brain areas involved in memory or during aging is unknown. We evaluated young (3
months) or aged (18 months) rats in a task of object recognition, and we explored concomitant changes
in RyR expression. Methods: animals were habituated during three consecutive days before exposure to
four different objects during 5 min for three consecutive sessions, separated by 5 min intervals. Within
24 hours after the last session, the configuration was changed to assess both spatial or recognition
memory, repositioning two objects or replacing one familiar object by a novel object, respectively.
Six hours after concluding the behavioral test qRT- PCR analysis of hippocampal extracts isolated
from rats was performed. Results: We found that young and aged rats spent more time exploring the
novel object when tested 24 hours after the last session. Conversely, both groups displayed significant
differences when exploring repositioned objects. Additionally, we found in young rats that the mRNA
levels of the RyR2/RyR3 isoforms increased in the hippocampus but not in the PrhC, after object
recognition. Our data suggest that the hippocampus has a greater susceptibility to the aging process
than PrhC and that the increased RyR2/RyR3 mRNA expression in the hippocampus may be required
for recognition memory.
MO019
COMPARISON OF VISUOMOTOR KINETICS AND KINEMATIC
COMPONENTS, IN A COMBINED AND SEQUENTIAL LEARNING TASK
Burgos Pablo(1,2), Mariman Juan (1,2), Maldonado Pedro (1,2), 1. Program of Physiology and Biophysics, Faculty of Medicine, Universidad de Chile, Santiago, Chile 2. Centro de Neurociencias de la
Memoria (Cenem), Iniciativa Científica Milenio
Humans can learn to perform motor movements that contain both kinematic and kinetic components.
Are these movements best acquired separately, or combined in a single task? Using a computer and
an analog gamepad, 12 people learn a continuous visuomotor task (video game), which require manipulating an object without colliding, while destroy static and moving targets. People learn either
kinematic movement; a cursor, rotated 90°CW respect to normal movement, or learned a kinetics
adaptation (high elastic resistance) for shooting. One group (n = 6) practice 5 days in a game that
combine both movements (Whole) while another group (n = 6) practice a game that sequentially
contained only kinematic or kinetic movements (Parts). All subjects were evaluated the first and the
last day in training. We recorded the cursor location and the eye movements with an EyeLink II system.
We found that performance increased with practice, in both groups, measured as the number of hits
and distance advance in the game. However, the combined movement group showed better performance. We found a decrement in the duration of fixations, without changes in the number of fixations,
in both groups. Furthermore, we found a decrement in duration and distance of saccades and no
changes in speed and number of saccades, in both groups. In the analysis of the average distance
between the cursor and gaze position during the ejection of the game, we found an incremented for the
combined group versus a decrement in the sequential group. Our results demonstrate that while there
is little difference in the gaze performance between learning this task sequentially or in a combined
form, the dynamics of eye-hand movement coordination show differences in the way these motor tasks
are learnt. Supported by Iniciativa Cientifica Milenio (CENEM)
MO018
SPATIAL MEMORY MODIFICATIONS INDUCED BY ACUTE STRESS
ARE ASSOCIATED TO CHANGES IN ERK1/2, PP1, AND PP2B
ACTIVITY IN THE HIPPOCAMPUS
ORTIZ P(1), VERNOT JP(1), LAMPREA MR(2, 3), MÚNERA A(1, 3), (1) Physiological Sciences Department,
School of Medicine, Universidad Nacional de Colombia, Bogotá, Colombia; (2) Psychology Department,
School of Human Sciences, Universidad Nacional de Colombia, Bogotá, Colombia; (3)Behavioral Neurophysiology Laboratory, Universidad Nacional de Colombia, Bogotá, Colombia.
It has been extensively reported that acute stress either impairs or enhances memory processes according not only to the type of memory task being evaluated, but also to the timing and intensity of
the stress response. The hippocampus, which plays a central role in declarative memory, is peculiarly
sensitive to the effects of acute stress. In addition, it has been demonstrated that both acute stress
and memory processes modify the expression and activity of kinases and phospatases in the brain.
However, there is scarse evidence respecting how acute stress and memory processes interact on the
regulation of protein phosporilation in the brain. We therefore explored the interaction between training
in a spatial task and acute stress on spatial memory and the activity of ERK1/2, PP1, and PP2B in the
hippocampus. Acute stress alone increased the activity of ERK1/2, PP1, and PP2B in the hippocampus.
A single eigth-trial training session in the Barnes maze also induced increased activity of ERK1/2,
PP1, and PP2B; however, ERK1/2 and PP2B activity were higher after training than after acute stress,
while PP1 activity was lower after training than after acute stress. In contrast, when acute stress was
induced before a single training session in the Barnes maze, the learing-related changes in ERK1/2,
PP1, and PP2B activity in the hippocampus were either partially (ERK1/2) or completely blocked (PP1,
and PP2B). Animals submitted to acute stress before spatial training not only acquired the task at a
slower pace than controls, but also displayed impaired retrieval of the task when evaluated 24 hours
after training. These results indicate that acute stress-induced interference in activation of hippocampal ERK1/2, PP1, and PP2B after training in Barnes maze may explain, at least partially, the observed
impairments in spatial memory acquisition and retrieval.
MO020
SYNERGISTIC INTERACTION BETWEEN SEROTONIN
AND OPIOIDS IN THE DORSAL PERIAQUEDUCTAL GRAY
ASSESSED IN THE ELEVATED T-MAZE
Camila Maroni Roncon, Carla Biesdorf de Almeida, Helio Zangrossi Junior, Frederico Guilherme Graeff,
Elisabeth Aparecida Audi
Previous results showed that the anti-escape effect of serotonin (5-HT) in the elevated T-maze (ETM) is
antagonized by naloxone, and that the anti-escape effect of morphine is blocked by a 5-HT1A-receptor
antagonist. To further explore the 5-HT-opoid interaction, this study investigated the association of
sub-effective doses 5-HT and morphine administered intra-DPAG in rats submitted to the ETM. The
ETM is a model of anxiety that evokes two defensive responses in the same rat, namely inhibitory
avoidance and one-way escape, related to generalized anxiety and panic disorder, respectively. Male
Wistar rats (UEM Ethics Committee 024/2010) were microinjected (0.5 _L) with 5-HT (2 _g) or saline
5 min before microinjection of morphine (0.3 _g) or saline. The following groups were formed: saline/
saline (n=7), 5-HT/saline (n=5), saline/morphine (n=5), 5-HT/morphine (n=6). Rats were submitted to the ETM test, 10 min after the last injection. Locomotion was assessed in an open field, as
control for nonspecific motor effects. Repeated-measures analysis of variance (RMANOVA) was used
to analyze both avoidance and escape data. Locomotion data were analyzed by one-way ANOVA. When
appropri¬ate, the Fisher post-hoc test was used. Significance level was set at p < 0.05. RMANOVA
showed a significant main effect of treatment [F(1,19) = 12.68; p < 0.01] and pre-treatment X
treatment [F(1,19) = 4.79; p < 0.05]. Post-hoc comparisons showed that sub-effective doses of
5-HT + morphine significantly increased the escape latency compared to the compared to control at
escape 1 and 3 (p < 0.01). These results indicate that 5-HT and opioids act synergistically on neurons
controlling escape (panic) in the DPAG.
MO021
THE ANGIOTENSIN(1-7)/MAS RECEPTOR/NITRIC OXIDE AXIS
MODULATES EPISODIC-LIKE MEMORY
MO022
DISTINCT TRACES FOR APPETITIVE VERSUS AVERSIVE
OLFACTORY MEMORIES IN DPM NEURONS OF DROSOPHILA
LAZARONI TLN (1), SANTOS RAS (2, 3), BADER M (2), PEREIRA GSP (1), (1) Universidade Federal de Minas
Gerais, Núcleo de Neurociências,Belo Horizonte, Brazil; (2) Universidade Federal de Minas Gerais,
Laboratorio de Hipertensao Bioquímica,Belo Horizonte, Brazil; (3) Max Delbruck Center of Molecular
Medicine, Berlin, Germany
CERVANTES-SANDOVAL I and DAVIS R.L. Department of Neuroscience, The Scripps Research Institute,
Jupiter FL, USA.
Aim: Our previous data showed object recognition memory deficit in mice with genetic deletion of Mas
(MasKo), the endogenous receptor of Angiotensin-(1-7). The deficit was reversed by the injection of
losartan, which suggest that the MasKo memory impairment is dependent of AT1 activation. Both Mas
and AT1 activation modulates the postsynaptic intracellular levels of NO (nitric oxide). Furthermore,
NO is an important neuromodulator of object recognition memory in the hippocampus. Thus, our working hypothesis is that the memory impairment of MasKo is due to a hippocampal nitrergic system
downregulation. Methods and Results: The nitrite concentration in the whole and CA1 region of the
hippocampus and cortex of FVB/N and MasKo mice was measured by the Griess’s method. MasKo
exhibited a lower quantity of nitrite in the whole hippocampus compared to FVB/N. Next, through the
implantation of bilateral cannulae in the hippocampus, we administered SNAP (NO donor) to MasKo
and L-NAME (NOS inhibitor) to FVB/N, immediately after training in the object recognition task. SNAP
reverted memory deficit in MasKo while L-NAME impaired memory in FVB/N animals. To investigate if
the decrease in the nitrite levels in MasKo hippocampus is due to a downregulation in the NOS expression, we quantified the active nNOS and active neuronal eNOS expression by westernblot and also
active AKT and PI3K, the main activator enzyme of NOS and the main Mas activation second messenger,
respectively. Despite we had not found difference in PI3K and active AKT levels between genotypes,
the hippocampus of MasKo exhibit an upregulation of total nNOS and eNOS. However the active nNOS
is not increased in MasKo hippocampus and a neuronal eNOS decreased expression in the of MasKo
was observed. Conclusion: Our results showed that the memory impairment of MasKo is probably due
a lack of NO modulation. We also may suggest that the upregulation of total NOS expression could be
a tentative to compensate the decreased level of NO in the hippocampus of MasKo, but no successful activation of nNOS or neuronal eNOS is occurring in knockout neurons. Finally, we showed that
hippocampal nitrergic system modulates object recognition memory in MasKo. Sources of Research
Support: CNPq, FAPEMIG
MO023
SUCKLING STIMULATION PROMOTES THE CIRCADIAN
DISPLAY OF NURSING-LIKE BEHAVIOR IN VIRGIN RABBITS
LEMUS AC(1), GONZÁLEZ-MARISCAL G(1), and AGUILAR-ROBLERO R.A(2), (1) CIRA, CINVESTAV-UAT, Tlaxcala, México; (2)Instituto de Fisiología Celular, Universidad Nacional Autónoma de México
Rabbits nurse once a day with circadian periodicity. These characteristics are modulated by litter
size as mothers suckling 4 pups or less enter the maternal nest several times a day. Although these
findings suggest that suckling regulates circadian nursing the specific contribution of milk output
needs to be determined. Thus, in this work we used virgin rabbits, induced to behave maternally by
ZnSO4 lesions to the olfactory epithelium, but unable to deliver milk. Olfactory discrimination tests
-between water and male urine- were made before bilaterally infusing 5% ZnSO4 into the nostrils and
on days 1, 2, and 18 post-lesion. Starting on post-lesion day 3 virgins were given litters of six foster
pups (replaced daily) and observed continuously (through a closed-caption TV circuit) for 15 days to
determine the number of daily visits to the nest box and the female’s interaction with the pups. On the
first day of pup exposure most virgins were not maternal, despite being anosmic for at least two days.
By day 8 of exposure to pups 70% of lesioned virgins behaved maternally: on most days they entered
the nest box only once, crouched over the litter and allowed suckling. Yet, unlike lactating mothers,
nursing behavior episodes were absent for several days in some virgins. Results indicate that suckling
stimulation is, indeed, a key element that maintains the circadian periodicity of nursing behavior. Other
factors, e.g., peripheral oscillators in the olfactory bulb, may also contribute in this regard. We also
observed that ventral self-licking, food and water intake were mostly displayed during the dark phase,
as occurs in lactating rabbits.
How are sensory stimuli such as odor cues represented in the brain when learned in association with
aversive vs appetitive stimuli?. Here, we combine behavioral and functional optical imaging assays to
analyze a memory trace that forms in the dorsal paired medial (DPM) neurons after conditioning flies
with odors associated with aversive and appetitive unconditioned stimuli (US). Our results show that
the DPM memory trace, which forms with a delay after conditioning represents a consolidation trace
rather than an intermediate-term memory trace. The appetitive consolidation trace is distinguished
from the aversive consolidation trace in at least three fundamental ways. First, the DPM neurons do not
respond to a US of sucrose by itself, in contrast to their robust response to a US of electric shock. Second the consolidation trace is more persistent after appetitive vs aversive conditioning. Third, the consolidation trace generated by appetitive conditioning is expressed as increased calcium influx into the
DPM processes that innervate both the vertical and horizontal lobes of the mushroom bodies, whereas
it is constrained to the processes innervating the vertical lobes after aversive conditioning. The broader
and more persistent appetitive consolidation trace accounts for the persistent behavioral memory
formed from single-trial appetitive conditioning events compared to single-trial aversive conditioning.
MO024
THE INTERACTION BETWEEN THE CHOLINERGIC AND THE DOPAMINERGIC
SYSTEM OF THE MEDIAL PREOPTIC AREA/ ANTERIOR HYPOTALAMUS IN
THE MALE SEXUAL BEHAVIOUR OF THE RAT
Ramos-Sánchez E.(1), Velázquez-Moctezuma J.(1) y Domínguez-Salazar E.(1), (1)Área de Neurociencias,
Departamento de Biología de la Reproducción, Universidad Autónoma Metropolitana Unidad Iztapalapa. México, D.F.
Sexual behavior of the male rat has been described as a set of mounts in wich the pennis of the male
may enter or not the vagina of the female, when the pennis does not enter the vagina, it’s called a
mount, but when it does it’s called an intromission, both present deep pelvic movements by the male,
followed by the dismount of the female, the difference between both, is the more violent dismount of
the female when an intromission is completed.For a male rat, it takes from eight to twelve intromissions to acomplishes one ejaculation.Lesions of the MPA/HA , both electrical and chemical, supress
completely the male sex behaviour in the rat by interfering the sexual motivation and the ejecution of
the copulatory behaviour. Within the neurotransmitters implied in the display of the male sexual behaviour, acethylcholine (Ach) and dopamine(DA) both increase their concentration in the MPA/AH moments
before the copulatory behaviour initiates and while the behaviour is being displayed. Our hypothesis is
that dopamine is involved in the motivational aspects of the male sex behaviour , and acethylcholine
is involved in the enforceable aspects of the behaviour, therefore by injuring the cholinergic and/or
the dopaminergic system of the MPOA/AH of male rats the sexual behaviour and sexusl motivation will
dissapear. We will have four groups of expert sexual male rats, one lesioned with AF64-A (cholinergic
toxin), other lesioned with 6-OH-DA (dopaminergic toxin), other injuried with both neurotoxins, and the
last one injectd with saline (SHAM). Tests of sexual behavior and sexual incentive motivation has been
performed in the days 1, 3, 7, 14, 21, 28 after the lesionwas. Preliminary results indicate that, injuries
made with AF64-A in the MPA/AH enhance sexual behavior and delay the sexual saciety of the male rat,
whereas injuries made with 6-OH-DA do not affect the sexual behaviour. We acknowledge the technical
assistency of Leticia Vaca. This project is supported by PROMEP 14411500 and UAM 1440712.
MO025
EFFECTS OF UNDERNUTRITIONS ON MOTIVATION AND SEXUAL
PERFORMANCE OF SEXUALLY NAIVE MALE RATS
BUENROSTRO-JÁUREGUI MH(1), ROJAS J(1), JUÁREZ J(1), (1) Instituto de Neurociencias, Centro Universitario de Ciencias Biológicas y Agropecuarias, Universidad de Guadalajara, Guadalajara, Jalisco,
México.
It has been reported that undernutrition (UN) has a negative impact on motor activity, attention to
novel stimuli and the ability to respond socially. There is evidence that severe malnutrition has effects
on sexual behavior of sexually experienced rats (SE), affecting significantly the production of gonadal
hormones and their receptors, and copulatory efficiency, increasing the number of mounts and the
ejaculatory latency. These effects are not observed under moderate food restriction (low UN). It is
known that female in estrous phase is a highly significant stimulus for the male and in addition, it’s a
novelty stimulus if males are sexually naive (SN). On the basis that chronic undernutrition can affect
sexual behavior of sexually experienced males as well as the response to salient and novelty stimuli, we
set out to study the effect of moderate undernutrition on the sexual activity of sexually naive male rats.
Thirty adult male Wistar rats were divided into three groups: undernutrition-SN, undernutrition-SE and
free-feeding- SN. Malnourished groups were food restricted for 13 days, initially 50% of their normal
diet was available in order to rats reach the 85% of their body weight. Starting of day 14, they were
given food ad libitum and exposed to estrous females; motivation and sexual performance parameters
were recorded during consecutive sessions. This testing period lasted up for 3 weeks All subjects in
free-feeding-SN and undernutrition-SE groups displayed sexual behavior which was observed only in
50% of undernutrition-SN rats. This last group showed also, a significant decrease in the number of
ejaculations in test of consecutive sessions. There were no significant differences between groups
in sexual performance parameters. Results suggest that moderate undernutrition in sexually naive
subjects affects the evaluation of the estrous female as a sexual stimulus without being impaired
sexual performance.
MO027
EMERGENCE OF COMPLEX RHYTMS BY DESYNCHRONIZATION
OF DROSOPHILA CIRCADIAN CLUSTERS
Beckwith EJ(1) and Ceriani MF(1). (1)Fundación Instituto Leloir, IIB-BA, CONICET, Buenos Aires, Argentina.
The set of adaptations that lead to the adjustment to the 24h environmental changes are the result
of the action of the circadian clock, which is present in all forms of life. In Drosophila, the underlying
molecular mechanism has extensively been studied, and is composed of two interlocked transcriptional–translational negative feedback loops along with post-translational modifications of proteins.
The identification of the molecular components has enabled the localization of the neuronal substrate
of the clock in the fly brain. About 150 neurons comprise the circadian network and can be divided
into the small and large ventral lateral neurons (sLNv and lLNv, respectively), which are considered
the central pacemaker, the dorsal lateral neurons (LNd), three groups of dorsal neurons (DN1, DN2,
and DN3) and the lateral posterior neurons (LPN). Defining the rules that govern the communication between these different clusters will shed light onto how molecular oscillations translate into
coherent behavior. Slowing down the pace of the molecular clock within the LNvs by reduction of the
critical kinase SHAGGY (SGG) and the activation of the BMP pathway concomitantly, separates the
endogenous period of this neuronal cluster from that of the rest of the network. This condition led to
complex circadian behavior when flies were kept in free running conditions. Flies exhibited two or three
stable locomotor activity rhythms simultaneously: an extremely long component, likely driven by the
LNvs; a second one around 24h probably reflecting the endogenous period of the rest of the network,
and, whenever present, a third shorter component that could be accounted for the endogenous period
previously reported for the LNd clusters. These results clearly demonstrate that although there is a
hierarchy among clusters, the proper functioning of the circadian system and the emergence of a wild
type locomotor activity pattern is indeed a network property.
MO026
PREFRONTAL ELECTROENCEPHALOGRAPHIC ACTIVITY
DURING THE WORKING MEMORY PROCESSES INVOLVED
IN A SEXUALLY-MOTIVATED TASK IN MALE RATS
ALMANZA-SEPÚLVEDA ML(1), HERNÁNDEZ-GONZÁLEZ M(1),OLVERA-CORTÉS E(2),GUTIÉRREZ-GUZMÁN,
BE,and GUEVARA MA(1), 1 Instituto de Neurociencias, Universidad de Guadalajara, Francisco de Quevedo 180, Col. Arcos Vallarta, C. P. 44130, Guadalajara, Jalisco, México 2 Laboratorio de Neurofisiología
Experimental,Centro de Investigación Biomédica de Michoacán, IMSS.Camino de la Arboleda 300, Exhacienda de San José de la Huerta, C.P. 58341, Morelia, Michoacán, México
The prefrontal cortex it has been involved in the working memory function. Several studies have demonstrated that the rat is capable to perform tasks that involve working memory using food or drink as
reward. The sexual behavior is also a highly rewarding motivated behavior and an efficient incentive
in classical operant tasks. In this work was investigate if functional activity of the medial prefrontal
cortex (mPFC) change in relation to working memory processes involved in the performance of a sexually motivated task in male rats. Male Wistar rats bilaterally implanted in the mPFC were submitted
to a non-matching to sample task in a T-maze using as reinforcer sexual interaction with a receptive
female during 4 training days. In base to the performance throughout the training days in the task, the
rats were classified in two groups, good-learning and bad-learning. Only the good-learning rats showed
an increase in the absolute power of the 8-13 Hz band during the sample-run and test-run, which could
be related with the learning of the working memory elements of the task. The good-learner rats showed
also, only during the maintenance phase (when the rule was learned), an increased correlation of the
8-13 Hz band during the sample run, indicating that a high coupling between prefrontal cortices is
necessary to the adequate processing that allow to the rats take the correct decision in the maintaining phase. Together, these data shown that mPFC activity change in relation to the working memory
processes involved in a sexually motivated task of male rats.
MO028
THE MEDIAN PREOPTIC NUCLEUS, ORGANUM VASCULOSUM OF
LAMINA TERMINALIS AND THE LATERAL HYPOTHALAMUS SHOWS
A PARALLEL ACTIVATION DU-RING FOOD ANTICIPATORY ACTIVITY
MARÍA LUISA MORENO (1,2), ELVIRA MORGADO (2), ENRIQUE MEZA(2), LILY YAN (3),LANCE KRIEGSFELD(4),
and MARIO CABA (2), (1)Doctorado en Ciencias Biomédicas, CIB,U.V.; (2)Centro de Investigaciones
Biomédicas, Universidad Veracruzana, Xalapa, Veracruz, México. (3) Department of Psychology and
Neuroscience Program, Michigan State University(4), Department of Psychology and Neuroscience, UC
Berkeley.
In nature and under laboratory conditions rabbit pups are fed with circadian periodicity for one brief
period of 3-5 min. Since 2–3 h before nursing, pups increase their locomotor activity, termed food
anticipatory activity (FAA). FAA is the behavioral output of a putative food entrainable oscillator distinct
from the suprachiasmatic nucleus, the master clock, and several regions in the brain are entrained by
scheduled feeding. Here we explored two regions, the Organum vasculosum of lamina terminalis (OVLT)
and the median preoptic nucleus (MnPO), not analyzed in previous works in rabbit pups, a natural
model of FAA. Besides that we analyzed activation of orexin (ORX) cells in the lateral hypothalamus
(LH). Sections were processed for immunohistochemistry for FOS and FOS/ORX, during a complete 24 h
cycle in nursed pups. To determine whether oscillations persisted in the absence of food ingestion, we
also examined both proteins in fasted subjects. We compared rhythms of FOS in OVLT and MnPO with
those of FOS and ORX in LH. In OVLT, MnPO and LH, FOS was significantly high at time of nursing, and
then, levels further increase 1.5 h nursing, thereafter levels drop to increase again in advance of next
nursing bout. Similar pattern was found in FOS/ORX cells. In fasted subjects these rhythms persisted
(without the postprandial peak) in OVLT and MnPO but not in LH. Present datas in the OVLT and MnPO
are very important in considering the role of these areas in arousal behavior. Moreover, these areas
project to LH orexin cells, so we propose that the activation of OVLT and MnPO is part of a node with
the LH, important in the regulation of FAA. This work was supported by CONACyT 223274 to MLM and
UC Mexus-CONACyT collaborative grant CN-10-439 to Mario Caba and Lance Kriegsfeld.
MO029
CIRCADIAN RHYTHMICITY OF THE GLUTAMINE SYNTHETASE ENZYME
UNDER THE INFLUENCE OF THE FEEDING ENTRAINABLE OSCILLATOR
De Ita-Pérez Dalia, Méndez Isabel and Díaz-Muñoz Mauricio
The suprachiasmatic nucleus (SCN) controls the circadian activity of the organism, maintaining a time
order across the interface with peripheral oscillators, as the liver. However, when experimental animals
are exposed to a restricted feeding schedule (2 h per day) an emergent clock, known as the Feeding
Entrainable Oscillator (FEO) takes the command of the circadian activity. The liver as a central organ
in the supply of energy to the body, functions in the specialization of many metabolic pathways according to the arrangement and anatomical characteristics of its cell populations: periportal (PP) and
pericentral (PC) hepatocytes. This arrangement across the liver acinus is known as “hepatic zonation”.
The hepatic zonation adapts to changing environmental conditions, such as the nutritional status.
This adaptation is regulated by different signals including the oxygen gradient and the metabolites
and hormones concentration. The glutamine synthetase (GS) is restricted to 2-3 lines of hepatocytes
around the PC acinar zone. This enzyme has an important role in nitrogen metabolism. In this work,
we analyzed the circadian rhythm of the GS mRNA by qPCR, as well as the protein expression by immunohistochemistry and fluorescence microscopy, both in Ad Libitum feeding and by letting the FEO
to set in. Our results show a rhythm in the GS mRNA in both Ad Libitum (acrophase at 20:00 h and
bathiphase at 08:00 h) and restricted feeding conditions (acrophase at 14:00 h and bathiphase at
02:00 h). Furthermore, the protein levels of GS have a similar pattern than the mRNA expression at
11:00 and 02:00 h in each of the groups. These results suggest that the GS has a circadian rhythmicity
whose variation seems to be related to the nutritional status of the organism.
MO031
COHERENT NEOCORTICAL 60-200 HZ HIGH GAMMA AND
OSCILLATIONS ARE NOT PRESENT DURING REM SLEEP
Santiago Castro(1), Atilio Falconi(1), and Pablo Torterolo(1), (1)Department of Physiology, School of
Medicine, Universidad de la República, Montevideo, Uruguay
During cognitive processes there is a profuse interaction amongst different regions of the cerebral
cortex. The extent of these interactions can be examined by quantitative electroencephalographic activity (EEG) analysis using a mathematical algorithm called “coherence,” which reflects the “strength”
of functional interactions between cortical areas. Since the states of sleep and wakefulness may have
a deep impact in these interactions, the present study was conducted to analyze the EEG coherence
during alert wakefulness (AW), quiet wakefulness (QW), non-REM (NREM) sleep and REM sleep. Current
evidence from electro- and magnetoencephalography (EEG/MEG) has consistently shown oscillations
>60 Hz (high gamma band) are correlated to a wide range of cognitive processes. So, in this report
we focused in the high gamma EEG frequency band (60-200 Hz). Four adult cats were implanted with
electrodes in the frontal, parietal and occipital cortices to monitor EEG activity. The z-coherence and
power spectrum values of the high gamma frequency band, separated in 3 bands, 60-100 Hz, 100-150
Hz, and 150-200 Hz, from pairs of EEG recordings from these areas were determined. An increase
in z-coherence values occurred between almost all cortical regions in the 3 separated high gamma
frequency bands during AW compared with the other behavioral states (p < 0.05). As the animal transitioned from AW to QW and NREM sleep, coherence decreased to a moderate level. Remarkably, the EEG
coherence of the high gamma band was almost absent during REM sleep (p < 0.05). Gamma power
was also greatest during alert wakefulness, minimal during NREM sleep and of an intermediate value
during REM sleep and quiet wakefulness (p < 0.05). The virtual absence of high gamma frequency
coherence during REM sleep may underlie the uniqueness of the cognitive processes that occur during
dreams, which is mostly a REM sleep phenomenon.
MO030
TIME OF IMMUNOLOGICAL CHALLENGE DETERMINES
THE PRODUCTION OF TNF-A, IL-6 AND ANTIBODIES
GUERRERO-VARGAS NN1, SALGADO-DELGADO R1, BASUALDO MARIA DEL CARMEN1, GUZMAN-RUIZ MARA,
A1, ESCOBAR C2 AND BUIJS RM RUUD 1. (1)Departamento de Fisiología Celular, Instituto de Investigaciones Biomédicas, ,Universidad Nacional Autónoma de México, México DF. (2)Departamento de
Anatomía, Facultad de Medicina, Universidad Nacional Autónoma de México, México DF.
Most physiological processes exhibit a daily rhythm including immune variables. Several studies have
shown a relationship between mortality rate and the given high dose of bacterial lipopolysaccharide
(LPS) with the moment of the light dark cycles. This difference in survival suggests a time of the day
dependent vulnerability of the rodent to immunological challenges, which may agree with the expression of clock genes in the immune system and their involvement in the immune response. However the
relationship between the central clock the suprachiasmatic nucleus (SCN) and the immune system
remains relatively little explored. In order to examine the participation of the biological clock in the
activity of the immune system, after a “moderate” immunological challenge, we evaluated interleukin
production, temperature response and the antibody response after an LPS or DNP-OVA challenge respectively at two time-points (ZT2 and ZT14). Next we evaluated the activation of the SCN at the same
time points by means of c-fos and used SCN lesioned animals to explore its involvement in the response
LPS challenge. Animals receiving LPS increased dramatically their activity of the SCN. Such LPS injection during the active period (ZT14) resulted in a stronger immune and thermoregulatory response than
in the beginning of the sleep period. The higher response of the innate immune system in the active
period correlated with a higher antibody response 14 days after the immunological challenge. The
thermoregulatory and immune responses were more severe in the SCN lesioned animals leading us to
suggest that the presence and activity of the SCN is essential to inhibit the response of the immune
system. Our results demonstrate that the intensity of the immune response depends on the presence
and activity of the SCN.
MO032
CANNABINOID CB1 AND CB2 RECEPTORS INVOLVEMENT
IN THE VASCULAR TONE REGULATION BY CANNABINOIDS
N RAT MESENTERIC ARTERY
López-Dyck, E(1), Sánchez-Pastor, E(1), Andrade, MF(2) y Elizalde, A(1), (1)Centro Universitario de Investigaciones Biomédicas. Colima, Colima, México. (2)Instituto Tecnológico de Colima. Villa de Álvarez,
Colima, México.
Mesenteric artery is a resistance vessel, which has an important function in the arterial pressure maintenance, necessary to lead oxygen and nutrients to cells. The vascular tone can be modulated through
synthesis and release of vasoactive substances of the endothelium as well as through substances that
can cause relaxation or contraction of the smooth muscle in the medium layer of the arteries. Some
of these modulator substances are the cannabinoids, which are derivatives of cannabis sativa plant,
being ∆ 9-THC the main component. They have been applied with therapeutic objectives through the
years, and at the same time they are one of the most used abuse drugs. It has been shown that cannabinoids are able to produce changes in the vascular tone through different mechanisms including
the activation of the cannabinoid receptors (CB1 and CB2), as well as the activation of other kind of
receptors as the GPR55 receptor and the vanilloid type receptor TRPV1. In the present study we have
done tension experiments to elucidate the direct role of the CB1 a CB2 receptors on the vascular tone
in the rat superior mesenteric artery. We used two synthetic cannabinoids that are selective agonists
for CB1 (ACPA) and CB2 (JWH-133) receptors. The cannabinoids were applied in arterial rings with or
without endothelium to examine the possible participation of endothelium in the vascular effects. The
results show that ACPA activates CB1 receptors in smooth muscle, as it is able to produce a similar
vasodilation in both intact-endothelium and no-endothelium rings of the mesenteric artery. Meanwhile,
JWH-133 seems to activate CB2 receptors in smooth muscle cells as well as in endothelial cells, as it
caused a vasoconstriction in intact-endothelium rings, and vasodilation in no-endothelium rings. Thus,
the effect of the cannabinoids depends on which receptor is being activated and/or the presence of
endothelium.
MO033
PARTICIPATION OF METALLOPROTEINASES SYSTEM IN CARDIAC
REMODELING DURING RAT PREGNANCY AND POSTPARTUM
SALAZAR-ENRÍQUEZ D(1), LIMÓN-MIRANDA S(2), SOTO-ROSALES Y(2), MIRANDA-RODRÍGUEZ MG(2), CASTRO-RODRÍGUEZ EM(1), MUÑIZ J(1) and VIRGEN-ORTIZ A(2), (1)Centro Universitario de Investigaciones,
Biomédicas, Universidad de Colima, Colima, México;(2)Departamento de Ciencias Químico Biológicas y
Agropecuarias, Universidad de Sonora, Navojoa, Sonora, México.
Introduction. Cardiac remodeling (cardiac hypertrophy and fibrosis) consists of short and long-term
responses to myocardial injury that underlie the mortality and morbidity associated with heart failure.
Tissue inhibitors of metalloproteinases (TIMPs) regulate the ECM turnover through negative regulation
of matrix metalloproteinases (MMPs), which degrade the ECM structural proteins in heart. MMPs and
TIMPs are supposed to be involved in mediated cardiac dysfunction after pathological stimulus (hypertension, myocardial infarction). Although the signaling pathways underlying pathological stimulusinduced cardiac adaptation have been extensively studied, little is known about the molecular mechanisms that result in the response of the heart to pregnancy and the rapid reversal of cardiac remodeling
during postpartum. Methods and results. We investigated the expression level of TIMP1, TIMP4, MMP1,
MMP2, MMP9, collagen I and III in cardiac remodeling during rat pregnancy and postpartum. We used
an n=6 rats by group: pregnant-rats (18 days) and postpartum-rats (7 days). Protein expression level
to MMP2, MMP9, TIMP1, TIMP4, collagen I and III was evaluated inmunoblotting. The results indicate
a significant increase in the expression of TIMP-1 and collagen III in left ventricle from pregnant rats,
whereas MMP-9, MMP2 and collagen I decreased during pregnancy; all these changes were reversed
in postpartum. Conclusions. These data suggest that the system of MMPs and TIMPs play an important
role in cardiac remodeling induced by pregnancy promoting changes in the proteins expression such
as collagen type I and type III.
Acknowledgement. This research was supported by CONACYT-México through project CB-2010-155238
to Virgen-Ortiz A.
MO034
THYROID HORMONE-INDUCED CARDIAC ARRHYTHMIA
IS DUE TO CA2+ HANDLING ALTERATIONS RATHER THAN
GENE EXPRESSION MODIFICATIONS
de Alba-Aguayo DR1, Pavón N2, Mercado-Morales M1, Guerrero-Hernández A1, López-Casamichana
M3. Rueda A1 1Departamento de Bioquímica CINVESTAV-IPN, 2Departamento de Bioquímica, Instituto
Nacional de Cardiología “Ignacio Chávez” and 3Posgrado en Ciencias Genómicas UACM. México, D.F.
México.
Increased serum levels of thyroid hormone 3,3´,5-triiodothyronine (T3) (hyperthyroidism), strongly
affect cardiac function and promote arrhythmia, which molecular basis are not completely understood.
Due to the key participation of ryanodine receptor (RyR) mediated Ca2+ leak and Sarco/Endoplasmic
Reticulum Ca2+ pump (SERCA2a) activity in maintaining cytoplasmic/luminal Ca2+ balance and
therefore in the generation of triggered activity and arrhythmia, we used an experimental model of
rat hyperthyroidism (2mg/Kg daily i.p, 12 days) showing Ca2+ handling alterations, in whole hearts
(extrasystoles) and isolated left ventricle cardiomyocytes (triggered activity) to determine the role of
RyR and SERCA2a in Ca2+ handling modifications associated to hyperthyroidism. We analyzed local
(Ca2+ sparks) and global (Ca2+ transients) Ca2+ handling alterations in hyperthyroid cardiomyocytes (confocal microscopy). We evaluated modifications of RyR functional expression and Ca2+- dependent activity by binding assays while SERCA activity was monitored by a fluorescence-based Ca2+
uptake assay. mRNA levels of both proteins were measured by quantitative realtime PCR (qPCR). Fluo3-loaded cardiomyocytes from hyperthyroid rats showed a significant increase of up to 100% (with
respect to controls depending on stimulation frequency) in the Ca2+ transient flux. Also, Ca2+ spark
amplitude and mass were increased (39 and 64%) with no modifications on additional Ca2+ spark
properties. The significantly faster Ca2+ removal constant at all tested frequencies, is supported by
in vitro Ca2+ uptake assays (162% increased) suggesting an increased SR load that may contribute
to triggered activity generation. The increased RyR and SERCA pump activities turn into an augmented
occurrence (30%) of Ca2+ waves and abnormal wave-like arrowhead-shaped Ca2+ release events
(60%) in hyperthyroid cardiac cells. However, unlike to what has been reported, we found a 35% decrease in the number of functional-RyRs, with no change in its Ca2+ dependent activity. Additionally
qPCR showed no significant change on mRNA levels of both proteins. Funding: ICyTDF Project No. 331.
MO035
EXPRESSION OF CYCLOOXYGENASE-2 AND RENIN
IN HYPERTENSION BY NITRIC OXIDE DEFICIENT
MO036
NEURAL CONTROL OF A MOTOR PATTERN IN ZEBRAFISH:
AN OPTOGENETIC ANALYSIS
GUZMAN HERNANDEZ ELIZABETH, IBARRA BARAJAS MAXIMILANO
FAJARDO O(1), ZHU P(1), FRIEDRICH RW(1), (1)Friedrich Miescher Institut for Biomedical Research,
Basel, Switzerland
Prostaglandins are critical regulators of kidney function due to their influence on renal vascular tone
and tubular excretion of electrolyte and water.In the renovascular hypertension the prostaglandins, in
particular PGE2 and prostacyclin, stimulate renin secretion and gene renin expressionfromjuxtaglomerular cells.
This study aimed to determine the association between cyclooxygenase-2 activity (COX-2) and renin
expression in arterial hypertension evoked by nitric oxide (NO) deficiency. Male Wistar rats received
the NO synthase (NOS) inhibitor NG-nitro-L-arginine methylester (L-NAME, 75 mg/kg/day), captopril
(30 mg/kg/day), celecoxib(1 mg/kg/day) and both drugsin drinking water during 2 days. Systolic blood
pressure (SBP), renal cortical COX-2 and renin expression, the 6-keto-PGF1a and TXB2 (stable metabolites of prostacyclin and TXA2 respectively) renal production and the plasmatic angiotensin II were
determined. SBP increased in L-NAME treated rats compared with control group. The administration of
captopril and captopril + celecoxib decreased SBP compared with L-NAME treated rat. Renal cortical
COX-2 and renin mRNA were increased by L-NAME and captopril treatment compared with control
group. Captopril + celecoxib inhibited this effect but celecoxib did not modify COX-2 expression despite decreasing renin expression. The renal release of 6-keto-PGF1 was increased after L-NAME and
captopril compared with control rats while celecoxib inhibited synthesis of 6-keto-PGF1a. The renal
productionof TxB2 in L-NAME treated rats showed no differences with control. However, treatment with
captopril raised synthesis of TxB2 and celecoxib inhibited the synthesis of TxB2. L-NAME increased
plasmatic angiotensin II compared with control group, while captopril and celecoxib abolished this
increase. In conclusion, COX-2 induces the activity of renin angiotensin system at initial development of NO-deficient hypertension. Authors wish to thank Consejo Nacional de Ciencia y Tecnología
(102022), PAPIIT (IN2230009), DGAPA, UNAM andPAPCA 2009-2010 Grant (35) for partial financial
support. Doctoral fellow from CONACYT (2078).
To study the relationship between neuronal activity in defined populations of neurons and behavioral
output, we screened zebrafish larvae expressing channelrhodopsin-2 (Chr2) for changes in swimming
behavior evoked by exposure to blue light. Here we present results from a stable line that moves
backwards in response to blue light. Detailed video analysis reavealed that tail and fin movements
during channelrhodopsin evoked swimming closely resemble J-turns, a motor motif that occurs during
prey capture and serves to adjust the position of the fish relative to its prey. J-turn-like fin and tail
movements also occurred in response to blue light stimulation when the head of larvae was embedded
in agarose, indicating that it is an intrinsic motor pattern. Mapping of behavioral responses to focal
blue light stimulation revealed that J-turn-like swimming is triggered specifically by optical stimulation
of the ventral anterior optic tectum or superficial pre-tectum. We are currently combining focal optical
stimulation with calcium imaging in a brain explant preparation and in vivo to study the distribution
of neuronal activity associated with J-turn-like swimming, as well as performing two-photon neuronal
ablation to further confirm the neuronal population commanding this behavior. These results are beginning to unravel the higher-order neuronal circuitry controlling a defined motor behavior.
MO037
NEUROPHYSIOLOGY OF TIME INTERVAL CATEGORIZATION IN THE
PRESUPPLEMENTARY MOTOR AREA OF THE RHESUS MONKEY
MO038
STRUCTURAL CORRELATES OF MGLUR-MEDIATED LTD AT INDIVIDUAL
SPINES OF CA1 PYRAMIDAL NEURONS
MENDOZA G(1), MÉNDEZ JC(1), PRADO L(1) and MERCHANT H(1), Dpto. de Neurobiología Conductual y
Cognitiva, Instituto de Neurobiología, UNAM, Querétaro, QRO. México.
Ramiro-Cortés, Y. and Israely, I.
Champalimaud Centre for the Unknown, Champalimaud Neuroscience Program, Portugal.
The presupplementary motor area (pre-SMA) is a major component of the network engaged in processing of temporal information during motor tasks. In addition, several fMRI studies suggest that
this area also participate in perceptual timing. To test this hypothesis, we recorded single unit activity in the pre-SMA of one monkey performing a relative temporal categorization task (TT). In this task,
the monkey had to assign different interval durations to ‘short’ or ‘long’ categories according with
previously learned prototypes. In each 120-trial run of the task, one of three sets of eight different
stimuli was presented to the monkey. For each set, the shortest four values were considered as ‘short’
and the remaining four as ‘long’. Crucially, the two longest intervals of the set one corresponded to
the two shortest intervals of the set two, and the same was true for the sets two and three. As a
result, one interval (absolute magnitude) acquired different relative values (shorter or longer than)
according with the context in which it was presented. Analyses of variance showed that the activity
of pre-SMA neurons was modulated by the absolute or relative duration of the interval, and by the
monkey´s categorical response. These response modulations were observed during the stimulus presentation and/or the delay epoch before the presentation of the targets used for the expression of the
categorical decision. These results show that pre-SMA neurons are able to represent explicit temporal
information in absolute and relative terms, as well as the categorical decisions involved in the TT.
Dendritic spines are highly dynamic structures whose morphology and lifespan are modified as a
response of synaptic efficacy changes which are thought to be the physiological basis for learning
and memory. These changes can result in either potentiated or depressed synaptic transmission (e.g.
LTP or LTD) at individual synapses, and may physically alter neuronal connectivity. Indeed, there is a
correlation between the increase in synaptic efficacy and the increase in spine volume when individual
synapses are potentiated through the uncaging of glutamate and monitored by live twophoton imaging. Long lasting changes in synaptic efficacy require new protein synthesis, similarly to long lasting
memory formation. Protein synthesis dependent synaptic potentiation leads to long lasting growth of
spines (> 4 hours), whereas spine volumes return to baseline (~ 1.5 hours) following weaker synaptic potentiation. ynaptic tagging and capture at the single spine level shows that individual spines can
cooperate for the expression of plasticity by sharing proteins. When one spine is strongly stimulated
the neighboring spine is able to show a long lasting increase in synaptic efficacy in response to a
weak stimulus. Interestingly, when multiple spines are stimulated within the same dendritic domain,
they show dynamic structural plasticity changes, wherein some spines grow and others shrink in a
negatively correlated fashion, indicating that spines can undergo bidirectional structural changes. This
suggests that synaptic activity in neurons can lead to spine shrinkage, however it is unclear whether
depressing stimuli can directly induce such changes. Therefore, we investigate if long lasting, protein
synthesis dependent LTD mediated by metabotropic glutamate receptors can directly induce structural
changes in dendritic spines that are also long lasting. Using two-photon imaging and glutamate uncaging, we examine whether long lasting depression lead to structural changes at individual spines.
We aim to determine the structural correlates of synaptic depression, to define the learning rules for
bidirectional changes in synaptic efficacy.
MO039
REGULATION OF SYNAPTIC STRUCTURE BY SYNCAM 1
INVOLVE CROSSTALK WITH OTHER SYNAPTOGENIC
ADHESION COMPLEX
MO040
GABA_ EXPRESSION IN THE MEDIAL NUCLEUS
OF THE TRAPEZOID BODY
Perez de Arce K.(1)and Biederer T.(1), Department of Molecular Biophysics and Biochemistry School
of Medicine. Yale University. New Haven, CT, USA.
Synapses are specialized sites of adhesion between neurons that are organized by several trans-synaptic complexes. Specifically, immunoglobulin proteins of the SynCAM family (Synaptic Cell Adhesion
Molecules) participate in axodendritic contact assembly and regulate excitatory synapse number,
morphology, and function in vitro and in vivo. However, how SynCAMs work together with other adhesion complexes to orchestrate the synaptogenic process has not been addressed. Therefore, we are
interested in investigating the crosstalk between SynCAM 1 and other adhesion proteins and their
contribution to a presumptive ‘adhesion code’ that may instruct different aspects of synaptogenesis.
We have observed that knock-out mice lacking of one of this synapse-organizing molecule show
altered expression and distribution of functionally related adhesion proteins from different gene
families. Moreover, in co-culture assays the recruitment of presynaptic proteins suggests additive effects when SynCAM 1 and other synaptogenic proteins are overexpressed. In addition, our preliminary
data from double knock-out mice support that the deletion of two adhesion molecules that belong to
different families can induce select synaptic changes. These results illustrate how SynCAM 1 cooperates with other adhesion molecules to modulate synapse organization.
REYES-HARO D(1), ROSAS-ARELLANO A(1), GONZÁLEZ-GONZÁLEZ MA(1), MILEDI R(1), MARTINEZ-TORRES,
A(1), (1) Instituto de Neurobiología, Universidad Nacional Autónoma de México, Mexico.
The calyx of Held synapse (CoH) is the largest in mammals. It is located in the medial nucleus of the
trapezoid body (MNTB) and forms part of the auditory pathway. Modest GABAergic signaling is present
in the CoH before hearing onset, when glutamatergic transmission predominates. In mice, after postnatal day 12, the absolute strength of glycinergic transmission increases markedly, while GABAergic
signaling remains constant. The persistent GABAergic transmission in the MNTB is mediated by a
slowly, desensitizing component. In this study we recorded GABAmediated responses from postsynaptic
principal neurons (PPNs) and found that they are sensitive to TPMPA, suggesting the involvement of
GABA_ subunits. RT-PCR and immunohistofluorescence in the MNTB confirmed GABA_ expression in
PPNs. Interestingly, GABA_3 was present only before hearing onset, and there was a switch to GABA_1
and GABA_2 expression in adult animals.
MO041
DIFFERENTIATED EFFECTS OF ALLOPREGNANOLONE IN DIFFERENT
IMMOBILITY RESPONSES IN CANNULATED RATS IN THE ACCUMBENS
NUCLEUS AND PERIAQUEDUCTAL GRAY MATTER
Hernández-Navarro,BC(1);Pacheco-Rosado,J(1);Miranda-Paez,A(1);Fregoso-Aguilar,T(1). (1)Escuela
Nacional de Ciencias Biológicas, Instituto Politécnico Nacional. Depto. de Fisiología, D.F, México.
Many species under stress conditions show immobility reactions that are similar to those observed in
human psychiatric disorders such as Parkinson and esquizofrenia. It has been found that neuroactive
steroids such as testoterone and allopregnanolone (Alop), a metabolite of progesterone, modulate
immobility responses (IR’s) such as catalepsy. In this study, we compared the effect of Alop on the
expression of different IR’s in rats cannulated in the accumbens nucleus (Acc) and the periaqueductal
gray matter (PGA). 40 adult male Wistar rats (180 – 300g) were distributed in 4 groups. Each group
was submitted to brain surgery using standard stereotaxic techniques to implant a guide cannula
aimed at Acc and the PGA. The treatments used were: Control (without drug), cyclodextrin (10%) and
allopregnanolone (8 μ g / μ L), which were administered for a period of 90 s. After 5 minutes of local
administration, each group was induced to the following behavioral tests: i) immobility catalepsy (CAT),
ii) immobility by clamping the neck (PIN), iii) Dorsal immobility, and iv) activity in open field test (OFT).
These tests were induced following the methodology described in other articles; under constant intertribal intervals (30 s.) for 10 trials. Alopregnanolone 1) significantly increased the duration of the CAT
exhibited by rats administered both Acc and in the PGA (Two way ANOVA test for repeated measures;
p<0.05); 2) also enhanced the duration of the PIN (p< 0.05); 3) significantly increased the duration
of ID in the Acc, but decreased in the PGA and, iv) significantly decreased the exploratory activity in the
OFT in rats administered in the Acc, but had no effect on the PGA. Taken together, these results lead to
think that Alop showed a differential effect on the expression of defensive responses evaluated. This
can perhaps be explained due to activation of the basal ganglia mediated through Acc. However, in
the case of PAG, the neurosteroid maybe increases the duration of the PIN through an effect related to
analgesia. Therefore, we propose a modulation by the Acc and the PGA on the functioning of the basal
ganglia that causes triggering of the IR’s and analgesia. This could be considered to study different
locomotion disorders in humans.
MO042
CONTROL OF EXCITABILITY IN STRIATAL CHOLINERGIC
INTERNEURONS: MECHANISM UNDERLYING ISAHP
TUBERT C(1), SANCHEZ G(1), MURER MG(1), RELA L(1). (1)Laboratorio de Fisiología de Circuitos Neuronales, Departamento de Fisiología, Facultad de Medicina, Universidad de Buenos Aires, Argentina.
Parkinson’s disease is a neurodegenerative disorder caused by nigrostriatal dopaminergic neuron loss.
Its main symptoms result from a deficient dopaminergic control of striatal mechanisms involved in
instrumental learning, action selection and initiation. Acetylcholine released by a small population
of tonically active interneurons (ChIs), is a main modulator of striatal function. Tonic activity in ChIs
depends on intrinsic mechanisms. Action potentials open K+channels, either by opening Cav channels leading to activation of KCa channels or directly by opening Kv channels. This produces an
afterhyperpolarization (AHP) with three phases: fAHP, mAHP, and sAHP. The molecularmechanisms that
mediate IsAHP in ChIs are still unknown, but it is supposed to be Ca2+ dependent. We have previously
shown that a reduction of IsAHP results in hyperactive ChIs in a rat model of Parkinson’s disease, seen
as a lack of “accommodation” (abrupt stop of firing during sustained current injection). Thus, IsAHP
may be a novel target to treat the hypercholinergic state in Parkinson’s disease. Here we studied the
maturation and pharmacology of IsAHP in ChIs from mouse brain slices. Both in C57 wild type mice
and C57 mice in which the ChAT promoter drives the expression of the red fluorescent protein tdTomato,
ChIs showed a marked accommodation during depolarizing current injection and a marked IsAHP. Accommodation was insensitive to UCL2077, a blocker of atypical KCNQ K+ channels mediating Ca2+dependent IsAHP in some hippocampal neurons. Moreover, UCL2077 had no effect on IsAHP in ChIs.
In contrast, margatoxin, a blocker of voltage-gated K+ channels with selectivity for Kv1.3 channels
strongly reduces IsAHP and accommodation in ChIs. Thus, our data suggest a novel voltage-dependent
component of IsAHP in ChIs which needs further validation as a therapeutic target in animal models of
Parkinson’s disease. Future studies will allow us to establish the presence of Kv1.3 in ChIs.
MO043
THROMBOSPONDIN-1 (TSP-1) LEVELS
IN PLASMA OF DOWN SYNDROME PATIENTS
MO044
AUTOMATED SCREENING TECHNOLOGY USING MULTIPLE
ASSR TO BONE- AND AIR- CONDUCTED STIMULI
HERNÁNDEZ-GUZMÁN DAVID ANTONIO (1), BUSCIGLIO JORGE (2), GARCÍA OCTAVIO (1), 1. Coordinación de
Psicofisiología. Facultad de Psicología. Universidad Nacional Autónoma de México. Mexico City, Mexico.
(2) Department of Neurobiology and Behavior and Institute for Memory Impairments and Neurological
Disorders, University of California Irvine. Irvine, California. USA.
Pérez Abalo MC (1), Hernández MC (1), Santos E (1), Rodríguez E (1), Hernández O (1), Mijares E (1). (1)
Departamento de Audición y Lenguaje, Centro de Neurociencias de Cuba, Habana, Cuba
Down’s syndrome (DS) or trisomy 21 is the most frequent genetic cause of mental retardation. The people with DSare more likely to develop Alzheimer’s disease (AD). Cognitive impairment in the progression
of AD in DS patients may be related to the presence of soluble A b 42 in brain and reductions in spine
dendritic number. In addition an increased plasma level of A b 42 levels is present in DS patients.
Thrombospondin-1 (TSP-1) is a glycoprotein released from the b-granules of platelets in response to
stimulation with thrombin. In central nervous system TSP-1 is synthesized and secreted by astrocytes.
We previously showed DS brains exhibit marked deficits in TSP-1 expression and that TSP-1 possess a
potent modulatory effect in spine formation and density. To investigate whether TSP-1 could be a biomarker for the development of AD in DS we determined TSP-1 levels in plasma of normal patients (NL),
DS patients and DS patients with AD diagnosed (DS/AD). TSP-1 levels were determined using ELISA immunoassay. Preliminary results suggest that TSP-1 levels are partially reduced in DS patients compared
to control, while DS/AD show a marked decrease of TSP-1 levels. Experiments in progress are directed
to establish whether reduction in TSP-1 levels correlates with cognitive impairment. This work was
supported by National Institutes of Health (ADRC grant AG16573) and PAPIIT-UNAM (grant IN217211).
Introduction: Developing screening technology that can differentiate transient and permanent hearing
impairments is an important research goal. This could reduce false positive rates in the initial screen
(due to transient conductive hearing losses) and further enhance UNHS efficiency. Objective: Here we
describe a clinical trial of an automated screening device (Neuronic-06) designed for such purpose.
Methods: This portable equipment uses the simultaneity principle of multiple auditory steady state
responses (ASSR) to present air- and bone- conducted stimuli at the same time (AC-BC ASSR). A sample
of 180 newborns (360 ears) with and without high risk factors was screened at the maternity ward
within the first 48-72 hours after birth. Each infant was tested (in a random order) with both AC-BC
ASSR and automated otoacoustic emissions (OAE). A confirmatory clinical and electrophysiological
evaluation (at 2–3 mo of age) was used as the gold standard to estimate their diagnostic efficiency.
Results: Both automatic devices performed reliably in the maternity ward showing concordant pass/
fail results in most ears for AC stimuli (ML-Chi Square=13.7 gl.=1; p< 0.002). However, the overall failure rate could be reduced significantly when both conduction modes were considered (AC-BC
ASSR 7.3%, 26/355 vs. OAE: 25%, 84/339). Moreover, the new AC-BC ASSR device could identify a
considerable number of infants with transient conductive impairments that failed with the OAE. The
estimated diagnostic efficiency (sensibility and specificity rates) was higher (100% and 95%) for the
AC-BC ASSR device than for the OAE system (50% and 83%). Conclusions: The AC-BC ASSR technology
prototype performed quite well in this initial clinical trial, differentiating transient conductive hearing
losses from permanent impairments. This screening technology further developed and field tested may
become a valuable complement for UNHS protocols.
MO045
NO ASSOCIATION BETWEEN TOTAL BILIRUBIN LEVELS IN
NEONATES FROM TZELTAL, CHOL AND MESTIZO ETHNIC
GROUPS IN THE STATE OF CHIAPAS, MEXICO
MO046
RESTING EEG ACTIVITY AND OVARIAN HORMONES AS PREDICTORS
OF DEPRESSIVE SYMPTOMS IN MID-LIFE WOMEN WITHOUT A
DIAGNOSIS OF MAJOR DEPRESSION
López Narváez María Lilia(1,2), Martínez Hernández Fátima Cristel(3*), Jimenez Santos Maria Antonia
(3), Bermudez Ocaña Deysi (3), Aguilar Iremi (4), Juárez Rojop Isela Esther (4), López Narváez Amelia
(1), Tovilla Zárate Carlos Alfonso(2,3), 1. Hospital General de Yajalón, Yajalón, Chiapas, México. 2. CIGEN, Centro de Investigación Genómica, Comalcalco, Tabasco, México. 3. Universidad Juárez Autónoma
de Tabasco, División Multidisciplinaria de Comalcalco, Comalcalco, Tabasco, México. 4. Universidad
Juárez Autónoma de Tabasco, División Académica de Ciencias de la Salud, Villahermosa, Tabasco,
México.
SOLIS-ORTIZ S(1),PEREZ-LUQUE E(1),PACHECO-ZAVALA P(2), (1)Dept.de Ciencias Médicas,Univ.
de Guanajuato,León,Guanajuato,México. (2)Instituto de Mexicano del Seguro Social,UMF
No.47,León,Guanajuato,México.
Neonatal hyperbilirubinemia affects 60% of full-term newborns and remains a significant cause of
hospital readmission during the first week of life. This is manifested by jaundice, the yellow-orange tint
found in the sclera and skin of infants with total serum bilirubin levels greater than 5 mg/dL. Ethnicity
is an important factor for neonatal hyperbilirubinemia. This study explored total serum bilirubin levels
in three ethnic groups of Chiapas, Mexico (Tzeltal, Chol and Mestizo groups). The aim of the study was
to examine whether the level of total serum bilirubin is associated with any specific ethnic group. This
study was conducted in 113 neonates of three different ethnic groups from Chiapas, México. Total
serum bilirubin was not significantly higher in neonates of any of the three ethnic groups (p=0.38).
In addition, when we analyzed for differences between ethnic and mestizo groups no significant differences were encountered (p=0.20). Our results showed no significant differences in total serum
bilirubin levels among three ethnic groups in a population sample from Chiapas, Mexico. However,
more studies are necessary in which larger samples must be considered to determine conclusively
this no association.
Introduction. The aim of this study was to examine the effects of depressive symptoms on resting EEG
and their correlation with endogenous hormone levels in postmenopausal women without a diagnosis
of major depression. Method. Fifty postmenopausal women aged 48 to 60 years were assessed for
depressive symptoms using the Beck Depression Inventory. Twenty-three scored between 0 and 9 and
were considered the group with minimal depressive symptoms, and 27 scored between 10 and 35
and were considered the group with moderate depressive symptoms. EEG activity was recorded during
rest with eyes closed with 22 electrodes placed according to the 10-20 International System. Relative
power for delta, theta, alpha1, alpha2, beta1 and beta2 were analyzed and compared between women
with minimal and moderate depressive symptoms. Endogenous hormonal levels of estrone, estradiol,
progesterone, follicle-stimulating hormone and luteinizing hormone were obtained and correlated with
the EEG parameters. Results. The women with moderate depressive symptoms showed more relative
alpha1power (p = 0.01) and less relative beta2 power (p = 0.03) compared with the group with
minimal depressive symptoms. Progesterone was negatively correlated with the theta band (p =
0.005) and positively correlated with the beta2 band (p = 0.02) in women with moderate depressive
symptoms. Estrone was negatively correlated with the alpha2 band (p = 0.05), and estradiol was
positively correlated with the theta band (p = 0.02) and negatively correlated with the beta2 band
(p = 0.05) in women with minimal depressive symptoms. Conclusion. These findings suggest that
moderate depressive symptoms in postmenopause are accompanied by increased slow and decreased
fast EEG activity and are associated with endogenous progesterone
MO047
THROMBOSPONDIN-1 (TSP-1) DEFICIT AFFECTS NOVEL OBJECT
RECOGNITION TASK. POSSIBLE RELATION WITH DOWN’S SYNDROME
MO048
BEHAVIORAL AND BRAIN RESPONSE TO THE MATERNAL
SMILE IN PREMATURE AND HEALTHY INFANTS
López-Niño Janintzitzic (1), Torres María (2), Martínez-Coria Hilda (2), Busciglio Jorge (2), García Octavio (1), (1)Coordinación de Psicofisiología. Facultad de Psicología. Universidad Nacional Autónoma
de México. Mexico City, México. (2)Department of Neurobiology and Behavior and Institute for Memory
Impairments and Neurological Disorders, University of California Irvine, Irvine, California. USA
DELGADO-HERRERA M(1), SANTIAGO-RODRÍGUEZ E(1) AND HARMONY T(1), (1) Unidad de Investigación en
Neurodesarrollo “Dr. Augusto Fernández Guardiola”, Instituto de Neurobiología, Universidad Nacional
Autónoma de México (UNAM), Juriquilla, Querétaro, 76230, México.
Down syndrome (DS) is the most common cause of mental retardation. Cognitive deficits in DS have
been linked to alterations in dendritic spine development and their structure. Dendritic spines are the
primary sites of excitatory synapses, and spine defects might lead to synaptic and circuits alterations
in DS. We had previously shown that TSP-1 is a critical modulator of spine formation and density.
Furthermore, TSP-1 can reduce the alterations in spine morphology and number found in DS. To investigate whether TSP-1 deficits can have an effect on mice behavior, we evaluate novel object recognition
task (NOR) and novel context in TSP-1 knockout mice. We found that TSP-1 knockout mice showed a
significant cognitive impairment in NOR task and context-dependent novel. NOR task has been associated to hippocampal activity. Interestingly we also found that Ts65Dn mice a model of Down syndrome
show TSP-1 deficit in hippocampus. These results suggest that TSP-1 can be involved in novel object
recognition memory and cognitive impairment observed in Down syndrome. This work was supported by
National Institutes of Health (ADRC grant AG16573) and PAPIIT-UNAM (grant IN217211).
Perinatal brain injury occurs by the presence of various risk factors, among them prematurity, hypoxiaischemia, infection and inflammation. When the prematurity is added with other factors can generate
damage to the periventricular white matter resulting exist a hypomyelination in those areas. Cognitive,
sensorial and social/emotional sequels have been reported. Emotions allow us to generate specific
responses for effective social interaction. In healthy infants, frontal and temporal (superior temporal
gyrus) activation to happy faces compared with neutral faces has been reported. The aim of this study
was to determine the behavioral and electrical brain response to perceive maternal smile in preterm
and healthy infants. Seven infants (4 preterm and 3 controls) with mean age of 7.8+0.70 months
were studied. The infant perceives images expressing neutral, maternal and no maternal smile with
synchronous EEG recording. Behavioral response was measured in three variables: looking, affect, and
motor behavior. Quantitative analysis EEG was performed and power spectra was obtained by Fourier
Fast Transform. The looking time to the stimuli of premature infants and controls was the same 1.45 s
(60%) per trial. The predominant affect was the neutral affect in both groups of infants. And, there no
exist significant differences in the type of movement associated with some stimulus among premature
and healthy infants. In EEG analysis, spectral peaks during the smile face perception were observed in
frontal and temporal regions (anterior and posterior) in 4-8 Hz in comparison with neutral face. They
were greater amplitude in healthy than in premature infants. There were no differences between maternal and no maternal smile. In conclusion, these finding suggests that the brain of premature infant
at 8 months old responds in frontal and temporal areas to the smile, but not behaviorally, regardless
of whether is maternal smile or not.
MO049
EMBODYING THE EXECUTIVE: HEAD MOVEMENTS
FACILITATES INTERFERENCE CONTROL IN PRESCHOOLERS
MO050
MATURATIONAL CHANGES IN THE HUMAN
ENVELOPE FOLLOWING RESPONSES
Michael Padilla Mora (1); Alejandra Rodríguez Villalobos (1); Allan Esquivel Sibaja (1); Jaime Fornaguera Trías (1,2). (1) Programa de Investigación en Neurociencias, Universidad de Costa Rica, Costa
Rica. (2)Departamento de Bioquímica, Escuela de Medicina, Universidad de Costa, Costa Rica Rica.
Mijares E (1), Perez Abalo MC (1), Torres A (1), Vega M (1), Lage A (1). (1) Departamento de Audición y
Lenguaje, Centro de Neurociencias de Cuba, Habana, Cuba.
Embodied approaches to cognition remarks the influences of motor actions and patterns of movement
as important regulators in a variety of cognitive dynamics. Pioneer works have started to shed light over
the effects of specific movement patterns on the cognitive executive performance of adults, but the
subject remains unexplored in children samples. Head movements like nodding and shaking (balancing
the head along the Y and X axis, respectively) has been considered among the subset of body actions
that could exert influence on this kind of performance. In particular, head shaking has evidenced an
effect that facilitates the performance of adults in inhibitory control and cognitive flexibility tasks. The
present research explores the effect of patterns of head movements on preschoolers’ performance in
an inhibitory control tasks. Fifty three children from public kindergartens participate in this study as
part of a multigroup intersubjects experimental design. Participants performed head-shaking, nodding or remain still (as controls), according to their experimental group, before the execution of two
Stroop interference tasks. Results indicate that the head-shaking group obtained significant better
performances than the nodding and control groups in the interference task, while the nodding and
control groups performance do not differ significantly. In this sense, results show that head shakings
can facilitate the interference control in children of preschool age, and support the need to explore
the influence of movement patterns onto other cognitive executive processes. Discussion considers the
evidence from the perspective of the embedded cognition as an intersection between recent models of
neural and cognitive development in young children.
Introduction: The auditory ability to discriminate rapid changes in the envelope of language sounds
is essential for speech comprehension. This ability is deteriorated in multiple sclerosis, auditory neuropathy, sensorineural hearing loss, and primary developmental language disorder. Human envelope
following responses (EFRs) is usefulness for objective measurement of temporal processing in the
auditory system. Objective: To evaluate the age-depend changes of the EFRs during the first two years
of live. Methods: The EFRs were recorded in a sample of 29 well babies distributed into three age
groups: G1: 12 newborns (0-29 days), G2: 13 babies (1-12 months), and G3: 4 babies (24-35 months
of birth). EFRs were evoked by white noise carrier stimuli with a sweep of modulation frequencies (MF)
from 20 to 200 Hz presented at 50 dB HL. Results: The age related changes affected both morphology
and EFRs detectability. These maturational changes are more evident in newborns. The main morphology differences were to expenses from frequencies below 50 Hz, were the first component P1 (located
between 30-50 Hz) was not well defined in none of the 3 groups of ages. There was a significant effect
of age over the EFRs amplitude. For all MF the newborns had significantly smaller responses than the
two older groups. Also the EFRs amplitude was significantly larger for G3 than G2 except for the MF
between 26-38 Hz. The detectability of the response increased with age for all MF, reached a 100 % of
detectability in G3. Conclusions: The present study provides the first evidences on the maturation of
EFRs. Some understanding of normal EFRs development would facilitate a better use of this technique
in clinically objective measurement of auditory temporal processing in infants who cannot provide
reliable behavioral responses.
MO051
EFFECT OF INTERACTION OF PICTURES OF BALLERINA SCULPTURES
AND CLASSICAL MUSIC ON SUBJECTIVE TIME PERCEPTION
MO052
EXPOSITION TO IMAGES OF THE “IDEAL” BODY INCREASES BODY
DISSATISFACTION AND HEALTHY FOOD CHOICE IN COLLEGE STUDENTS
NATHER F C(1), MORETTO, M S(1), BUENO, J L O (1), (1)Universidade de São Paulo, Ribeirão Preto, Brazil
LAUS MF(1), BRAGA COSTA TM(2) and ALMEIDA SS(1), (1)Department of Psychology, Univ. of Sao Paulo,
Ribeirao Preto, Brazil and (2)Univ. of Ribeirao Preto, Ribeirao Preto, Brazil.
Visual perception of movement in static images affects the perception of time. Duration was judged
longer for images of ballerina sculptures of Edgar Degas requiring more movement than for the ballerinas requiring less movement. This study verified if these same images of ballerina sculptures
implying different movements presented with musical pieces with fast and slow tempo affect the
perception of time of untrained and dance trained individuals. One hundred and six undergraduate
students were asked to reproduce time duration of a 36 s presentation of dancer sculptures’ photographs in different ballet positions and classical music (simultaneously). Visual stimuli were two
digital photographs of dancer sculptures of Degas: Prelude to dance (3.0-point stimulus) and First time
of the great arabesque (6.0-point stimulus). These stimuli were obtained from “Body Movement Ranking Scale”, a reference scale of body movement intensity represented in static visual stimuli. A piece of
the classical music “Idyll” by Christoph Gluck, typical of Classical Ballet class, was used as acoustic
stimuli: the original music in slow-tempo (slow stimulus) was modified to fast tempo (fast stimulus).
Compound stimuli (visual/acoustic) were randomly presented in sequences (3.0/slow-6.0/slow; 3.0/
fast-6.0/fast; 6.0/slow-3.0/slow; or 6.0/fast, 3.0/fast) to the Untrained (n=57) and Trained (n=49)
groups of participants. Data were submitted to One Way and Two Way (ANOVA) analysis of variance with
Student-Newman-Keuls test for post-hoc comparisons. The data confirmed that the implied movement
had an effect on time estimations of Untrained and Trained groups of participants: the greater the
body movement in the image larger was the estimation of time. This result suggests that there was
a prevalence of visual modality of stimuli over the auditory modality in the time estimations in both
groups untrained and trained individuals.
Introduction: Exposition to idealized images from the media increases body dissatisfaction, especially
among women. However, the impact of the internalization of these cultural norms on eating behavior
is still unknown. Moreover, there are no studies in Brazil exploring the influence of media on body
satisfaction and food choices. Objective: To study the influence of the “ideal” body conveyed by media
on body satisfaction and food choices in college students. Methods: Students (n=159) were divided
in experimental (EG - exposed to nine pictures of each sex depicting the “ideal” body) and control
(CG - exposed to nine pictures of neutral objects) groups. Subjects were submitted to the Figure Rating
Scale and to the Food Photographs Scale, before and after exposition to the pictures. Results: Before
the exposure mean (SD) dissatisfaction was (in kg/m2), to experimental EG and CG respectively, -0.13
(5.19) and +0.13 (5.66) among men, and -2.13 (4.06) and -2.38 (4.35) among women. Additionally,
56.4% of men of the EG and 65% of the CG selected health foods to eat in the afternoon, while,
among women, healthy choices were observed in 72.5% of the EG and 77.5% of the CG. After viewing
the pictures, dissatisfaction increased significantly among men (M=-0.77; SD=5.99; p<.05) and
women (M=-2.88; SD=4.65; p<.05) of the EG, but not of the CG (p>.05). Interestingly, there was
a significant increase (p<.05) on choices classified as healthy among participants of the EG (10.1%;
p<.01), especially among women (12.5%; p<.05), which did not occurred in the CG. Conclusion:
Internalization of the idealized media images contributes to body dissatisfaction and improves food
choice, suggesting an attempt to fit in this socially accepted ideal. Brazilian students display preoccupations similar to others Western societies; indicating that media may play a significant role in body
image and eating behavior.
MO053
SOCIAL INTERACTION AND CORTICOSTERONE RESPONSES
FOLLOWING SOCIAL DEFEAT IN THE MONGOLIAN GERBILS
(MERIONES UNGUICULATUS)
FLOREZ S(1,2),RUGE V(2),and CARDENAS F(1),(1)Grupo de Neurociencia y Comportamiento, Univ.de Los
Andes,Bogotá,Colombia and (2)Univ.Konrad Lorenz, Bogotá,Colombia
Social defeat stress is known to be involved in behavioral and neuroendocrine changes that might be
similar to those occurring in the development of many mental disorders like depression in subordinate
individuals. Here we show how social defeat stress affected social interaction and corticosterone
responses in subordinate male Mongolian gerbils. Experiment 1; each of 12 gerbils was defeated by
dominant gerbil in a short confrontation using the intruder/resident paradigm (10 min) during 3 consecutive days. Experiment 2, the same animals were tested for social interaction one day after the last
episode of social defeat. Finally, Experiment 3 the social interaction was tested four weeks after the
last social interaction test and corticosterone levels were measured. The results showed that defeat
animals spent less time in social interaction zone (t = 2,35; p<0,05) and changes in corticosterone
levels compared with control group. On the other hand, we created and ethogram for all the behaviors
that we observed during social defeat and social interaction for dominant and subordinate animals.
These data suggest that Mongolian gerbils could be a useful model for studying behavioral responses
to stress, especially in neurobiological mechanism involved with the regulation of social behavior.
MO055
FORCEFUL INVASION OF PERIPERSONAL SPACE IS ASSOCIATED
WITH ABNORMALITIES IN PREMOTOR CORTEX: A SMRI STUDY
IN VICTIMS OF URBAN VIOLENCE WITH PTSD
Rocha-Rego V(a), Pereira MG(b), Oliveira L(b), Mendlowicz M(b), Fiszman A(a), Marques-Portella C(a),
Berger W(b), Chu C(c), Joffily M(a), Moll J(d), Figueira I(a), Volchan E(a), (a)Universidade Federal do Rio
de Janeiro, Brazil;(b)Universidade Federal Fluminense, Brazil;(c)University College London, UK;(d)D’Or
Institute for Research and Education, Brazil.
Background: Posttraumatic stress disorder (PTSD) studies have reported structural abnormalities in
brain regions related to stress regulation and fear circuits such as hippocampus, amygdala, and anterior cingulate/ventromedial prefrontal cortex. Premotor areas are involved in the preparation of action
in response to a threatening situation and in the representation of the peripersonal space. Urban
violence is an important and pervasive cause of human suffering, especially in large urban centers
in the developing world. Violent events, such as armed robbery, are very frequent in some cities, and
these episodes increase the risk of PTSD. Assaultive trauma is characterized by forceful invasion of the
peripersonal space. Could this traumatic event be associated with structural alteration in premotor
areas in PTSD? Methodology/Principal Findings Structural magnetic resonance imaging scans were
acquired from an urban violence-exposed sample consisting of 16 PTSD patients and 16 age- and
gender-matched controls. Psychometric questionnaires differentiated PTSD patients from trauma-exposed controls in PTSD symptoms, affective and resilience predispositions. Voxel-based morphometric
analysis revealed that, compared to controls, the PTSD patients showed significant reductions in gray
matter volume in the ventral premotor and in the pregenual anterior cingulate cortices. Conclusions:
Volume reduction in premotor cortex observed in PTSD victims of urban violence may be associated
with a disruption in the dynamical modulation of the safe space around the body. Smaller volume in
pregenual anterior cingulate cortex in this sample is consistent with the findings in PTSD neuroimaging
studies that investigated other types of traumatic events.
MO054
STUDY VALIDITY AND CONFIABILITY THE BATTERY
LURIA INICIAL TO IDENTIFY ALTERATIONS
Ramírez Benitez Y. University Cienfuegos. Dept Psychology. Center Neurosciencie of Cuba. Dept. Neurosciencie School.
Introduction: The Battery Luria Initial has had a clinical utility of impact in Cuba. Investigations demonstrate the effectiveness of the instrument to organize diagnosis strategies and rehabilitation neuropsychological in preschool children (5 - 6 years) with delay in the acquisition of functions psychological
superiors. Method: A study descriptive longitudinal correlacional of panel intends to Determine the
validity of the battery Luria Initial to identify alterations neuropsychological in the preschool age in a
Cuban population with backwardness in the process of acquisition of the functions psychological superiors. It calculates the coefficient of Cronbach, it defines the% of the explained variance and it shows
the value predictor of the executive functions of the battery two years after having applied with the test
SESH 1.1 (System of Evaluation and Pursuit of the patient with Hypothyroidism). It uses a sample of
126 children: 89 with TDAH, 25 with smaller neurological signs and 12 with factors of neurological risk
for early hypoxia. Results: The instrument has a smaller internal consistency that the Spanish norms
(0.92), but it maintains a reliable statistical value (0, 82). The% of the variance explains to 58, 64
comparative% with the original 59.73% and with 62, 50% compared with the Mexican 68, 51%. The
executive factor of the battery turned out to be a strong predictor of the executive functions. Conclusions: The instrument is valid to identify alterations neuropsychological in Cuban children with TDAH,
records of early hypoxia and smaller neurological sign. It presents a strong value predictor of executive
alterations after two years of applied the instrument.
MO056
EFFECTS OF RED-WINE ON PLANNING CAPABILITY IN RELATION
TO THE MENSTRUAL CYCLE: AN ELECTROENCEPHALOGRAPHIC STUDY
SANZ-MARTIN, A., GUEVARA, M.A., SANTANA, G., HERNÁNDEZ-GONZÁLEZ, M., GUMA, E.
INSTITUTO DE NEUROCIENCIAS, UNIVERSIDAD DE GUADALAJARA
Several investigations have shown that the metabolism of alcohol and some cognitive functions vary
during the menstrual cycle. Besides, both alcohol ingestion and hormonal variations during menstruation have been associated with characteristic changes in electroencephalographic activity (EEG). The
objective of the present study was to determine whether EEG activity during performance of a planning
task (Tower of London, TOL) is affected by previous ingestion of red wine, and if these EEG patterns vary
in relation to different phases of the menstrual cycle. For this purpose, women consumed a moderate
dose of alcohol or placebo during the post-menstrual and post-ovulatory phases of the menstrual cycle
and then, 35 minutes after liquid ingestion, EEG activity was recorded during performance of TOL. A
deleterious effect of red wine on TOL performance was potentiated in the premenstrual phase, related
to higher alpha1 relative power, probably as a result of the low progesterone levels characteristic of
this menstrual phase. These data demonstrate the feasibility of examining the interaction of alcohol
and menstrual cycle phases on cognitive performance by means of EEG recording, and contribute to a
better understanding of the brain mechanisms that underlie the cognitive changes that occur during
menstrual cycle under the alcohol effects.
MO057
EVALUATION OF THE NEUROPROTECTIVE
EFFECT OF PROPOLIS COLOMBIAN
MO058
THE BLOCKED OF INTERLEUKIN-1 RECEPTOR IN TEMPORAL CORTEX
PREVENTS THE NEUROTOXICITY OF AMYLOID B-25-35 IN RATS
GALLEGO DY(1), FIGUEROA J(1), and OROZCO CA(1), (1) Facultad de Medicina Veterinaria y de Zootecnia,
Universidad Nacional de Colombia, Colombia.
A. DIAZ (1), E. RAMIREZ (1), I. MARTINEZ (1), M. RUBIO-OSORNIO (2), E. ZENTENO (3), J. GUEVARA (3), D.
LIMON (1). (1)Lab. de Neurofarmacologia. Facultad De Ciencias Quimicas. BUAP, Puebla, Mexico; (2)
Lab. Experimental. de Enfermedades Neurodegenerativas, Inst. Nacional de Neurologia y Neurocirugia,
MVS, Mexico DF., Mexico; (3)Depto Bioquímica, Facultad de Medicina, UNAM, Mexico DF., Mexico.
Oxidative Stress is product of excessive formation of oxidizing species and decrease of activity of endogenous antioxidant systems. This condition has aroused great interest because it could be related to
etiopathogenesis of Neurodegenerative Diseases associated with aging, like Alzheimer and Parkinson.
Development of antioxidant therapies for treating these neuropathies, has allowed identifying natural
substances with neuroprotective properties in in vitro models. One of those substances is the propolis,
which has been so studied for its high content of polyphenols (antioxidants). It has been suggested that
high antioxidant activity of propolis is related with concentration of polyphenols like flavonoid, which
is determined by the botanical and the geographical origin of each sample of propolis. After considering the botanical diversity found in Colombia, our study evaluated if this botanical diversity could de
related with possible neuroprotectant properties of 26 Colombian propolis. It study was evaluated in
two different models of in vitro neurodegeneration: H2O2 and KCl. The propolis samples were obtained
from 3 different regions of Colombia. Results obtained were compared with neuroprotectant activity
of Brazilian Green Propollis. The viability data obtained with MTT test showed that none of Colombian
propollis samples were able to prevent death in human neuroblastoma cell line SHSY-5Y exposed to
H2O2 or KCl (p_0.05). Data obtained from the LDH assay supports the previous data, also showing no
protection from Green Propolis of Brazil when treated with KCl (p_0.05). In conclusion, after considering that propolis samples included in our study failed to develop cytoprotective activity, we consider it
is necessary to initiate new studies that can establish why, despite its antioxidant properties, none of
the samples included in this study were able to avoid cell death, and if this lack of effect can be related
to some process in the production or storage of propolis.
Recent evidence has shown that the injection of Ab25-35 into the temporal cortex (TCx) of rats increases the interleukin-1 b (IL-1 b); however, it is unclear how the IL-1 b could be involved in the
progression of A_25-35 toxicity to cause neurodegenerative events and memory impairment. The aim
of our work was to evaluate the role of IL-1b in the neuronal damage and spatial memory impairment
generated by A_25-35 in the rat’s TCx. We used adult male Wistar rats (250 to 280 g). The animals
were divided into three groups: Vehicle, A b 25-35, and interleukin receptor antagonist (IL-1ra)+A b
25-35 (n=8 per group). These groups were injected with 1-_L vehicle (control) or 1-_L of A_25-35
[100_M] in the TCx by stereotactic surgery. The IL-1ra (10 and 20 μg/ μL) was injected 10 min before
the injection of vehicle or A b 25-35 in the TCx, respectively. The learning (20 days post-injection) and
memory (30 days post injection) tests evaluated in the radial maze. After the animals were decapitated
(n=4 per group); their brains were embedded in paraffin. The slides were treated to quantify the
number of undamaged neurons in the TCx by H&E staining. The rest of the animals was killed, the brain
were dissected to obtain TCx to quantify the concentration of IL-1 b by ELISA method. Our findings show
that A b 25-35-injection into the TCx delayed acquisition of learning and impaired spatial memory
(35 and 41%). The previous administration of IL-1ra prevents the memory dysfunction induced by
Ab25-35- injection (25 and 30%). The A b 25-35 induced an increase of IL-1 b and the loss of neurons
(41%) in the TCx 30 days after injection. The previous administration of IL-1ra, significantly reduce
the A b 25-35-induced neurodegeneration. This study suggests that involvement of IL-1 b is a critical
point in the progress of the neurodegeneration and cognitive impairment induced by A b 25-35 injection into TCx of rat.
MO059
EXCITOTOXICITY IN HIPPOCAMPUS BY NMDA: THE EFFECTS
IN EXPRESSION THE AMPA RECEPTORS AND THE PARAWIXIN 10
MO060
STRIATAL MITOCHONDRIAL DYSFUNCTION LEADS TO
APOPTOSIS AFTER CHRONIC EXPOSURE TO PARAQUAT
*Helene Aparecida Fachim1,2, Melina Iyomasa3, Maria Luiza Nunes Mamede Rosa2,3; Wagner Ferreira
dos Santos1,2. 1Departamento de Biologia, FFCLRP-USP, Ribeirão Preto, SP-Brazil; 2 INeC-Instituto de
Neurociências e Comportamento de Ribeirão Preto, Ribeirão Preto, SP-Brazil; 3 Faculdades Integradas
Padre Albino- FAMECA, Catanduva, SP-Brazil.
Czerniczyniec, A. (1); Lores Arnaiz, S. (1); Bustamante, J. (1). (1) Laboratory for Free Radical Biology,
University of Buenos Aires, Argentina
The aim of this work was to evaluate, in a time course, the changes on the expression of AMPA glutamate receptors and the effects of Parawixin 10 after intrahippocampal NMDA injection. Male Wistar
rats (250g) were divided into three groups, control (0.6μL saline), NMDA (7.2μg/0.6μL) and treated
with Pwx10 (2.5 μg/1.0 μL). All groups were bilaterally injected into hippocampus and the treated
group received the Pwx10 into VL after 24h the NMDA injection during 1 week. The NMDA group was
further divided into 4 subgroups: 24 h, 1 wk, 2 wks and 4 wks (time after injury when animals were
sacrificed). We evaluated the expression of GluR1 and GluR2 subunits analyzed by immunohistochemistry and the treated group was evaluated by Nissl staining. An increase of GluR1 was found in CA1 in
both 2 wks (20%) and 4 wks (35%) subgroups. In contrast to GluR1, a de crease in GluR2 was found
in CA1 any time after injury (60%, 24 h; 75%, 2 wks and 78%, 4 wks). In the hilus of dentate gyrus
(HDG) an increase in both GluR1 (46%, 2 wks) and GluR2 (28%, 24 h; and 25%, 2 wks) was observed.
Only the expression of GluR1 has changed after injury in CA3, we found an increase 2 wks (22%) and 4
weeks (21%) after injury. In Pwx10, we observed in CA1 a larger number of cells when compared with
the NMDA group (27%) and no alteration in CA3 and Hilus. We concluded that glutamate is involved on
the mechanisms of injury triggered by intrahippocampal NMDA injection in different ways, considering:
i) GluR1 or GluR2 subunit, ii) specific area of the hippocampus and iii) time after injury. In addition,
the Pwx10 could confer protection on this model.
Paraquat has been described as a potential environmental neurotoxin associated with neurodegenerative diseases. It can generate oxidative stress producing brain damage after chronic exposure. As
mitochondrial dysfunction has been implicated in neurodegenerative diseases, the aim of this work
was to evaluate striatal mitochondrial function and the contribution of mitochondria to the molecular
mechanism of apoptosis in an experimental model of neurotoxicity induced by paraquat. Sprague-Dawley adult female rats received paraquat (10 mg/Kg i.p.) or saline once a week during a month. Results:
State 4 oxygen consumption was increased by 74 % and state 3 oxygen consumption was decreased
by 33% in striatal mitochondria from treated animals, resulting in a decreased respiratory control
after paraquat treatment. As a consequence, a clear mitochondrial depolarization was induced. In addition, a 34% in Complex I activity was observed after paraquat treatment. Also, increased oxygen free
radicals production as superoxide anion and hydrogen peroxide, was observed in striatal mitochondria
after paraquat treatment, being 17 % and 48 % respectively, as compared with control animals. As a
consequence, striatal mitochondrial cardiolipin oxidation significantly increased after paraquat treatment. The observed mitochondrial dysfunction led to membrane permeability alterations, showing increased mitochondrial Bax association, and cytochrome c and AIF release to the cytosol. These results
show that paraquat treatment was able to induce apoptotic intrinsic signalling pathways involving a
clear mitochondrial dysfunction in striatal rat tissue.
MO061
POST-ISCHEMIC ADMINISTRATION OF PROGESTERONE REDUCES
NOGO-A, NG-R AND RHO-A EXPRESSION IN THE HIPPOCAMPUS
OF RATS SUBJECTED TO GLOBAL CEREBRAL ISCHEMIA
MO062
PROGESTERONE AND ALLOPREGNANOLONE REDUCE THE
REACTIVE GLIOSIS AND PRESERVE THE FUNCTIONAL INTEGRITY OF
THE HIPPOCAMPUS AFTER GLOBAL CEREBRAL ISCHEMIA IN RATS
ESPINOSA-GARCÍA C(1), AGUILAR-HERNÁNDEZ A(1), CERVANTES M(2) and MORALÍ G(1), (1)Unidad de
Investigación Médica en Farmacología, Centro Médico Nacional Siglo XXI, IMSS. México, D.F. and (2)Facultad de Ciencias Médicas y Biológicas “Dr. Ignacio Chávez”, Universidad Michoacana de San Nicolás
de Hidalgo, Morelia, Michoacán. México.
Aguilar-Hernández A(1), Espinosa-García C(1), Cervantes M(2), Moralí G(1)
(1)Unidad de Investigación Médica en Farmacología, Centro Médico Nacional Siglo XXI, IMSS. México,
D.F. (2)Facultad de Ciencias Médicas y Biológicas “Dr. Ignacio Chávez”, Universidad Michoacana de San
Nicolás de Hidalgo, Morelia, Michoacán. México.
Nogo-A, a myelin-associated growth inhibitor, binds to Nogo receptor (Ng-R), activates the Rho-A GTPase, and limits the plasticity after CNS injury. We assessed the effect of progesterone (P4) on the
expression of Nogo-A, Ng-R, and Rho-A in the hippocampus following global cerebral ischemia (GCI).
Adult male Sprague-Dawley rats were subjected to GCI for 15 minutes by the four-vessel occlusion
model. P4 (8 mg/kg, i.v.) or its vehicle (2-hydroxypropyl-betacyclodextrin 20% in sterile water), were
administered at 15 min, 2, 6, 24, 48, and 72 h of reperfusion. Rats subjected to sham procedures were
used as controls. Rats were sacrificed either at 72 h or 7 days of reperfusion, or at 14, 28, or 97 days
of reperfusion after being tested for spatial learning and memory in the Morris Water Maze (MWM).
Nogo- A, Ng-R, and Rho-A were evaluated by immunohistochemistry in the hippocampus. A weak immunoreactivity (IR) to Nogo-A, Ng-R and Rho-A was found in pyramidal neurons of all hippocampal
subfields in the sham groups. In contrast, a strong IR to Nogo-A, Ng-R and Rho-A was observed either
in damaged neurons of the CA1 subfield, or in some undamaged neurons at CA2, CA3 and the hilus,
evident from 72 h and persisting until 14 days after GCI. Treatment with P4 reduced Nogo-A, Ng-R, and
Rho-A IR in the pyramidal neurons of the various CA subfields, particularly at 14 days of reperfusion,
this effect coinciding with a more efficient performance of spatial learning and memory in the MWM,
as compared to non-treated rats. Present results suggest the reduction of growth inhibitory molecules
Nogo-A, Ng-R, and Rho-A, as a part of the restorative effects of progesterone possibly allowing plastic
phenomena to occur, able to support the functional preservation of the hippocampus following GCI.
This study assessed the effects of Progesterone (P4) and 3-alpha,5-alpha-allopregnanolone (ALLO) on
the astroglial and microglial reaction in the hippocampal Ammon’s horn of rats after global cerebral
ischemia (GCI), and on spatial learning and memory in the Morris Water Maze (MWM). Male adult
Sprague-Dawley rats were subjected to 15 min of GCI by the four-vessel occlusion model and treated
i.v. at 15 min, 2, 6, 24, 48 and 72 h after ischemia with: 1) P4, (8 mg/kg); 2) ALLO, (4 mg/kg); or 3)
vehicle (2-hydroxypropyl-beta-cyclodextrin, 20% in sterile water). Rats subjected to Sham procedures
were included as controls. Rats were sacrificed at 14, 28, or 97 days post-ischemia, after being tested
for the seven previous days in the MWM. Astrocytic and microglial reaction were analyzed by immunohistochemistry for GFAP and OX-42, respectively. Pyramidal neurons were counted in CA1, CA3 and the
hilus. Global ischemia resulted in a severe neuronal loss and an intense glial reaction with hypertrophy
of astrocytes and microglial cells along most of the Ammon´s horn, at the three periods of study. P4
treatment reduced the magnitude and extension of the glial reaction, as expressed by the number and/
or location of hypertrophic cells, mainly at 28 and 97 days after GCI, and preserved spatial learning
and memory, in spite of a severe neuronal loss, with few (about 15%) pyramidal neurons remaining in
CA1. ALLO exerted similar effects as those of P4, but with a slightly better preservation of pyramidal
neurons in CA1. These results suggest a neurorestorative effect of both P4 and ALLO, by reducing the
glial reaction possibly contributing to preserve the functional integrity of the hippocampus after GCI, in
spite of a low sparing of pyramidal neurons.
MO063
MESENCHYMAL STEM CELL-MEDIATED NEUROPROTECTION
IN AN EXPERIMENTAL MODEL OF PARKINSON’S DISEASE
MO064
GENE THERAPY BASED IN RNAI AGAINST CDK5 PREVENTS COGNITIVE
IMPAIRMENT IN RATS WITH TRANSIENT FOCAL CEREBRAL ISCHEMIA
Pereira MCL(1,2), Secco M(2), Janjoppi L(1,2), Rodini CO(2), Zatz M(2); Okamoto OK(2), (1)Disciplina de
Neurologia Experimental, Escola Paulista de Medicina - Universidade Federal de São Paulo, SP, Brazil.
(2)Centro de Estudos do Genoma Humano, Departamento de Genética e Biologia Evolutiva, Instituto de
Biociências, Universidade de São Paulo, SP, Brazil.
Gutiérrez-Vargas Johanna (1), Cardona-Gómez Gloria Patricia (1), (1) Group of Neuroscience, Cellular and Molecular Neurobiology Area, School of Medicine, SIU, Universidad de Antioquia, Medellín,
Colombia.
Cell therapy strategies are under consideration for Parkinson’s disease (PD) but, to date, clinical trials
with allogeneic transplantation of fetal neuroprogenitor cells in PD patients have not found significant
motor improvements and reported adverse effects. Here, we present evidences from a pre-clinical
study supporting alternative therapy with mesenchymal stem cells (MSC), based on indirect neuroprotective effects in an experimental model of PD. Intrastriatal injection of human umbilical cord-derived
MSC (hUC-MSC) in rats previously exposed to the neurotoxin 1-metyl, 4- phenyl, 1, 2, 3, 6-tetrahydropyridine (MPTP) inhibited neuronal loss in the substantia nigra (SN) and prevented onset of motor
deficits. Conversely, intrastriatal injection of fibroblasts, a xenotransplantation control of human cells
without stem cell properties, was highly detrimental, causing significant degeneration of SN neurons
and motor deficits independently of MPTP. Few hUC-MSC were detected not only in the vicinity of the
injection site, but also in other brain regions such as the medial septal nucleus, peripheral zone of
the striatum, and in the SN. Although engrafted hUC-MSC did not expressed Tyrosine Hydroxylase (TH),
suggesting lack of neuronal differentiation in vivo, TUNEL assays indicated lower amount of apoptotic
neurons in rats treated with hUC-MSC compared with control animals (sham and fibroblast-treated
animals). Moreover, increased TGF-beta levels were only found in brains of sham and fibroblast-treated
animals exposed to MPTP, suggesting response to an inflammatory condition. Our results suggest that
hUC-MSC induce potent neuroprotective adjustments in the brain, involving anti-apoptotic and antiinflammatory effects. These findings provide a rationale for further clinical trials with hUC-MSC aiming
at delaying disease progression and intensification of motor deficits, through paracrine effects rather
than direct neuronal replacement.
CDK5 is a kinase involved in synaptic plasticity, however deregulation in its activity contributes to
neurodegenerative processes. In this study, we evaluated the effect of silencing of CDK5 on cognitive
function after cerebral ischemia. Wistar rats subjected to focal cerebral ischemia, were intrahipocampal injected during the occlusion period of the middle cerebral artery (MCA). Physiological parameters
were measured (blood pressure, pH, pO2, pCO2) before, during and after cerebral ischemia. From 24
hours to two weeks post-ischemic neurological evaluation was performed and spatial learning and
memory tasks were analyzed. After, animals were sacrificed for histological analysis. Our findings
showed that ischemic animals treated with shCDK5miR (Isch-CDK5miR) required less time to reach
the hidden platform, respect to the ischemic animals treated with the control version shSCRmiR (IschSRCmiR). But shCDK5miR treatment did not reverse the memory affection showed by the ischemic rats.
Nevertheless, the Relearning during the transfer phase, Isch-CDK5miR treated animals were capable
of learning a new platform (position B), in less time without forgetting previously learned (position A),
compared to Isch-SRCmiR animals. Those results were supported for the reversion of neuropathological
hallmarks in the Isch-CDK5miR group. So, silencing of CDK5 prevents neuronal loss, reactive microglia,
tauopathy and glial hyper-reactivity caused by cerebral ischemia. In summary, our data suggest that
silencing of CDK5 in acute phase of ischemia/reperfusion prevent the neurodegeneration and cognitive
deficits caused by cerebral ischemia in a late time.
MO065
LESIONS OF ORBITOFRONTAL CORTEX DID NOT AFFECT
REINFORCEMENT OMISSIONS EFFECTS IN RATS
MO066
BRAIN ELECTRICAL ACTIVITY IN STROKE PATIENTS UNDER
TRANSCRANIAL MAGNETIC STIMULATION THERAPY
JUDICE-DAHER DM(1), and BUENO JLO(1), (1)Dept. of Psychology, Univ. of Sao Paulo, Ribeirao Preto,
Brazil.
Estrada Vinajera, Genco Marcio(1), Morales Chacón, Lilia (2) and Gómez Fernández, Lázaro (3). (1)
Institute of Neurology and Neurosurgery, Havana, Cuba. (2)International Center of Neurological Restoration, Havana, Cuba. (3)International Center of Neurological Restorati, Havana, Cuba.
The reinforcement omission effects (ROEs) have been attributed to both motivational and attentional
consequences of the surprising omission of reinforcement. Studies developed in our laboratory have
been shown that amygdala is part of a circuit involved in the ROEs modulation. The view that amygdala
lesions block ROEs is supported by evidence involving this area in responses correlated with motivational processes. These processes depend on the operation of separate amygdala areas and their
connections with other brain systems. Some studies have suggested that the interaction between the
basolateral complex of amygdala and cortical areas is important to the modulation of motivational
processes. Recent neuroimaging studies in human revealed that reward delivery enhances activity of
subcortical (nucleus accumbens and amygdala) and cortical (prefrontal cortex) structures, whereas
reward omission reduces the activity in these same structures. Thus, the present study aimed to clarify
whether the mechanisms related to ROEs depend on orbitofrontal cortex (OFC). Rats received bilateral
excitotoxic lesions of OFC or sham OFC lesions. After postoperative recovery, rats were trained on a
fixed-interval 12 s with limited hold 6 s signaled schedule of reinforcement. After acquisition of stable
performance, the training was changed from 100% to 50% schedule of reinforcement. Results showed
that the rats of both groups presented ROEs: the response rate was higher following nonreinforcement
than following reinforcement. Moreover, the response rates of the rats of both groups were not different
in the period following nonreinforcement when compared to the period preceding nonreinforcement.
These findings confirm previous studies showing that ROEs are not related to facilitation behavior
induced by nonreinforcement. Results also showed that there were no differences between the performance of the rats of both groups following nonreinforcement. Thus, these data did not support the
hypothesis that OFC included in the neural substrate involved in the ROEs modulation.
A double-blind prospective and longitudinal study was carried out at the International Center of Neurological Restoration of Havana to assess the electrical brain activity and to evaluate the clinical
evolution in a sample of 9 subjects with chronic stroke after rehabilitation and the application of low
frequencies repetitive Transcraneal Magnetic Stimulations (1Hz - rTMS) for therapeutic purposes. The
sample in study was randomly divided into two groups: 5 patients received sham rTMS stimulation
and 4 patients received real rTMS sessions ,both with daily sessions for 20 days. Electroencephalograms (EEG) were recorded before and after rTMS. The neurophysiological measures used were the
resting EEG power spectrum, the Delta/Alfa ratio (DAR), the spike-frecuency and the spike-amplitude.
Clinical characterization of these patients before and after the rTMS was assessed using Scandinavian
and Barthel Index scales. Sham rTMS group showed a significant overall stroke hemisphere increase
(p<0.05) in Alpha power spectra , whereas effects on the power of the theta and beta EEG bands significantly decreased (p <0.05). In nonstroke hemisphere slow and fast-frequency band power spectra
increased significantly (p <0.05). 1 Hz rTMS and Neurorehabilitation caused a tendency toward increase (p=0.06) in the Alpha band power spectra . DAR diminished 23 % more in the 1 Hz rTMS group
than in the sham rTMS group, and the spike-frecuency also increased in the first group (1 Hz rTMS)after
stimulations. There was a tendency to increased Scandinavian Scale score (p = 0.06), was greater in
the 1 Hz rTMS group. Stroke patients who received 1 Hz rTMS sessions experienced a propensity to the
cortical activation in both brain hemispheres, an increment tendency of cortical excitability and had a
better clinical recovery and of the brain electrical activity.
MO067
ELECTROPHYSIOLOGICAL STUDY OF NEUROPROTECTIVE
EFFICIENCY OF SINESTROL AND HYDROPONIC TEUCRIUM POLIUM L
ON HIPPOCAMPAL NEURONS AFTER BILATERAL OVARIECTOMY
MO068
STUDY OF MECHANISMS OF NEURONAL PROTECTION
BY NATURAL FLAVONES AFTER OXIDATIVE STRESS AND
THEIR RELATIONSHIP WITH THE MOLECULAR STRUCTURE
K.V. Simonyan (1), V.A. Chavushyan (1), H.M. Galstyan(2). (1) L.A. Orbeli Institute of Physiology, NAS RA
Armenia. (2) G.S.Davtyan Institute of Hydroponics Problems, NAS RA, Armenia.
ECHEVERRY C(1), ARREDONDO F(1), ABIN-CARRIQUIRY JA(1), Martinez M(1), MIDIWO J(2), OCHIENG
C(2),KERUBO L(2), DAJAS F(1), (1)Departmento de Neuroquímica, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay, and (2)Department of Chemistry, University of Nairobi,
Kenya.
Objectives: Bilateral ovariectomy (OVX) in female rats, which are offered as experimental model,
causes neurodegeneration in the nervous system of rats and imitates systemic disorders in postmenopausal women’s organism. The aim of present work was to determine the comparative action
of Sinestrol and Teucrium polium on hippocampal synaptic transmission of rats, plasticity, and cell
survival following OVX. Method: Electrophysiological studies by extracellular recording of hippocampal
single-neuronal spike activity under high-frequency stimulation (HFS) of ipsilateral entorhinal cortex
(EC) were performed on: 1) intact Albino rats, 2) after 6 week of OVX, 3) after 6 week of OVX (after 3
weeks i/m Sinestrol, 0.1ml 2%), 4) after 6 week of OVX (after 3 weeks i/m Teucrium polium, 20 mg/
kg). Results: In intact rats the excitatory and inhibitory responses are: tetanic potentiation (TP) with
posttetanic potentiation (PTP) (TP+PTP 17%), tetanic depression (TD) with posttetanic depression
(PTD) (TD+PTD 42%) and TD with PTP (TD+PTP 41%). After 6 week of OVX dominates areactivity in
neurons of hippocampal CA3 fields (45%). The other neurons were characterized by low repeatability
and excitability: TD+PTD - 33%, PTP -14 %, TD+PTP - 8 %, TP - 0 %. Our data suggest that OVX
reduces hippocampal synaptic activity and the balance of excitatory and inhibitory responses of norm.
In OVX+Sinestrol and OVX+ Teucrium polium groups- TP+PTP - 6 and 52%, TD+PTD - 22 and
29%, TD+PTP - 71 and 11% and areactive units – 1 and 8%. Conclusion: Sinestrol and Teucrium
polium promote the reorganization of neuronal circuitries of hippocampus by modulation of anomalous
synaptic activity.
Scientific evidences point to flavonoids as effective tools for the control of oxidative stress. Provided
the recognized role of the latter in brain pathology, the study of the chemical structure of flavonoids
that better contribute to protect neurons against oxidative insults will be meaningful for the design of
new molecules for the treatment of neuropathology. A structure-activity relationship study was previously performed, evaluating the protective capacity of 13 natural flavones in primary culture of cerebellar granule cells submitted to an oxidative insult 24 h after the addition of flavones. The flavones
were isolated from Kenyan plants and they were structurally related to quercetin. Results showed that
only 4 flavones exhibited neuroprotection, indicating that specific structural features would control
this activity: an OH substitution in C5 and C7 position of the A-ring, an OH substitution in C3 position
of the C-ring, and variable B-ring substitutions. In the present study we explored the mechanisms
of action of the protective flavones evaluating markers of oxidative stress, assessing the intracellular reactive oxygen species using the dichlofluorescein-diacetate as a radical probe and the lipid
peroxidation products analyzing the thiobarbituric acid-malodialdehyde adduct by HPLC. In addition,
the bioavailability of molecules in cultures was evaluated by HPLC and the in vitro antioxidant capacity
of the flavones was measured by the ABTS assay. Preliminary results showed that the neuroprotective
flavones prevented oxidative stress in primary cultured neurons without correlation with the in vitro
antioxidant capacity of each molecule. Cellular bioavailability was diverse for the different flavones.
Our results showed that although neuroprotective flavones without the catechol group in B-ring were
less antioxidant capacity in vitro, they were more stable. These results could be valuable leads for
designing flavonoid molecules with neuronal protection capacity.
MO069
DIFFERENTIAL EFFECT OF CHRONIC UNDERNUTRITION
ON THE POSTNATAL DEVELOPMENT OF GAIT LOCOMOTION
IN THE FEMALE AND MALE RAT
MARTÍNEZ-ÁLVAREZ V(1)(2), GUADARRAMA JC(1), ALVARADO M(2), SEGURA-ALEGRÍA B (3) and JIMÉNEZESTRADA (1),(1)Departamento de Fisiología, Biofísica y Neurociencias,Centro de Investigación y
Estudios Avanzados, IPN, México;(2)Instituto de Neuroetología,Universidad Veracruzana, México. and
(3)Departamento de Biología,FES Iztacala,UNAM,México.
In order to analyze possible gender differences in the effect of chronic undernutrition on the locomotor
behavior of the rat we performed a kinematic analysis of gait during the postnatal development of
female and male rats. Adult Wistar female rats were maintained under different feeding conditions:
A) Control group: the rats and their offspring were kept under conditions of free access to water and
food. B) Undernourished group: three weeks before mating, gestation, lactation and post-weaning
periods the puppy rats were fed with half the food ingested by control animals (each group n= 8 per
litter). The recording of gait activity was performed once a week, for 9 weeks from the 4th or 5th day
of life of the offspring. Once quantified the weight, height and body mass, the kinematic recording
was performed by using one video-assisted computerized system developed in our lab and the stride
length speed data was normalized according to the body mass of animals. The chronic food deprivation induces a significant reduction in the morphometric parameters of male puppies (P> 0.01) but
not in female rats. At post-weaning stages of development, the gait of undernourished male rats is
characterized by strides of lower duration (25-30%) but higher normalized length (146.7 to 199.0%)
and notorious higher stride speed (158.0 to 657.1%) than the strides of control male rats (P> 0.01).
Meanwhile, the gait of the undernourished female rats is practically similar to that of control female
rats, at all the postnatal ages studied. Our results allow to suggest that chronic undernutrition affect
the body mass and the gait of the male rat but it doesn´t affect the morphometric and gait parameters
of the female rat. According to the later, It´s disclosed the existence of gender differences in the
alterations evoked by chronic undernutrition in the rat.
MO070
DOES UNILATERAL AMYGDALA LESION IMPAIR
THE REINFORCEMENT OMISSION EFFECT?
BUENO JLO(1), TAVARES TFT(1), JUDICE-DAHER DM(1), (1)Dept. of Psychology, Univ. of Sao Paulo, Ribeirao Preto, Brazil.
Recent studies showed that bilateral lesions which included both central nucleus (CeA) and basolateral complex (BLA) of amygdala eliminated the reinforcement omission effects (ROEs) when rats
were trained on a fixed-interval with limited hold signaled schedule (FI LH). However, bilateral lesions
involving only the CN or only the BLA can interfere with ROEs, but not eliminate them. These studies
suggested that the effects of lesions in amygdala subnudsclei differ from those of a larger or smaller
lesioned area. Furthermore, several studies in appetitive learning indicate that amygdala involvement
is lateralized: right amygdala may be more related than the left in the memory consolidation of aversively motivated training (e.g. reduced reward) and left amygdala is more involved than the right in the
exploratory activity and anxiety. Thus, the present study investigated the effects of unilateral neurotoxic
lesions which included both CeA and BLA in the right (Experiment 1) or left amygdala (Experiment 2)
on the ROEs. In all experiments, rats were first trained on a FI 6 s LH 6 s signaled schedule in which
correct responses were always followed by reinforcement delivery. Lesions were made after acquisition
of stable performance. Following postoperative recovery, the training was changed from 100% to 50%
reinforcement schedule. The results of the Experiment 1 and 2 showed that unilateral lesions (right or
left amygdala) did not impair the ROEs: the response rates were higher after reinforcement omission
than after reinforcement delivery for all groups. After reinforcement omission, the lesioned groups
presented the ROEs as well as their sham-operated groups. These results suggest that there was not a
differential involvement of the right and left amygdala in the ROEs, on a FI 6 s LH 6 s schedule, indicating that the amygdala involvement in the ROEs is not lateralized.
MO071
END-TO-SIDE TUBULIZATION: EFFECTS OF DULBECCO’S
MODIFIED EAGLE MEDIUM (DMEM) AND MATRIGEL®
IN INTACT MYELINATED FIBERS SPROUTING
MO072
EFFECTS OF MASTICATORY DEPRIVATION REGIMES AND
REHABILITATION ON SPATIAL MEMORY AND LAMINAR
DISTRIBUTION OF ASTROCYTES IN CA1
Barreira AA, Nascimento-Elias AH, Schiavoni MCL, Mota TS, Marques Jr W.
G.S.Davtyan Institute of Hydroponics Problems, NAS RA, Armenia.
MENDES FCCS(1), ALMEIDA MNF(1), FELÍCIO APG(1), FALSONI, M(1), ANDRADE MLF(1), BENTO-TORRES,
J(1), VASCONCELOS PFC(2), PERRY VH(3),PICANÇO-DINIZ(1), SOSTHENES MCK(1)* (1) Lab. de Investigações em Neurodegeneração e Infecção, HUJBB/ICB, Univ. Federal do Pará, Belém/PA, Brazil. (2)Dep. de
Arbovirologia e Febres Hemorrágicas, Instituto Evandro Chagas, Ananindeua/PA, Brazil. (3)Southampton Neuroscience Group, School of Biological Sciences, University of Southampton, England.
Recently we described the end-to-side tubulization (EST). EST is obtained by using a tube interposed
between the lateral region of the donor nerve and the stump of the target nerve. EST is associated with
functional fiber regeneration. Here we verify if the sprouting of intact fibers is stimulated by nerve
regeneration inducers (NRI) using EST. We used eight female Wistar rats, aged between six and eight
weeks in each of the 3 groups: empty tube (ESTU-G), DMEM-G and MATRi-G (Matrigel®). The peroneal
nerve was dissected 3mm below the sciatic nerve trifurcation under anesthesia and neurotmesis was
performed. The proximal stump was buried into the neighboring muscles and fixed with a stitch. The
distal stump was sutured to a 5mm long empty silicone tube. The other end of the tube was sutured in
the lateral portion of the tibial nerve 3mm below the origin of the buried branch. DMEM and MATRi were
introduced in the tube of their respective groups. Fifty three days later, the silicone tube was removed
and the peroneal nerves were sectioned 2mm after the distal end of the tube. The distal specimens
were embedded in plastic resin. The semi-thin sections were stained with toluidine blue. Morphometry
was done with a KS 400-Kontron software. In all animals a regeneration cable was formed and reached
the distal segment. The number of myelinated fibers in the ESTU-G was 710 (range: 192.00-1305.00
fibers). In the DMEM-G that number was was 720 (range: 253.00-1299.00) and in the MATRi-G it was
366,00 (range: 78.00-567,00). There was no significant difference between the number of myelinated
fibers of ESTU-G and DMEM-G (p = 0,05). The MATRi-G number of fibers was significantly smaller.
Therefore, differently of what occurs in sectioned nerve fibers, NRI seem not be active to induce sprouting in intact fibers. More studies are needed confirm these results.
We assessed long-term effects of environmental changes and masticatory deprivation and rehabilitation on spatial memory and correlate memory dysfunctions with CA1 astrocytic laminar distribution in
6- and 12 months-old mice. To do so female mice were housed from 21st post-natal day onwards in
enriched cages and fed with one of four diet regimes: continuous soft (SD) or hard (HD) diets, equal
periods of hard and soft diets (HD/SD), or alternate periods of hard, soft, and hard diets (HD/SD/HD). To
detect memory changes, all subjects were submitted to the Morris water maze and had their brains immunolabeled for glial fibrilary acid protein-GFAP to detect astrocytes. Estimations of laminar distribution were done by unbiased based stereological method. As compared to all other groups HD/SD show
the highest degree of memory impairment. In contrast, individuals from HD/SD/HD groups independent
of age preserved their ability to learn and remember the location of the hidden platform suggesting
that rehabilitation may reduce cognitive damage. Stereological estimations revealed that the laminar
distribution of astrocytes in CA1 was differentially affected by reduced mastication and age and these
variables seem to produce addictive effects. In the stratum pyramydale both HD and SD 6M individuals
showed a higher number of astrocytes than 12M equivalent groups, where was evidenced a significant
difference between 6- and 12-month-old at both HD and SD groups. As compared with age matched
individuals from all other groups the worse a spatial memory performance found in HD/SD 12M group
was associated with a higher number of astrocytes in the stratum pyramidale. We are starting to
investigate the molecular changes associated with these experimental groups.
MO073
EFFECT OF PRENATAL TRYPTOPHAN DEPLETION DURING
DIFFERENT EMBRYONIC STAGES ON THE CORTICAL
CYTOARCHITECTURE AND NEURONAL MORPHOLOGY IN RAT
Valle-Bautista Rocío(1),Flores – Cruz M. Guadalupe(1), and Escobar Alfonso(1), (1)Dpto de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas,UNAM,México Distrito Federal,MexDF.México.
Serotonergic system arose early during neurodevelopment, more precisely at rat’s embryonic day 10.5,
when the first transcription factors related to serotonergic phenotype are detected in rostral rhombomers. The early production of serotonin (5-HT) suggests that this neurotransmitter exerts a regulatory function is for the development of serotonin system and its targets during ontogeny. The dietary
restriction of tryptophan (Trp) is a 5HT depletion method that achieves decrease of central 5HT levels
due to Trp is a 5-HT precursor. The aim of this study is characterize the effect of 5-HT prenatal depletion during different rat embryonic stages on the adult cerebral cortex, analyzing its cytoarchitecture
and the morphology of pyramidal neurons. The behavior of the tryptophan deprived rats will also be
examined with the open field test. To achieve this objective, pregnant rats were assigned to one of following conditions: tryptophan deficient diet (TDD), tryptophan deficient diet + tryptophan (TDD+T)
and chow diet (Ch). Experimental manipulation was performed during one of the following gestational
periods: E8 to E12 (5-HT neurons differentiation period) and E13 to E17 (5-HT neurons proliferative period). At delivery newborn pups were euthanized; body and brain weighted and brainstems were sliced
and processed for tryptophan hydroxylase (TrpH) immunohistochemistry. Sections containing DR were
photodocumented and Trph immuno-reactive (ir) neurons quantified. HPLC for 5-HT was performed
at postnatal days 0, 20 and 40. Cortical morphology was assessed at P20 and 40 using Golgi-Cox
stain. At P40 Open field (OF) behavior was examined under two illumination conditions: intense or
dim light. Preliminary results suggest that Trp prenatal depuration by TDD during differentiation period
changes the normal pattern of TrpHir neurons distribution along DR. TrpHir neurons seems to exhibit
“medialized” DR
MO074
SPROUTY4 IS AN ENDOGENOUS NEGATIVE MODULATOR OF TRKA
SIGNALING AND NEURONAL DIFFERENTIATION INDUCED BY NGF
ALSINA FC(1), IRALA D(1), FONTANET PA(1), HITA FJ (1), LEDDA F(1,2), PARATCHA G(1,2), (1) Division of
Molecular and Cellular Neuroscience, Institute of Cellular Biology and Neuroscience “Prof. Dr. E. De
Robertis” (IBCN)-CONICET, School of Medicine, University of Buenos Aires (UBA), Buenos Aires, Argentina; (2) Laboratory of Molecular and Cellular Neuroscience, Department of Neuroscience, Karolinska
Institute, Stockholm, Sweden.
The Sprouty (Spry) family of proteins represents endogenous regulators of downstream signaling
pathways induced by receptor tyrosine kinases (RTKs). Using real time PCR, we detect a significant
increase in the expression of Spry4 mRNA in response to NGF, indicating that Spry4 could modulate
intracellular signaling pathways and biological processes induced by NGF and its receptor TrkA. In this
work, we demonstrate that overexpression of wild-type Spry4 causes a significant reduction in MAPK
and Rac1 activation and neurite outgrowth induced by NGF. At molecular level, our findings indicate
that ectopic expression of a mutated form of Spry4 (Y53A), in which a conserved tyrosine residue was
replaced, fail to block both TrkA-mediated Erk/MAPK activation and neurite outgrowth induced by NGF,
suggesting that an intact tyrosine 53 site is required for the inhibitory effect of Spry4 on NGF signaling. Downregulation of Spry4 using small interference RNA knockdown experiments potentiates PC12
cell differentiation and MAPK activation in response to NGF. Together, these findings establish a new
physiological mechanism through which Spry4 regulates neurite outgrowth reducing not only the MAPK
pathway but also restricting Rac1 activation in response to NGF.
MO075
CELLS WITH SEROTONERGIC PHENOTYPE MARKERS
IN THE FETAL NEOPALLIUM IN CO-CULTURES
MO076
MIRNAS DETECTION IN HUMAN EMBRYOS CULTURE MEDIUM:
ITS IMPORTANCE IN QUALITY EVALUATION
Hernández-R J (1), Manjarrez GG (2) and Boyzo MA (1), (1) Lab. de Neurontogenia, Depto. de Fisiología,
Biofísica y Neurociencias, CINVESTAV-IPN; (2) Unidad de Investigación Biomolecular, Hospital de Cardiología, Centro Médico Nacional Siglo XXI, IMSS.
(1)Cruz-Reséndiz Mónica, (1)Díaz-Martínez Néstor Fabián, (1)García-López Guadalupe, (3)Flores-Herrera Héctor, (2)Vega-Hernández Eva, (2)De la Jara-Díaz Julio Francisco y (1)Molina-Hernández Anayansi.
(1)Dpto. de Biología Celular;(2)Coordinación de Biología de la Reproducción;(3)Dpto. de Bioquímica,
Instituto Nacional de Perinatología, México, D. F.
In organotypic cocultures of the fetal rat cerebral cortex (neopallium, E13-E16), we have identified
cells with immunohistochemical markers of the serotonin synthesis machinery: tryptophan-5-hidroxylase, serotonin and Sert. As well as the 5-HT1A molecular signaling path. The serotonergic phenotype
is normally expressed early in the brainstem of the rat embryo, and these cells would develop a fiber
system whose terminals innervate various fetal brain areas, including the early cortex. But serotonergic, neuronal or glial somata, have not been described so far in the developing cerebral cortex. The
role of these serotonergic cells might be to support transiently processes related to corticogenesis.
In the Instituto Nacional de Perinatología-Mexico City, embryos obtained for assisted reproductive
techniques are selected by morphological evaluation at different days post fecundation. It has been
reported that the morphological evaluation is insufficient to ensure implantation with only one embryo,
for this reason more than one embryo is transferred to ensure pregnancy. However; this increases
the maternal-fetal risk due to multiple pregnancy. This problematic lead us to search for biomarkers
that can be found in the culture media and that could be used to evaluate embryo quality with the
best probability of implantation. microRNAs (miRNAs) synthesized by the embryo could work as this
biomarkers. miRNAs are small, non-coding RNAs that regulate protein synthesis at post-transcriptional
level and play a significant role during early development in mammals; it has been reported that they
are important for oocyte maturation and embryo development. Considering that miRNAs are regulators
of embryo development, we select 5 miRNAs and its variants, from previously reported microarray studies, to evaluate if we were able to detect them by RT-PCR in culture media from 3rd day embryos. In a
double-blind study and using stem-loop primers the RT reaction was carried out without previous RNA
extraction. Subsequently, PCR was performed and the presence or absence of the miRNA was verified
in 4 % agarose gels as a fragment of approximately 70-75 bp. The quality from each embryo was then
verified and the presence or absence of each microRNAs in the culture medium was tabulated depending of its corresponding quality. Results indicate that we were able to amplify miRNAs direct from
culture medium and that the presence or the absence seems to be related with the quality evaluated
by morphology. Supported by INPer and CONACyT fellowship to Mónica Sugely Cruz Reséndiz.
MO077
DOSE SERUM MICRORNAS COULD FUNCTION AS EMBRYO
BRAIN DEVELOPMENT BIOMARKERS?
(1)Cruz-Reséndiz M., (1)Lamadrid M., (1)Díaz N.F., (1)Pérez-De la Cruz E., (1)Sólis K.H., (2)FloresHerrera H., (1)García-López G. and (1)Molina-Hernández A. (1)Dpto. de Biología Celular;(2)Dpto de
Bioquímica, Instituto Nacional de Perinatología, México, D.F.
MO078
POSTNATAL DEVELOPMENT OF HOMER 1A IN THE HIPPOCAMPUS
Corinne J. Montes-Rodriguez and Bruce L. McNaughton.
University of Lethbridge, Canada.
The detection of tissue specific microRNAs in serum obtained from peripheral blood suggests that
these molecules. could be use as biomarkers in physiological and pathological conditions. Several
groups had reported changes on the expression of a large group of microRNAs during cerebral cortex
formation in animal models. These molecules are essential for survival and differentiation of newborn
neurons but not for expansion of neural progenitors during early neurogenesis in the mouse embryonic
neocortex as demonstrated by Dicer ablation. Recently, it has been reported that neural tube defects
related microRNAs are present in 19 week pregnant women serum. Here, study we explored the levels of
4 microRNAs (miR-124, miR-125a, miR-125b and miR-9) that are involve in early cortical neurogenesis
and undergo dynamic regulation during neuron differentiation in embryo neural progenitors from 11 to
13. We explored by RT-PCR the levels of these four microRNAs in serum from control and gestational
diabetic voluntaries at the 1st, 2nd and 3th trimester, and non pregnant women. Our results showed:
1.- significant increases during the 2th and 3rd trimester for miR-124, miR-125a and miR-125b and
a reduction on miR-9 during these period in healthy women, 2.- important reduction in the four microRNAs in gestational diabetes and 3.- no differences between non pregnant and gestational diabetes
women. Our results suggest that the four microRNAs could function as biomarkers. We further need
to explore if children from gestational diabetes mothers have intellectual developmental disorder as
compared with health mother progeny.
Homer 1a (H1a) is an immediate early gene involved in multiple forms of synaptic plasticity that
exhibits a postnatal increase in the rat forebrain (Brakeman et al., 1997). H1a reduces the density and
size of dendritic spines in cultured hippocampal neurons (Sala et al., 2003). The goal of this works was
to evaluate the H1a expression in the dentate gyrus (DG), CA1, CA3 and dorsal subiculum (DS) across
postnatal development. Brown Norway rats were sacrificed at different postnatal ages (P3, P5, P7, P9,
P15, P19, P23, P35, and adult). Maximal electroconvulsive shock (MECS) rats were studied at each
stage. Brains were removed, quick frozen in isopentane and stored at -80°C until sectioning. 20 μmthick sagittal sections across the whole brain were obtained. Fluorescence in situ hybridization (FISH)
for H1a was performed (Vazdarjanova et al., 2002). Z-stacks from CA1, CA3, DG and DS were acquired
with either 40X or 60X oil immersion objective lenses on a confocal microscope. Manual quantification
was performed by two experimenters blind to the conditions. In addition, large scale images of the entire sagittal sections were captured with an automated scanning microscope (NanoZoomer). H1a-blob
number was obtained by automated analysis using NDP analysis software (Lu and McNaughton, 2010).
Subsequent post-analysis for CA1, CA3, CA2, DG, and DS were computed. Manual quantification reveal
that from P3 H1a expression is found in a significant proportion of cells (around 50%) in DS, CA1 and
CA3. H1a positive cells reach a plateau in the second week of life for CA1, CA3 and DS. Laminar maturation of the DG was observed; H1a positive cells appear in the outer layer of the granular cells at the
beginning of postnatal development moving towards the inner layer across development. In the adult,
basically all granule cells express H1a. Automated analysis showed a similar trend than the manual
quantification. In conclusion, in CA1, CA3 and DS the maximum amount of cells capable to express H1a
reaches near adult levels by P7-P9. DG exhibits a linear H1a expression across postnatal development.
MO079
A NEUROSCIENCE FRAMEWORK FOR PUBLIC PRESCHOOL EDUCATION:
SUPPORTING THE REDESIGN OF PUBLIC EDUCATION CURRICULUM
MO080
NEUROEDUCATION: THE FIRST STEP FOR EDUCATIONAL
NEUROSCIENCE
ALFARO R(1), PADILLA M(1), CERDAS A.I (3), SIBAJA J(1); FORNAGUERA J(1,2). (1) Programa de Investigación en Neurociencias, Universidad de Costa Rica, Costa Rica. (2)Departamento de Bioquímica,
Escuela de Medicina, Universidad de Costa, Costa Rica Rica.(3)Departamento de Educación Preescolar,
Ministerio de Educación, Costa Rica.
Campos AL(1), Marquez MC(2),Zuluaga Jairo(3), Romero K(1), Ramirez LF(1), Ruiz C(1), Aguilar LA (1,4),
(1)Centro Iberoamericano de Neurociencias, Educación y Desarrollo Humano. Peru (2)Universidad Nacional Autonoma de Mexico. Mexico (3)Universidad Nacional de Colombia, Colombia. (4)Universidad
Peruana Cayetano Heredia, Peru
The connections between neuroscience and educational sciences have been a challenge for the advance of these disciplines. In Costa Rica, and given the necessity for a redesign of Public Education
Curriculum, the Neuroscience Research Program and the National Department of Preschool Education
have been working together on different research studies and educational applications. From these efforts several outcomes have arisen: the development of useful assessment instruments for educational
settings, intersectorial publications in collaboration and programs for public teacher instruction. One
major outcome has been the establishment of a nationwide program for the actualization of public preschool teacher’s premises and theoretical frameworks about cognition and neurodevelopment. In this
case, using a neurospsycological-neurocognitive framework that emphasizes executive functions (EF),
we have use cognitive processes constructs (working memory, inhibition control, planning and cognitive flexibility) as conceptual tools toward the understanding of the complex relations among child
development, nervous system functions and classroom environments that encompass play situations
and body movement activities. The instructional program highlights several psycho-motor and cognitive dimensions that can be used to design and improved classroom activities with preschoolers. Since
2011, a group of national and regional preschooler advisors is part of this initiative, in an attempt
to plant the seeds for the redesign of the national public education curriculum. Right now, several
workshops using this instructional program are taking place in different regions of Costa Rica. These
facts suggest that some Latin American countries can be turned into optimal scenarios for the materialization of real bridges between neuroscience and education.
The Neuroeducación is the result of the interaction of Neuroscience, Education and Psychology in order
to raise awareness of the importance of studying the nervous system and superior systems for the
implementation of learning strategies by professionals and students involved in these processes (development, memory, emotions, attention, etc.). In this regard, in recent years is developing the project
Neuroeducación Latin America, where an interdisciplinary group of different Latin American countries,
neuroscientists, psychologists and educators conduct basic and applied research, as well as conferences and courses taught in different countries of Latin America spreading the Neuroeducación, for
the purpose of promoting the development of the Neuroscience Education in the Region. We present in
this poster, proposals, progress and prospects for researchers from Latin American countries involved
in the development of this emerging line of neuroscience.
MO081
SECTIONAL NEUROANATOMY: PROPOSITION
OF A NEW MODEL FOR STUDY AND LEARNING
Silva, J.P. 1, Prado, C.M.2, Silva, P.D.S.1, Bim, W.R.3, Thomazini, J.A.1, Department of Surgery and
Anatomy1, Department of Pathology2, Laboratory of Human Anatomy3, Faculty of Medicine of Ribeirão
Preto, Universidade de São Paulo.
In the undergraduate courses of biomedical field, the course of Neuroanatomy frequently uses sections
of brain in different charts of sections for a better tridimensional view of the structures. To this end, the
students are encouraged to observe these sections, which are kept immersed in containers filled with
water during the practical classes. This method has proven efficient in learning, but because of overuse
and deterioration with the necessary manipulation of the anatomical parts during the time of study,
they must be replaced do to the great loss of cadaveric material and precious time of those who dissects. Using an apparatus which has been preconized and published in Anatomical Sciences Education
(pg.141-143, vol.3 2010), sections of brain and cerebellum were produced aiming to evaluate the efficiency of this device when compared to conventional sections during practical classes at the FMRP-USP.
Thus, the sections could be made with lower thickness and higher resolution. The parts were protected,
being preserved intact for a considerably longer time, maintaining the ideal level of hydration (10%
formaldehyde), optimizing the use of anatomical material and time of the lab technicians, without loss
of education quality. The sections were held immersed individually in an anatomical sequence in rigid
acrylic boxes within an other larger box of the same material. This system provides greater support,
with no visual distortion due to the thin wall thickness and refractive index boxes, suitable for easy
handling and allowing detailed observation of anatomical structures. In the future, questionnaires
will be used to know the opinion of the students to deepen our comparison between the two methods.
MO082
THE ROLE OF ETHICS IN EXPERIMENTAL RESEARCH WITH ANIMALS
PALLAS SL Neuroscience Institute, Georgia State University, Atlanta, Georgia, USA
Animal models are essential for progress in understanding nervous system structure and function, yet
the use of animals in research is increasingly being regulated and limited. Investigators must understand that the use of animals in their research is a privilege, not a right. Granting agencies, journals,
governments, and the public require that scientists conform to high ethical standards in the conduct
of their research. This presentation will address our collective responsibility to promote animal welfare
through the use of ethical practices in our own laboratories and in our universities. The critical need
for scientists to communicate to the public about the importance of ethical animal research to medical
progress will also be stressed.
MO083
BIOLOGICAL SCIENCE DISCIPLINES: IS THERE WAY
TO AN INTEGRATED CURRICULUM IN DENTISTRY?
MO084
NEUROSCIENCES IN COSTA RICA: A SUCCESSFUL EXAMPLE
OF MULTIDISCIPLINARY WORK
NORO LA(1), (1) Universidade Federal do Rio Grande do Norte, Brazil.
Jaime Fornaguera (1,2). (1) Programa de Investigación en Neurociencias, Universidad de Costa Rica,
Costa Rica. (2)Departamento de Bioquímica, Escuela de Medicina, Universidad de Costa Rica
Dentistry higher education institutions in Brazil generally have, over initial phase of the course, disciplines traditionally identified as “basic cycle”. Configure knowledge of great importance, with substantial contributions to the improvement of health, but are often decontextualized from competence and
abilities required by the National Curriculum Guidelines for undergraduate courses in Dentistry. There
is often a set of teachers that constitute a specific “body” to this area, with varied university education
and no involvement with the vocational area, as in public, as in private institutions. This study surveyed
the perceptions of students in advanced semesters on the knowledge acquired in these disciplines. It
was observed that isolated relevant themes were identified, however, the vast majority had great difficulty in relating the knowledge “acquired” in the start of the course with their professional education.
Students report that discouragement at this stage is the main reason of colleagues give up the course.
Most students, however, consider this phase as something natural to graduate in Dentistry. The excess
of information, detailed separately in each discipline, often leaves students perplexed by the complexity of content and concerned primarily with the approval. Effort is required of all managers, teachers
and students really worried about qualifying training, discussion and exploration of relevant changes
in the curriculum, allowing greater optimization of time for professional guidance. This content should
be included in context, articulated with the areas of professional and public health, making knowledge
modules that allow integration of knowledge and meaningful learning.
Since 1999 we are trying to develop a transdiciplinary work around neurosciences in the University
of Costa Rica. Some researchers belonging to different Institutes and academic faculties doing neurosciences research, are integrated. In our projects, step by step, different analysis levels were used,
contributing to understand the function and dysfunction of the nervous system. Research is running
from neurogenetics in humans and animals, trough animal models of neurological disorders, behavior
simulations, until executive functions of preschool children. Shortly we are studying, among others,
rearing effects (enrichment or isolation) on behavior and neurochemistry by rats, epigenetics and
individual differences, also using behavioral tests, the effects of differential maternal care on behavior
and neurochemical parameters, behavior simulation in order to reduce the number of animals for
research and more. Additionally, and working together with the Education Ministry of Costa Rica, we
are studying, among other, since 2006, executive functions, like working memory and inhibitory control
by preschool children. In this context we are developing some computer games using free software
(ie.Blender) to stimulate social interactions between them. In spite of the difficulties, neurosciences
in Costa Rica are on the right way to consolidate a researchers group that offer possibilities for the
interaction with other researchers around Latin America and beyond. The transdiciplinarity is not easy
as a theoretical approach but more difficult as an empirical method. Nevertheless it is possible.
MO085
MELANIN CONCENTRATING HORMONE (MCH) DECREASES
NEURONAL ACTIVITY IN THE MEDIAN RAPHE NUCLEUS
MO086
THE VALUE OF CT AND MRI IN THE DIAGNOSIS
OF NEUROTOXOPLASMOSIS IN AIDS PATIENTS
Claudia Pascovich*, Andrea Devera, Patricia Lagos, Alicia Costa, Atilio Falconi and Pablo Torterolo.
BARREIRO L(1), VAZQUEZ F(2), RODRIGUEZ E(1), (1)Hermanos Ameijeiras University Hospital, Havana,
Cuba, (2)Provincial Hospital, Matanzas, Cuba.
Hypothalamic MHCergic neurons project to several regions of the central nervous system, including the
dorsal (DR) and median raphe nuclei (MnR). These nuclei have a high density of serotonergic neurons
and are involved in the control of sleep. MCH-labeled tanycytes are present in the DR and MnR and are
specialized in transport substances from the cerebrospinal fluid (CSF) to the neuronal parenchyma;
this fact suggests that MCH could be absorbed from the CSF in order to modulate raphe neuron´s
activity. Indeed, we have demonstrated the presence of MCH in the CSF from several mammals and
that MCH microinjections into the DR produced a significant increment of REM sleep. In this study we
determined the effects of intracerebroventricular (i.c.v.) microinjection of MCH in standard extracellular recording of MnR neurons in adult Wistar rats anesthetized with urethane. We also studied the
effect of electrical stimulation of the lateral hypothalamus and juxtacellular microinjection of MCH on
MnR neurons. In 91% of the neurons recorded (n = 12), MCH i.c.v. decreases its firing rate from an
average of 5.6 ± 0.9 to 3.0 ± 0.9 Hz with a latency of about 1.5 minutes and a duration of about 3
minutes. Electrical hypothalamic stimulation decreases the firing rate in 7 of 8 raphe neurons recorded
showing an inhibitory effect which lasted about 30 minutes. Finally, juxtacelullar microinjection of
MCH, decreases the firing rate of MnR neurons (n = 8) from a value of 7.6 ± 0.5 to 0.3 ± 0.1 Hz.
The effect was followed by a rebound. Wilcoxon test was used to the statistical analysis. Statistical
significance was set at p < 0.05. We demonstrate that MCHergic hypothalamic neurons modulate MnR
neuronal activity and that part of this effect could be mediated by volume conduction through the CSF.
Partially supported by CSIC and PEDECIBA.
MO087
RECOMBINANT ADENOASSOCIATED VIRUS SEROTYPE 2
EXPRESSION IN DIABETIC RAT RETINA
DÍAZ-LEZAMA N(1),RAMÍREZ M(1), MORENO-CARRANZA B (1), MARTÍNEZ DE LA ESCALERA G (1), CLAPP C(1).
(1)UNAM Depto de Neurobiologia Celular y Molecular, Instituto de Neurobiología, Querétaro,Querétaro.
México
Diabetic retinopathy (DR) is a retinal vasoproliferative disease that constitutes the leading cause of
blindness among working-aged people. Current treatments for DR are not effective in all patients and
can be destructive, so that developing new strategies against DR has becomen a major research focus.
Ocular-gene therapy based on the AAV2 delivery of antiangiogenic molecules offers considerable promise for the treatment of DR.AAV2 produce long-term transgene expression in a variety of retinal cell
types with minimal toxicity. In this study, we investigated the retinal localization and level of expression of AAV2 transgenes in diabetic rat retinas. For this purpose, we used the streptozotocin-induced
diabetes rat model and the intravitreal injection of AAV2 encoding the green fluorescence protein(GFP).
Two weeks after inducing diabetes, diabetic rats (>250 mg/dl glucose in blood) and non diabetic rats
were injected intravitreally with AAV2-GFP and, after four weeks GFP-positive cells were investigated
in retinal criosections and in retinal flat-mounts by immunohistochemistry and direct fluorescence,
respectively. GFP was located in the retinal ganglion cell layer and in cellular projections conforming
the optic nerve. GFP fluorescence was significantly higher in the retina of diabetic vs non-diabetic
rats. Consistent with this difference, the expression of the AAV2 receptors (syndecan and perlecan),
evaluated by real time RT-PCR, was significantly higher in the diabetic vs the healthy retina. These
findings show that the intravitreal delivery of AAV2 transduces ganglion cells in the retina and that this
transduction increases in diabetes due, in part, to a higher expression of AAV2 receptors. It is proposed
that retinal conditions in DR favor the use of AAV2 vectors for the delivery of therapeutic molecules.
Supported by CONACYT grant 161594.
Purpose: Evaluate the utility of cerebral contrast CT and MRI in the diagnosis of this focal neurological
lesion in AIDS patients and based on this, we also proponed a diagnostic neuroimaging protocol to follow up with this specific kind of patients when neurotoxoplasmosis is clinicaly suspected. Methods and
Materials: A non contrast and a contrast CT and an MRI was performed in the same day to all patients
who were received from an Institute of Tropical Medicine in Havana to our radiology department, who
came to us after a clinical and neurological evaluation with the suspect of neurotoxoplasmosis. The
same study was perform three weeks later after the beginning of the specific treatment for this entity
to evaluate them unless of course that another complications occurs or the patient status were severe.
Results: We evaluated 41 patient who had the presumptive diagnosis of cerebral toxoplasmosis, the average age was 32 years old, the male sex represented a 78% of all patients, the principal clinical findings was headache (78%) and local motor defect (48.7%), the topographic of the lesions were more
common on gaglios de la base, parietal lobules, and thalamic regions, the majority of the lesions were
multiples and show a ring patron of enchasment after the administration of IV iodine based contrast.
Conclusion: The combination of both methods (CT and MRI) were capable to show cerebral lesions in
this entity the MRI were light more effective to show lesions located in the cerebellum. We estimated
the sensibility for both methods and were 97.57% for contrast CT and 100% for MRI. We establish an
images protocol to AIDS patients with the clinical suspect of cerebral toxoplasmosis, that we haven’t
before and we are planning to extend it to the rest of the hospitals who manage this patients in Cuba.
MO088
THE POLYCYSTIC OVARIAN SINDROME INDUCED BY
ESTRADIOL VALERATE OR CHRONIC COLD EXPOSURE AFFECTS
IN DIFFERENT WAY THE MONOAMINES CONCENTRATION IN
THE CELIAC-SUPERIOR MESENTERIC GANGLIA
LINARES R, ROSAS G,AYALA Ma E, MORALES L and DOMÍNGUEZ R. Biology of Reproduction Research Unit,
Physiology of Reproduction Laboratory FES Zaragoza, UNAM, AP 9-020, CP 15000, México, DF, México.
In the development of polycystic ovary syndrome (PCOS), participates the sympathetic nervous system.
In rats with PCOS induced by estradiol valerate (EV) injection or by chronic cold stress, the ovarian
noradrenergic tone is higher than in control animals. The ovaries of animals treated with EV increased
noradrenergic tone which depends on the integrity of the superior ovarian nerve (SON). In rats with
PCOS induced by EV injection or cold exposure the tyrosine hydroxylase activity and noradrenaline
(NA) levels in the celiac ganglion (CG) were higher than in control. The lesion the dorsal raphe nucleus
(NDR) blocks ovulation and this effect is abolished by the unilateral section of the SON, suggesting a
neural connection between the NDR and ovaries. To test the hypothesis that there is a relationship
between the catecholaminergic and serotonergic system level CG which perpetuate the PCOS induced
by EV or cold stress, we assessed the concentration of NA, dopamine (DA), serotonin (5-HT) and their
metabolites in the CG of rats with PCOS, induced by EV or stress. 10 day-old female rats of the CIIZ-V
strain were injected with corn oil (Vh) or 2 mg estradiol valerate (EV). The rats exposure to cold stress
were placed from 24 days of age in a room at 4°C for 3 h/d for 8 wk (monday to friday) until sacrifice
at day 80 of age. The VE-treated rats did not ovulate, and NA level was higher than Vh (7.3±1.5 ng/
mg vs. 3.7±0.8 p <0.05). Ovulation rate was not modified by cold and 5-HT level was higher than
in Vh group (7.4±1.2 ng/mg vs. 1.8±0.4 p <0.05). Present results suggest that the mechanisms
triggering the PCOS by EV and cold stress are different at the level of the CG.
MO089
FLUCTUATION IN DENDRITIC LENGTH OF CA1 AND CA3
PYRAMIDAL CELLS IN DORSAL HIPPOCAMPUS
DURING ESTROUS CYCLE: ADULT RATS
López-Mendoza A, Silva-Gómez AB Lab.Neurofisiología Experimental, Escuela de Biología, BUAP, Puebla,
México.
Hippocampus is an important structure of the central nervous system. Had been widely studied because to its functional role in learning and memory mechanisms and due to its peculiar organization
and development. Previous studies show total dendritic length of CA3 neurons is 35% shorter in male
than female rats. While, number of branching points is 25% less in female rats respect male rats.
On the other hand, spine dendritic density in apical arbor of CA1 neurons show changes related with
estrous cycle. About 30% less spines there are during proestrus and estrus in relation with other
phases. This difference can be related with natural fluctuations of steroids primarily estrogens whose
receptors are expressed amply in hippocampus. The present study was designed in order to analyze the
total dendritic length of CA1 and CA3 dorsal hippocampus a long the estrous cycle. Thirty two Wistar
rats obtained of Claude Bernard vivarium (BUAP) were included in this study. Animals were housed
in a temperature and humidity controlled environment on a 12-12 h light-dark cycle. Daily vaginal
smears were taken and then the rats were assigned in proestrus, estrus, metestrus, or diestrus group.
Perfused brains were removed and processed with Golgi- Cox stain. After, ten neurons of CA1 and CA3
hippocampal region were selected and drawn with camera lucida. Total dendritic length and length
per branch order were calculated. We observed that basolateral dendritic trees are similar between
neurons during all phases of estrous cycle; however, the apical dendrites of CA1 neurons are shorter
(24%) in proestrus in contrast with the other two phases. Also, in CA3 neurons similar results were
showed. With this information, we conclude that hippocampus has great influence by estrogens and
short periods, like estrus cycle, are sufficient to observe retraction and elongation of dendritic arbors.
MO091
OVARIAN PLEXUS NERVE SECTION RESTORES OVULATION IN
A POLICYSTIC OVARIAN SYNDROME (PCOS) MODEL
Díaz-Ramos. J.A. Espinoza-Moreno J.A. Morales-Ledesma L.Biology of Reproduction Research Unit,
Physiology of Reproduction Laboratory FES Zaragoza, UNAM, AP 9-020, CP 15000, México, DF, México.
In rat ovaries with estradiol valerate (EV)-induced PCOS, sympathetic activity and ovarian norepinephrine (NE) content increases compared to control animals. Such changes depends on the integrity of
the superior ovarian nerve (SON), since bilateral section of the SON restores ovulation in both ovaries,
while unilateral SON section only restores the innervated ovary funtion. It has been suggested that
PCOS origin is not only associated to increased in cathecolaminergic ovarian activity, since we have
demonstrated that electrical stimuli of SON increases the activity of the ovarian plexus nerve (OPN), as
OPN does to the SON, suggesting a posible comunication between those two neural ovarian pathways.
In order to analyze the role of SON and OPN in the EV-induced PCOS, 10 days old female rats of CII-ZV
strain were injected with 2 mg of EV or vehicle, 14 days later were submitted to unilateral section of
the SON (Right-SON; Left-SON), OPN (Right-OPN; Left-OPN) or both (SON+OPN). Animals were sacrified
at 90±2 days of age, when they presented a cornified vaginal smear and oulation rate was evaluated.
Ovulation rate in PCOS+SON group was significatively lower than Vh+SON group (8/28 vs. 28/32,
p<0.05). The number of ova shed by innervated ovary in the PCOS+right-SON section was lower than
control group (1.21±0.68 vs 4.31±0.7, p<0.05).The ovulation rate in PCOS+OPN section was
compared to Vh+OPN group (15/25 vs 15/18, NS). In the PCOS+left-SON+OPN group only 2 out of
10 animals ovulated on the denervated ovary and the number of ova was lower (3) compared to the
higher number of ova shed (12. 6±1.4) observed in 5 out of 10 animals in the same group, but in the
innervated ovary. Similar responses were observed in rats EV+rigth-SON+OPN. This study suggests
that SON and OPN play an stimulating role in the development and persistence of the PCOS.
MO090
HYPOGLYCEMIC EFFECTS OF THE CHLOROFORMIC LEAF EXTRACT
OF CARICA PAPAYA IN EXPERIMENTAL DIABETIC RAT MODEL
Ruiz-Ramos D(1), Miranda- Osorio P.H(1), Juárez-Rojop I.E(1), Bermúdez-Ocaña D.Y(2), Roa-de la Fuente
F(3), Ramón-Frías T(1), Ble-Castillo J.L(1), Rodríguez–Hernández A(4), Díaz-Zagoya J.C(5), (1)DACS,
Universidad Juárez Autónoma de Tabasco, Tab., México; (2)DAMC, Universidad Juárez Autónoma de
Tabasco, Comalcalco, Tabasco, México; (3)DACB, Universidad Juárez Autónoma de Tabasco, Cunduacán,
Tabasco, México; (4)Instituto Mexicano del Seguro Social, Xalapa, Veracruz; (5)Facultad de Medicina,
UNAM, México, D.F., México
Recent decades have shown a surging interest in traditional plant treatment for diabetes therefore, the
purpose of this study was to assess the hypoglycemic effect of the chloroformic extract of C. papaya
leaves in diabetic rats. Several studies have reported that some parts of the C. papaya plant exert hypoglycemic effects in both animals and humans. Diabetes was induced in rats by intraperitoneal administration of 60mg/kg of streptozotocin (STZ). The chloromic extract of C. papaya was administered in
three different doses (31, 62, 124 mg/Kg; via oral) during 4 weeks a diabetic and non-diabetic animals.
The chloroformic extract of Carica papaya (0.75 g and 1.5 g/100 mL) significantly decreased blood
glucose levels in diabetic rats. It also decreased cholesterol, triacylglycerol and amino-transferases
blood levels. Finally, an antioxidant effect of C. papaya extract was also detected in diabetic rats. These
data suggest that the aqueous chloromic extract of C. papaya possess hypoglycemic effect; however,
high doses may induce toxicity. Its hypoglycemic effect is not completely clear, although it could be
useful for preventing diabetic complications.
MO092
EFFECTS OF CHOLINERGIC AFFERENTS TO THE LEFT
SUPRACHIASMATIC NUCLEI ON THE STEROID HORMONES
SECRETION AND OVULATION IN ADULT CYCLIC RATS
Vieyra Elizabeth, Ramírez Deyra de los Ángeles, Morales Leticia and Domínguez Roberto.
Facultad de Estudios Superiores Zaragoza UNAM.
In mammals the master circadian pacemaker regulating the cyclic function of female reproduction,
is located in the suprachiasmatic nuclei (SCN) of the hypothalamus. The bilateral lesions of the SCN
abolish estrous cyclicity, the preovulatory LH surge and ovulation. The SCN receives information from
various regions of the CNS, some of which are cholinergic. This study was designed to analyze the
effects of muscarinic receptor blockade with atropine (ATR) in the left-SCN at 9:00 of proestrus on
ovulation and serum concentrations of progesterone (P4), estradiol (E2). Adult female rats of the CII-ZV
strain at 9:00 hours at the proestrus were micro-injected with 0.5 μl of saline (Vh) or 62.5 ng of the
atropine, into the left SCN. The animals were sacrificed 24 h later. The micro-injection of ATR resulted
in lower E2 level than Vh injected ones (ATR 47.52±1.0 vs. Vh 56.95±3.3, p<0.05). No significant
modifications in P4 levels were observed. The ovulation rate was not modified by ATR, but the number
of ova shed by the right ovary was lower than Vh injected animals (ATR 3±0.5 vs. Vh 6.5±0.7
p<0.05). Present results suggest that at 09.00 of the proestrus day, the stimulation of the muscarinic
receptors in the left SCN, originate a neural signal which by a multisinaptic pathway modulates the
last steps of the follicular growth and maduration in an asymmetric way. The low E2 levels suggest
that the activity of the P450aromatase is also stimulated by such pathway. Supported by DGAPA IN
218911-3;CONACyT 29238.
MO093
EFFECTS OF HYPERTHYROIDISM ON EXPERIMENTAL MODELS
OF ANXIETY, PANIC AND DEPRESSION IN RATS
Nascimento, M.P. and Schenberg, L.C. Department of Physiological Sciences, Federal University of Espírito Santo, Vitória, ES, Brazil.
Thyroid diseases have also been associated with anxiety states, panic attacks, depression, phobias
and obsessivecompulsive disorder. The clinical data are, however, very contradictory. Therefore, this
study evaluated the effects of experimental hyperthyroidism in rats in the open field (OF), social interaction (SI), forced swimming (FS), elevated plus-maze (EPM) and elevated T-maze (ETM). Male Wistar
rats were treated for 10 days (i.p.) with saline (controls) or with 30 mcg/day and 60 mcg/day of
L-thyroxine (T4) (T30 and T60 groups, respectively). Plasma levels of T4 and T3 and behavioral effects
were evaluated by ANOVA followed by t-tests for independent samples. The differences in the control
group were considered significant for P <0.05. The groups did not differ T30 and T60 plasma levels of
T3 and T4, have been increased by about 60% and 50% respectively. However, they differed in behavioral tests, indicating different brain effects of these treatments. In the OF test, the T4 increased the
rearing, exploration, olfaction and peripheral locomotion, confirming the clinical data of hyperactivity.
In contrast, T4 increased the immobility time in FS suggesting a depression-like effect. In the other
tests were only observed effects to the lowest dose of T4. Thus, rats of the T30 group in the EPM test
showed a significant increase in the percentage of open arm entries, suggesting an anxiolytic effect.
Nevertheless, the anxiety levels were not changed in the tests of IS, AR and LTE. Therefore, our data
suggest that the symptom of ‘nervousness’ reported by patients with hyperthyroidism is distinct from
the anxiety of the animal models used in this study. On the other hand, although the lower dose of T4
reduced the escape latency in the ETM, suggesting a panic-like effect. Our results suggest that mild
hyperthyroidism facilitates panic disorder and depression.
MO094
EFFECT OF EXPERIMENTAL HYPERTHYROIDISM ON
THE DEFENSIVE BEHAVIORS INDUCED BY STIMULATION
OF PERIAQUEDUCTAL GRAY MATTER
Nascimento, M.P. and Schenberg, L.C. Department of Physiological Sciences, Federal University of
Esp__rito Santo, Vitória, ES, Brazil
The defensive behaviors induced by electrical stimulation of the dorsal periaqueductal gray (DPAG)
have been associated with panic attack (PA). Mood disorders and anxiety, including PA, can be influenced by dysfunction of the hypothalamic-pituitary-thyroid axis. Moreover, previous studies have
shown that experimental hyperthyroidism facilitated the escape response in the elevated T-maze (ETM),
a model of PA. Therefore, this study evaluated the effects of experimental hyperthyroidism by administration of L-thyroxine (T4) on the thresholds of the defense responses of the DPAG. Male Wistar rats
(n=58) were implanted with electrodes in the DPAG and that had galloping with intensities below 70
_A were treated for 10 days (i.p.) with saline (controls) or with 30 mcg/day and 60 mcg/day of T4 (T30
and T60 groups, respectively). The acute effects and the chronic effects were examined. Plasma levels
of T3 and T4 and the behavioral effects of T4 were evaluated by ANOVA followed by t-tests for independent samples. Response accumulated frequencies of DPAG-evoked behaviors were subjected to the
threshold logistic analysis. Differences were considered significant for P <0.05 (Bonferroni test). In
group T30, acute treatment caused increases in the thresholds of trotting (26.7%), galloping (54.9%)
and jumping (33.1%), and chronic treatment of the thresholds of immobility (50.2%), exophthalmos
(36.4%), trotting (43.9%), galloping (71.5%) and jumping (57.7%). In the T60 group, significant
increases were observed in the galloping in both acute treatment (27%) and chronic (77.7%). The results of this and previous studies suggest that models of panic attack the DPAG and ETM are different,
this effect may be mediated by mechanisms quite different at the level of this structure. Finally, these
results corroborate the seemingly contradictory findings of epidemiological studies.
MO095
EFFECT OF GLUCOCORTICOIDS AND OVARIAN STEROIDS
ON A CELL CULTURE OF A HUMAN NEUROBLASTOMA (SH-SY5Y)
MO096
OBESITY, ANXIETY AND DEPRESSION IN OUTPATIENTS WITH
TYPE 2 DIABETES IN A MEXICAN POPULATION
Dueñas Zulma (1), Arboleda Gonzalo (2) Caicedo Juan Carlos (3), (1) Departamento de Ciencias Fisiológicas, Facultad de Medicina. Universidad Nacional de Colombia, Bogotá D.C., Colombia. (2)
Departamento de Patología, Facultad de Medicina. Universidad Nacional de Colombia, Bogotá D.C.,
Colombia (3)Estudiante candidato a Doctor, Doctorado en Ciencias Biomédicas, Facultad de Medicina.
Universidad Nacional de Colombia, Bogotá D.C., Colombia.
Sanchez Mejia Lizbeth (1*), Tovilla Zárate Carlos(1), López Narvaez Lilia(2), Juárez Rojop Isela(3), Frías
Ramón, Teresa(1), Martinez Hernandez Fatima C.(1), Padron Rafael (4), Pool García Sherezada(4), Espadas Méndez Gregorio E.(5), 1 Universidad Juárez Autónoma de Tabasco, División Multidisciplinaria de
Comalcalco, Comalcalco, Tabasco, México. 2. CIGEN, Centro de Investigación Genómica, Comalcalco,
Tabasco, México. 3. Universidad Juárez Autónoma de Tabasco, División Académica de Ciencias de
la Salud, Villahermosa, Tabasco, México. 4.-Hospital General de Comalcalco, Tabasco. Secretaria de
Salud, Comalcalco, Tabasco, México. 5.-Laboratorio Espadas,Comalcalco, Tabasco.
Steroid hormones are involved in modulating the effects of stress on the nervous system 1,2 . Several
studies have shown that stimulation with low or high doses of glucocorticoids triggers the activation of
proapoptotic signaling pathways, while a basal tone promote cell survival cascades. The 17b- Estradiol
has been shown to protect against different types of tissular injury4. These routes could be activated
in a synergistic or opposite way, depending on the intensity of the stimulation. In the present work
we explore the effects of different doses (0.1, 0.5, 1, 10, 20, 40, 50, 100, 500 and 1000 μ M) and
periods of exposure (24, 48 and 72 hours) to a dexamethasone, a glucocorticoid receptor agonist, and
to ovarian steroids 17b- Estradiol and medroxyprogesterone in SH-SY5Y cells, as well as the effects
of the co-stimulatory treatment with these hormones. MTT reduction trials have been conducted to
assess the activity of the mitochondrial dehydrogenases and to estimate the percentage of viability
and the degree of cell metabolic activation. It was found that dexamethasone increases the viability of
the cell culture in doses of 100 to 500uM and a decrease with doses of 1000uM at 24 hours. With 100
uM 17b-Estradiol the cell viability increased within the next 48 hours, but did not reverse the effect
produced by 1000 uM of dexamethasone. In general, the intensity of responses was longer at 48 hours
with different hormonal treatments, which could be interpreted as an increase in cellular metabolic
activity due a mitochondrial stress.
Background: Obesity is a very important factor for the development of depression and anxiety. There
is evidence indicating a relationship between depression and anxiety in diabetic patients. However,
the relationship between obesity and depression and anxiety in diabetes has been poorly analyzed.
The aim of this study was to assess the prevalence of anxiety and depression in groups of obese and
normal-weight individuals with type 2 diabetes and to analyze the severity of depression in type 2 diabetics when taking into account gender, normal-weight and obese factors in people with this condition.
Methods: This study included 467 patients with type 2 diabetes, 236 with normal weight and 231 with
obesity. All participants completed a demographic questionnaire, the Hamilton Anxiety Rating Scale
and the Hamilton Depression Rating Scale. Anthropometric characteristics were applied. To analyze
the data, the Mann-Whitney U-test was employed. Results: In patients with obesity, 48.48% (95%
CI: 41.82-55.14) were positive for anxiety and 49.78% (95% CI: 43.11- 56.44) for depression. With
regard to depression symptoms, a significant difference between normal-weight and obese individuals
with type 2 diabetes (p=0.05) was found. Also, when we analyzed depression scores, significant
differences were encountered for gender between normal-weight and obesity groups in the range of
severe (p=0.01) and very severe (p=0.04) cases. Significant differences were not observed when
we analyzed for anxiety. Conclusion: In view of the existing relationships observed among obesity,
depression, anxiety and gender in type 2 diabetics, a psychological intervention is necessary for an
integral managing of these patients.
MO097
HIGH FAT THERMOLYZED DIET ALTERS MONOCARBOXYLATE
TRANSPORTERS AND ENERGETIC METABOLISM IN THE
HIPPOCAMPUS OF DIABETIC RATS
DE ASSIS AM(1,2), RECH A(1), LONGONI A(1), MUSSULINI BH(1), PASQUALI MA(1), REPOND C(3), SOUZA,
DO(1), PELLERIN L(3), MOREIRA JCF(1), PERRY MLS (1), (1) Department of Biochemistry, Institute of
Health Basic Science, Federal University of Rio Grande do Sul, RS, Brazil. (2) Department of Health
Science, Health Sciences Federal University of Porto Alegre, RS, Brazil. (3) Department of Physiology,
University of Lausanne, 1005, Lausanne, Switzerland.
Diabetes mellitus (DM), a state of chronic hyperglycemia, is a common disease and one of the leading
causes of morbidity and mortality in developed countries. The aim of this study was to evaluate the
effect of high fat thermolyzed diet on monocarboxylate transporters (MCT) and energetic metabolism
in the hippocampus of diabetic. Diabetes was induced by an intraperitoneal (i.p.) injection of alloxan (150 mg kg-1 b.w.). Rats were divided into four groups: (1) the control group (C, n=10), which
received standard laboratory rat chow; (2) the control diabetic group (D, n=10), which received
an injection of alloxan and the same diet as group 1; (3) the high fat thermolyzed diet group (HFTD,
n=10), which received a diet enriched with fats that had been heated for 60 min at 180 °C to which
a vitamin mixture was added after heating; (4) the high fat thermolyzed diet diabetic group (D+HFTD,
n=10), which received an injection of alloxan and the same diet as group 3. After one month of diet
the rats were sacrificed by decapitation and the hippocampus quickly removed and processed for
further analysis. In the glucose oxidation to 14CO2 we didn’t observe statistical differences. However,
we note that the HFTD diet and diabetes increases the _-hydroxybutyrate oxidation to 14CO2, and we
have a decrease in the lactate oxidation only in D+HFTD group. In western blot analysis, we observed
an increase in the MCT1 and MCT2 immunocontent only in the D+HFTD group. A high fat thermolyzed
diet decreased lactate oxidation and increased _-hydroxybutyrate oxidation to 14CO2, MCT 1 and 2
immunocontent in diabetic rats (D+HFTD) in the hippocampus. We note a relationship between oxidation this substrates and his transporter.
MO099
UP-REGULATION OF MATRIX EXTRACELLULAR PROTEIN TENASCIN
C AND TRANSFORMING GROWTH FACTOR BETA IN HIPPOCAMPUS
DURING EPILEPTOGENESIS IN A TEMPORAL LOBE EPILEPSY MODEL
Landgrave-Gómez J(1), Mercado-Gómez O(1), Nebreda-Corona A(1), Arriaga-Avila V(1) and GuevaraGuzmán R(1), 1Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma
de México, 04510.
Introduction. Temporal lobe epilepsy (TLE) is a neurological disorder that affects people of all ages, it
is characterized by recurrent, spontaneous brain seizures, being the hippocampus, the structure that
has been widely studied due to its relationship with TLE. Seizures have shown to up-regulate the expression of numerous extracellular matrix molecules (ECM). One of great importance is Tenascin C (TNC),
which has been shown to be expressed during embryonic development, as well as in wound healing
and cancer invasion in various tissues. Their physiological roles include regulation of cellular behavior
and matrix organization during tissue remodeling. Objective. Analyze the participation of TGF- _ effects
upon the expression of the ECM protein TNC in a TLE model throughout different times. Methodology.
Male Wistar rats weighting 250 grs were used (n=4). For the model, animals were injected with scopolamine 30 min after pilocarpine were dissolved in saline and animals received an injection to induce
status epilepticus. Control animals followed the same procedure avoiding pilocarpine injection and receiving a saline injection. Rat hippocampus was dissected and homogenized in lysis buffer and. Protein
expression was analyzed using western blot and immunohistochemistry techniques. In order to analyze
the protein expression of TGF- _ both control and experimental samples (n=4) from the time course
were prepared for quantifying TGF-_ isoforms by bead array immunoassay. Briefly, rat hippocampus
were homogenized and collected for protein quantification. After dilutions, 80 μg protein were used
for assay following procedures according to the manufacturer’s instructions with each standard curve,
quality. The plate was read on a Luminex™ 100 instrument and analyzed with the Bio-Rad software.
Results. Our data showed that TNC is over-expressed in the hippocampus of rats with temporal lobe
epilepsy. By other hand we have demonstrate not only the presence of TGF-_ but also the up-regulation
of this transcription factor in the nervous system, this data suggest that TGF-_ may be involved in the
signaling pathway of TNC in the central nervous system. We also found dispersion of the granular cells
of the hippocampus of rats with TLE a morphology that have only seen under pathological conditions,
another reports have shown that TNC have antiadhesive roles. So we suggest that the over expression
of TNC is associated with this morphology. Conclusion. Our results indicate that TGF-_ and TNC are
up-regulated in TLE conditions suggesting that TGF-_ may be implicated in part, in the over expression
of TNC being an important inducer in the morphological alterations on temporal lobe epilepsy.
MO098
REGULATION OF PITUITARY PROLACTIN SECRETION
IN A RODENT MODEL OF DIABETES
Lemini M., Ruiz-Herrera X., Martinez de la Escalera G., Macotela Y., and Clapp C. Instituto de Neurobiología, UNAM. Campus Juriquilla, Querétaro, México.
Prolactin (PRL), the pituitary hormone fundamental for lactation, may play a role in diabetes. PRL acts
on pancreatic _ cells to stimulate their proliferation, survival, and insulin production. Recently, high
levels of PRL were reported in the circulation of diabetic patients, and this increase was smaller in
patients with advanced diabetic retinopathy suggesting the action of factors able to upregulate and
downregulate pituitary PRL production during the course of the disease. Two of such factors may be
tumor necrosis factor _ (TNF_) and transforming growth factor _ (TGF_), which contribute to insulin
resistance and systemic complications in diabetes. Also, TNF_ stimulates and TGF_ inhibits the in
vitro secretion of PRL by pituitary cells. Here, we show that TNF_ and TGF_ antagonize each other’s
actions on the synthesis and secretion of PRL by the GH4C1 pituitary cell line. TNF_ induced a dosedependent stimulation and TGF_ a dose-dependent inhibition of PRL mRNA and protein levels in cell
lysates and conditioned medium, as revealed by qPCR and radioimmunoassay. The stimulatory and
inhibitory effects of all doses of TNF_ and TGF_ were blocked by co-incubation with a single concentration of TGF_ (10 ng/ml) and TNF_ (50 ng/ml), respectively. The type-2 diabetes model of male rats
fed a high-fat diet (HFD) displays insulin resistance and increased body-weight. These rats showed
reduced PRL mRNA expression in the pituitary gland and protein levels in the circulation. Notably, the
mRNA pituitary levels of TGF_ were increased and those of TNF_ were decreased in these rats. These
findings suggest that opposing effects of pituitary TNF_ and TGF_ regulate the production and secretion of PRL in diabetes. Supported by CONACYT SALUD-2011-1-161594 and PAPIIT-UNAM IB200411.
MO100
SOURCE OF ICTAL EPILEPTIFORM DISCHARGES IN
CHILDREN WITH ABSENCE SEIZURES
Aguilar-Fabré L(1), Galán-García L(2), Bosch-Bayard J(2), Rodríguez-Valdés R (2), Ricardo-Garcell J(3),
and García-García R(1), (1)Pediatric Hospital Juan Manuel Márquez, Havana, Cuba; (2) Neuroscience
Center of Cuba, Havana, Cuba and (3) Neurobiology Institute, UNAM, Querétaro, México.
Introduction: Generalized seizures are considered initiate, at some point, and quickly involve neuronal
networks distributed on a bilateral basis. Objective: Study the spatial location of the generators of ictal
epileptiform discharges in a group of patients with typical absence seizures. Patients and Methods:
Were studied 33 patients (17 female and 16 male), aged between 4 and 10 years with the video-electroencephalogram and clinical diagnosis of typical absence seizures and untreated with anti-epileptic
drugs. We used Neuronic software Quantitative EEG Tomographic (brain electrical tomography) to calculate and localize the source of ictal epileptiform activity, which allows the fusion of functional data
obtained through the EEG and the anatomical information provided by magnetic resonance imaging.
This software uses the LORETA (Low Resolution Electromagnetic Tomography) method with anatomical
restrictions in the location of the distributed cortical sources of bioelectrical activity. For the analysis
was considered the point of maximum voltage of the spike component of the spike-wave complex in
the first second of each crisis. Results: Analysis of the spatial location of ictal epileptiform discharge
revealed that the 63.63% of the anatomical generators of this activity were in frontal regions distributed in the dorsolateral in 56% and 44% mesial areas. Turn the frontal structures mostly involved in
the solutions were the cingulum (23.70%), the middle and superior frontal gyrus (14.90% and 9.60%
respectively) and the supplementary motor area (12.30%) Generators of ictal epileptiform discharges
in parietal, temporal and occipital lobes (21.21%, 9.09% and 6.06% respectively) were also found.
Conclusions: The frontal regions have an important role in the generation of typical absence seizures
which could be in correspondence with their relations with the thalamus and reticular system activator
ascending.
MO101
MICRORNA EXPRESSION PROFILE AND SUDDEN UNEXPECTED DEATH
IN EPILEPSY: WHAT DOES THE PRECLINICAL MODEL TELL US?
Gabriela Matos(1), Camila Guindalini(1), Fulvio A. Scorza(2), Esper A. Cavalheiro(2), Sergio Tufik(1),
Monica L. Andersen(1). (1): Departamento de Psicobiologia and (2)Neurologia Experimental, Universidade Federal de São Paulo (UNIFESP), Brazil.
INTRODUCTION: MicroRNAs (miRNAs) regulate gene expression and have an important role in biological
and pathological processes. Recently, the modulating role of miRNAs in epilepsy was demonstrated in
the literature; however few studies have focus on possible target sites of sudden unexpected death
in epilepsy (SUDEP). The phenomenon occurs mainly during the night, and most likely during sleep.
OBJECTIVE: The present study evaluated the miRNA expression profile in heart and prefrontal cortex of
rats submitted to pilocarpine-induced status epilepticus (SE). METHODS: The study was conducted in
adult male Wistar-Hannover rats at 10 weeks of age. Fifty days after pilocarpine-induced SE, arrays
were performed on miRNA enriched RNA extracted from the prefrontal cortex and heart of rats. MiRNA
expression was analyzed using Affymetrix GeneChip miRNA 2.0. RESULTS: Epileptic brain induced significant altered expression in 9 miRNA. The altered miRNA were related to inflammatory process in the
prefrontal cortex as well as to modulation of cardiac function in the heart of rats with spontaneous
recurrent seizures. CONCLUSIONS: Our results revealed that miRNA expressed in prefrontal cortex and
heart might be involved with the occurrence of SUDEP, once important sites were affected by epilepsy.
These findings strengthen the hypothesis of a relationship between SUDEP and miRNA-induced altered
gene expression. FUNDING: Associação Fundo de Incentivo à Pesquisa (AFIP), Fundação de Amparo à
Pesquisa do Estado de São Paulo (FAPESP), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) and Ministério da Ciência e Tecnologia (MCT).
MO103
SPATIO-TEMPORAL DISTRIBUTION AND EXPRESION OF
TOLL-LIKE RECEPTOR 4 IN RAT HIPPOCAMPUS FOLLOWING
PILOCARPINE-INDUCED STATUS EPILEPTICUS
NEBREDA-CORONA A(1), MERCADO-GÓMEZ O(1), LÓPEZ-HERNÁNDEZ A(1), AND GUEVARA-GUZMÁN R(1).
(1)Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México,
04510.
Introduction: Temporal lobe epilepsy (TLE) is a neurological disorder that affects people of all ages;
it is characterized by recurrent, spontaneous seizures, being the hippocampus the structure associated with TLE. Several reports have shown that neuroinflammatory processes are crucial in epilepsy.
Recently, Maroso et al, (2010) have demonstrated that Toll-like receptor 4 (TLR4) and its ligand HMGB1
protein are implicated in the generation of seizures. Objective: Analyze the TLR4 expression and their
spatio-temporal distribution throughout hippocampus in acute time course following pilocarpineinduced status epilepticus. Methodology: Male Wistar rats weighting 250-300 grs were used (n=4/
group) for the acute time-course (1, 3, 6, 12 and 24 hours). Animals were injected with lithium chloride
(3 mEq/kg i.p.) 18-24 h prior to pilocarpine injection (30 mg/kg i.p) to induce status epilepticus (SE)
for 1 h and immediately attenuated with diazepam injection (5 mg/kg). Hippocampus were dissected
and homogenized in lysis buffer, centrifuged at 14,000 rpm for 30 min and supernatants collected.
40_g of protein were electrophoresed for TLR4 protein content by Western blot technique. Another
group of animals were performed for immunohistochemistry studies. Results: Our preliminary data
showed a progressive increase of TLR4 protein content in the hippocampus of rats from the first to 24
hours after pilocarpine-induced status epilepticus. Interestingly, TLR4 immunoreactivity wasincreasing
progressively in CA1, CA3 pyramidal layer and granular cell layer and hilus of the hippocampal dentate
gyrus through the acute time course. Conclusion: Our results indicate that TLR4 is early expressed in
hippocampus after pilocarpine-induced status epilepticus. Moreover, TLR4 immunoreactivity increases
progressively in CA1, CA3 pyramidal layer and granular cell layer and hilus of dentate gyrus suggesting
that TLR4 signaling pathway plays a critical role for neuroinflammation events contributing to ictogenesis and lately, a progressive neuronal cell death. This project was supported by PAPIIT IN200110 and
CONACYT 152613 grants.
MO102
ASSESSMENT WITH QUANTITATIVE MAGNETIC RESONANCE
IMAGING IN TEMPORAL LOBE EPILEPSY PATIENTS ASSOCIATED
WITH MILD FOCAL CORTICAL DYSPLASIA
TRÁPAGA QUINCOSES O MD MSc (1), MORALES CHACÓN L MD, PhD (1), ESTUPIÑAN B MD (1), RODRIGUEZ,
R MSc (1), SÁNCHEZ CORONEAUX A (1), ZALDÍVAR BERMÚDEZ M (1). (1) Centro Internacional de Restauración Neurológica CIREN, La Habana, Cuba.
Objective: To evaluate temporal lobe cortical surface through quantitative magnetic resonance imaging
(MRI) and it’s relation to postsurgical evolution in patients with temporal lobe epilepsy associated
with mild focal cortical dysplasia with MRI negative. Methods and subjects: Measurements of cortical
surface area (SA), cortical thickness (CT), folding index (FI) and volume were generated with FreeSurfer
in 10 patient and 20 subject controls. High resolution pre-surgical T1-weighted volume scans 160
contiguous slices were obtained for each subject. Results: The patient group displayed significantly
reduced volume in enthorrin al cortex, parahippocampus, superior and inferior temporal gyrus; SA
was also greater in ipsilateral neocortical epileptogenic zone when compared to the control group. An
increase of the CT was also shown in entorrinal cortex and parahippocampus. In addition, the ipsilateral
neocortex showed an increase folding index (p < 0.0001 Test Mann-Whitney). Class 1 Engel’s patient had
greater volume of mesial structures and smaller volume in neocortex. CT was lower in enthorrinal cortex
and parahippocampus, whereas the SA has a tendency tended to be higher in best evolution patients. (p
< 0.0008 Test Mann-Whitney). Conclusions: Patient’s with TLE associated with mild FCD showed significant volume reductions and CT increase in enthorrinal cortex and parahippocampus. There was also
an increase of the SA and a significant volume decrease in ipsilateral temporal lobe epileptogenic zone.
Patients who had better clinical evolution showed bigger volume in the mesial structures associated with
smaller neocortical volume and SA increase (superior and inferior temporal lobes).
MO104
ELECTROPHYSIOLOGICAL AND BEHAVIORAL EFFECTS OF THE
INTERACTION EPILEPSY-DEPRESSION IN AN ANIMAL MODEL
AYALA-RODRÍGUEZ J.D.(1), VALDÉS-CRUZ A.(2), MARTÍNEZ-MOTA L.(3), and FERNÁNDEZ-MAS R.(2), (1)
Facultad de Psicología, UNAM, México DF, México; (2) Laboratorio de Neurofisiología del Control y la
Regulación, Dirección de Neurociencias, Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz,
México D.F., México and (3) Laboratorio de Farmacología Conductual, Dirección de Investigaciones en
Neurociencias, Instituto Nacional de Psiquiatría Ramón de la Fuente Muñíz, México D.F., México.
Depression is the most common psychiatric disorder associated with temporal lobe epilepsy. The neuronal mechanisms underlying this comorbidity and the effects that can express one over the other are
unknown. The aim of the present study was to investigate the effect of amigdaloid kindling (AK) in the
expression of despair in the forced swimming test (FST), measured as immobility, and anhedonia in the
sucrose preference test; and the effect of the FST over the threshold to generate tonic-clonic seizures
after having been kindled. For this purpose, 33 adult male Wistar rats were used and divided in an
experimental group (n=11), implanted with an electrode in the amygdala to be kindled, a sham group
(n=11), non-kindled animals, and a control group (n=10), which was not implanted. Fullykindled
rats were considered when they expressed 5 stage 5 seizures after being daily electrically stimulated,
whereas sham and control group were handled daily. When achieved full-kindling, rats were exposed
to the FST; while anhedonic effects were assessed since the third stage 5 seizure. One day after the
FST, the threshold to generate seizures was measured. Experimental group expressed more immobility
in the FST than sham group (p<0.05), yet kindling group did not differ from control group. Moreover,
sham group showed less immobility than control group (p<0.05). No difference was observed in the
sucrose preference test. Furthermore, there was no difference between threshold before the FST and
the one after the FST. Our data suggest that the only implantation of an electrode in the amygdala may
affect the performance in the FST, whereas the expression of generalized seizures can change this
condition. Concerning the threshold to generate tonic-clonic seizure, it seems that the expression of
depressive-like behavior may affect the sensibility to generate generalized seizures; although, more
studies are needed to corroborate this result.
MO105
ANTICONVULSIVE EFFECT AND CORTICAL DESYNCHRONIZATION
INDUCED BY HIGH-FREQUENCY STIMULATION OF NUCLEUS
RETICULARIS THALAMI
PANTOJA-JIMÉNEZ CR(1),MAGDALENO-MADRIGAL VM (1), LÓPEZ-RUÍZ E(2),ALMAZÁN-ALVARADO S(1), and
FERNÁNDEZ-MAS R(1), (1)Lab. Neurofisiología del Control y la Regulación;(2)Lab. Cronobiología. Dirección de Investigaciones en Neurociencias, Instituto Nacional de Psiquiatría Ramón de la Fuente Muñíz,
Cd. de México, México.
The nucleus reticularis thalami (NRT) is a sheet of gabaergic neurons integrated in the thalamocortical
and corticothalamic circuits. These circuits participate in the sleep spindles generation, synchronization and propagation of generalized seizures (GS). The aim of this study was to determine if highfrequency stimulation (HFS) of the NRT is capable to prevent the development of seizures unchained by
pentilenetetrazol (PTZ). Experiments were performed using Wistar male rats stereotaxically implanted
in left NRT (AP +1.4, L 1.7, H 6.2). Screw epidural electrodes were directed to prefrontal cortex for
EEG recording. Rats were classified as follows: (a) control group, only receiving PTZ injection without
HFS, (b) HFS-adjacent group (HFS-Adj), had a tip electrode in adjacent nuclei, and (c) HFS-NRT group,
received PTZ injection after NRT electrical stimulation (100 Hz, 0.5 ms, 200 μA) during 10 min. In
PTZinjection- schedule, the animals received an initial dose of 20 mg/kg of PTZ, and every 15 min an
additional dose of 10 mg/kg until the occurrence of a convulsive seizure enduring the duration of 5 min
(status epilepticus). HFS-NRT significantly reduced the duration, and increased the onset of latency to
elicit tonic-clonic GS. In addition, the latency and necessary doses to exhibit status epilepticus were
twofold higher in HFS-NRT group than control and adjacent groups. Electrical stimulation (HFS-NRT,
HFS-Adj) facilitates spike-wave discharge (SWD). Adjacent group have shown a progressive excitability
development as control group. Power spectral analysis revealed desynchronization between cortex and
NRT during SWD. This data further highlights the role of NRT in modulating the expression of seizures
and provides experimental support for the concept that this thalamic region may be a promising target
for focal stimulation to treat intractable epilepsy in humans. Supported by INPRFM NC 123240.1
MO107
ASSOCIATION STUDY OF THE SNPS RS2180619 AND RS1535255 OF
THE CNR1 GENE-PROMOTER REGIONS AND THE CAPACITY TO INHIBIT
IRRELEVANT STIMULI DURING WORKING MEMORY PERFORMANCE
MO106
SNP RS2180619 BUT NOT RS1535255 OF THE CNR1 GENE-PROMOTING
REGIONS ARE ASSOCIATED WITH WORKING MEMORY PERFORMANCE
Román-López TV(1), Ortega-Mora I(1),Carrillo-Sánchez K(2), Barrera-Tlapa MA(1), Rosas-Escobar CB(1),
Muñoz-Torres Z(1), Flores-Barrera LY(1), Hernández-Morales S(2), Vadillo-Ortega F(4), Prospéro-García
O (3), Ruiz-Contreras AE (1). (1)Laboratorio de Neurogenómica Cognitiva, Facultad de Psicología UNAM
(2)Unidad de Secuenciación e Identifición de polimorfismos, INMEGEN (3) Laboratorio de Canabinoides, Facultad de Medicina UNAM (4) Laboratorio de Fisiología y Metabolismo del Embarazo, Facultad
de Medicina UNAM.
Individual differences in cognitive function can be explained by genetic polymorphisms. CNR1 gene
codes for the cannabinoid receptor 1 (CB1) of the endocannabinoid system, which is widely distributed
in brain regions participating in cognitive functions. We analyzed two single nucleotide polymorphisms
(SNP), rs2180619 and rs1535255, that are localized in promoting regions of the CNR1, attempting to
explain individual differences in performance on a working memory (WM) task (n-back). The rs2180619
presents AA, AG and GG genotypes; and the rs1535255 presents TT, TG and GG genotypes. Previous
studies have identified for both rs2180619 and rs1535255 the GG genotype as a risk factor for anxiety,
drug abuse and impulsivity. It is also possible that the GG genotype is related to reduce efficiency of
WM; this type of memory allow to maintain, manipulate and update information in a goal-directed behavior. We predicted that participants with the GG genotypes of SNPs rs2180619 and rs1535255 would
performed worst on the n-back task, compared to subjects with none risk allele. Participants were
young healthy volunteers, dependence and abuse-free, and absence of neurological or psychiatric antecedents. Subjects performed the n-back task at two levels of difficulty (2 and 3-back). TaqMan probes
were used to determine genotypes, and the d’ index was calculated for performance. For rs2180619, no
significant differences were observed as a function of Genotype; however, a significant interaction was
found between Genotype and Level of difficulty in performing the task (P<0.05). None significant results were obtained for rs1535255. These results suggest that individual differences in WM efficiency
in healthy volunteers may be associated with the different genotypes of rs2180619 of CNR1, but not to
rs153522 genotypes, involving the function of CB1 and the endocannabinoid system in WM in humans.
MO108
GENE EXPRESSION PROFILE OF PLEIOTROPHIN KNOCKOUT
MICE HIPPOCAMPUS BY MICROARRAY ANALYSIS
Ivett Ortega-Mora (1), Talía V. Román-López (1), Karol Carrillo-Sánchez (2), Zeidy Muñoz-Torres (1),
Miguel A. Barrera-Tlapa (1), Lorena Flores-Barrera (1), Cintia B. Rosas-Escobar (1), Salvador Hernández-Morales (2), Felipe Vadillo-Ortega (1), Oscar Prospéro-García (1), Alejandra E. Ruiz-Contreras (1).
(1) Universidad Nacional Autónoma de México, Mexico. (2) Instituto Nacional de Medicina Genómica,
Mexico.
GONZÁLEZ CASTILLO C (1,2), ORTUÑO SAHAGÚN D (1), GUZMÁN-BRAMBILA-C (1), RAISMAN VOZARI R (4),
PALLAS M (5), ROJAS MAYORQUÍN AE (2,3) (1)Universidad de Guadalajara, Dpto. Biología Celular y
Molecular, Guadalajara, Mexico,(2)Universidad de Guadalajara, Dpto. Ciencias Ambientales, Instituto
de Neurociencias, Guadalajara, Mexico,(3)Instituto Nacional de Geriatría, Dpto. de Investigación Básica, Distrito Federal, Mexico,(4)Centre de Recherche de L’institut du Cerveau et de la Moelle Epiniere
(CRICM), Paris, France,(5)Universitat de Barcelona, CIBERNED, IBUB, Barcelona, Spain .
Selective attention allows us to filter information, selecting only relevant stimuli and inhibiting the
irrelevant ones. The accuracy on these attention abilities affects the efficiency of working memory
and informs about our ability to maintain and manipulate information for brief periods of time in
goal-directed behaviors. Individual differences in working memory performance may be explained by
genetic variability. Attention and working memory involve the participation of diverse systems of neurotransmission and neuromodulation, including the endocannabinoid system. One of its receptors, the
cannabinoid receptor 1 (CB1) is widely distributed in brain regions involved in attention and memory
functions. CNR1 codes for CB1, and polymorphisms of this gene have been associated to pathologies
such as addiction and schizophrenia and, more recently, also with cognitive functions. Two single
nucleotide polymorphisms (SNPs) are localized in the CNR1 gene-promoter regions, rs2180619 (G>A)
and rs1535255 (G>T). G allele in both SNPs has been related to drug abuse, impulsivity and anxiety.
The present study tested whether efficiency on a working memory task that challenged subjects’ capacity to selectively attend a stimulus while simultaneously inhibiting the irrelevant ones, are related to
a different performance according of the different genotypes of SNPs rs2180619 and rs1535255 of
the CNR1 gene. We observed that the homozygotes for the risk allele GG for the rs2180619 performed
lower on the task than those who carry the allele A (AG and AA). None significant results were found
for the rs1535255. These results indicate that the alternative forms of SNP rs2180619 of the CNR1
gene-promoter region are associated with the capacity to selectively attending and inhibitin information, suggesting that this polymorphism does exert a functional effect at CB1. Acknowledgments:
This research was supported by grants PAPIIT-DGAPA UNAM No. IN217308 for AERC, and CONACyT No.
129103 for OPG. Genetic analyses were conducted by INMEGEN.
Pleiotrophin (PTN) is a neurotrophic factor expressed in certain regions in the adult CNS. Its expression increases after cerebral lesion or damage, and in some degenerative diseases like Parkinson´s.
This peptide has been related with the nigrostriatal system development and with the compensatory
mechanisms which take place during Parkinson disease. However, its precise role is not yet established. Thus to obtain new insights, we analyzed the gene expression profile of 22 thousand genes in
the hippocampus from PTN knockout mice. For the group analysis, we select only the genes that varies
with a media z-score over 3.0, by these criteria only 50 genes were over expressed and 52 genes were
down expressed when compared PTN(-/-) vs their genetic controls. From these, a total of 41 identified
genes (40%) are of unknown function, which indicates that the PTN deficiency elicit an unexplored
response. Increased expression genes known are mainly related to neuroprotection (Mgst3, Shc3,
Phlda1), cell differentiation and proliferation (Nestin, Casp6, Gsh1), and transcriptional regulation
(Nrf3). Conversely, genes that diminished its expression are mainly related to cytoskeleton (Memo1,
Nebulette), cell cycle regulation (MAK, septin 3, Btg2), neural development (Cnpy1), Ion transport
(Slc11a2, Slc12a2, Slc9a9) and signal transduction (Htr1d). Observed changes in gene expression in
the hippocampus of PTN KO mice, are consistent with a compensatory mechanisms which involves
the production of neuroprotective factors and promotion of cell differentiation and proliferation, in
response to the distress function of neural cells, mainly because their cytoskeleton can be altered and
probably also some of their ion transport and signal transduction processes results affected. Outcome
of this analysis constitute a pivotal starting point to the identification and study of the groups of genes
involved in the compensatory mechanisms activated by the absence of PTN, providing a model to
analyze some specific aspects of neurodegenerative diseases.
MO109
GENE EXPRESSION PROFILES OF NUCLEUS ACCUMBENS,
PREFRONTAL CORTEX AND HIPPOCAMPUS IN AN ANIMAL MODEL
OF SCHIZOPHRENIA: A PROPOSAL FOR CANDIDATE GENES
Alma D. Genis-Mendoza (1) R. Ileana Gallegos-Silva(1) Mavil López-Casamichana(1) Humberto Nicolini(1,2) Carolina López-Rubalcaba(3), (1)Universidad Autónoma de la Ciudad de México, D.F. Mex.
(2)Servicios de atención psiquiátrica Secretaria de Salud, D.F. Mex. (3) Centro de Investigación y de
Estudios Avanzados del IPN, (CINVESTAV-Sede Sur) Departamento de Farmacobiología, D.F. Mex.
Introduction: It has been suggested that schizophrenia may be induced by failures or injuries during
the early brain development of individuals, involving a reduction in the neural connections in different brain regions. In this approach, we evaluated the differences in brain gene expression using a
recognized experimental model of schizophrenia: the animal model of ventral hippocampal lesion in
neonatal rats (VHLN) compared to sham. Methods: Through microarray technology, we obtained gene
expression profiles of three brain areas (nucleus accumbens, prefrontal cortex and hippocampus) of
young (45 days) and adult (90 days) Wistar male rats exposed or not to VHLN. Results: Based on three
criteria: 1) Z-score values> 2, 2) expression in more than one brain area, and 3) participation in
relevant cellular pathways for the central nervous system (CNS), we have found over-expressed ppp3cb
and dctn1 genes and sub-expressed jag1, chrna4, ide, sod, limk2 and cpz . Conclusions: Two of the
proposed genes in this paper: cpz and limk2, have not been previously associated with schizophrenia,
so future studies will be necessary in order to understand their possible roles in the etiology of this
disease.
MO110
G-PROTEINS MODULATE THE INACTIVATION
OF N-TYPE VOLTAGE-GATED CALCIUM CHANNELS
REYES-VACA A, ARENAS I,and GARCIA D.E, Dpto. de Fisiología, Facultad de Médicina, UNAM, México.
N-type voltage-gated calcium channels (CaV2.2) are found in many neuronal cells (Westenbroek et
al., 1992), in which they regulate calcium influx into the neuron associated to many important physiological functions. Therefore, the precise regulation of calcium influx by mechanisms as modulation of
voltage-dependent G-proteins and inactivation of CaV2.2 are important to understand different kinds of
patterns neuronal communications (Hirning et al., 1988). The activation of G-proteins maintain stable
current amplitude during a large test pulse potential (Garcia-Ferreiro et al., 2001) and after a strong
depolarization transient reversal of inhibition instead of removal modulation of voltagedependent Gproteins (Elmslie et al., 1990). So we propose that G-proteins modulate of the inactivation of CaV2.2.
We used whole cell patch clamp techniques to measure inward currents of CaV2.2 from sympathetic
cervical ganglia (SCG) neurons and here we show that dialysis with GTP_S of SCG evoke alterations
in inactivation current kinetics, these alterations are concentrate-dependent of GTP_S. Moreover, the
U-shape inactivation curve of CaV2.2 decrease 80% under the same condition mentioned before. Our
data have provided important clues about of how G-proteins modulate inactivation of CaV2.2 and we
help to understand their implications in many physiological functions. Supported by UNAM-DGAPAPAPIIT-IN200710 and Secretaría de Educación Pública (SEP).
MO111
PGB ACUTELY AFFECTS LARGE P/Q MEDIATED
CURRENTS AND P/Q CHANNEL´S CELLULAR DISTRIBUTION
MO112
CALTX BLOCKS CALCIUM CURRENTS FROM DORSAL
ROOT GANGLION NEURONS FROM RAT
Carina Weissmann(1), Fracisco J. Urbano(1), Carlota González Inchauspe(1), Mariano N. Di Guilmi(1),
Osvaldo D. Uchitel(1) (1) IFIBYNE-CONICET, Argentina.
LóPEZ O(1), SALCEDA E(1), LICEA A(2), SOTO E(1); (1)Inst. de Fisiología BUAP, Puebla, México; (2)CICESE,
Ensenada, México.
We set out to investigate the mechanism of action of pregabalin (PGB) -an anticonvulsant and analgesic drug used in the treatment of epilepsy and neuropathic pain- on P/Q-calcium channels. We previously reported that slices from calyx of Held of WT-mice incubated acutely with PGB (500 μ M) show
slightly reduced P/Q-calcium (CaV2.1) currents compared to untreated ones (Di Guilmi et al, 2010).
In this work, replacing calcium by barium, we showed greater differences between PGB-treated and
untreated slices (17±1.2% reduction), without any changes in voltage activating properties. We also
analyzed HEK293t cells transfected with subunits of CaV2.1 channels, and detected by an eGFP-tagged
_1 subunit. Fluorescent cells yielded robust barium-mediated currents that decreased (56±12%)
after PGB (500 μ M) treatment. Thus, at a real synapse as well as in an heterologous system, PGB
applied acutely determined the reduction of large CaV2.1-mediated barium currents. To test whether
the effect of PGB was dependent on the magnitude of CaV2.1-mediated currents, we analyzed the
effect of PGB in transgenic R192Q KI mice. These mice express a familial hemiplegic migraine type-1
mutation and show greater current amplitude during long lasting action potentials (APs) stimulation
compared to WT animals (Inchauspe et al, 2010). KI slices incubated with PGB decreased the currents
to WT-levels when stimulated with long duration APs (larger currents). This effect was absent with short
APs, Using time-lapse fluorescence microscopy of HEK293t transfected cells. We were able to follow
the distribution of the channels after acute incubation of PGB showing decreased (~30%) membrane
fluorescence and suggesting the internalization of through acute PGB-mediated mechanism. These results not only provide the mechanism of action of PGB, but also highlight the importance of the drug as
a potential candidate to use in other calcium channelopathies to drive currents to steady state levels.
We previously demonstrated that fraction 13 (CalTx, Bernaldez et al., 2011, Toxicon 57, 60-67) from
the venom of Conus californicus partially blocks total calcium currents from rat dorsal root ganglion
(DRG) neurons. CalTx sequence (NCPAGCRSQGCCM) is strikingly different from regular _-conotoxins,
making it a novel calcium conotoxin. We further characterize CalTx action and selectivity upon Ca2+
currents in primary culture DRG neurons. The concentration-response curve of CalTx effect (0.03 to 30
μ M) on the Ca2+ current gave an IC50 of 4.96 ± 2 μ M and a Hill slope of 1.6 ± 3 (N = 36). LVA
currents were not affected by CalTx while HVA currents were inhibited by 10 μ M CalTx. Using 3 μ M
nifedipine (Ltype selective blocker) significantly reduced the peak Ca2+ current 30 ± 12% (N =
6) (P < 0.05), while 10 μ M CalTx reduced the peak Ca2+ current 36 ± 5% (n = 7) (P < 0.05).
In the presence of 3 μ M nifedipine application of 10 μ M CalTx (N=6) produced an additional block
of 5%, attaining a total of 36 ± 7% block, indicating that preapplication of nifedipine occluded
83% of the CalTx effect. To block N-type current we use 1 μ M _- conotoxin MVIIA (N-Type selective
blocker) which reduced the peak Ca2+ current in 46 ± 9% (N=13) (P < 0.05). The application
of 10 μ M CalTx (N=6) in the presence of the _-MVIIA produced an additional block of 8% attaining
a total block of 54 ± 9% respect to the control. Since both the L and N calcium current antagonists
occluded the most part of the CalTx action (_85%) we conclude that most probably the action of the
CalTx is non-selective among the HVA Ca2+ currents. Further experiments are required to determine
its interactions with P/Q and R type selective blockers.
MO113
LIGHT-INDUCED CHANGES IN THE LIPIDS OF THE PHOTOSENSITIVE
MEMBRANE OF DROSOPHILA PHOTORECEPTORS PRESUMABLY INVOLVED
IN THE ACTIVATION OF THE LIGHT-DEPENDENT TRP AND TRPL CHANNELS
MO114
DOPAMINE D1-RECEPTOR AGONIST A-68930 DECREASES
THE NA+ CURRENT VIA A PKA-INDEPENDENT MECHANISM
IN THE COCHLEAR SPIRAL GANGLION NEURONS
Muñoz Y(1,2), Fuenzalida K(3), Gatica A(4), Peña-Cortés H(5), Roth A(1), Bacigalupo J(1,2) and Delgado
R(1,2). (1)Dept. of Biology, Fac. of Sciences, Univ. of Chile, Santiago, Chile;(2)Millennium Institute for Cell
Dynamics and Biotechnology, Univ. of Chile, Santiago, Chile;(3)Fac. of Biological Sciences, Pontifical Catholic Univ. of Chile, Santiago, Chile;(4) Institute of Nutrition and Food Technology, Univ. of Chile, Santiago,
Chile; (5) Biotechnology Center D. Alkalay L, Technical University Federico Santa Maria, Valparaíso, Chile.
Valdes-Baizabal C(1), Soto E(1), Vega R(1), (1)Laboratorio de Neurofisiología Sensorial, Instituto de
Fisiología, BUAP, Puebla, México.
Drosophila light-dependent channels, TRP and TRPL, localize to the photoreceptor rhabdomere, the
photosensitive membrane. Although these channels have been studied extensively, their activation
mechanism has not been determined. Photoisomerized rhodopsin couples to a G-protein, activating
phospholipase C (PLC). Its lipid product, diacylglycerol and its polyunsaturated fatty acids (PUFAs)
metabolites have been implicated in opening TRP/TRPL, while. IP3 does not have a role. Direct measurements of changes in these lipids in the native membrane are not available. A key question is
whether light induces changes in the rhabdomere in these lipids during the light response. We developed a enriched-rhabdomeral membrane preparation, by differential centrifugation, to address the
fatty acid composition of these membrane from wild type flies adapted to dark or light as well as the
Gaq;G_q mutant, which is unable to respond to light. Using gas chromatography (GC) coupled to mass
spectrometry (MS), we evaluated the fatty acid (FA) composition. Our results show a total of seven fatty
acids, derived from phospholipids, mono, di and triacylglycerides, free fatty acids and sterol esters.
C20 and C22 PUFAs were absent in all lipids analyzed. Moreover, we found that phospholipids were
shorter than in mammals; in Drosophila, the longest phospholipid fatty acid was C18, whereas mammalian it was up to C24. In the phospholipids, ~70% of the fatty acids were unsaturated, similar
to several mammalian cells. There were more unsaturated FAs in the wt than in the mutant, except
for free FAs. Monounsaturated FAs were predominant in triacylglycerides and PUFAs in phospholipids.
PUFAs and diacylglycerol did not change with light. The DAG species were quantified using a more
sensitive instrument (Orbitrap, a highperformance technique of mass analysis) and observed that only
one diacylglycerol species changed with light. Support: FONDECYT 1100730, MIDEPLAN ICM P05-001-F,
CONICYT Scholarship N° 22110957
In the cochlear system, dopaminergic efferent terminals synapse upon the afferent neurons innervating
inner hair cells, regulating the afferent synapse gain. Two broad families of dopamine receptors have
been distinguished: D1- and D2-like. They are coupled to G protein and activate different intracellular
pathways. In this work we studied the D1 action on the Na+ current and the PKA pathway involvement
in this action in the rat cochlear spiral ganglion neurons. Cochlear spiral ganglion neurons (SGN) were
isolated from Long-Evans C-II rats (P8-P9). Cells were grown in culture for 14-18 hours. Whole cell
current were recorded using patch clamp techniques. Recordings of the total current of the SGN shown
that perfusion of 300 nM A-68930 (D1-like agonist) inhibited the peak inward currents of cochlear
afferent neurons 44 ± 4 % (n = 4, P = 0.002), while the outward currents were not modified by
the drug. Recordings of the isolated Na+ current of SGN shown that application of 300 nM A-68930
decreased the maximum amplitude of the Na+ current 28 ± 5 % (n = 11, P = 0.001), and caused
a significant hyperpolarizing shift of the inactivation V1/2 curve from -74 ± 1 mV to -81 ± 1 mV (P
= 0.012). The addition of 1 μM H89 (PKA inhibitor) in the intracellular solution, showed that Na+
current decrease of 16 ± 5 % (n = 6, P = 0.02). No significant changes were found in the activation
or inactivation voltages. The inhibitory effect of A-68930 with and without H89 were not significantly
different (P =0.13). Additionally, the perfusion of 500 μM 8-Br-AMP (cAMP analog) had no effect on
the sodium current. These results suggest that the activation of D1 receptors in spiral ganglion neurons
follow a PKA-independent signal pathway.
MO115
PRESYNAPTIC CALCIUM CHANNELS REGULATION
BY GHRELIN RECEPTOR (GHSR1A) ACTIVITY
MO116
EFFECTS OF THE STREPTOMYCIN AND NEOMYCIN IN ACID SENSING
IONIC CURRENTS IN THE COCHLEAR SPIRAL GANGLION NEURONS
LÓPEZ SOTO EJ(1), RODRÍGUEZ S(1), AGOSTI F(1), PERELLÓ M(2), RAINGO J(1).
(1)Laboratory of Electrophysiology, Multidisciplinary Institute of Cell Biology (IMBICE). (2)Laboratory of
Neurophysiology, Multidisciplinary Institute of Cell Biology (IMBICE).
GONZÁLEZ-GARRIDO A (1), VEGA R (1), SOTO E (1), (1) Univ. Autónoma de Puebla; Instituto de Fisiología,
Puebla, Puebla, México.
Ghrelin acts via the growth hormone secretagogue receptor type 1a (GHSR1a), a G protein coupled
receptor that has an unusually high basal activity. In neurons, GHSR1a regulates gene expression,
electric activity and neurosecretion. Here we tested if basal and evoked activity of GHSR1a modifies
presynaptic calcium channels activity as a mechanism to control neurotransmitter release. For this,
we performed cell-attach patch-clamp recordings in HEK cells expressing GHSR1a and N-type calcium
channels (CaV2.2). We found that the amount of GHSR cDNA plasmid used during the transfection
inversely correlates with the percentage of transfected cells with detectable CaV2.2 basal current
(n=22 cells). Of note, the percentage of transfected cells with detectable CaV2.2 basal currents is
not affected by a mutated form of GHSR1a that lacks constitutive activity. Ghrelin treatment inhibits
CaV2.2 basal current levels in a concentration-dependent manner (16.0±2.1 and 48.8±3.3 % of
total CaV2.2 current for ghrelin 100 and 500 nM, respectively; n=18). This ghrelin-induced inhibition
of CaV2.2 current is partially washable and fully independent of the applied voltage. We then conclude
that basal and evoked GHSR1a activity inhibits presynaptic calcium channels and this effect could
count for the physiological effect of ghrelin at presynaptic terminals. We are currently investigating the
pathways mediating this effect and the modulation of these pathways by newly synthesized agonist and
antagonist of GHSR1a. Supported by PICT2010-1589 and PICT2010-1954.
It is known that aminoglycoside antibiotics such as streptomycin and neomycin are ototoxic, this
ototoxicity can be attributed to an increase of excitability. Previously, we found that acid sensing ionic
channels (ASIC) are functionally expressed in the spiral ganglion neurons, and that aminoglycosides
may interact with ASICs. It has been demonstrated that action potentials can be elicited by increasing
concentration of protons in spiral ganglion neurons, thus increasing the excitability. Using cochlear
spiral ganglion neurons in primary culture from the C57/BL mouse, P4 -P5, (L15 media, 37 °C, 5%
CO2, 95%O2, 18-24h) we studied the effects of the streptomycin and neomycin in the ASIC current activated by transient acidification of the extracellular media. Perfusion of 100 μM streptomycin blocked
the peak of the ASIC current 38 ± 4.5 % (n = 10, P < 0.05), however the most interesting effect
was a slowing of the desensitization of the ASIC current 840 ± 170 % (n = 10, P < 0.05) which
is reflected in a 46 ± 11 % (n = 10, P < 0.05) increase in the integral of the current. Moreover,
100 μM neomycin also blocked the peak of the current 26 ± 5 % (n =6, P < 0.05) and slowed
the desensitization 137 ± 44 % (n = 6, P < 0.05) with an increase in the integral of the current of
42 ± 6 % (n = 6, P < 0.05). The increase in the integral of the current may consequently produce
an overexcitation of the spiral ganglion neurons leading to neuronal damage.This phenomena could
contribute to the aminoglycoside ototoxicity.
MO117
EFFECT OF CONSUMPTION OF T2 DIETARY SUPPLEMENT IN THE
BEHAVIOR OF MICE
MO118
DIETHYLPROPION’S EFFECTS ON SLEEP, FOOD
CONSUMPTION AND BODY WEIGHT
Torres-Flores Mayra Itzel(1,2), Mónica Apodaca-Aragon(3), Edilberto Sánchez(3), Octavio Garcia(1,2),
(1)Coordinación de Psicofisiología,Facultad de Psicología, Universidad Nacional Autónoma de México,
Mexico City, México;(2) Programa Único de Especializaciones en Psicología, Neurobiología de la Conducta, Facultad de Psicología, Universidad Nacional Autónoma de México,Mexico City, México and (3)
Proyecto Neuroalimentación,Palsgaard, Mexico City, México.
Kalyanasundar Balsubramanian, Solorio Jessica and Ranier Gutierrez,.Department of Pharmacology,
CINVESTAV-IPN, 07360 Mexico City, Mexico.
Down syndrome (DS) or trisomy 21 is the most frequent genetic cause of mental retardation. Nutritional
therapies have been argued to restore cognitive function and implement newborn development in
DS. T2 is a newly developed dietary supplement and its use in patients with DS reduces anxiety and
improves attention. However the cellular and molecular mechanisms as well as its effect on other behaviors are unknown. In this work we explored whether administration of T2 dietary supplement in mice
have effect in the test of novel object recognition (NOR), a paradigm assessing short-term recognition
memory and elevated-plus maze (EPM), a model used to anxiety-related behaviors. Our results show
that two months after consuming the T2 dietary supplement, mice improve the performance on NOR
task. Furthermore we observed a significant reduction on anxiety levels. Experiments in progress are
directed to identify the cellular mechanisms involved in behavioral effects produced by the consumption of T2 dietary supplement.
MO119
INVESTIGATION OF INTERACTIONS BETWEEN NEONATAL STRESS
AND DIETARY DEFICIENCY OF N-3 POLYUNSATURATED FATTY
ACIDS (N-3 PUFAS) THROUGHOUT LIFE ON HIPPOCAMPAL
BDNF LEVELS IN ADULT RATS
Ferreira CF (1,3); Bernardi JR(1); Krolow R(3); Arcego DM(3); Senter G(1); Fries G(2); Aguiar BW(2);
Kapczinski F(2); Goldani MZ(1); Silveira PP(1); Dalmaz C(3). Laboratory of Translational Pediatrics,
Center for the Study of Child and Adolescent Health (LPT / NESCA) FAMED, HCPA, UFRGS. 2Laboratory of
Molecular Psychiatry (LPM), FAMED, HCPA, UFRGS. 3Laboratory of Neurobiology of Stress, Department
of Biochemistry, UFRGS.
Introduction and Aims: Early exposure to different interventions, as diets and stress, are associated with persistent alterations in neurochemistry and behavior, and can be considered a trigger of psychiatric disorders in
adulthood. We aimed at determining whether neonatal interventions interact with a diet deficient in n-3 PUFAs
applied during development, focusing on central and peripheral levels of brain-derived neurotrophic factor
(BDNF) in adult male rats. Methods: Seventeen litters were randomized into non-handled (NH), Handled [H,
mother-offspring separation for 10 min/day from 1ST-10TH postnatal day (PND)] and Separated (S, separation
for 3 h/day from 1ST-10TH PND) groups. On PND 35, male pups were randomized into adequate (Adeq) or
deficient (Def) diet in n-3 PUFAs (n = 6-8 per group) for 17 weeks. The weight and food intake were measured
weekly. Then, animals were decapitated, plasma and hippocampi were collected. Commercial kits were used
for measuring hippocampal and serum BDNF. Hippocampal BDNF gene expression was measured by RT-PCR
using a TaqMan commercial kit (Invitrogen). Statistical tests used were two-way or repeated ANOVA. Significance levels were set at p<0.05. Results: Body weight showed a group and a diet effect, where H group had
higher weight (p=0.007, n=13-17/group), and the Def decreased the body weight of all groups (p=0.008),
without effect on food consumption. Serum BDNF levels remained unchanged in all groups (p>0.05). Hippocampal BDNF gene expression was marginally increased in H group (p=0.057), since H animals had higher
RNA quality integrity number than NH. However, mature BDNF protein levels decreased in animals fed a DEF
(p=0.037). Conclusions: Our results indicate that the vulnerability described by deficiency of n-3 PUFAs
may initiate by central neurotrophins post-transcriptional modifications, prior to any alteration of peripheral
substance. This model can be a useful tool for studying the interaction between the early environment and
the life-course nutrition on different neurochemical outcomes. Financial Support: FIPE/HCPA, CNPq, CAPES.
The diethylpropion (DEP) is an amphetamine’s like drug that decreases food intake, but also produces
insomnia. DEP acts by increasing norepinephrine and releasing dopamine in the nucleus accumbens
(NAc). Despite that DEP has been widely used for short-term treatment of obesity, there is a paucity
of information about how DEP decreases food intake and result in insomnia. Here we first evaluated
the effects of DEP on body weight, Chow and High Fat Diet (HFD) intake as well as on insomnia. We
found that a daily dose of DEP at beginning of dark phase (active-phase), during 14 days, produced a
significant decrease on Chow intake and weight-loss in a dose dependent manner. Rats consuming a
HFD during DEP treatment displayed a significant weight-loss; however weight-loss was stronger in the
group that received both DEP and HFD was removed. After treatment all animals returned to control
body weight levels, and body weight rebound was stronger in rats with the bigger weight-loss. Administration of DEP during the beginning of light phase (inactive-phase) produced an increase in locomotor
activity accompanied by head-swings (like those on exploratory behavior). This hyperarousal state
could last the entire light-phase (> 8-10 h). Surprisingly, after DEP cessation resulted in an abnormal
increase in food intake during the light phase, therefore it is not recommended to administer DEP near
sleeping time. Finally, in order to evaluate whether DEP was acting by modulating NAc’s brain activity,
we recorded the local field potentials (LFPs). Despite that in saline-treated rats, delta band is mainly
observed during slow-wave sleep, rats treated with DEP had an increase in delta power accompanied
by hyperarousal brain state. In summary, all this results suggest that an increase in delta power in
the NAc could be an important mechanism by which DEP would mediate its appetite-suppression and
insomnia effects.
MO120
PUPS´S POSITIONS WITHIN THE HUDDLE RELATES WITH
PHYSIOLOGICAL DIFFERENCES IN BROWN ADIPOSE TISSUE
GARCIA-TORRES E (1-2), CASTELÁN F (1), HUDSON R (3), and BAUTISTA A (1). (1) Centro Tlaxcala de
Biología de la Conducta, Univ. Autónoma de Tlaxcala, México, (2) Instituto de Neuroetología, Univ.
Veracruzana, México, (3) Instituto de Investigaciones Biomédicas, Univ. Autónoma de México, México.
In mammals, interactions among siblings can strongly affect individuals’ early development. Competition for limited resources, common among mammalian siblings, is a major mechanism shaping phenotypic differences. In newborn rabbits, siblings compete for thermally favorable positions within the
nest where individuals obtain differential thermal benefits in relation to the position that they occupy
in the litter huddle. Brown adipose tissue (BAT) is the principal site of facultative non-shivering thermogenesis where heat production increases in response to low ambient temperature via mechanisms
triggered by sympathetic nervous system. The aim of this study was to investigate the physiological
differences in BAT associated with pups’ positions within the litter huddle, after acute cold exposure.
We used six litters of seven pups which were exposed to an environmental temperature of 20°C for
three days. On the third day the most central and most peripheral pup from each litter were exposed
to 10 °C for 30 min. During this time we registered interscapular BAT temperature every 5 min. The
pups were then killed, the interscapular BAT was removed, and its histological features analyzed.
Results show that the temperature and vacuole number in the BAT were greater in the central than in
the peripheral pups after cold exposition. We concluded that pups’ position within the litter huddle
is associated with physiological differences in BAT response during cold exposure. Apparently, central
pups have more resources to confront thermal challenges as a result of their prenatal and posnatal
three-day life histories.
MO121
PERINATAL FASTING AND MITRAL CELLS DEVELOPMENT IN THE RAT
C. Torrero(1), M. Regalado(1), L. Rubio(1), M. Salas(1). (1)Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, UNAM, Querétaro, Querétara, México.
Perinatal food restriction in the rat interferes with the CNS neuronal development, particularly with the
sensorial systems. The olfactory system is highly vulnerable to changes in the olfactory input by the
reduction in the number of neurons, and deficits in the dendritic tree organization. These anatomical
alterations interfere with the mother-litter bonds affecting the mother recognition, nipple attachment,
survival of the newborn and later social development. The current study analyzed the effects of perinatal undernutrition on the mitral type II neuronal development (Golgi-Cox) to provide anatomical
evidence for early olfactory discrimination. Undernutrition included the pregnant food intake reduction,
followed by the rotation (12 h) of a nipple-ligated and a normal dam between litters. Body and brain
weights were consistently reduced in the subjects of the U group. The soma measurements (area and
perimeter) and the dendritic tree (number of branches, and dendritic density) of mitral type II cells in
control (C) and underfed (U) rats at 12, 20, and 30 days of age were evaluated. In the U subjects the
area and perimeter of the mitral cell soma were significantly reduced (p<0.05). Moreover, in the U
rats the number of mitral cells dendrites had a tendency to be reduced at 12 days of age, with reductions at 20 and 30 days of age. The dendritic density was also consistently reduced at 20 and 30 days
postnatally. Current findings suggest that the integration of afferent input from the olfactory receptors
may be modified and then interfering with the mother-litter interactions and early olfactory learning.
MO123
METABOLIC SYNDROME IN RESPONSE TO
DISRUPTION OF THE SLEEP-WAKE CYCLE COMBINED
WITH CAFETERIA DIET IN YOUNG RATS
VELASCO MA, ESPITIA E, ANGELES-CASTELLANOS MA, and ESCOBAR-C
Introduction: Modern lifestyle characterized by light and activity at night promotes disruption of circadian rhythms including temporal disruption of the sleep/wake cycle. Activity at night and short sleep
increase appetite for carbohydrates and fat-rich food, better known as cafeteria diet. It is suggested
that this process can lead in a long term to overweight and obesity. This study explored the association
between forced activity during the night and ingestion of cafeteria diet in young rats. We evaluated
indicators of overweight and metabolic syndrome. Method: Male young Wistar rats were exposed to different conditions in the first 4 h of their sleep period for 12 wks: cafeteria diet in cage (CF), cafeteria
diet+ forced activity (CF/FA), forced activity period (FA) and a control undisturbed group (C). Activity
was induced with a slow rotating wheel (33 cm diameter × 33 cm long) with 4 concentric subdivisions
in which rats were placed individually for 4 h. Due to the speed of the wheels, rats do not need to walk
they can groom and even lie down. Cafeteria diet consisted of 2 variants: Potato chips+Pork sausage
or salty Crakets+Oreo cookies. These diets were presented on alternate days during 12 wks. Body
weight and food intake was followed throughout the experiment. Levels of glucose, cholesterol and
triglycerides and abdominal fat were measured at the end of the protocol. Results: CF/FA rats attained
a weight gain of 26% and high abdominal fat as compared with control rats. Also, CF/FA exhibited high
glucose levels, high cholesterol and triglycerides, features of metabolic syndrome. Such signs were not
evident when cafeteria diet was offered without sleep disturbance (CF). A 4 wk recovery interval for
the CF/FA group allowed normal glucose levels but the increased adiposity remained. Conclusion: This
model provides evidence that disturbed sleep patterns increase the consumption of cafeteria diet and
produces signs of metabolic syndrome.
MO122
BRAIN-DERIVED NEUROTROPHIC FACTOR IS LINKED
TO INSULIN SENSITIVITY AND ANOREXIGENIC EFFECTS
AFTER CHRONIC EXERCISE IN ADULT RATS
JIMÉNEZ A(1), ROCES E(1), MONTERO S(1,2), LEMUS M(1), LUGO A(1), MELNIKOV V(2), RODRÍGUEZ A(2),
GAMBOA A(3), MUÑIZ J(1). (1,2)CUIB and Facultad de Medicina, Universidad de Colima, Colima, México;
(3)INCMN Salvador Zubirán, D.F., México.
Recent evidence indicates that brain-derived neurotrophic factor (BDNF) contributes to food intake
and body weight control, acting as an anorexigenic factor in adult rats. It was demonstrated that BDNF
participates in insulin signaling in peripheral organs. Besides, physical exercise in rodents increases
BDNF production with it further secretion to general circulation. In this study we addressed whether
endurance training (treadmill for 8 weeks) modulates BDNF expression in plasma and insulin sensitivity (insulin immunolabelling in pancreatic beta- cells and hepatic glycogen); anorexigenic effects were
further analyzed. Adult male Wistar rats (200-250 g) were used, they were randomly divided into 5
groups: a) control (C) (without training, n=6); b) medium-intensity exercise training (70 % VO2MAX)
(MIT, n=6); c) as in b after an injection of a TrkB receptor inhibitor (K252a, 50 μg/100g i.p./day
during the last two weeks) (MIT+K252a, n=4); d) heavy-intensity exercise training (80 % VO2MAX)
(HIT, n=5); e) as in “d” after K252a (HIT+K252a, n=4). We measured: food intake, body weight,
insulin sensitivity (IS), glucose tolerance test (GT), immunohistochemistry of the pancreas and glycogen content in liver (liver histology). Control rats showed an increase in weight gain and food intake
in comparison with all other groups. Chronic exercise rose liver glycogen content in MIT+K252a vs C
group. During GT test, C group showed higher hyperglycemia when compared to MIT and MIT+K252a
groups (347.33±68.1 mg/dL vs 242.5±32.2 mg/dL and 216.0±25.15 mg/dL, respectively). Using
pancreatic immunoreaction for insulin, we show that the level of color density (Grey scale, that is
inversely proportional to insulin-content in the cells) was significantly lower in beta- cells in MIT
group vs C group (943.23 ±162.84 vs 1811.98±5.2). Together, our study indicates that exercise
training increases insulin sensitivity, and promotes anorexigenic effect; it further suggests that BDNF
is involved in these synergistic actions.
MO124
A COMPUTATIONAL MODEL FOR POST-SCRATCHING
LOCOMOTION IN THE CAT
TAPIA JA(1), TREJO A(1), REID JD (1), and MANJARREZ E(1), (1) Instituto de Fisiología, BUAP, Puebla,
PUE. México.
Switching between different motor tasks had been observed in the turtle (Berkowitz & Hao, 2011) and
in the cat (Trejo et al, 5th Symp on Motor Sys, SFN-2011). These authors suggest that different motor
behaviors share elements of their respective central pattern generators (CPG). Furthermore, Ijspeert et
al (2007) proposed a salamander CPG capable of switching from walking to swimming by means of a
differential drive input to the same CPG. The aim of the present study was to develop a computational
model to explain this switching between walking and scratching in the cat. This model is based on a
series of modified Morris - Lecar equations (Perez et al, 2009; Tapia et al. 5th Symp on Motor Sys, SFN2011). The set of differential equations was solved in MatLab using 4Th Order Runge-Kutta method.
The model was constructed with two hypothetical neural circuits. The first group of the model consists
of 20 medullary reticular formation neurons (MRFn), which receive a tonic input from a simulated
cutaneous afferent; and a second group, which simulates the spinal CPG network and is capable of
produce alternation between extensor and flexor motoneurons (40 asymmetrically interconnected ML
neurons). Our computational model reproduces the switching between scratching and locomotion as in
our previous experiments. The model exhibits this behavior by means of a decrease of MRFn drive towards the CPG network. The simulated episodes begin with a tonic input to the MRFn network, which in
turn, activates the flexor component of the simulated CPG. This sole activation is sufficient to produce
a scratching episode with a 5Hz alternation. Later, the ending of this tonic input produces a decrease
in the firing frequency of the MRFn. Thereupon, the CPG shifts to a slower alternation regime (1 Hz).
This model reproduces the electrophysiological and behavioral findings observed in the descerebrate
and intact cats, respectively. We propose that this exchange between scratching and locomotion is
caused by the command of a simple supraspinal inputs towards the CPG, thus allowing different motor
tasks within the same circuit.
MO125
CENTRAL CO2 CHEMOSENSITIVE NEURONS:
INSIGHTS FROM MATHEMATICAL MODELS
MO126
SORTLAB - SOFTWARE FOR AUTOMATIC SORTING
OF EXTRACELLULAR ACTION POTENTIALS
QUINTERO MC(1), CORDOVEZ JM(2), and PUTNAM R(3), (1)(2)Depto. de Ingeniería Biomédica, Universidad de Los Andes, Bogotá, Colombia and (3)Dept. of Neuroscience, Cell Biology, and Physiology, Wright
State University Boonshoft School of Medicine, Dayton, Ohio.
GÁMEZ J.A.(1), and MERCHANT H.(1), (1)Dpto. de Neurobiología Conductual y Cognitiva, Instituto de
Neurobiología, U.N.A.M., Querétaro, Querétaro, México.
Unconscious breathing is thought to be controlled by central chemosensitive neurons in the brainstem.
The cellular factors that determine the response of these neurons to increased CO2/H+ are typically
attributed to acid-induced increased firing rate pathways (accelerators). Although these activating
pathways seem to explain the increased firing rate of chemosensitive neurons in many regions of the
brainstem; a marked reduction in the CO2/H-induced increased firing rate during postnatal development has been observed in chemosensitive neurons from the locus coeruleus (LC). This reduction
in the chemosensitive response of LC neurons has been hypothesized to be due to the development
of a decelerating pathway that arises from CO2/H+ activation of calcium channels, which in turn
induces the activation of calcium-sensitive potassium channels. This mechanism, which we refer to as
a braking pathway, is proposed to exert the observed limiting effect on the neuronal responses to CO2.
Although this braking pathway may play an important role in setting the magnitude of the neuronal
chemosensitive response to CO2/H+, limited attention has been paid to this pathway. In order to
investigate the contribution of such a braking pathway in the magnitude of the firing rate in individual
neurons, we have developed a mathematical model of excitable single neurons that simulates the
voltage-gated currents using the Hodgkin-Huxley formulation. The model includes a voltage-sensitive
sodium current (INa), an L-type calcium current (ICa), a delayed-rectifier potassium current (IKDR), and
a calciumsensitive potassium current (IKCa). In our simulations we found that inhibition of the L-type
calcium current led to a larger hypercapnic-induced firing rate response, which constitutes theoretical
evidence that a braking pathway might be driven by the activation of calcium channels which then
increase potassium conductance. These findings support the hypothesis that a braking pathway can
limit the neuronal firing frequency in response to increased CO2/H+.
The detection and analysis of the neuronal activity is the starting point for the understanding of various
brain functions. Extracellular recordings are the most practical option for in vivo preparations in the
Central Nervous System. Extracellular electrodes can receive information from several neurons at the
same time; therefore it is of utmost importance to assign each spike to the neuron that generated it.
In this work, we propose the use of a spike detection algorithm based on the wavelet transform, and a
classification step based on the time sliced Expectation-Maximization algorithm that can estimate the
number of neurons present in a recording. A genetic algorithm was used to find the optimal parameters
for each of the detection and classification steps. The Matthews correlation coefficient was used to
evaluate the performance of each parameter sets. We implemented these algorithms as a Matlab module named Sort Lab. This module is extensible, as it includes the functionality to incorporate and mix
additional algorithms. Moreover, it allows comparing the performance between different detection and
classification algorithms by using artificial and real signals. The real signals used were extracellular
recordings from the medial premotor cortex of a rhesus monkey (Macaca mulatta), and the artificial
signals were created by processing the output signal of a neural network simulator. Our proposed
algorithm had a better spike sorting performance than other open source software packages available
on the internet. Sort Lab significantly reduces the time needed to assign the spike waveforms found
in an extracellular recording, in comparison with manual spike sorting by a human expert. Because of
these two characteristics, this software is an important tool for any neuroscience laboratory that works
with single unit extracellular recordings.
MO127
RETRIEVAL OF HIPPOCAMPAL MEMORIES AND THE GENERATION
OF THETA/GAMMA RHYTHMS: A SIMULATION STUDY
MO128
GENETIC SELECTION AND CHARACTERIZATION OF TWO NEW RAT
LINES DISPLAYING DIFFERENT LEVELS OF EXPLORATORY BEHAVIORS
RECIO RS(1),CAMARGO RY(1), (1) Univ. Federal do ABC, Brazil.
BRITO TM(1), MORATO S(1), (1)Faculty of Philosophy, Sciences and Letters of Ribeirao Preto – University
of São Paulo, Brazil.
The CA3 area of the hippocampus contains a large number of recurrent connections and many scientists believe that it works as an autoassociative network. This network permits the storage of activation patterns, representing memories, and their later retrieval using only a partial cue of the original
pattern. During exploratory behavior of rats, this area generates local field potential (LFP) signals
with components in the theta (4-7 Hz) and gamma (over 30 Hz) ranges. In this study we evaluate
the relationship between the retrieval of stored patterns in a CA3 networks and the generated LFP
signals. We implemented a biologically plausible model of the CA3 area using the GENESIS simulator. The model is based on experimental data and contains 100 pyramidal, 10 basket and 10 OLM
neurons. We used the model to simulate the generation of LFP signals during memory retrieval. The
LFP is evaluated based on the electric dipoles formed by potential differences inside the neuron. To
analyze the LFP signals, we used the statistical package R. We found two frequency bands, theta and
gamma, during the retrieval of stored patterns. Inside the upper phase of each theta cycle, there are
about 5 gamma cycles, with amplitude modulated by the phase of theta. Comparing the LFP signals
with the spike times and activation patterns, we saw that during each gamma cycle a single pattern is
retrieved. Moreover, during a theta cycle a single pattern is retrieved, with the first gamma containing
the presented cue and subsequent gamma cycles containing increasingly more accurate retrievals of
the pattern. Consequently, each theta cycle enables the network to converge to a different attractor
state, organizing the retrievals of different memories.
Aim: The effects of bidirectional genetic selection in two strains of Wistar rats (Filô High/Low Exploration) on exploratory behavior was investigated. Methods: Wistar rats were bred according to the high
or low time spent in the open arms of an elevated plus-maze (EPM). In each of six generations, two
rats of each sex with the highest or lowest exploration score were selected and mated, generating,
respectively, the “Filô high exploration“ (Filô-HE) and “Filô low exploration” (Filô-LE) strains. Treatment:
At 60 days of age, sixth generation animals were exposed to the EPM, open-field (OF) and elevated aversion gradient (EAG). Measurements of locomotion and time spent in risk areas were taken. Statistical
analysis: unpaired Student t-test, comparing Filô-HE versus Filô-LE (P <0.05). Results: Filô-HE males
and females exhibited higher values than their Filô-LE counterparts in: (a) time exploring the open arms
of the EPM (s) (t [10]= 9.88, P=0.03 and t [12]=33.7, P=0.01, respectively), (b) time exploring
the central area of the OF (s) (t [10]=15.92, P=0.03 and t [12]=2.91, P=0.04, respectively),
(c) distance run in the OF (m) (t [10]=1.34, P=0.00 and t [12]=0.02, P=0.00, respectively),
(d) time exploring the open arm of the EAG (s) (t [10]=18.56, P=0.03 and t [12]=4.93, P=0.00,
respectively), (e) the frequency of EAG open arm entries (t [10]=23.47, P=0.03 and t[12]=5.49,
P=0.00, respectively), but not in (f) the latency to enter the open arm of the EAG (s) (t[10]=8.03,
P=0.03 and t [12]=15.43, P=0.00, respectively). Conclusion: The genetic selection for high and
low levels of exploration (Filô-HE and Filô-LE strains) affect exploration measures which are related to
anxiety in the EPM and OF, as well as measures related to impulsivity in the EAG
MO129
POSTFATIGUE TENSION IS REDUCED BY MITOCHONDRIAL
ATP SENSITIVE POTASSIUM CHANNEL OPENERS
MO130
ROLE OF FOOT SENSITIVITY FOR POSTURAL
CONTROL IN YOUNG AND ELDERLY SUBJECTS
Sánchez-Duarte E(1), Trujillo T. X(1), Saavedra M. A(3), Huerta V. M(1), Montoya-Pérez R(2). (1) Centro Universitario de Investigaciones Biomédicas, Universidad de Colima, Colima, Colima, México; (2)
Coordinación General de Estudios de Posgrado, Universidad Michoacana de San Nicolás de Hidalgo,
Morelia, Michoacán, México and (3) Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán, México.
UEDA LS and CARPES FP, Fed Univ of Pampa, Lab of Neuromechanics, Uruguaiana, RS, Brazil
Introduction. The decrease in the ATP has an important role in the development of muscle fatigue
and any event that alters the production of this can determine the tendency of muscle fatigue. It is
been proposed that mitochondrial KATP channels (mitoKATP) plays an important role in protecting the
muscle during fatigue. As such, the aim of this study was to determine the participation of mitoKATP in
the muscle fatigue process induced by repetitive electrical stimulation, exploring the effect of Diazoxide and Nicorandil (mitoKATP channel openers) and a mitoKATP channel blocker 5-Hidroxidecanoato
(5-HD), on the tension of slow skeletal muscle of chicken in a model of fatigue in vitro. Anterior Latissimus Dorsi muscle of chicken was dissected and mounted on an experimental recording chamber
which through a mechanic-electric transducer, an amplifier and a analog-digital interface allowed
to acquire the muscle tension generated by a computer and a “software” of data acquisition. We
performed a fatigue protocol by twitches, which consisted of repetitive electrical stimulation (pulses of
100 Volts, 300 ms duration, frequency of 0.2 Hz). The bundle was stimulated until the force decreased
by 60 %. We used concentrations of 10, 30 and 100 uM Diazoxide and Nicorandil and 500 _M of
5-Hidroxidecanoato (5-HD). In dose response curves the mayor effect for Nicorandil was 10 uM and
30 uM by Diazoxide. No effect was observed by 5-HD in a dose response curve or in the presence of
the openers. As regards the openers, a further increase was observed during the postfatiga tension
applying Nicorandil compared with the effect of Diazoxide, this might talk to us about the specificity of
the drug or the condition involved in the activation of the channel due its interaction with intracellular
metabolites such as NO, PKC and PKG. Further studies are required to board this issue.
MO131
EFFECTS OF THE K ALLELE (P.E531K) IN GENE CPT1B, AND
THE W ALLELE (P.R64W) IN THE ADRB3 GENE ON THE OXIDATION
OF FFA DURING AEROBIC LOAD IN YOUNG ADULTS
GÓMEZ-GÓMEZ E(1), RÍOS-MARTÍNEZ M.E(1),DELTORO-EQUIHUA MARIO(2), CASTRO-RODRIGUEZ
E(1),BALTAZAR-RODRIGUEZ L.M(2), RAMÍREZ-FLORES M(1), PÉREZ-HUITIMEA A.L(1), GUERRERO-ALMEIDA
L(3),MUÑIZ-MURGUÍA J(1). (1) Centro Universitario de Investigaciones Biomédicas, Universidad de Colima, Colima, Colima, México; (2) Facultad de medicina, Universidad de Colima, Colima, Colima, México
and(3) Centro Andaluz de Medicina del Deporte, Sevilla, España.
The oxidation of free fatty acids (FFA) represents an important source of energy for muscle contraction
during exercise of long duration, which is determined by FFA release from the adipocyte, transport
through the blood and membranes of muscle tissue. Population studies of genetic association indicate
that the rate of lipolysis in the adipocyte and the translocation of FFA in the mitochondrial matrix
could be affected by single nucleotide polymorphisms (SNPs) of two genes, the p.R64W, from gene
encoding ADRB_3 of adipocyte and the p.E531K, in the gene encoding the protein carnitine palmitoyl
transferase 1 in skeletal muscle (CPT1B). To determine whether these polymorphisms affect the rate
of oxidation of FFA (oxFFA), a group of 37 volunteers: 18 men and 19 women 23.4 (± 3.9) and 22.4
(± 2.1) years old respectively, previously genotypified, ran 30 minutes at 65% VO2max in treadmill.
During the race, and 30 min of recovery, were measured: oxygen consumption, CO2 production, RQ,
and indicators of lipolysis: plasma concentrations of glycerol, fatty acids (FFA) and B-hydroxybutyrate
(B-Hi). Those who do not carry the K allele and carriers of wildtype “E / E” p.E531K; showed RQ values
significantly lower (p <0.05, greater oxFFA) at minutes 10, 20 and 25 , and increased blood levels of
B-hydroxybutyrate at 15 and 30 minutes post-exercise compared with the K allele and genotype K/K
carriers. There was no significant effect on blood levels of Gli and FFA by the p.R64W, nor additive effect
with the K allele of p.E531K.
Lower foot sensitivity among elderly has been suggested as determinant for impaired gait and posture.
Taking together, these impairments contribute to greater risk of falling. According to changes in center
of pressure (CoP) the foot regions may experience different pressure loads. Even known that heel presents changes in tissue stiffness and thickness influencing impact absorption, there are few studies
addressing the role of different foot region for postural control. It is not clear if different foot regions
contribute equally for postural control. This information might be useful for therapies and sensorial
stimulation procedures aiming at postural control improvement to avoid falls among older subjects.
Aiming at investigate this lack in the literature our study was to analyze the relationship between foot
sensitivity and postural control in young and elderly subjects. Forty-two subjects volunteered to this
study; they were assigned to a group according to age (young or elderly). Subjects were assessed
regarding anthropometry, foot sensitivity and postural control with eyes closed. Postural control was
analyzed by CoP traces while standing. The indexes of foot sensitivity and postural control were correlated and compared between groups by using Pearson r correlation and analysis of variance for _
= 5%. Elderly had worst foot sensitivity and postural control than young. CoP amplitude in anteroposterior direction and area of CoP in elderly were significantly correlated to general foot sensitivity,
but not with sensitivity in specific sites of the foot, whereas for young the forefoot region was more
related to postural control. Therefore, the lower foot sensitivity among elderly might play import role
for impairment in postural control, but specific sites of foot presenting lower sensitivity did not play
differenced role for postural control. Therefore, therapies aiming at improvement of foot sensitivity are
encouraged to address the whole foot instead of specific sites.
MO132
A ROLE FOR WNT/FRIZZLED SIGNALING ON POST-SYNAPTIC
MATURATION OF THE NEUROMUSCULAR JUNCTION
Jaime Teneb*(1), Evelyn Avilés*(1), Patricia Hanna(1), Daniel Sandoval(1), Juan Pablo Henríquez(1)†,
(1) Laboratory of Developmental Neurobiology, Department of Cell Biology, Faculty of Biological Sciences, Universidad de Concepción, Concepción, CHILE. (*equal contribution; †[email protected])
ABSTRACT: The neuromuscular junction (NMJ) is an archetypal model to study synapse formation,
growth, maturation and maintenance. During post-natal development, the post-synaptic apparatus
matures from an initially homogeneous plaque, formed by clusters of acetylcholine receptors (AChRs),
to a branched pretzel-like morphology. Even though plaque-to-pretzel maturation likely relies on the action of AChR disaggregating signals, the molecular mechanisms involved are largely unknown. Growing
evidence demonstrates that pathways triggered by Wnt ligands play positive and negative roles on NMJ
assembly. Even though a B-catenin-dependent Wnt cascade disaggregates AChR clusters, the possible
role of Wnt pathways on NMJ maturation has not been addressed. Here, we show that the Wnt receptor
Frizzled-9 (Fz9) is expressed in developing skeletal muscles during NMJ assembly. In mature fibres, Fz9
is localized in synaptic, but AChR-free areas. Electroporation of feet muscles with a plasmid coding for
Fz9 resulted in accelerated NMJ maturation. Importantly, silencing of endogenous Fz9 with the short
hairpin plasmid shFz9 delayed post-synaptic maturation. Consistently, in cultured myotubes overexpression of Fz9 inhibited agrin-induced AChR clustering whereas its silencing increased aggregation.
Fz9 expression results in the accumulation of B-catenin and activation of a Wnt/B-catenin-dependent
pathway. Together, our results thus far support the novel view that a Wnt signal mediated by the Fz9
receptor positively modulates post-synaptic maturation of the NMJ by inhibiting AChR clustering likely
through B-catenin. (Funded by FONDECYT 1100326).
MO133
THE EFFECT OF TWO CELLULAR SUBSTRATES ON THE SPONTANEOUS
ACTIVITY OF CHICK EMBRYONIC VENTRICULAR CARDIOMYOCYTES
MO134
EFFECT OF SODIUM ASCORBATE IN POSTFATIGUE
TENSION OF SLOW SKELETAL MUSCLE
Carlos Jesús Terrón de Alba1, Laura A. Oropeza Ramos3, Tatiana Fiordelisio Coll2, Hortensia G. González
Gómez1, Depto. Física (1), Depto. Ecología y Recursos Naturales (2). Facultad de Ciencias UNAM, Centro UNAMems-Depto. Electrónica (3).
MARTÍNEZ-MONTES M(1), SÁNCHEZ-DUARTE E(2), TRUJILLO X(2), HUERTA M(2), SAAVEDRA-MOLINA A(3),
CORTÉS-ROJO C(4), MONTOYA-PÉREZR(4). (1) Facultad de Biología, Universidad Michoacana de San
Nicolás de Hidalgo, Morelia, Michoacán, México; (2) Centro Universitario de Investigaciones Biomédicas, Universidad de Colima, Colima, Colima, México; (2) Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán, México; (4) Coordinación
General de Estudios de Posgrado, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán, México.
Cardiac frequency contractions are not strictly periodic; there are many variations and physiological stimuli during heart development. Many of these factors are mediated by the autonomic nervous
system and the endocrine system; in adition it has been shown in isolated cardiomyocytes, i.e. without
endocrine or nervous stimuli the ocurence of intrinsic variability in the cell excitability. Manny studies
has proposed that interactions between extra cellular matrix (ECM)-cell, are involved directly with
physiological activity through mechano electric signals which are related with elasticity, excitability
and even with cell shape and position. With the aim to contribute in the understanding of the relationship between ECM-cell in this work we perform a comparative analysis between two cellular substrates
(BSA and Poly-lysine) as well as their repercussions on spontaneous activity in primary cultured ventricle myocytes of embryonic chick heart with seven days “in ovo”. Ventricle myocites monolayers were
obtain by enzymatic dissociation; to record their activity cell cultures were incubated with the calcium
sensor fluo-4 AM and then mounted on a chamber on the stage of an inverted microscope and perfused
with normal saline solution saturated with 95% O2 and 5% CO2. Image sequences were adquiere and
analysed Results show evident differences in the calcium mobilization linked to cell adherent; in the
case of BSA calcium activity is intermittent, oscillations combined with quiet periods. Nevertheless in
the case of Poly-L-lysine the oscillating activity is continuous and very regular. These differences are
clearly reflected in the cell contractions and calcium mobilization, our results are an approximation
to characterize the effects of the components about extracellular matrix over the behavior and the
spontaneous activity. This wok was partially supported by PAPIIT UNAM IN223310
MO135
NEUROMUSCULAR ACTIVATION PATTERNS EXCHANGE AS EFFECT
OF AN UNSTABLE SHOE CONSTRUCTION DURING WALKING
G. Balbinot1,2; C. P. Schuch1,2; M. A. Vaz3; M. A. Zaro1,2, 1-Neurosciences Graduate Program, Federal
University of Rio Grande do Sul-UFRGS, Porto Alegre/RS, Brazil, 2-Biomechanic Lab, IBTeC, Instituto
Brasileiro do Couro, Calçados e Artefato, Novo Hamburgo/RS, Brazil, 3-Exercise Research Laboratory,
School of Physical Education, Federal University of Rio Grande do Sul-UFRGS, Porto Alegre/RS, Brazil.
INTRODUCTION: Human walking is characterized by the action of several muscular groups in a specific
order, a neuromuscular activation pattern. Corticospinal and corticobulbar pathways project their information from upper motor neurons to initiate complex voluntary movements. Organized descending
motor control commands (central pattern generator; CPG), act like a local neural circuit in order to
rapidly synchronize muscle activation. The movement of a single limb during locomotion can be thought
as a cycle consisting of two phases: (a) a stance phase (StP), during which the limb is extended (in
the present study divided into two halves -StP and +StP); and (b) a swing phase (SwP), during which
the limb is flexed to leave the ground and then brought forward to begin the next StP. The CPG receives
proprioceptive information from periphery and relies up on this information to command neuromuscular activation patterns during the gait cycle, these patterns are dependent of walking dynamics (such
as speed and balance) and on shoe design and characteristics (shape, insole air compartments),
among others. AIM: The aim of this study was to assess the effect of an unstable shoe (insole air
compartments) on neuromuscular activation pattern during walking. METHODS: 10 healthy subjects
(4 men 29.1_5.9 years, leg length 0.97_0.06 m and body weight 82.9_7.9 kg; 6 women 28.7_2.1
years, leg length 0.87_0.04 m and body weight 57.3_8.2 kg) were instructed to walk at 4.5 km.h-1 on
a treadmill during 5 minutes. Neuromuscular activation was measured in 7 different muscles (tibialis
anterior, soleus, peroneus brevis, medial gastrocnemius, vastus lateralis, rectus femoris and biceps
femoris) considered to be representative of the main muscular groups involved in gait activity. Subjects
performed treadmill walking wearing (a) conventional shoes and (b) unstable shoes in a random order.
Fatigue is conceived as a decrease in the development of force in muscle, and is been documented as
a multifactorial process as peripheral nervous system. In that manner it is been proposed that reactive
oxygen species (ROS) play an important role in the regulation of several signaling routes which are
related to correct function of the muscle specially during fatigue, it is been reported that antioxidants
at low concentrations are beneficial for cells, however at higher doses could detrimental. As such, the
aim of this study was to determine the effects of sodium ascorbate on the tension of slow skeletal
muscle of chicken in a model of fatigue in vitro. Anterior Latissimus Dorsi (ALD) muscle of chicken was
dissected and mounted on an experimental recording chamber by placing the proximal end to the bottom of the chamber and the distal end hook mechanic-electric transducer (Grass FT03), which through
an amplifier and a 320 CyberAmp analog-digital interface (Digidata 1322A) allowed to acquire the
muscle tension generated by a computer (Pentium 4) and a “software” of data acquisition (AXOTAPE,
pCLAMP 9.2). We performed a fatigue protocol by twitches, which consisted of repetitive electrical
stimulation (pulses of 100 Volts, 300 ms duration, frequency of 0.2 Hz). The bundle was stimulated
until the force decreased by 60 %, then was applied the study drug for 6 min to observe its effect. We
used 10 uM of sodium ascorbate. So far we were able to see that in the presence of sodium ascorbate
was an increase of postfatigue tension of 31.45 +- 6.88 in total tension and 24.95 +- 10.48 in
maximum tension, agreeing with the report that a lower doses can be beneficial. However, further
studies are required to board this issue with higher doses.
Neuromuscular activation of seven muscles at three different phases of the step cycle, i.e., -StP, +StP
and SwP, were obtained with two 4-channel electromyography (EMG) systems (Miotool Ltd., São Paulo,
Brazil). The root mean square percentage of EMG activity (relative to the 100% of step cycle) was
calculated for each gait phase (i.e., -StP, +StP and SwP) for each subject and all computational
routines were custom written in LabVIEW® 8.5 software. RESULTS: From seven measured muscles,
only five showed statistical differences in EMG intensity pattern. Compared to the control shoe, the
unstable shoe EMG signal showed an increase for rectus femoris -StP and for vastus lateralis +StP
and a decrease for tibialis anterior +StP, soleus SwP, rectus femoris +StP, vastus lateralis -StP and
medial gastrocnemius SwP. For the calf muscles the unstable shoe construction resulted in a decrease
of 8.8% (p=0.046) for tibialis anterior +StP, of 7.4% (p=0.046) for soleus SwP, and of 10.6%
(p=0.001) for medial gastrocnemius SwP. For the thigh muscles the unstable shoe construction
resulted in an increase of 5.5% (p=0.009) for rectus femoris -StP, 5.0% (p=0.003) for vastus
lateralis +StP and a decrease of 12.84% (p=0.009) for rectus femoris +StP and 4.4% (p=0.001)
for vastus lateralis -StP. CONCLUSION: Unstable shoe might not result in absolute increase of EMG
activation but in a switch of activation levels, where some muscles are more active than others at
different phases of the gait cycle.
MO136
ANXIOLYTIC AND ANTIDEPRESSANT EFFECT OF RITALIN®
(METHYLPHENIDATE HYDROCHLORIDE) IN ADULT MICE
FEITOSA MA(1), LINHARES MI(1), VENANCIO ET(1), LIMA CNC(1), FONTELES MMF(1), SOUSA FCF(1). (1)
Departament of Physiology and Pharmacology, Federal University of Ceará, Fortaleza, Brazil.
Introduction: Attention-deficit hyperactivity disorder (ADHD) is a prevalent and debilitating disorder diagnosed on the basis in persistent levels of over activity, inattention and impulsivity. Stimulant medications have been effective for the treatment of this disorder, and the methylphenidate (MPH) is the most
prescribed therapeutic agent. Methods: MPH was evaluated in classical animal models to the screening
of drugs with activity in anxiety and depression, such as elevated plus maze (EPM) and forced swimming test; and a neurochemistry study, through the level of monoamines, such as dopamine (DA),
norepinephrine (NE) and 5-hidroxytriptamine (5-HT) was realized. The MPH was administered acutely in
all tests at doses of 2,5; 5; 10 e 20 mg/Kg, through the oral via (p.o.) in adults mice. Results: Results
showed that the MPH presented an anxiolytic effects in the model of EPM, since the dose of 20mg/kg
increased almost all the parameters analyzed (Number of entries in the open arms (NEOA): 10,14±
1,18, p<0,05; Time of permanence in the open arms (TPOA): 113,3±9,02, p<0,01; Percentage of
time in the open arms (PTOA): 49,54±3,48, p<0,05) when compared with the respective control
(NEOA: 5,11±0,75; TPOA: 69,75±7,27; PTOA: 30,67±2,44). MPH presented antidepressant effect
of Central Nervous System (CNS), since in the forced swimming, decreases the time of immobility at
dose of 20 mg/Kg (MPH: 91,38±8,97, p<0,01; Control: 143,2±7,60). The anxiolytic effect was
proved by the increased level of serotonine at higher doses, and the antidepressant action was proved
by the increased level of Norepinephrine in striatum. Conclusion: These effects showed that MPH presented anxiolytic and antidepressant effect proved by monoamines analysis.
MO137
OVEREXPRESSION AND KNOCK-DOWN OF DMP53, BASKET AND DRICE
IN DOPAMINERGIC NEURONS AFFECT LIFE SPAN AND LOCOMOTOR
ACTIVITY IN DROSOPHILA MELANOGASTER EXPOSED TO PARAQUAT:
IMPLICATIONS IN PARKINSON´S DISEASE
Hector F. Ortega-Arellano(1), Carlos Velez-Pardo(1), Marlene Jimenez-Del-Rio(1), (1)School of Medicine,
Medical Research Institute, Neuroscience Research Group, University of Antioquia (UdeA), Calle 62 #
52-59, Building 1, Room 412; SIU. Medellin, Colombia.
Understanding the mechanism(s) by which dopaminergic neurons are eroded in Parkinson’s disease
(PD) is critical for effective therapeutic strategies. Recently, our research group has demonstrated in
vitro that paraquat (PQ) induces apoptosis by oxidative stress mechanism involving activation of the
p53 transcription factor, c-Jun N-terminal kinase (JNK), caspase-3 and cell death. Since those signalling molecules are highly similar to Drosophila melanogaster, we hypothesized that these molecules
might be operative in Drosophila exposed to PQ. By using GAL4/UAS system, in this work, we report
for the first time that PQ differentially affects life span and locomotor activity in overexpression or
knock-down Dmp53, basket and drICE Drosophila flies lines. Specifically, overexpression Dmp53 and
Basket proteins sensitize flies lines to PQ exposition that result in significantly decrease life span and
movement abilities. In contrast, untreated or treated knocked-down (by RNAi) Dmp53, Basket and drICE
flies were significantly resistant to aging and PQ toxic effects. Although RNAi fly lines treated with PQ
were moderately affected, the survival proportion and locomotor activity were significantly increased
(almost two-fold) when compared to overexpressing fly lines. Interestingly, the polyphenol gallic acid
significantly ameliorate life span, climbing abilities and number of neurons in both overexpression and
knock-down Dmp53 fly lines treated with PQ compared to untreated ones. These findings altogether
support the notion that oxidative stress mechanism plays an important role in loss of dopaminergic
neurons in PD. Furthermore, these results open new avenues for the screening, testing and development of novel antioxidant drugs against oxidative stress stimuli in PD.
MO138
MK-801-INDUCED COGNITIVE DEFICIT IN RATS IS IMPROVED
BY CLOZAPINE: INVOLVEMENT OF SEROTONIN 5-HT1A RECEPTOR
MO139
NEUROANATOMICAL PROFILE OF ANTIMANIAC EFFECTS
OF HISTONE DEACETYLASES INHIBITORS
López Hill X (1), Scorza MC (1), (1)Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
Camila O. Arent(1), Samira S. Valvassori(1), Gabriel R. Fries(2), Laura Stertz(2), Camila L. Ferreira(1), Jéssica LopesBorges(1), Edemilson Mariot(1), Roger B. Varela(1), Felipe Ornell(1), Flávio Kapczinski(2), Monica L. Andersen(3),
João Quevedo(1); (1)Laboratory of Neurosciences and National Institute for Translational Medicine (INCT-TM), Postgraduate Program in Health Sciences, Health Sciences Unit, University of Southern Santa Catarina, Criciúma, SC,
Brazil. (2) Bipolar Disorders Program, Laboratory of Molecular Psychiatry and National Institute for Translational
Medicine (INCT-TM), Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil (2)Department of Psychobiology,
Universidade Federal de São Paulo, São Paulo, SP, Brazil.
Cognitive deficit in schizophrenic patients is a core feature of the illness. It involves domains such as
attention, learning and memory. Clinical evidences have suggested that, in comparison with typical
antipsychotics drugs, atypical (AAT) drugs can enhance cognition in schizophrenia. However, the receptors by which AAT exert this effect is still under study. It is known that AAT are 5-HT1A receptor (partial)
agonists, which may be relevant for their actions in treating schizophrenia. The N-methyl-d-aspartate
receptor (NMDAR) antagonists have been used as an animal model of cognitive deficits in schizophrenia. MK-801, the most potent NMDAR antagonist, induces cognitive deficit measured by Transfer
Latency (TL). TL is a behavioral parameter for the evaluation of spatial learning and memory in animals
which can be measured using the elevated plus-maze test. We investigated the effect of Clozapine (Clz)
in cognitive deficit induced by MK-801 using the TL. Additionally, we determined if 5-HT1A receptors
are involved in the Clz action. Wistar male rats were injected with Clz (1 mg/kg) or vehicle and 5 min
later MK -801 (0.05 kg/kg) or saline were administered. Moreover, WAY-100635 (selective 5-HT1A
antagonist) was pre-injected (0.3 mg/kg) in animals and then treated with Clz (1 mg/kg) and MK-801
(0.05 kg/kg). In both experiments, TL1 was evaluated after 30 min of drug injections whereas animal´s
performance without drugs was measured in TL2 and TL3, 24 an 48 h later, respectively. TL2 was more
prolonged in animals treated with MK-801 than saline, indicating an amnesic effect of the drug. TL3
was similar to control value. Clz attenuated the increase in TL2 observed after MK-801 treatment.
Interestingly, WAY-100635 prevented the attenuation of the MK-801-induced amnesic effect by Clz,
demonstrating the involvement of 5-HT1A receptors in the mechanism of action of Clz. These results
provide a significant implication for cognitive improvement in schizophrenia.
Introduction: An increasing number of studies have evaluated the potential therapeutic relevance
of histone deacetylases (HDAC) inhibitors in mood disorder, as bipolar disorder (BD). It has been
suggested that limbic system, which controls impulsivity and psychosis, is dysfunctional in BD. The
present studies aims to evaluate the effects of microinjection of HDAC inhibitors in the ventricle,
amygdala, striatum, prefrontal and hippocampus on mamphetamine- induced manic-like behavior in
rats. Methods: Rats were given a single intracerebral (in the ventricle, amygdala, striatum, prefrontal or
hippocampus) injection of artificial cerebrospinal fluid (ACSF), sodium butyrate (SB) or valproate (VPA)
followed by an intraperitoneal injection of saline or m-AMPH 2 h before the open-field task. The activity
of HDAC was evaluated in amygdala, striatum, prefrontal and hippocampus of animals (n=15). The
microinjection of SB and VPA in the ventricle, amygdale, striatum, prefrontal, but not in hippocampus
blocked the hyperactivity induced by m-AMPH. In addition, SB and VPA inhibited the HDAC activity;
however, this effect varied depending on the experimental procedure and the brain structure evaluated.
Results: Our results suggest that the antimanic effects of SB and VPA, HDAC inhibitors, are related
to the amygdala (ACSF+ACSF:34±6; ACSF+SB:28±6; ACSF+VPA:36±6; m-AMPH+ACSF:69±4; mAMPH+SB:30±6; m-AMPH+VPA:40±3; P<0,001), striatum (ACSF+ACSF:19±6; ACSF+SB:27±3;
ACSF+VPA:31±4; m-AMPH+ACSF:61±6; m-AMPH+SB:44±3; m-AMPH+VPA:32±9; P<0,001) and prefrontal (ACSF+ACSF:27±5; ACSF+SB:34±5; ACSF+VPA:29±8; m-AMPH+ACSF:71±10; m-AMPH+SB:41±4;
m-AMPH+VPA:31±4; P<0,001), but not the hippocampus (ACSF+ACSF:30±4; ACSF+SB:21±5;
ACSF+VPA:36±6; m-AMPH+ACSF:57±5; m-AMPH+SB:45±4; m-AMPH+VPA:44±5; P<0,001). More
studies are needed to clarify the therapeutic effects of the HDAC inhibitor in BD and thereby develop
new drugs. Discussion: In summary our results suggest that the antimanic effects of SB and VPA,
HDAC inhibitors, are related to the amygdala, striatum and prefrontal, but not the hippocampus. More
studies are needed to clarify the therapeutic effects of the HDAC inhibitor in BD and thereby develop
MO140
PREFRONTAL CORTICAL THINNING AND AMYGDALA
VOLUME DECREASE IN PSYCHOPATH OFFENDERS
MO141
EEG ABNORMALITIES IN PSYCHOPATH AND
NON-PSYCHOPATH VIOLENT OFFENDERS
Ana Calzada-Reyes 1, Mitchell Valdés-Sosa 2, Alfredo Alvarez Amador 3, Lídice Galán-García 4, Lester
Melie-García 5, Yasser Alemán-Gómez 5. (1) Department of Clinical Neurophysiology, Institute of Legal Medicine, CUBA, (2)Department of Cognitive Neuroscience, Cuban Center of Neuroscience, CUBA,
(3)Department of Clinical Neurophysiology, Cuban Center of Neuroscience, CUBA, (4) Department of
Neurostatistic. Cuban Center of Neuroscience, CUBA, (5)Department of Neuroimaging. Cuban Center
of Neuroscience, CUBA
Ana Calzada-Reyes (1) Alfredo Alvarez Amador (2)Mitchell Valdés-Sosa (3)Lidice Galán-García (4) (1)
Department of Clinical Neurophysiology, Institute of Legal Medicine, CUBA (2)Department of Clinical
Neurophysiology, Cuban Center of Neuroscience, CUBA (3) Department of Cognitive Neuroscience, Cuban Center of Neuroscience, CUBA (4), Department of Neurostatistic. Cuban Center of Neuroscience,
CUBA
Psychopathy is characterized by a lack of empathy and the formation of transient and exploitive interpersonal relationships .The goal of this study was to determine whether brain regions implicated in
emotional processing and behavioral regulation showed structural alterations in psychopath offenders.
Using a surface-based whole brain analysis to detect associations between gray matter thickness and
the PCL-R total score were identified in entire cortex analyses in 97 violent offenders (44 offenders with
and 55 without psychopathy defined by the PCL-R scale. We found that psychopathy was associated
with highly significant (FDR=0.001) thinning of the cortical surface within the left inferior orbitofrontal gyrus, right rectus, bilateral middle frontal gyrus, left insula, left precentral gyrus and associative
occipital cortices. One negative association between amygdala volume and orbitofrontal thickness was
found in psychopath group. These findings concur with reports of prefrontal and amygdala deficits in
psychopaths and support the hypothesis that neurocognitive operations mediated by the amygdala and
VL/OFC contribute to with deficits in decision making and emotional processing deficits’ associated
with psychopathy.
Previous EEG studies attempted to examine violent behavior as homogeneous construct. Up to date,
there is no other research studying Low-Resolution Brain Electromagnetic Tomography (LORETA) technique in psychopath offenders. Objective: To find electrophysiological differences specifically related
to the psychopathy construct and independent of the violent behavior. The current investigation compares the QEEG and the current source density measures of violent psychopath offenders to a non
psychopath violent group. Methods: The resting EEG activity and LORETA for the EEG spectral fast bands
were evaluated in 58 violent offenders, 31 with and 27 without psychopathy according to the Hare
Psychopathy Checklist—Revised. All subjects were assessed using the DSM IV-R criteria. The EEG
visual inspection characteristics and the use of frequency domain quantitative analysis techniques
(Narrow band spectral parameters) are described. Results: QEEG analysis showed a pattern of excess
of beta activity on the left parietotemporal Regions and bilateral occipital areas and decrease of alpha
band on the left centro-temporal and parieto-central derivations in the psychopath group. LORETA
signified an increase of beta activity (17.18 Hz) in psychopath group relative to a nonpsychopath group
within fronto-temporo-limbic regions. Conclusions: These findings indicate that QEEG analysis and
techniques of source localization may reveal differences in brain electrical activity among offenders
with psychopathy, which was not obvious to visual inspection. Taken together, these results suggest
that Abnormalities in a frontotemporo-limbic network play a relevant role in the neurobiological basis
of psychopathy.
MO142
COMBINED EVALUATION OF BRAINSTEM REFLEXES IN
PATIENTS WITH EARLY AMYOTROPHIC LATERAL SCLEROSIS
MO143
QUANTITAVE EVALUATION OF HIPOKINESIA ON
PARKINSON’S DISEASE USING SENSOR GLOVES
Alvarez Herrera I(1), Zaldivar Vaillant T(2), Lara Fernández G(3), Soto Lavastida A(3), Gutiérrez Gil J(1),
(1)Dept. of Clinical Neurophysiology, Institute of Neurology and Neurosurgery, La Habana, Cuba (2)
Dept. of Neurogenetics, Institute of Neurology and Neurosurgery, La Habana, Cuba (3)Motor Neurons
Diseases Section, Institute of Neurology and Neurosurgery, La Habana, Cuba.
Díaz-Vera T(1),Gómez-Fernández L(1),Álvarez-Sánchez M(2),Díaz-de la Fe A(2),Martínez-Montes E(3),(1)
Dpto de Neurofisiología Clínica,Centro Internacional de Restauración Neurológica, La Habana, Cuba;(2)
Clínica de Trastornos del Movimiento ,Centro Internacional de Restauración Neurológica, La Habana,
Cuba;(3)Dpto de Neuroestadística,Centro Nacional de Investigaciones Científicas, La Habana, Cuba.
Introduction: Brainstem reflexes (BSR) have been used to document upper motor neuron (UMN) involvementin amyotrophic lateral sclerosis (ALS). The authors hypothesized that combined evaluation of BSR
is more informative than a separate analysis of each in early ALS. Objectives: To determine whether a
battery of BSR discriminates ALS patients from controls better than the independent evaluation of each
reflex. Methods: Masseter inhibitory (MIR), masseter direct (MR), blink reflex (BR) and BR habituation,
were evaluated in 11 definitive spinal ALS patients (<1 year of evolution) and 15 age-matched healthy
controls, following published guidelines (masseter reflexes through chin taps; BR electrically, its habituation in a paired stimulation paradigm). To evaluate discriminating capabilities of BSR between
control and patient groups, stepwise discriminant analysis were performed in two ways: 1-including
variables from only one type of reflex in each model; and 2-including variables from all reflexes in
a combined model. Results: MR and MIR model misclassified 23,08% of subjects (Wilks’ lambda
p<0,0603). With BR model, misclassification reached 33,33% (Wilks’ lambda p<0,0475). In BR
habituation model the 30% was wrongly classified (Wilks’ lambda p<0,1667). The combined model,
which included MR amplitude, MIR duration, BR R2 duration and R2 habituation (ISI=1000ms), was
the most efficient, providing accurate classification of 94,46% of subjects(Wilks’ lambda p<0,0007),
only one control incorrectly allocated. Conclusion: The combined use of BSR allows better discrimination of early ALS patients from healthy subjects. UMN dysfunction is susceptible of earlier detection
assessing the global changes in excitability of brainstem circuits through conjoint evaluation of BSR.
Introduction: Instruments that facilitate the realization of quantitative (objective) mensuration of cardinal signs in Parkinson’s Disease (PD) like the bradykinesia, would assist more effective therapeutic
intervention. Objectives: To evaluate the utility of sensor gloves on quantitative evaluation of bradykinesia on Parkinson’s Disease. Methods: The authors carried out a study of type cases and controls,
organized in two groups: 13 patients with clinical diagnosis of idiopathic PD in “on” state and 24
controls, to which were carried out a registration of the “finger tapping” movement using sensor gloves
(5DT-14Ultra) the analysis of the amplitude was calculated through the power spectra derived from
a Fourier Transform (FFT). Also we examine the relationship between glove data obtained, the clinical
scale employed (UPDRS) and the early and late components of the premotor potential. Results: The
authors observed that patients presented a smaller speed in the execution of the movements, demonstrated to reach their maximum amplitude at smaller movement frequency (1,5-2Hz) than controls
(3,5-4Hz), as well as, a significant decrease of the amplitude of movement toward the frequencies of
movement =3Hz. The most favorable values in the clinical scale employed were in connection with
broader movements toward the high frequencies (=3.5Hz). Our study demonstrated a relationship
between amplitude of movement and the area of the earlier and later components of the premotor potential. A bigger area associated to a broader movement. Conclusion: The authors conclude that sensor
gloves are a useful device as quantitative complement of the clinical evaluation in the patients with PD.
MO144
SACCADIC EYE MOVEMENTS AS BIOMARKERS OF COGNITIVE
IMPAIRMENTS IN SPINOCEREBELLAR ATAXIA TYPE 2
MO145
RELIABILITY AND LONGITUDINAL CHANGES OF SACCADIC EYE
MOVEMENTS IN SPINOCEREBELLAR ATAXIA TYPE 2 PATIENTS
RODRÍGUEZ-LABRADA R (1), VELÁZQUEZ-PÉREZ L (1), OBERSCHMIDT C (2), CANALES-OCHOA N (1), AGUILERA-RODRÍGUEZ R (1), MEDRANO-MONTERO J (1), ESTUPIÑAN-RODRÍGUEZ A (1), PEÑA-ACOSTA A (1),
GONZÁLEZ-ZALDIVAR Y (1), VÁZQUEZ MOJENA Y (1), CRUZ MARIÑO T (1), AUBURGER G (2); (1) Centre for
the Research and Rehabilitation of Hereditary Ataxias, Holguín, Cuba; (2) Clinic for Neurology, University Hospital, Frankfurt am Main, Germany.
RODRÍGUEZ-LABRADA R (1) VELÁZQUEZ-PÉREZ l (1), CANALES-OCHOA N (1), OBERSCHMIDT C (2), SÁNCHEZCRUZ G (1), MEDRANO-MONTERO J (1), AUBURGER G (2); (1)Centre for the Research and Rehabilitation
of Hereditary Ataxias, Holguín, Cuba; (2) Clinic for Neurology, University Hospital, Frankfurt am Main,
Germany.
Background: Saccadic abnormalities has been proposed as suitable endophenotypes for Spinocerebellar Ataxia type, 2 (SCA2), but have never assessed as sensitive biomarkers of cognitive dysfunctions.
Objective: To evaluate the saccadic abnormalities as sensitive biomarkers for the cognitive dysfunctions in SCA2. Methods: Pro-saccade and anti-saccade tasks were assessed by electronystagmography
in 110 SCA2 patients, 56 presymptomatic subjects and their paired controls. Standardized frontalexecutive tests, event-related evoked potentials (ERP) and ataxia scoring were applied. Results: SCA2
patients showed significant decrease of saccadic velocity and deviation, in addition to prolongation of
saccadic latency. Presymptomatic subjects showed mildly saccadic slowing. Anti-saccadic errors rate
was significantly increased in both groups. Saccadic velocity and anti-saccadic errors rate showed
significant correlation with the cerebellar impairment and mutation size. Saccadic latency correlated
negatively with the performance of the Stroop test, the verbal fluency test and the Wisconsin Card
Sorting Test in patients. Nevertheless, neither saccadic velocity nor dysmetria correlated with the
frontal-executive parameters. Besides, prolongation of saccadic latency was associated to decreased
amplitude of P300 component of the visual ERPs. Antisaccadic errors rate increased with execution
deficits on Stroop and verbal fluency tests in symptomatic subjects. Conclusions: As saccadic latency
and antisaccadic error rate were not influenced either by the cerebellar impairment or mutation size,
but to the frontal-executive performance, these oculomotor parameters should be used for the monitoring of these cognitive functions rather than for the assessment of disease progression. Also, saccadic
latency could serve as biomarker for attentional deficits and alterations in the processing of visual
incoming information. Therefore, saccadic movements provide promising biomarkers to assess the
effect of the rehabilitation and other therapeutical options over the cognitive functions in SCA2.
MO146
THE SCA2 CUBAN KINDRED WAS FOUNDED BY
HISPANICS BETWEEN 1408AD AND 1733AD
LAFFITA-MESA JM(1), VÁZQUEZ MOJENA Y(1), VOLPINI V(2), PENA SERRANO L(1), VELAZQUEZ PEREZ LC(1),
AUBURGER G(3), GISPERT S(3).1: Center for Research and Rehabilitation of Hereditary Ataxia -CIRAH-. 2:
Molecular Genetics Department, Medical and Molecular Genetics Centre-IRO, Hospital Duran i Reynals,
Autovía de Castelldefels km 2.7, 08907, L’Hospitalet de Llobregat, Barcelona, Spain. 3: Experimental
Neurology, Goethe University Medical School, Theodor Stern Kai 7, 60590 Frankfurt am Main, Germany.
Introduction: SCA2 reach the highest prevalence rate in the eastern region of Cuba, where a founder
population was reported, however little is known about this foundational event. Objective: 1) To determine genetic similarities in the SCA2 locus using tightly linked microsatellite markers and intragenic
SNIPs in Cuban and Spanish SCA2 individuals affected. 2) To gain insights in the mutational history
of the SCA2 gene in Cuba using chronologic approaches. Methods: Haplotypic profiling using STR and
SNIPs were performed. In addition, sequencing and genealogical data were provided. Microsatellite,
SNIPs and sequence were used to determine the probable era that the SCA2 mutation appeared in
Cuba. Results: STR haplotypes from SCA2 families are very homogeneous, with sparse families and
individuals showing rare haplotypes. Based on DMLE+2.3, using 6 STR spanning a region of 3cM with
growth rate 0.45-fold per generation, our calculations estimate that this mutation originated around
392 years ago, showing a clear picture of a recent mutation origin at about 15.68 generations ago
(95%Confidence Interval, 10.23 to 24.56 generations). This 392 year range places the arrival of the
SCA2 mutation at 1615AD in the period (1408-1733AD) and to be brought by Hispanic immigration to
the eastern region of Cuba during the introduction of slavery. Conclusions: The importance of estimating age of mutation revolves around the conditions and life style by which SCA2 onset in Cuba and
reached the tremendous prevalence in our region.
Background. Saccadic pathology is a key feature of Spinocerebellar Ataxia type 2 (SCA2). Nevertheless
there are few follow-up studies of saccadic eye movements in SCA2, limiting the appropriate characterization of these measures as SCA2 disease biomarkers. Objective. To assess the progressive changes
of saccadic measures by a follow-up design in SCA2 patients, and to evaluate the test-retest reliability
and internal consistency of these parameters. Methods.: Forty SCA2 patients and 30 healthy controls
underwent 3 assessments of saccadic movements over a 2-years period. Quantitative longitudinal
changes were analyzed by repeated measures ANOVA, whereas test–retest reliability and internal
consistency were assessed by Intra-class correlation and Cronbach’s coefficient alpha, respectively.
Results: ANOVA followed by Bonferroni post-hoc analysis detect a subtle worsening of saccadic velocity, deviation and latency during the follow-up period in SCA2 patients compared to controls. Therefore, the progression rate of saccadic abnormalities in SCA2 patients was significantly higher than
controls but these progression rates did neither correlate with CAG repeats, disease duration nor
ataxia score. All saccadic variables showed significant test–retest reliability. Cronbach’s alpha coefficients indicated very high internal consistency (_>0.73) for saccadic velocity and latency in SCA2
group. Conclusions. Given the moderate reliability and consistency of saccadic measures in SCA2 in
spite of the subtle changes detected across time they has been proposed as objective parameters to
assess progression of neurodegenerative process and to evaluate the effect of therapeutical options,
highlighting the role of saccadic velocity as the best reliable marker to assess the progressive effect
of polyQ toxicity in the brainstem.
MO147
THE CONTRIBUTION OF THE SELF POLYQ LOAD [SOMATIC MOSAICISM]
IN THE CNS TO THE ONSET, DISEASE DURATION AND PROGRESSION
RATE OF SCA2 AND PHENOTYPIC DELINEATION
LAFFITA-MESA JM (1), VAZQUEZ MOJENA Y(1), CUELLO ALMARALES D(1), VELAZQUEZ PEREZ LC(1). Molecular Neurobiology, Center for Research and Rehabilitation of Hereditary Ataxia, Holguin, Holguin,
Cuba, 80100.
Introduction: SCA2 show strong relationship among CAG and the onset of ataxia. Objective: 1) To compare the somatic mosaicism of the expanded CAG of SCA2 gene in CNS. 2) To determine the influence
of somatic mosaicism on SCA2 phenotype and its relationship with CAG size and architecture and
linked haplotype. 3) To gain insights about the dynamic of the CAG expansion in CNS. Methods: We have
analyzed CAG expansions in 12 different sites of SCA2 deceased patients with discordant phenotypes
and somatic mosaicism indices, peaks number, CAG range and skewness of the CAG in each region
was determined. Also, detailed clinical data using rating scales trough life with follow-up using neurophysiology biomarkers were used to generate phenotypic profiles. In silico analysis were done to obtain
models of ataxin-2 protein with polyQ domains enlarged with different sizes which are contained in the
same lineage of the different CNS we found somatic mosaicism. In addition, we determined ataxin-2
expression in frozen tissues that we analyzed somatic mosaicism. Results: Regions of the brain with
greatest level of somatic mosaicism were motor cortex, occipital grey matter, olive, pons, and globus
pallidus. While those regions more compromised in SCA2, like cerebellar cortex showed lesser somatic
mosaicism. Early onset was associated with wide ranges of CAG in the CNS (with differences up to 1017 CAG units respecting the major CAG) in contrast to delayed onsets. Conclusions: Our results bring
data about the role of the somatic mosaicism as the major modifier of the SCA2 phenotype.
MO148
DE NOVO MUTATED ATAXIN-2 INTERMEDIATE-LENGTH P
OLYGLUTAMINE IN FAMILIAL ALS, NOVEL ALS CASES
DUE TO ENLARGED POLYQ AND META-ANALYSIS
MO149
ANXIOLYTIC EFFECTS OF THE BILATERAL INTRA-AMYGDALOID
INJECTION OF THE DOPAMINE D1 RECEPTOR ANTAGONIST SCH23390
IN DIFFERENT UNCONDITIONED RAT MODELS OF ANXIETY
LAFFITA-MESA JM(1), RODRIGUEZ JM(2), MORENO R(1), VAZQUEZ MOJENA (1), LAGUNA SALVIA L(2), KOURI,
V(3), VELAZQUEZ PEREZ L(1), MARTINEZ RODRIGUEZ AP(3). 1: Molecular Neurobiology, CIRAH, Holguin,
Cuba. 2: Clinical and Surgical Hospital Lucía ´Íñiquez Landín, Holguín, Cuba. 3: Institute of Tropical
Medicine ‘Pedro Kourí’, Havana, Cuba.
Palomares C.E(1), Crespo R.M(1),Fuxe K(2), Pérez de la Mora M(1), (1)Division of Neuroscience, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico. (2)Division of
Cellular and Molecular Neurochemistry, Department of Neuroscience, Karolinska Institutet, Stockholm,
Sweden
Introduction: Cytosine Adenine Guanine expansions above certain threshold are the genetic cause
for development of SCA2 and now have been associated with Parkinsonism, ALS and FTDLP-U. Data
about the source for sporadic ALS or familial cases is largely unknown. Results: Here we are reporting two de novo mutations in the ataxin-2 gene associated with familiar ALS following an autosomal
dominant pattern. We also found sporadic ALS cases with intermediate polyQ expansions in ataxin-2
gene. Meth-analytical techniques showed that intermediates alleles are showed incremented risk for
ALS and that are more frequent in ALS than in SCA2, which suggest different nature and pathological
mechanism underlying both disorders. Conclusions: Our results emphasizes in the ataxin-2’s pleytropism which might related with generic physiological function of this protein. This _ndings support
our previous conjectures based on populations studies [1] about the role of large alleles normals as
source for new mutations, involved in neurodegenerative pathologies associated to CAG expansions in
the ataxin-2 gene. Furthermore, confirm the incremented risk of intermediate ATXN2 allele for develop
ALS. Reference(s) [1] Laf_ta-Mesa JM et al., Unexpanded and Intermediate CAG Polymorphisms at SCA2
Locus (ATXN2) in the Cuban Population: Evidences About the Origin of Expanded SCA2 Alleles. European
Journal of Human Genetics (2011) 0, 000–000. doi:10.1038/ejhg.2011.154.
The amygdala plays a central role in anxiety. Dopaminergic fibers from the ventral tegmental area
strongly innervate the main and the intercalated paracapsular (IPC) islands which surround the basolateral (BLA) complex of the amygdala and are the richest dopamine D1 structures of this region. It
has been proposed that D1 dopamine receptor activity attenuates the inhibitory control exerted by the
medial prefrontal cortex (mPFC) upon the amygdala and has an important influence on the trafficking
of impulses between mPFC and BLA, and from the latter to the central amygdaloid nucleus. Behaviorally, the intra-amygdaloid infusion of D1 agonists and antagonists elicits anxiogenic and anxiolytic effects respectively on conditioned models of anxiety. However, the role of D1 receptors in unconditioned
anxiety is less known and even contradictory. The aim of this study was to evaluate the effects of the
infusion of the selective D1 receptor antagonist, SCH23390 in closed proximity to the IPC islands of
rats submitted to the elevated plus-maze and the shock-probe burying test. The results showed that
the bilateral microinjection of SCH23390 at an intermediate (50ng /side) but not at lower (15ng/side)
or higher (150 ng/side) dose significantly increased the time spent and the number of entries into the
open arms of the elevated plus-maze as compared with their saline-treated controls. In agreement with
this, the infusion of SCH23390 (50 ng/side) increased the burying behavior latency and decreased
the burying behavior in the shock-probe burying test. No effects on locomotion in the open-field test
were found at any SCH23390 dose injected either in rats submitted to the elevated plus-maze or to
the shock-probe burying test. These results indicate that the bilateral blockade of D1 receptor activity
within the IPC islands results in anxiolytic effects and support an anxiogenic role for these receptors in
the amygdaloid modulation of unconditioned anxiety.
MO150
MULTIFACETED ACTIONS OF POLYPHENOLS AS
THERAPEUTIC AGENTS IN ALZHEIMER´S DISEASE
MO151
MOLECULAR ANALYSIS OF HUNTINGTON’S DISEASE
IN A CUBAN POPULATION
Lakey, J (1), Durant, A (1), Rao,K.S.J (1), (1) Institute for Investigation and High Technology
VAZQUEZ-MOJENA Y (1), LAFFITA-MESA J.M (1), LAGUNA-SALVIA L (2), GONZALEZ-ZALDIVAR Y (1), ALMAGUER-GOTAY D (1), ALMAGUER-MEDEROS LE (1), RODRIGUEZ-LABRADA R (1), VELAZQUEZ-PEREZ L (1); (1)
Centre for the Research and Rehabilitation of Hereditary Ataxias, Holguín, Holguin, Cuba, (2) Section of
Neurology, Clinical & Surgical Hospital, Holguin, Holguin, Cuba.
The etiology and pathology Alzheimer´s disease (AD) is multifactorial. AD has complex pathology which
involves, oxidative stress, metal deposition, aggregates of amyloid and tau, immune responses and
disturbances in cholinesterase´s. Also there is no biomarker for early detection of AD. Because of the
above complexes, the drug discovery has become big challenge. Most of the drugs targeted towards
amyloidal load reduction in cells. Now Scientists are looking at natural products which has multifaceted mode of action. Polyphenols are aromatic compounds containing hydroxyl groups such as curcumin,
resveratrol, EGCG, are suggested to modulate neurodegenerative changes. The aim of this paper is to
present new hypothesis on the chemistry of polyphenols and their multifaceted mode of action. This
hypothesis provides new dimension on how polyphenols modulate APP processing be enhancing cell
survival through SAPP-alpha, reduction in amyloid beta, protecting mitochondrial functional dynamics,
enhancing DNA repair, and reducing redox potential of cell. The relevance of thesis working hypothesis
in developing polyphenol based drugs are augmented.
Objective: To assess the frequency of (CAG) n expansions and the allele distribution in the HTT gene
in a Cuban population. Background: Huntington’s disease is the most frequent polyglutamine disorder
at worldwide (1, 2); nevertheless there are not estimates of the frequency of Huntington’s disease
(HD) mutation in Cuban subjects affected by choreic phenotypes. Methods: One-hundred twenty-seven
members of families with choreic phenotypes and 35 unrelated healthy controls underwent molecular
analysis to assess the size of (CAG) n tract in the HTT gene. Results: In all, 38 HTT allele classes
were observed ranging from 12 to 67 CAG repeats. Sixty-one individuals carried one expanded allele,
between 39 to 67 units, whereas the HTT allele carrying 45 repeats was the most common expanded
allele. Full-penetrant alleles were observed in 95.1% of HD mutation carriers. Regarding the unexpanded alleles, the allele containing 16 CAG repetitions was the most frequent in both HD families and
control individuals. Additionally we found a 3.8% of intermediate alleles significantly associated to
affected families. Conclusions: This is the first molecular characterization of the HD mutation in Cuba.
The study reveals a noteworthy frequency of HD mutations in the studied population with a remarkable
percentage of full-penetrant expansions providing new opportunities for disease management and
genetic testing.
MO152
BIOMATERIALS FOR THE RELEASE OF SEMAPHORINS INTO THE BRAIN
Rios Ramírez A(1), Giordano Noyola M(1), Tamariz Domínguez E(2), (1)Departamento de Neurobiología
Conductual y Cognitiva, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Juriquilla, Querétaro, México;(2) Departamento de Biomedicina, Instituto de Ciencias de la Salud, Universidad
Veracruzana, Xalapa, Veracruz, México.
Protein release into the central nervous system is restricted by the presence of the blood brain barrier.
One potential strategy is the release of substances of interest into the central nervous system by the
use biomaterials that should be biocompatible, and biodegradable. Also, the products of biodegradation should not be neurotoxic. In particular, biomaterials could be used for site-specific delivery of
proteins with chemotropic properties, to form concentration gradients and to stimulate and direct
axonal growth of implanted cells, for example in models of Parkinson’s disease, promoting proper reinnervation and restoration of the nigro-striatal pathway. In this study two biomaterials were evaluated,
methylcellulose hydrogels and microspheres of a copolymer of lactic acid-glycolic acid (PLGA) wherein
was encapsulated recombinant semaphorin 3A (sema 3A-Fc). This protein has an attractive effect
on dopaminergic ventral midbrain neurons (VM) during the formation of the nigro-striatal pathway
and repellent in dorsal root ganglion neurons (DRG) during embryonic development. In vitro tests
showed that the encapsulation and release of proteins in PLGA microspheres is of low efficiency and
no concentration gradient is formed, as compared with methylcellulose hydrogels (MCH). Evaluation
of the biological effect of released Sema 3A-Fc in primary cultures of VM and DRG showed that the
chemotropic protein is efficiently released from MCH and retains its functionality. We observed increased growth of VM dopaminergic axons compared with control; in contrast, in primary cultures of
DRG retraction of axons near the Sema3A-Fc source was detected. Furthermore behavioral tests in rats
unilaterally implanted with MCH in the striatum at 1 week, 15 days and 1 month post-transplantation
showed no alterations in locomotor activity and other behavioral tests. The results so far indicate that
MCH could be used to release chemotropic proteins into the brain in a controlled way, without inducing
neurological or behavioral alterations.
MO154
EFFECT OF TIBOLONE ON MEMORY AND LEARNING IN AGING MOUSE
NERI-GOMEZ T (1,2), DIAZ-CINTRA S (3), AGUILAR-VAZQUEZ A (3), ESPINOSA-RAYA J (2),GUERRA-ARAIZA
C (1). (1) Unidad de Investigación Médica en Farmacología, Instituto Mexicano del Seguro Social. (2)
Laboratorio de Farmacología Conductual, Escuela Superior de Medicina, Instituto Politécnico Nacional.
(3) Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, Qro., México.
Sex steroids exert different effects in the central nervous system (CNS), such as preserving neural
function and promoting neuronal survival. Therefore, the age-related decrease in sex steroids may have
a negative impact on neural function. Progesterone, testosterone and estradiol prevent neuronal loss
in the CNS in different experimental animal models of neurodegeneration. However, hormone replace
therapy may increases the incidence of endometrial, prostate and breast cancer. A strategy to reduce
these latter is the use of tibolone (TIB), which also has estrogen and progestin components. However,
the role of TIB in the process of learning and memory in aging is unknown. The aim of this study was
to evaluate the long term effect of TIB (1 mg/Kg orally daily for 12 weeks) on the memory and learning
of aging mice. For this purpose, three behavioral animal models (T maze, object and object-in-context
recognition tasks) were employed. In the T maze there was an increased latency in the TIB group. In the
object and object-in –context recognition tasks, administration of 1mg/Kg of TIB mice increased the
percentage of time spent investigating the novel object. These data suggest that 1 mg/Kg of TIB improve
the memory and learning in aging mouse. Acknowledgments: SIP-IPN, COFAA.
MO153
SYNERGIST EFFECTS OF N-ACETYLCYSTEINE AND DEFEROXAMINE
TREATMENT ON BEHAVIORAL AND OXIDATIVE PARAMETERS INDUCED
BY CHRONIC MILD STRESS IN RATS
RÉUS G.Z(1), ARENT C.O (1) RIBEIRO K.F(1), MINA F(1), STECKERT A.V(1,2), DAL-PIZZOL F(2), QUEVEDO
J(1), (1) Laboratório de Neurociências; (2) Laboratório de Fisiopatologia Experimental, Universidade do
Extremo Sul Catarinense, Brazil.
A growing body of evidence has pointed to a relationship between oxidative stress and depression.
Thus, the present study was aimed at evaluating the effects of the antioxidants n-acetylcysteine (NAC),
deferoxamine (DFX) or their combination on sweet food consumption and oxidative stress parameters
in rats submitted to 40 days of exposure to chronic mild stress (CMS). Our results showed that in
stressed rats treated with saline, there was a decrease in sweet food intake and treatment with NAC
or NAC in combination with DFX reversed this effect. Treatment with NAC and DFX decreased the oxidative damage, which include superoxide and TBARS production in submitochondrial particles, and also
thiobarbituric acid reactive substances (TBARS) levels and carbonyl proteins in the prefrontal cortex,
amygdala and hippocampus. Treatment with NAC and DFX also increased the activity of the antioxidant
enzymes, superoxide dismutase and catalase in the same brain areas. Even so, a combined treatment
with NAC and DFX produced a stronger increase of antioxidant activities in the prefrontal cortex, amygdala and hippocampus. The results described here indicate that co-administration may induce a more
pronounced antidepressant activity than each treatment alone. In conclusion, these results suggests
that treatment with NAC or DFX alone or in combination on oxidative stress parameters could have
positive effects against neuronal damage caused by oxidative stress in major depressive disorders.
MO155
DESIPRAMINE HAS ANTIDEPRESSANT-LIKE EFFECTS
IN THE FORCED SWIMMING TEST IN SPRING AND
WINTER, BUT CLOMIPRAMINE ONLY IN WINTER
PEREZ-PADILLA EA (1,2), ALVAREZ-CERVERA FJ (2), BATA-GARCIA JL (2), PINEDA-CORTES JC (2), GONGORA-ALFARO JL (1,2). (1) Facultad de Medicina, Universidad Autonoma de Yucatan, (2) Depto. Neurociencias, Centro de Investigaciones “Dr. Hideyo Noguchi”, Universidad Autonoma de Yucatan
Evidence suggests that the efficacy of antidepressants could be influenced by seasonal changes. Here we assessed
whether the winter and spring seasons influence the effect of equimolar doses of the tricyclic antidepressants
clomipramine (serotonin reuptake inhibitor = SRI, 1.1 mg/kg) and desipramine (noradrenaline reuptake inhibitor
= NRI, 0.96 mg/kg) on immobility (passive behavior), and on climbing and swimming (active behaviors) displayed
by male Wistar rats in the forced swimming test (FST; two sessions of 15 and 5 min, 24 hours apart, in 30 cm deep
water). There were 10 rats in each experimental group. Three doses of each drug were applied between sessions.
The time spent in each behavior was counted in 5 s periods (bins). The difference of bins between the second and
first sessions was used as a measure of antidepressant effects (positive and negative values indicate increase and
decrease of the measured behavior, respectively). The change in bin counts between both sessions was analyzed
with the paired t-test (two-tailed). During the first session of the FST rats had higher immobility in winter than in
spring. Immobility of control animals had a significant increase during the second session, both in winter (4.7
± 1.4 bins, p<0.01) and in spring (8.3 ± 2.4, p<0.01) seasons. In winter the increase in immobility was
prevented either with clomipramine (2.7 ± 3.6, n.s.) or desipramine (3.8 ± 3.1, n.s.). In spring desipramine was
effective (0.8 ± 2.3, n.s.) but clomipramine was not (8.3 ± 2.3, p<0.01). Climbing behavior of control animals
decreased during winter (-4.0 ± 1.4, p<0.05), and showed a non-significant trend to decrease during spring
(-5.5 ± 2.5, n.s.). In winter, the decrease in climbing behavior was prevented by both clomipramine (-2.4 ± 3.7,
n.s.) and desipramine (-4.2 ± 2.8, n.s.). In spring, a significant reduction of climbing occurred in animals treated
with clomipramine (-6.1 ± 2.4, p<0.05) but not with desipramine (-1.2 ± 2.0, n.s.). Control animals did not
show swimming behavior in winter, while small amounts of it occurred during spring, with a non-significant trend
to decrease during the second session (-1.7 ± 1.7, n.s.). In winter, neither antidepressant elicited the swimming
behavior. In spring, a significant decrease of swimming occurred in animals treated with clomipramine (-1.6 ± 0.7,
p<0.05) but not desipramine (-1.1 ± 0.6, n.s.). These results suggest that the antidepressant-like effects of NRIs
remain constant in winter and spring, while the efficacy of SRIs is reduced during spring. (Funded by Universidad
Autonoma de Yucatan, Mexico and CONACYT grant 1831-M9211 to JLGA).
MO156
EFFECTS OF PERIPHERAL AND CENTRAL ADMINISTRATIONS OF
YOHIMBINE ON PANIC-LIKE BEHAVIORS PRODUCED BY ELETRICAL
STIMULATION OF DORSAL PERIAQUEDUCTAL GRAY MATTER OF RATS
MÜLLER C.J.T.(1), SCHIMITEL F.G.(1), SILVA T.S.(1), SCHENBERG L.C.(1), Department of Physiological Sciences, Health Sciences Centre, Federal University of Espírito Santo, Vitória, ES, Brazil.
Appropriate doses of the a2-adrenoceptor antagonist yohimbine (YOH) precipitate panic attacks in
predisposed patients but not in healthy volunteers. YOH also facilitates the shuttle-box escape of rats
submitted to electrical stimulation of the dorsal periaqueductal gray matter (DPAG), which is a model
of panic attack. However, it is unknown whether the YOH facilitates all the responses evoked by electrical stimulation of DPAG, i.e., immobility, exophthalmus, trotting, galloping, jumping, defecation and
micturition. Moreover, it remains unclear whether the YOH effects are mediated at the DPAG properly
or elsewhere in the brain, such as at the Locus Coeruleus (LC), the main noradrenergic nucleu in the
central nervous system. Accordingly, here we compared the effects of YOH administered either intraperitoneally (i.p.) or intracranially (i.c.) into the DPAG or LC, on the behaviors produced by electrical
stimulation of the. Rats with electrodes in the DPAG and stimulated electrically were divided in three
groups (n=20/group): 1) YOH i.p. (2, 5 and 10 mg/kg); 2) YOH in DPAG (0,28 nmol/150nL), 3) YOH
in LC (0,021 nmol/100 nL). Control sessions were performed with vehicle. Drug and vehicle were
administered according to a balanced order 30 min (i.p.) or 10 min (i.c.) before respective stimulation
sessions spaced 48 h or 96 h apart. The effects were assessed through threshold regression analysis. Peripheral injections of 5 mg/kg YOH facilitated DPAG-evoked immobility, trotting and galloping,
thereby mimicking the drug panicogenic effects in humans. Moreover, YOH microinjections into the LC
facilitated DPAG-evoked immobility, defecation and micturition. However, YOH microinjections into the
DPAG attenuated immobility, trotting and defecation and failed to change galloping and jumping, but
facilitated micturition. Present data suggest that the YOH panicogenic effects, mainly the attention
behavior, are mediated for the LC and not by DPAG.
MO158
GABA/5-HT INTERACTIONS: CLONAZEPAM AND 5-HT7 RECEPTORS
IN THE HIPPOCAMPUS AND THE RAPHE NUCLEUS OF RATS
Bravo-Tobar ID(1), Urbina M(1) and Lima L(1). (1)Laboratorio de Neuroquímica. Centro de Biofísica
y Bioquímica. Instituto Venezolano de Investigaciones Científicas (IVIC). Caracas 1020A. Venezuela.
Clonazepam (CLON), a benzodiazepine acting on GABAA receptors is widely used to treat various anxiety
and depressive disorders. Thus, CLON is a useful tool for studying GABA-serotonin (5-HT) interactions.
In the present work we investigated the effect of CLON (5 and 10 mg/kg i.p.) given daily for 7 or 14
days on kinetic parameters: capacity and affinity (Bmax and KD) of 5-HT7 receptors as evidence for
GABA-benzodiazepine and serotonergic systems communication. Binding of the selective antagonist
[3H]-SB-269970 to 5-HT7 receptors in rat hippocampal and raphe membranes was performed. Saturation experiments revealed that administration of CLON (5 mg) during 7 days significantly decreased
Bmax and KD values in the hippocampus, and increased Bmax and decreased ligand affinity in the
raphe. Bmax and KD were significantly decreased with the treatment of 5 mg of CLON during 14 days
in the hippocampus. In the raphe, Bmax and KD were significantly increased. Treatment with 10 mg of
CLON did not produce changes in the hippocampus, in contrast to the raphe, in which elevated Bmax
and KD were observed. The results show that CLON, acting on GABAA receptors, modulates 5-HT7 binding sites in a differentially in the two brain areas, also according to doses and time of administration,
then suggesting a mechanism of action for GABA/5-HT cross talking explaining part of CLON and 5-HT7
receptors roles in anxiety and affective alterations.
MO157
A NEW PHARMACOLOGICAL MODEL TO THE STUDYING OF
NEUROPROTECTIVE DRUGS IN THE ISOLATED GUINEA-PIG ILEUM
VENTURA-MARTINEZ R(1), RODRÍGUEZ R(1), ANGELES-LOPEZ G(1), GOMEZ C(1)
(1) Department of Pharmacology, Faculty of Medicine. UNAM, Mexico.
Previous studies from our laboratory found that intestinal ischemic in situ induces profound alterations of the contractile responses to electrical and chemical stimulation, and produces structural damage in myenteric neurons. These studies had suggested that the isolated ileum of the guinea-pig could
be a useful model for studying neuronal ischemia and neuroprotection. With the purpose to improve
this model, in this work we evaluated the contractility of the guinea pig ileum subjected to intestinal
ischemia and reperfusion in vitro. For this, segments of 2 cm of the guineapig ileum were placed for
tension recording in 20 ml organ baths containing Krebs-bicarbonate solution and a mixture of 95% O2
and 5% CO2, and maintained at 37 °C. The preparations were allowed to equilibrate for 30 min under
1 g of tension. The sensitivity of the tissue preparations was tested with acetylcholine (ACh, 1x10-5
M) and then electrically stimulated using rectangular current pulses (0.3 Hz, 3.0 ms, 14 V). Hypoxia
was induced by bubbled the preparations with a mixture of 95 % N2 and 5% CO2. Hypoglycemia was
obtained by removing glucose from the Krebs solution. After periods of hypoxia and hypoglycemia,
the effect of reperfusion was evaluated. We measured the contractile responses to ACh and electrical
field stimulation and determined the maximal contraction . Our findings demonstrated that hypoxia
and reperfusion in vitro of the guinea-pig ileum inhibits the spontaneous motility and the contractile
responses to pharmacological and electrical challenges in the isolated intestinal preparations. These
results suggest that the isolated ileum of the guinea pig could be a more practical and economic way
to screen potential neuroprotective compounds. However, a complete pharmacological characterization
of this model is needed to validate its capacity to detect useful neuroprotective activity.
MO159
INTERACTION BETWEEN PURINERGIC RECEPTORS P2X4 AND P2X7
Pérez-Flores G (1), Vaca L (2), Pérez-Cornejo GP (1) and Arreola J (3), (1) Escuela de Medicina y (3) Instituto de Física, Universidad Autónoma de San Luis Potosí, San Luis Potosí, México and (2) Instituto de
Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad Universitaria, México, DF, México.
The ATP-gated P2X7 receptor (P2X7R) channel is linked to a number of cellular events, including morphological changes in cells, increased permeability to large molecules and cell death. Function of
P2X7R is regulated by P2X4R independent of P2X4 channel function and does not require formation of
heterotrimeric channels. Here, we tested the idea that both receptors communicate through a proteinprotein interaction, which is of physiological relevance. Using Fluorescence Resonance Energy Transfer
technique (FRET) and P2X4-CFP / P2X7-YFP constructs expressed in HEK-293 cells, we show that FRET
signal increased after P2X7R activation with 100 uM BzATP. In contrast, activation of P2X4R with 20
μM ATP (a concentration that does not activates P2X7R) did not increase the FRET signal. Thus, we
hypothesize that P2X7R activation brings both receptors in close proximity in order for them to interact.
Since both receptors are coexpressed in several tissues we tested the physiological relevance of this
interaction by measuring ethidium bromide uptake, bleb formation and cell death in HEK-293 cells
expressing P2X7R alone and in cells coexpressing P2X7R and P2X4R, both cell groups were stimulated
with 100 uM Bz-ATP. Ethidium bromide uptake decreased by 80% when P2X4 was co-expressed with
P2X7R; bleb formation and cell death also decreased in HEK-293 cells coexpressing both receptors.
Additional experiments were carried out in freshly dissociated mouse parotid acinar cells that endogenously express both receptors. In acinar cells, ethidium bromide uptake was slower than in HEK-293
cells expressing P2X7R alone. In addition, bleb formation was nearly absent in acinar cells. Taken
together our observations suggest that activation of P2X7R is necessary for the interaction between
P2X7 and P2X4 although P2X4R regulate P2X7R functions and that interaction between P2X4R and
P2X7R is physiologically relevant.
MO160
TRKB RECEPTOR INDUCES THE ACTIVATION AND
NUCLEAR TRANSLOCATION OF THE TYROSINE KINASE
C-ABL IN HIPPOCAMPAL NEURONS
MO161
NMDA RECEPTOR SUBUNITS EXPRESSION IN
THE HIPPOCAMPUS AFTER HABITUATION TO A NEW
ENVIRONMENT AND SYNAPTIC PLASTICITY INDUCTION
Chandía A.1, Bronfman F.C2, Lazo OM2, Álvarez A.R1, 1Laboratorio de Señalización Celular, Depto. de
Biología Celular y Molecular, 2Departamento de ciencias Fisiológicas, Facultad de Ciencias Biológicas;
Pontificia Universidad Católica de Chile, Santiago, Chile.
MV Baez (1), MV Oberholzer (1), MC Cercatto (1), M Snitcofsky (1), AI Aguirre (1), DA Jerusalinsky (1)
(2). (1) Instituto de Biología Celular y Neurociencia (IBCN) CONICET-UBA. (2) Universidad de Buenos
Aires (UBA)
Introduction: BDNF is a neurotrophic factor that upon binding the TrkB (Tyrosine kinase B receptor)
modulates key aspects of nervous system development and maintenance such as neuronal survival,
regulation of neuronal architecture and synaptic plasticity. Studies on oncogenic cells have shown that
TrkA interacts with c-Abl. c-Abl is an intracellular tyrosine kinase that participates in axonal path finding, dendrites outgrowth and synaptic plasticity having the ability to associate with different proteins
and to be localized in the nuclei and cytoplasm, suggesting that the ability of c-Abl to regulates different processes depends on its intracellular localization. Thus, the aim of this study was to evaluate
whether after BDNF binding, TrkB interacts and activates c-Abl, modulating its activity. Methods: Rat
hippocampal neurons cultures (7DIV) were treated by different times either with BDNF alone or in
the precense of K252a, an inhibitor of TrkB tyrosine kinase activity. The levels and the localization of
c-Abl and phospho-c-Abl were evaluated by western blotting and immunofluorescence. In addition,
sub cellular fractionation was performed to assess the relative abundance of c-Abl in cytoplasmic and
nuclear fractions. Finally, we performed a co-immunoprecipitation assay to evaluate the association
between TrkB and c-Abl. Results: The incubation of hippocampal neurons with BDNF during 1,5 and
3 hrs, increased both total and phosphorylated levels of c-Abl, indicating its activation. The use of
K252a, prevented the changes induced by BDNF over c-Abl levels and its distribution. Besides, BDNF
treatment promoted the interaction of c-Abl with TrkB followed by the nuclear translocation of activated
c-Abl. Conclusions: Our results suggests that the activation of TrkB by BDNF actives the tyrosine kinase
c-Abl and modulates its cellular localization. Probably the TrkB/c-Abl signaling pathway modulates
some functions described for this receptor in neuronal development. FONDECYT 1120512, ARA and
1885273 for FCB.
N-methyl-D-aspartate (NMDA) receptor (NMDAR) subunits change during development and their expression at the surface is modified shortly after synaptic plasticity induction at hippocampal slices. However, there is scarce information on subunits expression after synaptic plasticity induction or memory
acquisition, particularly on adult rats. In this work, GluN1, GluN2A and GluN2B were assessed by
westernblot in 1) adult rats exposed to a 5 min open field (OF) session that gives rise to habituation,
2) mature primary cultures of rat hippocampal neurons depolarized by KCl pulses and 3) hippocampal
slices from adult rats where long term potentiation (LTP) was induced by theta-burst stimulation (TBS).
Hippocampal GluN1 and GluN2A, but not GluN2B underwent conspicuous increases after habituation,
as assessed 70 min after OF exploration. The same subunits increased in cultured neurons as evaluated by total immunofluorescence 70 min after KCl stimulation. Similar changes occurred 70 min after
LTP induction by TBS in hippocampal slices. To investigate the underlying mechanisms in this subunits
increase, hippocampal slices from adult rats were treated either with cycloheximide or actinomycin D
during electrophysiological assays. Results showed that GluN2A increase was dependent on translation, while the rise in GluN1 was dependent on transcription and translation. In the three models
analyzed, changes were selective, detected in the same units at equivalent times. This might suggest
that an analogous phenomenon regulates NMDAR expression at the hippocampus after LTP induction
and after habituation to a new environment.
MO162
MANIPULATION OF BDNF SIGNALING DURING CRITICAL PERIOD
ALTERS TONOTOPIC ORGANIZATION AND RECEPTIVE FIELDS OF A1
MO163
NITRIC OXIDE MODULATES OFF BIPOLAR CELL
RESPONSES IN THE RETINA
Anomal RF (1), de Villers-Sidani E (2), Merzenich MM (3), Panizzutti RA (1); (1) Universidade Federal
University of Rio de Janeiro, Brazil, (2) Montreal University, Canada, (3) University of California - San
Francisco, Uniterd States.
VIELMA AH(1,2), SCHMACHTENBERG O(1),(1)Centro Interdisciplinario de Neurociencia de Valparaiso,
Facultad de Ciencias, Universidad de Valparaiso, Chile and (2)Programa de Doctorado en Ciencias
mencion Neurociencia, Universidad de Valparaiso, Chile
During critical period, the sensory experience powerfully shapes the representations of sensory cortical
areas. In rat primary auditory cortex (A1), this is exemplified by significant, long-lasting distortions
in frequency representation after mere exposure to repetitive frequencies during the second week of
life. In the visual system, the normal unfolding of critical period plasticity is strongly dependent on the
elaboration of brain-derived neurotrophic factor (BDNF), which promotes the establishment of inhibition. Here, we tested the hypothesis that BDNF is also a necessary player in the regulation of the critical
period window for spectral tuning in A1. Elvax implants filled with either a blocking antibody against
BDNF (N=4) or the BDNF protein (N=4) were placed on the A1 of rat pups throughout the critical
period window (P9. Another group, the control, was implanted with vehicle (N=9). These pups were
then exposed to 7 kHz pure tone for 7 consecutive days (P9 to P16) and their frequency representations were mapped. BDNF blockade completely prevented the shaping or cortical tuning by experience
and resulted in poor overall frequency tuning in A1. By contrast, BDNF infusion on the developing A1
strongly amplified the effect of 7 kHz tone exposure compared to naïve pup. We also observed that a
type of GABAa receptor was reduced in A1 after BDNF blockade, and elevated after BDNF infusion. These
results indicate that BDNF is involved in the maturation of tonotopy and in the development of inhibitory circuitry of A1, acting as a regulator of critical period plasticity on A1 cortical field.
Nitric oxide (NO) is involved in retinal signal processing, but its cellular actions are only partly understood. The main source of retinal NO is a subset of amacrine cells, which signal onto ON bipolar,
amacrine and ganglion cells. Previous studies showed that NO inhibits ganglion cell OFF responses,
but while NO is an established modulator of ON bipolar cells, little is known about its effects on OFF
bipolar cells. We investigated if NO regulates glutamate responses in OFF bipolar cells through the
activation of the soluble guanylyl cyclase-cGMP pathway. To this end, OFF bipolar cells were recorded
in vibratome sections of rat retina with whole-cell patch clamp and identified by morphological and
electrophysiological criteria. The cells were stimulated with a brief puff (1 s) of glutamate in the outer
plexiform layer, while their axonal arbors in the inner plexiform layer were superfused with a long
(10 s) puff of NO donors (NOC-12 and SNP) or the cGMP analogue 8-bromo-cGMP. Both NOC-12 and
8-bromo-cGMP eliminated the slow component of the response to glutamate, while the amplitude of
the fast component remained unchanged. Addition of the soluble guanylyl cyclase inhibitor ODQ to the
intracellular solution prevented this effect, suggesting a mechanism dependent on cGMP. Perfusion
with the NO synthase inhibitor L-NAME prolonged the timing of the glutamate response, which could be
reversed by the NO donors. These results show that NO alters the glutamate response characteristics
of OFF bipolar cells, and confirm that the retinal OFF pathway is modulated by NO. Acknowledgments:
Fondecyt 1120513 (OS), CONICYT PhD scholarship (AHV) and Millennium Institute CINV.
MO164
HIGHLY ENRICHED PRIMARY CULTURES OF CHICKEN RETINAL
HORIZONTAL CELLS EXPRESS THE PHOTOPIGMENT MELANOPSIN X
Luis P. Morera(1), Nicolás M. Díaz(1) and Mario E. Guido(1),(1)CIQUIBIC-Departamento de Química
Biológica, Facultad Ciencias Químicas, Universidad Nacional de Córdoba.
Retinal ganglion cells (RGCs) expressing the photopigment melanopsin (Opn4) display intrinsic photosensitivity. In the chicken retina, two Opn4 genes, Opn4x and Opn4m have been described of which,
Opn4m was restricted to the GC layer whereas Opn4x was limited to the forming GC layer and optic
nerve at early embryonic days (E), but by E15 its expression was mostly in Prox1 (+) horizontal cells
(HCs) (Verra et al., 2011). The aim of this work was to purify HCs from the chicken retina to obtain
primary cultures highly enriched in these cells. Disaggregated chicken embryonic retinas at E15 were
subjected to a discontinuous 1 to 4% bovine serum albumin (BSA) gradient (Morera et al., 2012). After
centrifugation, cells collected from the different phases were cultured for 4 days and characterized by
immunochemistry and morphology. Phases were examined with specific antibodies against Opn4x, HC
markers (PROX-1, Islet-1, calretinin) and markers for other retinal cell populations. Prox-1 (+) cells
from both the whole retina and the BSA gradient were quantified by flow cytometry. The results show
that only the fraction corresponding to 2.5% BSA contained most cells displaying PROX-1 and Islet-1
(+) immunoreactivities with a typical HC morphology resembling H1- and H3-type HCs (axon-bearing
“brush-shaped” and axon-less “candelabrum-shaped” respectively). Strikingly, Opn4x-immunoreactivity was observed in cultures from both the 2.5 and 3 % BSA gradient phases. Cells from the 3% phase
express the neuronal filament of 200 KDa (NF200) and display longer processes resembling typical
RGCs. 30% of cells from the whole disaggregated retina and 80% from the 2.5% BSA gradient phase
were Prox-1 (+). In conclusion, by means of this method we selectively separated specific retinal cell
types and obtained primary cultures highly enriched in HCs expressing the non-visual opsin Opn4x.
(Supported by ANPCyT-FONCyT PICT 2010 Nr. 647, CONICET, SeCyT-UNC, and MinCyT of Córdoba).
MO166
CHROMATIC PROCESSING IN THE ANTERIOR OPTIC
TUBERCLE OF THE HONEY BEE BRAIN
MOTA T(1-2), GRONENBERG W(3), GIURFA M(2), SANDOZ JC(2), (1) Laboratory of Neurodynamics and
Vision, Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of
Minas Gerais, Belo Horizonte, Brazil; (2) Research Center on Animal Cognition, Univesity of Toulouse,
UPS, Toulouse, France; (3) Department of Neuroscience, University of Arizona, Tucson, Arizona,US.
Color vision in honey bees has been extensively studied at the behavioral level and, to a lesser degree,
at the physiological level by means of electrophysiological intracellular recordings of single neurons.
Few visual neurons have been so far characterized in the lateral protocerebrum of bees. Therefore,
the possible implication of this region in chromatic processing remains unknown. We performed in
vivo calcium-imaging of interneurons in the anterior optic tubercle (AOTu) of honey bees upon visual
stimulation of the compound eye in order to analyze chromatic response properties. Stimulation with
distinct monochromatic lights (UV, blue and green) matching the sensitivity of the three photoreceptor
types of the bee retina induced different signal amplitudes, temporal dynamics and spatial activity
patterns in the AOTu inter-tubercle network, thus revealing intricate chromatic processing properties.
Green light strongly activated both the dorsal and ventral lobes of the AOTu’s major unit. Blue light
activated more the dorsal lobe whilst UV light activated more the ventral lobe. Eye stimulation with
mixtures of blue and green light induced suppression phenomena in which responses to the mixture
were lower than those to the color components, thus concurring with color-opponent processing. These
data provide strong evidence for an involvement of the AOTu in chromatic processing and suggest a
spatial segregation of color processing within this structure.
MO165
TESTOSTERONE IMPLANTS CHANGE SENSORY PROPERTIES OF
NEURONS IN THE TORUS SEMICIRCULARIS IN PLEURODEMA
THAUL (ANURA- LEPTODACTYLIDAE)
QUISPE M(1), PENNA M(2),MPODOZIS J(3) (1)Univ. of Chile, Santiago, Chile; (2) Dpt. of Physiology and
Biophysics,Instituto de Ciencias Biomédicas, Univ. of Chile, Santiago, Chile and (3) Dpt. of Biology,
Univ. of Chile, Santiago,Chile.
Anurans communicate through specific vocalizations; males form chorusing aggregations towards
which females orient for breeding. Most anuran species breed seasonally and typically male frogs
show seasonal changes in their testosterone levels. Testosterone induces changes in the morphology
of laryngeal muscles and in the motor neurons innervating this organ, which result in significant
changes in the vocal ability. Furthermore neurons of the main anuran auditory midbrain center, the
Torus Semicircularis have been shown to respond with higher selectivity to conspecific vocalizations
during the breeding season. The aim of the current study is to explore changes in the activity neurons
of Torus Semicircularis induced by manipulating testosterone levels. Males of Pleurodema thaul, a
Chilean frog that calls and breeds from August to December were used for radioimmunoassay measurements of testosterone levels . We found as in other anurans species, higher testosterone levels
during the breeding season. Subcutaneous testosterone pellet implants produce increases in plasmatic
testosterone after two weeks. Extracellular single-unit recordings of auditory neurons from implanted
males using a synthetic imitation of the conspecific advertisement call and variants differing in the
inter-pulse interval. Implanted males had larger proportions of neurons tuned to high frequencies
within the range of the dominant frequency of the call (2000 Hz). In addition, implanted males had
larger proportions of neurons tuned to long inter-pulse period. These results suggest that testosterone
alters the properties of the neurons during the breeding season of P. thaul, improving the sensitivity to
conspecific advertisement call.
MO167
QUININE INDUCED C-FOS EXPRESSION IN THE SOLITARY
TRACT NEURONS IMMUNOREACTIVE TO TYROSINE
HYDROXYLASE IN PREWEANING RATS
L. Rubio-Navarro(1), C. Torrero(1), M, Regalado(1), M. Salas(1), (1)Departamento de Neurobiología del
Desarrollo y Neurofisiología, Instituto de Neurobiología, UNAM, Querétaro, Querétara, México.
Newborn of altricial species maintains functional gustatory communication with the mother because
the neural substrate and the capacity to discriminate and promote gustofacial reflexes (GFR) are already operating. In neonatal rat the GFR can be modified by the application of sucrose (S) and quinine
(Q) in the mouth, to produce ingestion or rejection responses respectively. The present study analyzed
how perinatalundernutrition can affect the development of GFR responses during early development. In
the undernourished group (UG) pregnant dams received different percentage of a balance diet during
gestation. After birth pups continue the undernutrition by remaining 12h with a foster dam, and 12h
with a nipple-ligated mother. A droplet of sucrose S, sodium chloride (NaCl), Q and water (W) into the
lips at 1 and 3 days of age were placed and mouth opening frequency (MOF) and licking lips frequency
(LLF) were analyzed. Data related to GFR in day 1 at lower concentration (LC) responses show that MOF
increase in UG in NaCl and Q compared with CG. With no significant differences at higher concentrations (HC). At day 3 of age at LC the S and Q in UG subjects showed an increase in MOF compared with
CG. In the case of LLF at day 1 in CG, NaCl at LC increases compared with UG with no differences at
HC in contrast to CG. At day 3 of age at LC of Q the UG showed an increase compared with CG and at
HC a significant reduction in contrast with the CG. These results suggest that perinatal undernutrition
affects the basic components of the gustatory system necessary to produce GFR in the first postnatal
days, interfering with the integration of sensory characteristics of taste for food learning and the
hedonic aspect essential for taste palatability. Partly supported by IN207307 of DGAPA/UNAM, México.
POSTERS
TUESDAY NOVEMBER 6
TU001-TU165
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Addiction
Anatomy and Comparative Neuroanatomy
Autonomic Nervous System
Behavior: Learning and Memory
Behavior: Sexual and Maternal
Biological Rhythms and Sleep
Cardiovascular Physiology
Circuits, Synapses and Plasticity
Cognitive Functions
Damage, Regeneration, Neuroprotection and Recovery
Endocrinology, Neuroendocrinology, Neuroimmunology
Epilepsy
Ion Channels and Biophysics
Metabolism, Nutrition and Food
Methods, Novel Technologies, Models
Neurodegenerative and Psychiatric Disorders
Pharmacology
Receptors
Sensory Systems
Spinal Cord
Stem Cells and Neurogenesis
Toxicology
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TU001
SHORT TERM EFFECTS OF EXPOSURE TO THE SMOKE EXTRACT OF
CANNABIS SATIVA, DATURA STRAMONIUM, AND TOBACCO NICOTIANA
ON THE HIPPOCAMPUS OF MALE SPRAGUE DAWLEY (SD) RATS
USING NEUROCHEMICAL AND NEUROBEHAVIORAL PARAMETERS
TU002
OREXINS ARE AN AROUSAL SYSTEM INVOLVED
IN ANTICIPATION TO A PALATABLE SNACK
Blancas-Velázquez A., González García D, Rodríguez K., Escobar C. FACULTAD DE MEDICINA, UNAM,
CIUDAD UNIVERSITARIA.
Adekomi Damilare Adedayo. University of Ilorin, Ilorin, Department of Anatomy, Nigeria.
Background: Smoking is a toxic environmental pollutant Objective: The present study was carried out to
investigate the short term effects of exposure to the smoke extract of Cannabis sativa, Datura stramonium, and Tobacco nicotiana on the hippocampus of male Sprague Dawley (SD) rats using neurochemical and neurobehavioral parameters. Materials and Methods: 20 male SD rats were assigned into 4
groups. Rats in groups A, B, and C (treatment groups) were exposed to smoke from a completely burnt
0.74 g leaf extract of C. sativa, D. stramonium, and T. nicotiana each wrapped in 0.5 g of cotton wool
for 5 minutes three times daily respectively. The rats in group D (control group) were exposed to smoke
from completely burnt 1.24 g of cotton wool with the same parameters as observed with the treatment
groups. The duration of exposure was for 5d. Memory retention was evaluated through open-field
habituation test, classic maze test as well as spatial memory test. Moreover, exploratory motor activity and motor coordination were evaluated. Brain tissue specimens, were taken for histopathological
examination and quantitativ e histochemical analysis. Results: There was marked statistical reduction
in the body weight of the rats in group B exposed to the smoke extract of D. stramonium. On comparison
with the control group, it was observed that there was impairment in the behavioral characteristic test
the rats in groups A, B and C were exposed to. Histopathological and quantitative histochemical evaluations revealed distinct neurodegenerative changes in the hippocampus, inhibition of AchE activity, as
well as increase in the activity of MDA. Conclusion: These results suggest that smoking the leaf of C.
sativa, D. stramonium and T. nicotiana has deleterious effects on the hippocampus of rats as reflected
in impairment learning and memory, motor activity and motor coordination.
TU003
BEHAVIORAL AND NEURONAL INDICATORS
OF ADDICTION TO CHOCOLATE IN RATS
González García SD, Blancas Velázquez AS, Ubaldo Reyes LM, Escobar Briones C. FACULTAD DE MEDICINA, UNAM, CIUDAD UNIVERSITARIA, MEXICO.
Recent reports suggest that excessive consumption of palatable food or drugs induces similar neuroadaptive responses in the nucleus accumbens. CFosB is a stable, long lasting protein believed to
be involved in these changes. When 5gr. of chocolate are offered daily at the same hour for up to
3 weeks rats exhibit anticipatory activity expecting chocolate access and this behavior persists for
many days after the protocol is interrupted. The aim of this study was determine if this behavior can
reflect a process of addiction. Therefore we tested rats with a test of effort to show their need to get
the chocolate and determine changes of CFosB expression in nucleus accumbens (NAcc) and prelimbic
cortex. Methods. Male Wistar rats (250 g) were housed in individual cages in a 12/12 cycle, fed with
chow and water ad libitum. Rats were assigned to control or Chocolate group: they received for 21 days
5gr. of chocolate at 13:00. Brains were obtained of rats after Chocolate ingestion or during chocolate
anticipation. Brains were prepared for immunohistochemistry for . CFosB. We designed a wire box cube
in which we put the 5 gr. piece of chocolate. This allowed the animals to see and smell the chocolate
but could not touch, scratch or bite it. The aim was to determine the effort of rats to obtain the snack.
The behavior was recorded and DVD recordings were watched to assess the presence and quantity of
the approaching behaviors of rats to the wire box. Results. Our results demonstrate overexpression
of _FosB in the NAcc after 21 days of chocolate exposure. They also exhibited significant events of
effort to obtain chocolate. Conclusion: prolonged chocolate consumption produces changes at the
neuronal and behavioral level similar to those observed in drug abuse. Supported by CONACyT 82462
and PAPIIT 203907.
Introduction: Sweet and fatty food is strongly motivational for humans and rats. Rats become very
quickly expectant to a daily scheduled access to palatable food. This process entrains neuronal activity
in limbic areas. When the stimulus is withdrawn, behavioural and neuronal changes persist. Purpose:
The aim of this study was to identify in rats the involvement of alertness systems such as corticoids
and orexins during anticipation to a daily scheduled piece of chocolate Methods: Male Wistar rats
weighting 250-300gr were given 5gr of chocolate in the middle of their resting period daily during 3
weeks. Rats (control n=8, experimental n=8 ) were cannulated in the yugular vein and blood samples
were taken, two hours previous, two hours after and at the chocolate time. Samples were processed
to determine corticosterone, glucose and trigicerydes. Brains were obtained from rats (n=4) after
ingestion of chocolate, during anticipation of the palatable food (n=3); and from a control group that
never ingested chocolate (n=4). Rats were perfused with paraformaldehyde, brains were removed,
posfixed and cryoprotected in 30% sucrose. Brains were cut in 40um slices and were double-stained
for c-Fos and orexin immunohistochemistry . Double cells were counted. Results: Plasma corticosterone was not different from control at any time-point such as triglicerydes. Glucose had an elevation 2
hours after chocolate intake in experimental group compared with control. For neuronal analysis: The
groups sacrificed after ingestion and during anticipation of chocolate showed more double Fos-orexin
immunoreactive cells than controls in the hypotalamic perifornical area. Conclusions: The acquisition
of a perseverant behaviour do not involve the hypotalamic pituitary axis as the main arousal system.
Contrasting, the orexigenic system which is involved in arousal and processing of satiety was active
during ingestion and anticipation to a reward. Acknowledgments: This study was supported by CONACyT
82462 an PAPIIT UNAM. IN-203907.
TU004
ALCOHOL ABUSE AND ATHEROGENIC RISK INCREASE
AVENDAÑO D(1),ZEPEDA I(1) and CORTES(1), (1)Dpto. de Fisiología, Facultad de Medicina, BUAP, Puebla,
Puebla, México.
The abuse of alcohol among adolescents is considered a risky behavior to health. It is well known
that high-dose alcohol predisposes to neurological intoxication, liver cirrhosis and non-atherogenic
ischemic heart disease. Our work was aimed to determine the impact of chronic alcohol intake in
young adults as a risk factor to develop atherosclerosis. We performed a descriptive study of a sample
of 50 subjects aged between 18 and 22, which alcohol intake started 3 years before the study. We
included men and women with unknown pathological conditions. We also determined anthropometric
and biochemical parameters (lipid profile). The obtained results for the control group (n = 25) were:
Cholesterol: 158.24±12.16 mg/dl; Triglycerids: 121±6.33 mg/dl; Ch/HDL: 41.08±4.06 mg/dl; Ch/
LDL: 89.63±9.67 mg/dl; Coronary heart risk: 3.82±0.34 mg/dl; Atherogenic risk index: 2.2±0.3
mg/dl. For the population at risk (n=25) the results were: Cholesterol: 213.56±14.37 mg/dl; Triglycerids: 163.76±14.83 mg/dl; Ch/HDL: 35.96±2.77 mg/dl; Ch/LDL: 144.84±11.71 mg/dl; Coronary
heart risk: 6.0±0.44 mg/dl; Atherogenic risk index: 4.1±0.41 mg/dl. We conclude that chronic ethanol consumption is a risk factor linked with the development of ischemic heart disease related with
atherosclerosis in the examined young adults compared with subjects whose alcohol consumption
is null (p <0.001). Additionally, our results consider the sedentary lifestyle, a BMI> 26.6 coupled
with the chronic consumption of alcoholic beverages are risk factors that increase the probability of
cardiovascular disease.
TU005
REGULATION OF ALPHA-7 NICOTINIC ACETYLCHOLINE RECEPTOR
DURING NICOTINE WITHDRAWAL AND THE ROLE OF VARENICLINE
TRINDADE RS(1), GARRÃO NR(1), CLAUDIO-NETO S(1), ISNARDO-FERNANDES J(1), COELHO JM(2), FILGUEIRAS CC(1), ABREU-VILLAÇA Y(1), MANHÃES AC(1), (1) Dept. of Physiological Sciences Univ. Estadual do
Rio de Janeiro, Brazil; (2) Univ. Federal do Estado do Rio de Janeiro, Brazil
TU006
INCREASED PKM Z EXPRESSION AND ACTIVITY
IN CA1 - AND NOT CA3 REGION - OF THE HIPPOCAMPUS
IS ASSOCIATED WITH COCAINE EXPOSURE
Eugenin-von Bernhardi J, Ibanez R & Gysling K. Pontificia Universidad Católica de Chile, Chile.
The aversive aspects of the withdrawal syndrome (WS) are one of the major obstacles in the treatment
of tobacco dependence (TD). Changes in the levels of nicotinic acetylcholine receptors (nAChRs) have
been observed during this period. Studies show that alpha-7 nAChR is involved in the somatic symptoms of WS. This nAChR is mostly expressed in hippocampus. Varenicline is the most recent medication
for the treatment of TD and it is a full agonist of alpha-7 nAChRs. In this study we aim to ascertain
the level of alpha-7 nAChRs in hippocampus during withdrawal. From postnatal day (PN) 30 to 45, 34
Swiss mice had a 2% saccharin solution (VEH) to drink. Four procedures were adopted subsequently
(PN45 to PN55): 1) Varenicline (Sigma, 0.1 mg/kg/day – VAR1), 2) Varenicline (1,0 mg/kg/day – VAR2),
3) Exposure to 50μg/ml nicotine-free base (Sigma) in 2% saccharin solution (NIC), 4) Exposure to the
saccharin solution (VEH). Groups received treatment (varenicline+DMSO 8% or DMSO 8% only) by
gavage. From PN55 to PN60 or PN 70 the animals suffered a spontaneous withdrawal and were killed
at the last day of it for collection of tissues. Hippocampi were homogenized and submitted to Western blotting, by using policlonal antialpha7 and anti-actin antibodies, visualized by HRP conjugated
method and ECL (n = 3-5 per group). Digitalized images were quantified using ImageJ software (NIH)
and statistical analyses were performed on SPSS. Levels of alpha-7 nAChR were significantly reduced
in VEHNIC and VEHVAR1 groups on a 15 days withdrawal period (p<0,001). Due to the role of alpha-7
nAChR on cognitive processes, our results suggest that it contributes to WS. Curiously the lowest dose
of varenicline leads to a similar reduction.
Drug addiction is a chronic disease characterized by the compulsive seeking for drugs over any other
goal. Addictive drugs have the ability to activate the mesocortical limbic pathway, which is related to
the brain reward system. The protein kinase M Z (PKM Z) is an isoform of the protein kinase CZ (PKC
Z), exclusively expressed in brain tissue. Is has been shown that this protein is involved in long term
memory maintenance. Recent publications have shown that PKM Z also participates in the reward
memory, which is associated with drug addiction behavior. In this work we studied the changes in the
expression and activity of PKM Z in rat’s hippocampus after exposure to cocaine. We administrated
15 mg/Kg of cocaine, twice per day, by intraperitoneal injection for seven days. Then, animals were
sacrificed 24 hours after the last cocaine injection, and CA1 and CA3 regions of the hippocampus
were extracted separately. Lysates were analyzed by western blot to determine PKMZ expression levels.
PKM Z enzyme activity was determined with a Promega PepTag® assay for non-radioactive detection
of protein kinase C. Our results show that cocaine increased PKM Z (by two-fold) expression and
activity in the CA1 region of the hippocampus, but not in other hippocampal regions such as CA3. This
response could be mediated by dopamine 1 receptors (D1R), which activate the cAMP/PKA pathway
and related transcription factors, promoting an increase in enzyme expression and activity. Reports
by other investigators have demonstrated that dopamine-induced long term potentiation (LTP) can be
abolished by ZIP, a selective inhibitor of PKM Z. It has been also reported that CA1 and CA2 receive
neuronal inputs from the ventral tegmental area (VTA), while CA3 do not. We propose that cocaine, by
itself, promotes plastic changes in the hippocampal region, which could actively participate in addictive behavior in mammals.
TU007
DISTRIBUTION OF NEURONS ACROSS THE SURFACE
OF THE NON-HUMAN PRIMATE CEREBRAL CORTEX
TU008
TGF-_ INDUCES NEURONAL POLARITY THROUGH
AN ERK MAPK-DEPENDENT MECHANISM
Gabi M(1),Neves K(1),Torres LB(2),Kaas J(3),Herculano-Houzel S(1), (1)Universidade Federal do Rio de
Janeiro,Brazil;(2)Instituto Evandro Chagas, Belém, Brazil;(3)Vanderbilt University, USA.
Osorio JT(1,2), von Bernhardi R(2), and A. Alvarez AR(1),(1) Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile and (2) Laboratorio
de Neurociencia, Departamento de Neurología, Facultad de Medicina, Pontificia Universidad Católica
de Chile.
Brain evolution is often considered synonymous with brain expansion and, particularly, expansion of the cerebral cortex.
However, we recently showed that although the human cortex represents 82% of brain mass, it contains only 19% of
all brain neurons (Azevedo et. al.,2009), indicating that the relative size of the structure does not necessarily reflect its
relative number of neurons. The same might apply across cortical areas, given that neuronal densities have been shown
to vary extensively within the primate cerebral cortex (Collins et al., 2010). Here we initiate a systematic comparison
of the fronto-occipital distribution of neurons along the surface of the cerebral cortex across primates to determine if
cortical expansion occurs in a homogenous manner across the cortex and if the relative expansion of an area reflects
an increase in its relative number of neurons. One cortical hemisphere of Macaca fascicularis and Saguinus midas
each was embedded in agar and sliced into a series of 2mm coronal sections. The cortical grey matter of each section
was dissected away from the underlying white matter and weighed, and total numbers of neurons and other cells in
each section were determined with the isotropic fractionator. The cerebral cortex of both species exhibits a 6-fold
systematic variation of neuronal densities along the frontooccipital axis, with the lowest densities found in the frontal
and the highest in the occipital area, indicating that average neuronal size is largest toward the frontal areas. As a
consequence, half of all cortical neurons are concentrated in the posterior third of the cerebral cortex. The glia/neuron
(g/n) ratio varies over 6-fold among cortical regions in Macaca, and 3-fold in Saguinus, decreasing systematically from
frontal to occipital regions. The g/n ratio varies as a negative power function of neuronal density, decreasing as neuronal
density increases, exactly as found across species. This pattern suggests that the number of glial cells per neuron in
each cortical section increases with the increasing average size of neurons. We find that the cumulative percentage
of neurons varies along the fronto-occipital axis as similar functions of the cumulative percentage of cortical mass in
both species. This suggests that the two species share a similar neuronal distribution along the cortical surface, even
though the cerebral cortex is ten times larger in Macaca than in Saguinus. Cortical expansion in primate evolution thus
appears to have happened without an accompanying modification of the distribution of neurons across its surface, in
contrast with the hypothesis of a relative expansion of frontal regions with cortical expansion. Support: CNPq, Faperj,
INNT/MCT, James McDonnell Foundation.
The establishment and maintenance of cell polarity is a key event during embryo development as well
as in adulthood. Neurons are highly polarized cells. The establishment of neuronal polarity is manifested by the differentiation and functional specialization of two different domains: axons and dendrites.
Several signaling pathways involved in axondendrite polarization have been described, but it is still
unknown the exact mechanism by which polarization is established. Among the extracellular signals
participating in embryonic development, TGF-_ appear to be an attractive molecule that initiates the
polarization programs. It has been described that TGF-_ activates c-Abl, a tyrosine kinase that participates in neuronal morphogenesis and cytoskeletal rearrangement. Thus we decided to evaluate if c-Abl
activation could be the mechanism through whichTGF-_ induces neuronal polarization. We established
primary cultures of hippocampal neurons and treated them with TGF-_1 alone or in combination with
the c-Abl inhibitor, STI571. By immunofluorescence we detected the polarized expression of TGF-_
receptors at the axon and we observed that TGF-_1 acted as an inductor of neuronal polarization,
increasing the number of neurons positive for the axonal marker PHF1. Besides, we show for the first
time by western blot that TGF-_1 activated c-Abl in neurons. However, we also found that c-Abl inhibition using STI571 did not prevent TGF-_1-induced neuronal polarity, suggesting that this kinase does
not participate in TGF-_1-induced axonal specification. Interestingly, contrary to what was expected,
STI571 also induced neuronal polarization. When MAPK signaling pathway was interrupted using the
MEK inhibitor PD98059, we found that TGF-_1-induced neuronal polarity was prevented, although the
STI571-induced polarization was not prevented. Therefore, the activation of the neuronal polarization
by TGF-_1 and STI571 appears to occur through independent signaling pathways. Our results suggest
that TGF-_ induces neuron polarity through MAPK pathway.
TU009
EVIDENCE OF A SUFFOCATION ALARM SYSTEM WITHIN
THE PERIAQUEDUCTAL GRAY MATTER OF THE RAT
TU010
THE ROLE OF THE INTEROCEPTIVE INSULAR CORTEX
IN THE GASTROINTESTINAL MALAISE PERCEPTION
SCHIMITEL FG(1), MÜLLER CJT(1), TUFIK S(2), and SCHENBERG LC(1), (1) Department of Physiological
Sciences, Federal University of Espírito Santo, Vitória, Espírito Santo, Brazil. (2) Department of Psychobiology, Federal University of São Paulo, São Paulo, Brazil.
Aguilar MI(1), Kim S(2), Coleman T(2), Torrealba F(1) and Maldonado P(3). 1. Pontificia Universidad
Católica de Chile. 2. University of California, San Diego. 3. PDFB. ICBM. Fac. Medicina, Universidad de
Chile.
Dyspnea, hunger for air, and urge to flee are the cardinal symptoms of panic attacks. Patients also
show baseline respiratory abnormalities and a higher rate of comorbid and antecedent respiratory
diseases. Panic attacks are also precipitated by infusion of sodium lactate and inhalation of 5% CO2
in predisposed patients but not in healthy volunteers or patients without panic disorder. Accordingly,
Klein (Klein 1993 Arch Gen Psychiatry 50:306-317) suggested that clinical panic is the misfiring of
an as-yet-unidentified suffocation alarm system. In rats, selective anoxia of chemoreceptor cells by
potassium cyanide (KCN) and electrical and chemical stimulations of periaqueductal gray matter (PAG)
produce defensive behaviors, which resemble panic attacks. Thus, here we examined the effects of
single or combined administrations of CO2 (8% and 13%) and KCN (10-80 ug, i.v.) on spontaneous
and PAG-evoked behaviors of rats either intact or bearing electrolytic lesions of PAG. Exposure to CO2
alone reduced grooming while increased exophthalmus, suggesting an arousal response to non-visual
cues of environment. Unexpectedly, however, CO2 attenuated PAG-evoked immobility, trotting, and galloping while facilitated defecation and micturition. Conversely, KCN produced all defensive behaviors
of the rat and facilitated PAG-evoked trotting, galloping, and defecation. There were also facilitatory
trends in PAG-evoked exophthalmus, immobility, and jumping. Moreover, whereas the KCNevoked defensive behaviors were attenuated or even suppressed by discrete lesions of PAG, they were markedly
facilitated by CO2. Authors suggest that the PAG harbors an anoxia-sensitive suffocation alarm system
which activation precipitates panic attacks and potentiates the subject responses to hypercapnia.
The posterior insular cortex is a structure that receives and processes interoceptive signals. We hypothesized that the neural activity of this structure represents different bodily states. We recorded
single neurons from this cortex of awake rats while inducing a gastrointestinal malaise state by the
intraperitoneal injection of LiCl, and examined the behavioral effect of activating this cortex by electrical microstimulation. The analysis of our recordings and the microstimulation experiments yielded
three results that support our hypothesis. First, of the total of single units recorded, 12% (15/128) increased and 6% (8/128) decreased their firing rate associated with “lying on belly” (LOB), a behavior
that expresses gastrointestinal illness in non-vomiting species. These results indicate that the activity
of these neurons represent the gastrointestinal malaise perception. The remaining 6% (8/128) neurons increased their activity at LOB off and 5% (6/128) at Pica behavior, the tendency to eat substance
other than normal food. It is probably the activity of these two groups of neurons that is signaling the
transition to relief. Second, we observed an increase of the power spectrum of spikes and the local
field potential at the theta band associated to the perception of gastrointestinal malaise. In addition,
preliminary results show there is a causal effect between pair wise neurons associated to LOB. These
results indicate that this cortex represents, and probably is central to the perception of visceral malaise. Third, the electrical microstimulation of the posterior insular cortex at the same points where we
recorded single unit responses during the behaviors induced by LiCl injection, evoked LOB and/or Pica
in 7/7 rats. These results indicate that the electric activity of a few hundreds of neurons of this cortex
represents gastrointestinal malaise. We show for the first time that the neural activity of the posterior
interoceptive insular cortex signifies gastrointestinal malaise.
TU011
THE GLUTAMATERGIC AND ENDOCANNABINOID
NEUROTRANSMISSION INTO THE DORSAL HIPPOCAMPUS
CAN MODULATE THE CARDIAC BAROREFLEX ACTIVITY IN RATS
TU012
YAWNING DECREASES CORNEA TEMPERATURE
Ferreira-Junior NC, Lagatta DC, and Resstel LBM. Dept. of Pharmacology, School of Medicine of Ribeirão
Preto, Uni. of São Paulo, Ribeirão Preto, Brazil.
The dorsal hippocampus (DH) has direct influence on cardiovascular response, particularly during
defensive reactions, situations in which there are also baroreflex response inhibition. NMDA receptors
into DH are involved with cardiovascular modulation associated to the stress. CB1 receptors located
in presynaptic receptors within the DH can modulate the glutamatergic neurotransmission. Therefore,
the aim of the study was to verify the involvement of the DH glutamatergic and endocannabinoid
neurotransmission in the cardiac baroreflex modulation. Male Wistar rats (190- 240g) had bilaterally
implanted cannulae within DH. A catheter was posteriorly implanted into femoral artery for mean
arterial pressure (MAP) and heart rate (HR) recording. Baroreflex activation was induced by infusion
of phenylephrine or sodium nitroprusside through a catheter implanted into femoral vein. The drugs
microinjected into DH did not affects baseline of MAP or HR. The AP7 (10 nmol/500nL), NMDA receptor
antagonist, was able to decrease the baroreflex activity, which was characterized by linear regression slope reduction of both bradycardic (before= -2.17 ± 0.19 and after= -1.48 ± 0.15 bpm,
F(2,23)= 3.77, P<0.05) and tachycardic (before= -2.74 ± 0.18 and after= -1.85 ± 0.18 bpm;
F(2,23)= 4.04, P<0.05) responses, and non-linear regression slope retrenchment (before= -1.84
± 0.07 and after= -1.53 ± 0.07 bpm, F(2,23)= 5.35, P<0.05). The AM251 (10 pmol/500nL),
CB1 receptor antagonist, was able to increase the baroreflex activity, which was characterized by linear
regression slope enhancement of both bradycardic (before= -1.66 ± 0.14 and after= -2.31 ±
0.20 bpm, F(2,14)= 5.23, P<0.05) and tachycardic (before= -1.81 ± 0.25 and after= -2.84 ±
0.19 bpm; F(2,14)= 5.46, P<0.05) responses, and non-linear regression slope strengthening (before= -1.06 ± 0.05 and after= -1.65± 0.09 bpm, F(2,14)= 21.37, P<0.05). Thus, the results
show that endocannabinoid system into DH plays an important role on the cardiac baroreflex activity
probably modulating the glutamate release.
URIBE CA(1), CORTÉS M.C(1), BAUTISTA A(2), and EGUIBAR J.R(1), (1) Institute of Physiology, Benemérita
Universidad Autónoma de Puebla, Puebla, Puebla, México. (2) Centro Tlaxcala de Biología de la Conducta, Universidad Autónoma de Tlaxcala, Tlaxcala, Tlaxcala, México.
Yawning is a stereotyped behavior whose frequency increases after stress and in some pathological
conditions such as multiple sclerosis, stroke and migraine. All these circumstances have in common an increase in brain temperature. So, it has been proposed that yawning is a mechanism of
thermoregulation, because during yawning, the deep breathing cold air can ventilate the nasal and
pharynx cavities, and the contraction of the facial muscles increases blood flow, favoring heat loss
process through the skin of the face. We used our High-Yawning (HY) subline from Sprague-Dawley rats
strain, this subline yawns spontaneously around 20 times/h. The subjects were placed in a wooden
box that limits their movement (measures 21X11X7cm). One side of the box is open and allows take
thermographs of the subjects using an infrared camera (Fluke TiR1). Subjects were observed by 55
minutes taking thermographs every 5 seconds, taking temperature in the ear shell and in the cornea.
During the first 5 minutes of observation the ear shell temperature and the cornea were significantly
lower than the remainder of the observation (Friedman, _2= 35.6, D.F.=10, P ≤ 0.001, Tukey,
q=5.5, P<0.05). Yawning frequency during the first 5 minutes was also significantly lower than for
the remainder of the observation (ANOVA, F=2.3, P=0.03, Tukey, q=5.6, P=0.01). The analysis
of yawnings, show that 10 seconds before the yawning, cornea temperature was significantly greater
than ten seconds after the yawning (ANOVA, F=4.8, P=0.01, Tukey, q=4.4, P=0.005) around three
tenths of Celsius degree, but 20 seconds after yawning the cornea temperature returns to prior levels,
before yawning. These data suggest that increasing the head temperature during the observation could
influence the frequency of yawning. Our results showed clearly that cornea temperature decrease after
spontaneous yawning happen, suggesting that this behavior modulate facial temperature and probably
brain temperature.
TU013
CHARACTERIZATION OF ADRENAL GLAND AUTONOMIC INNERVATIONS
IN SPONTANEOUS HYPERTENSION RATS, THOUGH GOLGI-COX METHOD
Rojas Rendón N, Giles R, Flores G, Gómez- Villalobos M.J. Instituto de Fisiología. Laboratorio de Investigación Cardiovascular. Benemérita Universidad Autónoma de Puebla. 14 Sur 6301, San Manuel,
Puebla, Pue. CP 72570 México.
TU014
INSULAR CORTEX INACTIVATION DOES NOT MODIFY
THE CARDIOVASCULAR AND BEHAVIORAL RESPONSES
TO SEVERE HYPOXIA IN CONSCIOUS RATS
CASANOVA P, CONTRERAS M, DEL RIO R, TORREALBA F, ITURRIAGA R. Lab. Neurobiología, Facultad Ciencias Biológicas. P. Universidad Católica de Chile. Santiago, Chile.
Adrenal glands have a main role in the pathogenesis of hypertension. Autonomic innervations is rich
in the adrenal gland, however there is a little information related to their changes in hypertension,
then we study the changes in adrenal gland innervations, and in the periglandular fat tissue in normotense, pre hypertense and hypertensive rats, through Golgi-Cox method, and hematoxiline-eosine stain.
Methods. Male Sprague Dawley (SD), Wystar Kyoto (WK) and spontaneous hypertension (SH) rats, 16
weeks old were used. Weight (g) and systolic arterial blood pressure (SABP) were recorded, before de
animals were sacrificed. Hearts, adrenal glands with periglandular fat tissue were removed, washed,
weighted and then were incubated for 15 days in Golgi-Cox solution. After were cut by vibrotomo
(150 microns), processing and analyzed in light microscopy, Leica LAS-software. Morphology, size of
nerve cells and density (cell number/mm2) were determined. Haemotoxiline stain was made for to
get the cortex and medulla length from adrenal glands. RESULTS. SABP (mmHg) was higher in SH rats
compared against WK and SD rats (203±28, 163±22, and 128±18, P <0.001). Body/heart weight
radio was higher in SH rats compared with SD rats (1.06±0.03 against 1.52±0.06, and 3.1± 0.18
against 4.5±0.04, respectively, P <0.0001), without significance differences between WK and SH
rats. Adrenal glands weight (g) was reduced in SH rats (SD-0.041±0.004, WK 0.024±0.014, SH0.018±0.001, P<0.001), however the cortex-medulla radio was lower, with a significant increase in
medulla length. Nerve cell density was increased in medulla and in the periglandular fat tissue in SH
rats compared against SD rats and WK rats. CONCLUSION. The adrenal gland from SH rats show an increased medulla, associated to an increase in nerve cell density, also observed in the periglandular fat
tissue, suggesting that autonomic system is involved in the development of hypertension in this model
The insular cortex, a key region of the interoceptive system, is involved in the perception of visceral
and emotional responses. Indeed, patients with one-hemispheric insular cortex lesion show a reduced
perceptual sensitivity for dyspnea (air hunger), suggesting that the insular cortex participate in the
oxygen perception. Rats show an escape behavior in response to severe hypoxia, but the role played by
the insular cortex in this behavioral response remains unknown. Thus, we hypothesized that the insular
cortex inactivation may prevent the escape behavior in response to hypoxia. Accordingly, we assessed
the insular cortex inactivation with voltage-dependent Na+ channel blockers on the escape behavior,
arterial pressure and heart rate in conscious rats exposed to hypoxia. Male Sprague Dawley rats 250g
were implanted with telemetric Millar® transducers to measure arterial blood pressure, heart rate
and body temperature, and with microinjection cannulas in the right and left posterior insular cortex.
Neosaxitoxin (32.5 μM, 1μL/side), bupivacaine (26.5 μM, 1μL/side) or saline solutions (1μL/side)
were injected in both right and left insula. Immediately after injection, rats were exposed to hypoxia in
an acrylic chamber, and the behavioral and physiological responses were recorded. Neosaxitoxin and
bupivacaine injections in the posterior insula did not modify baselinearterial pressure or heart rate.
Hypoxia increased arterial pressure (~ 20 mmHg) and heart rate, produced a significant decrease in
body temperature post hypoxia (~ 0.7 ºC), and elicited an escape behavior when FIO2 reached ~5%,
but these responses were not altered by insular cortex inactivation. Our results showed that the insular
cortex inactivation by bupivacaine or neosaxitoxin does not modify the escape and autonomic response
to hypoxia, suggesting that the insular cortex has no effect in the control of autonomic cardiovascular
variables in conscious rats in response to severe hypoxia. Supported by CONICYT ACT-66.
TU015
SPATIAL-MEMORY RECOVERY INDUCED BY AMYGDALA
STIMULATION IN ANIMALS WITH FIMBRIA-FORNIX
LESION INVOLVED NEUROTROPHIC FACTORS
TU016
INTEGRATED TECHNIQUES TO STUDY THE
HOUSING EFFECTS IN RAT ANIMAL MODELS
Mercerón-Martínez D(1), Almaguer-Melian W(2), Serrano-Sanchez T(3), Lorigados-Pedre L(3), PavónFuentes N(3), Hidalgo-Portal L(4)and Bergado-Rosado J(2). (1) Dpto de Neuroestimulación, Centro de
Neurociencias de Cuba; (2)Dpto de Electrofisiología Experimental, Centro Internacional de Restauración Neurológica (CIREN), Cuba; (3)Dpto de Neuroinmunología, CIREN and (4)Dpto de Neuromorfología,
CIREN
The BDNF and NGF levels were measured in the hippocampus of fimbria-fornix lesioned male rats
after four days of training in the water maze and stimulation of the basolateral amygdala. The behavioral results confirm a previous report from our group: daily post-training stimulation of the amygdala
improves the learning abilities of the lesioned animals. BDNF levels were increased in lesioned and
trained animals, but stimulating the basolateral amygdala induces a significantly greater increase.
NGF levels showed a slight (but significant) increase in fimbria-fornix lesioned and trained animals,
but stimulating the amygdala does not produce a further increase. In separate groups of animals we
measured the levels of both neurotrophins in acute experiments, after 2 and 24 hours of stimulating
the amygdala. BDNF levels were significantly increased at both times, while NGF showed again only
slight increases (significant at 24 h). These results suggest that the BDNF response to amygdala stimulation (probably via the regulated pathway) might be of functional importance in the observed learning
improvement. The changes in NGF are most likely due to the accumulation of this protein (constitutively
synthesized) after removal of the septal axons.
Adriana Saborío Arce (1); Andrea Mora Gallegos (1); Jaime Fornaguera (1,2). (1) Programa de Investigación en Neurociencias, Universidad de Costa Rica, Costa Rica. (2)Departamento de Bioquímica,
Escuela de Medicina, Universidad de Costa, Costa Rica Rica.
Housing condition has shown to be a very important element that could modify physiological and morphological aspects of the CNS. We have used differences in housing (between social and environmental
enriched animals and isolated ones) to study the relationship between behavioral, neurochemical and
neuroanatomical changes in the rat brain. In this sense, in the last years, we have been working to develop and to set up some techniques to reach our goals. Housing conditions: Some animals are exposed
to an enriched cage (120cm length x 70cm width x 100cm height), with non-chewable plastic objects,
PVC tubes and running wheels placed randomly elsewhere in the cage. In contrast, other animals are
maintained isolated in a rectangular cage (24cm length x 18cm width x 18cm height). Behavioral
tests: Some tests and mazes are performed with different goals: open-field test (exploratory behavior
and general activity); hole-board maze (locomotion and anxiety-related behaviors); elevated-plus maze
(anxiety-related behaviors); radial maze (working memory and spatial long-term memory); and forcedswimming test (behavioral despair). Neurochemical analysis: High performance liquid chromatography
with electrochemical detection (HPLC-EC) and fluorescence detection (HPLC-F) are used to analyze,
post mortem, the neurotransmitter content of some brain regions in the rat. The substances measured
with these techniques are: monoamines and some aminoacids or derivatives. Neuromorphology: Several cells and structures of interest are localized using different kinds of brain tinctions (hematoxylin
and eosin, cresyl fast violet, and luxol fast blue). In addition, double immunolabel technique is used to
localize GFAP, glutamine synthetase, S-100_ and GAP-43 in the rat cortex and hippocampus. These proteins are analyzed post hoc using confocal microscopy. Together, all these integrated techniques allow
us to give a broader spectrum of the possible effects that different housing conditions may have and
to give further information about underlying processes at different levels: from behavior to proteins.
TU017
BEHAVIORAL AND NEUROCHEMICAL DIFFERENCES DEPENDENT
OF AGE AND HOUSING CONDITIONS ON WISTAR RATS
TU018
EVIDENCE THAT DOPAMINE IS RELEASED IN THE
STRIATUM TO PROMOTE AVERSIVE CONDITIONING
Andrea Mora Gallegos (1); Adriana Saborío Arce (1); Andrea Mora Gallegos (1); Jaime Fornaguera (1,2).
(1) Programa de Investigación en Neurociencias, Universidad de Costa Rica, Costa Rica. (2)Departamento de Bioquímica, Escuela de Medicina, Universidad de Costa, Costa Rica Rica.
Patricia A. Dombrowski (1), Suelen L. Boschen (1), Mariza Bortolanza (1), Etieli Wendler (1), Rainer K.W.
Schwarting (2), Marcus Lira Brandão (3), Philip Winn (4), Charles D. Blaha (5), Cláudio da Cunha (1).
(1)Departamento de Farmacologia, Universidade Federal do Parana, 81.531-980, Curitiba-PR, Brazil,
(2) Philipps-University of Marburg, Gutenbergstr. 18, 35032 Marburg, Germany, (3)INeC, 14040-901
Ribeirão Preto, SP, Brazil, (4) University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, (5)
Department of Psychology, University of Memphis, Memphis, TN 38152, USA.
Housing and age are parameters that have been studied in animal models that involve neuroplasticity,
neurodevelopment and behavioral analysis. These parameters have to be taken carefully into account
for the results interpretation. We directed our attention on plausible differences between young and
middle aged rats reared in different conditions using a behavioral test battery that measure spontaneous activity (Open Field Test) and spatial memory (Eight-Radial Arm Maze). Each age group was
assigned to one of three housing conditions groups (a) standard controls (SC), b) isolation (I) and
c) social and environmental enrichment (EE) for a period of three months previous to the behavioral
tests. One week after these three months animals were sacrificed and neuroanatomical and neurochemical analysis were performed. Analysis were carried out in three brain regions: prefrontal cortex
(PFC), hippocampus (HPC) and dorsal striatum (DS). Our results showed that in general young animals,
independently of rearing condition, have higher values than middle aged rats for locomotion, rearing
activity, grooming, distance traveled, reinforcers consumed in radial arm maze test, and duration of the
animals to complete the task. Additionally, we found differences in the concentration of neurotransmitters like serotonin (5-HT), norepinephrine (NE), dopamine (DA), Glutamate (Glu), GABA and their
metabolites in all studied brain regions. These results suggest that age is a more important parameter
than rearing condition to produce effects under the described conditions.
The aim of this investigation was to study what causes DA release in the striatum and how it affects
learning of conditioned avoidance responses. Sham and MPTP-lesioned rats were trained in the twoway active avoidance task. Other sham and MPTP groups were pseudo-trained by exposure to the
same tone and shock stimuli, but presented in a random and inescapable manner. Rats were given
up to 5 blocks of 40 trials. During the sessions, samples were collected at intervals of 5 min from a
microdialysis probe implanted into striatum. Extracellular DA concentration in the striatum of the
sham rats increased during early avoidance learning and decreased throughout training, returning to
baseline once the response was learned. This finding is in agreement with the hypothesis that DA release signaled prediction errors that occur when the animal predicts to receive a shock after the tone,
but it does not occur because the animal presented the avoidance response. Such prediction errors
disappear after the animal learns how avoid the shock. Critically, although the sham pseudo-trained
rats were exposed to the same stimuli, no significant alteration in the DA levels was observed in rat
striatum. This suggests that it was not the salience or negative hedonic properties of these stimuli that
caused DA release during the avoidance training. In addition, the avoidance scores of the shamtrained
rats in the second block correlated with the amount of DA released in the first block, suggesting that DA
promotes avoidance learning. This hypothesis is also supported by the finding that MPTP-treated rats
neither presented the peaks of striatal DA observed in the sham rats during the avoidance training sessions nor learned this task. In conclusion, the present findings suggest that positive prediction errors
induce DA release in the striatum that, in turn promotes learning of conditioned avoidance responses.
TU019
HIPPOCAMPAL NMDA RECEPTOR
SUBUNITS INVOLVEMENT IN MEMORY
TU020
ROLE OF PROTEIN SYNTHESIS IN MEMORY CONSOLIDATION AND
EXTINCTION OF ENHANCED TRAINING IN ACTIVE AVOIDANCE TASK
Snitcofsky M.(1), Baez M.(1), Colettis N.(1), Cercato M.(1), Aguirre A.(1), Cheli V.(1), Kornisiuk E.(1), Jerusalinsky D.(1,2), (1)Lab of Neuroplasticity and Neurotoxins (LaN&N), IBCN, Medicine School, Buenos
Aires University, Argentina. (2) CBC, Buenos Aires University, Argentina.
Gonzalez-Salinas S, Medina A C, Marin V, Quirarte G L and Prado-Alcala R A . Instituto de Neurobiologia,
UNAM. Mexico.
NMDA (N-methyl-D-aspartate) receptors (R) of the dorsal hippocampus are required to consolidate
inhibitory avoidance (IA) memory in rats and their inhibition with the channel blocker MK-801 immediately after IA training, gives rise to amnesia .This retrograde amnesia was prevented by previous
exposure to an open field (OF) -two sessions of 3 minutes each, 24 hours apart- that led to habituation
of exploration. Most of the hippocampal NMDAR subtypes contains GluN2A or GluN2B subunits. Inhibition of GluN2B-containing NMDAR by the selective antagonist ifenprodil enabled long-term memory
(LTM) formation of IA with a subthreshold (0.3 mA) training, and caused facilitation when the training
was just overtreshold (0.5mA), suggesting that hippocampal GluN2B containing receptors negatively
modulate this memory Intrahippocampal injection of ifenprodil also facilitated memory formation of
the hippocampus-dependent object location task. It was previously shown that a 5 min OF session led
to STM as well as LTM formation. Although OF habituation was impaired by intrahippocampal MK801, ifenprodil did not alter this memory, suggesting that it does not depend on GluN2B containing receptors.
Hippocampal protein extracts obtained 70 min after rat exposure to a 5 min OF session were analyzed
by Westernblot for the NMDAR subunits. While GluN2A significantly increased, GluN2B appeared to
remain unchanged, showing similar results to those obtained in other related models (i.e. LTP induction in hippocampal slices, Aguirre et al, IBRO 2011, Baez et al, 2012). These results corroborate that,
although NMDAR in the dorsal hippocampus are required during IA consolidation, receptor subtypes
containing GluN2B seem to inhibit memory consolidation of this tasks. Meanwhile, GluN2A increased
when memory consolidation is still going on, as happens during LTP establishment, suggesting that
they might be directly involved in synaptic plasticity underlying this process.
Recently, using an over-reinforced inhibitory avoidance task, it was demonstrated that protein synthesis was not necessary for memory consolidation. It was of interest to study if protein synthesis is
also unnecessary for another type of task (active avoidance), where consolidation and extinction were
measured after over-reinforced training. Training took place in an acrylic chamber with dark and illuminated compartments. In each of the twenty trials of the training session the rats were put inside the
dark compartment; if they did not cross to the lighted compartment in less than 10 sec a footshock was
delivered. In the consolidation protocol, 30 min before training rats received a subcutaneous injection
of cicloheximide (2.8 mg/kg) or vehicle. Independent groups received foot-shocks of 1, 2, 3 or 4 mA.
Forty-eight hours afterwards rats were subjected to a retention test. In the extinction protocol independent groups received foot-shocks of 2 or 4 mA. Rats received an injection of cicloheximide or vehicle
30 min before the first retention test. Each group was given 3 retention tests (extinction) spaced 24
hr apart. We found an amnesic effect of cicloheximide in the 1, 2, and 3 mA groups and a protective
effect of over-reinforcement on consolidation in the 4mA group. Also, we found that cicloheximide
interfered with extinction in the 2 mA group. The 4 mA groups treated with vehicle or cicloheximide
did not show extinction. In the light of our results and previous reports we think that consolidation
and extinction of over-reinforced tasks is carried out by distinct molecular requirements compared
to moderate conditions of training. We thank Norma Serafin, Angel Mendez, Isaias Turrubiate, Leonor
Casanova, Lourdes Ayala, and Martín Garcia for their important contributions to this work. Supported
by CONACYT (128259), PAPIIT (IN201712) and a scholarship from CONACYT (334752).
TU021
EFFECT OF TRANSCRIPTIONAL INHIBITION INTO THE AMYGDALA
IN MEMORY CONSOLIDATION OF AN ENHANCED TRAINING
TU022
A MODIFIED BURYING CAGE DESIGNED
FOR TESTING INFANT WISTAR RATS
Martínez-Moreno A(1), Medina AC (1), Quirarte GL (1), and Prado-Alcalá RA (1). (1), Dpto de Neurobiología Conductual y Cognitiva, Instituto de Neurobiología, UNAM. Querétaro, QRO. México.
Cueto-Escobedo J(1), Contreras CM(1,2), Bernal-Morales B(1), Guillén-Ruiz G(1), Rodríguez-Landa
JF(1), (1)Laboratorio de Neurofarmacología, Instituto de Neuroetología, Universidad Veracruzana, Xalapa, Veracruz, México (2) Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de
México, Xalapa, Veracruz, México.
A wealth of experimental findings has suggested that both inhibition of de novo protein synthesis and
mRNA inhibition disrupt the process of memory consolidation under normal conditions of training.
However, a growing body of evidence indicates that the application of amnesic treatments is ineffective when an organism has been subjected to enhanced training. In the present work we evaluated
the effect of transcriptional inhibition, through the bilateral intraamygdala administration of different
doses of DRB (20, 40 or 80 ng/ul/site) on memory consolidation of inhibitory avoidance training with a
relatively low intensity of footshock (1.0 mA). Also, we analyzed the effect of the optimal amnesic dose
of DRB under conditions of enhanced training, applying a footshock of relatively high intensity (3.0
mA). Our results show that DRB administration in doses of 40 and 80 ng/ul/site) in the amygdala produced an amnesic effect when training was conducted with a relatively low intensity of footshock (1.0
mA). However, DRB administration at a dose of 80 ng/ul/site) in the group that had been trained with
3.0 mA, was ineffective to impair long-term memory. Thus, a situation of enhanced training protects
memory from the amnesic effect of transcriptional inhibition into the amygdala. These data support
the view that in a situation of an enhanced training experience, the brain structures that are involve
in the storage of information, become functionally connected in parallel to maintain the mnemonic
trace. We thank Norma Serafin, Angel Mendez, Isaias Turrubiate, Leonor Casanova, Lourdes Ayala, and
Martín Garcia for their important contributions to this work. Supported by CONACYT (Grant 128259 and
scholarship to A.M.M. CVU 408044) and PAPIIT (IN201712).
The defensive burying test is an experimental model broadly used to explore anxiety-like behavior. Most
experimental models of anxiety are restricted to the use of adult animals, despite the fact that anxiety
disorders also occur during childhood, thus necessitating the adaptation of current models to the study
of young animals. We compared the effects of the chamber shape (i.e., rectangular vs. round) and size
of the defensive burying apparatus in 28-day-old Wistar rats. Infant rats that were tested in a round
chamber (19 cm diameter x 20 cm height) exhibited a shorter burying latency (p < 0.001) and longer
cumulative burying time (p < 0.001) than another group tested in a rectangular chamber of the usual
size (17 x 27 cm base, 30 cm height). Diazepam (1 mg/kg) also produced a longer burying latency (p <
0.01) and shorter cumulative burying time (p < 0.001) only in the round chamber. We conclude that a
smaller, round chamber may be appropriate for testing burying behavior in infant rats.
TU023
THE ROLE OF NUCLEUS ACCUMBENS AND DORSOLATERAL
STRIATAL D2 RECEPTORS IN ACTIVE AVOIDANCE CONDITIONING
TU024
SUBJECT-DRIVEN BIO-PROSTHETIC AVIAN VOCAL ORGAN BASED
ON A MATHEMATICAL MODEL OF THE PERIPHERAL EFFECTOR
BOSCHEN SL(1), WIETZIKOSKI EC(1,2), WINN P (3), and DA CUNHA C(1),(1)Univ. Federal do Parana, Curitiba, Brazil; (2) Univ. Paranaense, Francisco Beltrão, Brazil; (3)Strathclyde Institute of Pharmacy and
Biomedical Science, University of Strathclyde, Glasgow, Scotland, UK.
Ezequiel M. Arneodo(1), Yonatan Sanz Perl(1), Franz Goller(2), and Gabriel B. Mindlin(1), (1) Physics
Department, Univ. de Buenos Aires, Buenos Aires, Argentina; (2) Dept. of Biology, Univ. of Utah, Salt
Lake City, UT, USA.
The role of dopamine (DA) in rewarding motivated actions is well established but its role in learning
how to avoid aversive events is still controversial. Here we tested the role of D2-like DA receptors in the
nucleus accumbens (NAc) and the dorsolateral striatum (DLS) of rats in the learning and performance
of conditioned avoidance responses (CAR). Adult male Wistar rats received systemic, intra-NAc or intraDLS (pre- or post-training) administration of a D2- like receptor agonist (quinpirole) or antagonist ((-)
sulpiride) and were given two sessions in the two-way active avoidance task. The main effects observed
were: (i) sulpiride and lower (likely pre-synaptic) doses of quinpirole decreased the number of CARs
and increased the number of escape failures; (ii) higher doses of quinpirole (likely post-synaptic)
increased inter-trial crossings and failures; (iii) pre-training administration of sulpiride decreased
the number of CARs in both training and test sessions when infused into the NAc, but this effect was
observed only in the test session when it was infused into the DLS; (iv) post-training administration
of sulpiride decreased CARs in the testsession when infused into the NAc but not DLS. These _ndings
suggest that activation of D2 receptors in the NAc is critical for fast adaptation to responding to unconditioned and conditioned aversive stimuli while activation of these receptors in the DLS is needed for a
slower learning of how to respond to the same stimuli based on previous experiences.
Because of the parallels found with human language production and acquisition, birdsong is an ideal
animal model to study general mechanisms underlying complex, learned motor behavior. The rich and
diverse vocalizations of songbirds emerge as a result of the interaction between a pattern generator
in the brain and a highly nontrivial nonlinear periphery. Much of the complexity of this vocal behavior
has been understood by studying the physics of the avian vocal organ, the syrinx. A mathematical
model describing the complex periphery as a nonlinear dynamical system led to the conclusion that
nontrivial behavior emerges even when the organ is commanded by simple motor instructions: smooth
paths in a low dimensional parameter space. An analysis of the model provides an insight on which
parameters are responsible for generating a rich variety of diverse vocalizations, and what the physiological meaning of these parameters is. By recording the physiological motor instructions elicited
by a muted bird and computing the model on-line on a Digital Signal Processor, we produce realistic
synthetic vocalizations that replace the bird’s own auditory feedback. In this way, we build a bioprosthetic avian vocal organ controlled by a muted bird via its physiologically coded motor commands.
This subject-controlled, prosthetic vocal organ, allows for the realization of altered auditory feedback
experiments, in which the alterations in the feedback are produced consistently with alterations in the
motor instructions intended to produce it. In these experiments, we will be able to identify mechanisms
of acquisition and maintenance of the learned motor gestures that the bird uses to control its vocal
organ.
TU025
EFFECTS OF SAFETY LEARNING ON EXPLORATION
AND BRAIN CATECHOLAMINE LEVELS IN AGED RATS
Vasquez C.E., Hunter J.A., Cossio R.R., Britton G.B. Center for Neuroscience, Institute for Scientific
Research and Technology Services (INDICASAT AIP), Panama, Republic of Panama.
The objective of the present study was to examine the effects of aging in fear and safety learning
process. Learned safety has been shown to produce anti-depressant effects in mice, and its relation
with the aging process has not been explored. Aged female rats were trained in fear (FC) and safety
conditioning (SC) paradigms. FC animals were trained with tone and footshock pairings. SC animals received explicitly unpaired tone and shock presentations. Fear memory (freezing) was measured during
pre-tone, tone and post-tone periods in the training context in the absence of shock. Our preliminary
results showed no fear responses in the control group, a reduction of freezing during the tone in the
SC group, and elevated levels of fear to the tone in the FC group. The effects of fear and safety signals
following conditioning were tested using the Y maze (YM) and elevated-plus maze (EPM) paradigms. FC
and SC groups showed decreased spontaneous alternation in YM. However, the SC group showed more
arm entries than FC and control animals. In the EPM all groups spent more time in the closed arms, and
the FC group performed less arm entries relative to the SC and control groups. YM and EPM results were
consistent with a mouse model that showed increased exploration following SC training. In addition,
we measured levels of norepinephrine (NE) and dopamine (DA) in prefrontal cortex (PFC), hippocampus
(Hip) and striatum (STR), part of major neuroanatomical pathways of anxiety and depression. NE levels
were similar across groups and areas. However, SC produced high levels of DA in STR relative to FC and
control groups implicating striatal DA in safety learning. Ongoing studies are focused on structural
and molecular changes associated with FC and SC learning, including protein expression analysis and
stress markers associated with aging and depression.
TU026
THE DORSAL PREMMAMILARY NUCLEUS (PMD) AND
PERIAQUEDUCTAL GRAY MATTER (PAG) ARE REQUIRED FOR
THE EXPRESSION OF CONDITIONED DEFEAT IN WISTAR RATS
Faturi, CB (1); Junior, MJR (1); Canteras, NS (1), (1) Universidade de São Paulo, Departamento de
Anatomia.
Recently, our laboratory pointed out the dorsal pre-mammillary nucleus (PMD) and the dorsomedial
part of the periaqueductal gray (dmPAG) as critical sites for the expression of defensive behaviors in
the subordinate males exposed to dominant aggressive conspecifics during social defeat (SD). The main
of the present work was to evaluate if the innate and learned (Conditioned Social Defeat-CSD) defensive
behaviors share the same neural circuit. To this end, we used the resident/intruder paradigm. The CSD
test was conducted on the day following the SD, in an apparatus that consisted of one perspex chamber
(25x25x25cm) connected to a corridor (100x12x25 cm) leading to the cage where the SD took place.
15 minutes before the behavioral test, the animals received 0,256l of either muscimol (MUS 0,66g/6l)
or saline (CTL) in either the PMD or the dmPAG. During a five minute observation period, the time spent
in each part of the apparatus and the defensive responses were recorded. According to the results
the inactivation of the PMD reduced the percentage of time spent in risk assessment behaviors (PMD
inactivation 35.56%±12.75 x Control 65.72%±4.63; t=2.67, p=0.02). Conversely, dmPAG inactivation practically abolished contextual defensive behaviors, resulting in a dramatic decrease in the
time spent in risk assessment behaviors (dmPAG inactivation 17.43%±3.02 x CTL 57.21%±9.61;
t=3.80; p=0.003), as well as a in increase in relax locomotion (dmPAG inactivation 32.28±3.96
x Control 11.82%±2.90; t=-3.35; p=0.007) and in the time spent in the compartment were the
social defeat took place (dmPAG inactivation 46.34±3.71 x Control 16.12%±7.77). The present
results support the idea that innate and learned fear responses to social threats apparently share
the same circuit. The dmPAG inactivation had a more strikingly effect in decreasing learned defensive
behavior when compared to PMD. The reasons for these differences await further investigation.
TU027
LONG-TERM OMEGA-3 FATTY ACIDS SUPPLEMENTATION
IMPROVES BOTH MEMORY AND SYNAPTIC PLASTICITY IN
THE HIPPOCAMPUS OF CHRONICALLY STRESSED RATS
TU028
EARLY ENVIRONMENT MATTERS: BEHAVIORAL AND
NEUROCHEMICAL CHARACTERIZATION OF MATERNAL
CARE EFFECTS ON JUVENILE SPRAGUE-DAWLEY RATS
Miguel Angel Perez-Lizama(1,3), Juan Ahumada(2), Marco Fuenzalida(2), Alexies Dagnino-Subiabre(1),
(1)Laboratory of Neurobiology and Behavior (2)Laboratory of Synaptic Plasticity,Center for Neurobiology and Developmental Plasticity, Department of Physiology, Faculty of Science, University of Valparaíso,
Valparaíso, Chile.(3)Catholic University of North,Coquimbo, Chile.
Marianela Masís-Calvo (1), Andrey Sequeira (2), Andrea Mora-Gallegos(1), Jaime Fornaguera-Trías
(1,3) 1 Programa de Investigación en Neurociencias, Universidad de Costa Rica, Costa Rica (UCR) 2
Instituto de Investigaciones en Salud, UCR 3 Departamento de Bioquímica, Escuela de Medicina, UCR.
Introduction: Chronic stress produces dendritic atrophy in the CA3c pyramidal neurons and impairs
the spatial memory of rats, while the w-3 supplementation improves memory and learning in control
rats. Objective: The aim of this study was to evaluate, in a pathologic rat model of psychosocial stress,
the long-term effect of the two main types of w-3 fatty acids (DHA and EPA) on memory and synaptic
plasticity in the hippocampus. Methods: Male Sprague-Dawley rats were randomly assigned to six
experimental groups, 1) Control, 2) Stress; 3) Control+Vehicle, 4) Control+ Ω-3, for these treatments the animals were supplemented with water or a mix of Ω-3 (100 mg of DHA+25 mg of EPA)
respectively, by oral administration; 5) Stress+Vehicle, and 6) Stress+Ω-3 groups, these animals
were subjected to chronic restraint stress and supplemented daily with water or Ω-3 mix, respectively.
Ended end the stress protocol, memory, morphology of CA3 neurons, and synapses transmission in the
hippocampus were analyzed in all experimental groups by Y-Maze, Golgi stain and path clamp respectively. Results: Memory of the stressed rats was improved by Ω-3 supplementation, while it impaired
memory of control rats compared to vehicle-treated animals (DS of number of entries: Stress+Ω-3:
2.3±0.8; Control+Ω-3: -2.8±0.2; Control+Vehicle: 0.3±0.5 p < 0.0X). Stress-induced dendritic atrophy of CA3c pyramidal neurons was prevented by Ω- 3 supplementation. In addition, restraint stress decreased the probability of GABA releases and increased the Glutamate releases in
hippocampal CA1 region, whereas Ω-3 supplementation prevented these stress-dependent changes in
the synaptic efficacy. Conclusions: Our results demonstrate that Ω-3 supplementation prevented the
memory impairment, the dendritic atrophy of CA3c neurons, and the shift between the excitatory and
inhibitory systems produced by restrain stress. Acknowledgement: Funded by FONDECYT Nº 1100413
and INNOVA-CORFO Nº 06FC01IBC-71 grants (D-S, A), FONDECYT 11090059 grant (Fuenzalida), and
CONICYT fellowship (P-L, MA).
Maternal care represents a major constituent of early life environment and has the potential to program critical neurobehavioral responses to the stress. The aim of the present study was to determine
the effects of naturally occurring variations in maternal investment on behavioral and neurochemical
responses of Sprague-Dawley rats. A group of dams were classified in three maternal groups based
on their licking behavior in high, medium and low maternal care. Afterwards, the male offspring was
tested in a battery of behavioral tests: open field (OFT), elevated plus maze (EPM) and forced swimming test (FST). One week after the last test, monoamine concentrations were determined in three
brain regions: hippocampus, ventral striatum and prefrontal cortex. Our findings suggest a maternal
care effect on several anxiety-related variables: locomotion and grooming in OFT, exploration in EPM
and climbing behavior in FST. Such behavioral differences are related to an increased DOPAC concentration and 5-HT turnover in prefrontal cortex. These evidences suggest that natural variations
on maternal care modified diverse behavioral and neurochemical parameters depending on several
factors as strain, behavioral paradigm and to which elements within the paradigm are being analyzed.
In order to properly interpret the possible effects of maternal care, the relevance of the chosen design
is highlighted.
TU029
ANANDAMIDE IMPROVES COPULATORY BEHAVIOR
IN SEXUALLY SLUGGISH MALE RATS
TU030
MATERNAL LIPOPOLYSACCHARIDE-INDUCED SICKNESS BEHAVIOR
DURING LACTATION MODIFY MATERNAL–PUPS INTERACTION
CANSECO-ALBA A (1), RODRÍGUEZ-MANZO G (1), (1)Pharmacobiology Department, Cinvestav-Sede Sur.
Mexico City. México.
A.F. NASCIMENTO(1), L.F, Felicio(1), M.M, Bernardi(2), G.J, Alves(1), 1 Laboratory of Neurobiology of
Reproductive Behaviors, Department of Pathology, School of Veterinary Medicine, University of São
Paulo-USP, 05508-900, São Paulo, SP, Brazil.. 2 Institute of Health Sciences, Paulista University, São
Paulo, SP, Brazil
Sexual behavior in the male rat is an innate, stereotyped behavior. During a first sexual encounter, the
majority of sexually mature males will display sexual behavior in the presence of receptive females.
Although this first display is often deficient, after sexual experience the copulatory pattern becomes
very stable among individual males. However, in all rat populations there are some males that show
unusually long ejaculation latencies (EL, close to or longer than 30 min) which are not reduced by
repeated sexual experience. These animals are called sexually sluggish (SS) males. Dopaminergic drugs
(L-dopa and apomorphine) significantly increase the percentage of SS rats reaching ejaculation in
less than 30 min implicating dopamine transmission in this condition. Endocannabinoids (eCN) are
retrograde transmitters involved in the regulation of motivation and reward processing by acting at
the mesocorticolimbic dopaminergic system. Exogenous and endogenous CB1 receptor agonists were
reported to inhibit male sexual behavior; however, recent data from our laboratory showed that in male
rats, the eCN anandamide (AEA) rather exerts a biphasic effect on sexual behavior expression. Thus,
while high doses of AEA inhibited copulation, low doses have been found to facilitate sexual behavior
expression in sexually experienced, in sexually satiated and in non-copulating male rats. On these
bases, we hypothesized that AEA might improve copulatory behavior of SS rats. To test this hypothesis,
SS male Wistar rats were i.p. injected with 0.3 mg/kg AEA and subjected to a 60 min sexual behavior
recording with a receptive female. Results showed that AEA significantly reduced the EL of SS male rats
to less than 15 min. The fact that AEA improved sexual behavior expression in SS rats constitutes an
additional evidence of the facilitative effect of low doses this eCN on sexual behavior expression of
animals with different sexual conditions.
Maternal behavior (MB) in mammals has specific characteristics. The time period just after parturition
is particularly sensitive to physiological changes that can modulate the expression of this important
behavior. Lipopolysaccharide (LPS), an endotoxin derived from the wall of gram-negative bacteria,
which mimics bacterial infections, activates the immune system to release proinflammatory cytokines.
Behavioral changes induced by LPS, referred to as sickness behavior (SB) include fever, anhedonia,
decreased exploratory behavior, and poor learning and cognitive functions. In order to investigate,
a possible relationship between MB and SB on maternal-pups interaction, LPS (100μg/Kg, i.p.) was
administered to rats on lactation day (LD) 3. On LD5 the MB and maternal aggressive behavior were
observed. In relation to pups, the body weight and ultrasonic vocalization were assessed. Results
showed that the latency to pups retrieval were decreased; no differences were observed between the
remained parameters of MB. No differences were detected for maternal aggression either. In pups, the
vocalization pattern was modified, i.e., the number of ultrasonic emitted was reduced but the duration
was increased. No other differences were observed between control and LPS postnatal treated pups.
The reduced time to retrieval of pups may be related to maternal fever, signaling that the environment
was cold, and thus increasing maternal motivation. Moreover, since the pattern of pups vocalization
was similar to the one observed for rats showing anxiety, this fact may have a critical role in altering
the maternal behavior. Thus, both maternal fever and changes in pups vocalization may have caused
the decrease in latency for pup retrieval. GRANT: FAPESP n0
TU031
GUSTOFACIAL RESPONSES IN PUP RATS ARE
MODIFIED BY PERINATAL UNDERNUTRITION
TU032
THE FOOD ENTRAINABLE OSCILLATOR SYNCHRONIZES
THE CIRCADIAN RHYTHM OF REM SLEEP
Salas M(1), Torrero C(1), Regalado M(1), Rubio-Navarro L(1). (1)Departamento de Neurobiología del
Desarrollo y Neurofisiología, Instituto de Neurobiología, UNAM, Querétaro, Querétara, México.
Castro J(1), Ocampo-Garcés A(1), (1)Laboratorio de Sueño y Cronobiología, Facultad de Medicina,
Universidad de Chile.
Newborn of altricial species maintains functional gustatory communication with the mother because
the neural substrate and the capacity to discriminate and promote gustofacial reflexes (GFR) are already operating. In neonatal rat the GFR can be modified by the application of sucrose (S) and quinine
(Q) in the mouth, to produce ingestion or rejection responses respectively. The present study analyzed
how perinatalundernutrition can affect the development of GFR responses during early development. In
the undernourished group (UG) pregnant dams received different percentage of a balance diet during
gestation. After birth pups continue the undernutrition by remaining 12h with a foster dam, and 12h
with a nipple-ligated mother. A droplet of sucrose S, sodium chloride (NaCl), Q and water (W) into the
lips at 1 and 3 days of age were placed and mouth opening frequency (MOF) and licking lips frequency
(LLF) were analyzed. Data related to GFR in day 1 at lower concentration (LC) responses show that MOF
increase in UG in NaCl and Q compared with CG. With no significant differences at higher concentrations (HC). At day 3 of age at LC the S and Q in UG subjects showed an increase in MOF compared with
CG. In the case of LLF at day 1 in CG, NaCl at LC increases compared with UG with no differences at
HC in contrast to CG. At day 3 of age at LC of Q the UG showed an increase compared with CG and at
HC a significant reduction in contrast with the CG. These results suggest that perinatal undernutrition
affects the basic components of the gustatory system necessary to produce GFR in the first postnatal
days, interfering with the integration of sensory characteristics of taste for food learning and the
hedonic aspect essential for taste palatability.
Daily food restriction to a few hours during the rest phase can synchronize several circadian rhythms,
from gene transcription to locomotor activity, in a process called Food Enrainment. The most conspicuous consequence of Food Entrainment is the increased locomotor activity that precedes the scheduled
feeding window. This Food Anticipatory Activity (FAA) is considered an output of a Food Entrainable
Oscillator (FEO). Circadian rhythms that synchronize to the FEO become independent from the master
clock, a Light Entrainable Oscillator (LEO) located in the suprachiasmatic nucleus. This phenomenon
can be interpreted as the emergence of an alternative hierarchy within the circadian system. Under
photic entrainment, the sleep-wake cycle is under the control of the suprachiasmatic nucleus. Particularly, Rapid Eye Movement (REM) sleep is considered to be a confident reporter of the phase of the
hypothalamic LEO. Here we explored the chronobiology of REM sleep, analyzing circadian modulation
and REM sleep homeostasis under food restriction. Polisomnograms of rats were recorded under a
12:12=ligh:dark cycle during the entire experiment. The protocol consisted of three baseline days
and 14 days under food restriction (food available from ZT5 to ZT9; lights on at ZT0). After 7 days
of food restriction, FAA was evident in all animals. Wakefulness and NREM sleep exhibited no phase
preference. REM sleep was the only sleep state that maintained a circadian rhythm, with a nocturnal
acrophase. A selective suppression of REM sleep was observed two hours preceeding food delivery, at
the same time of FAA expression, without REM sleep homeostatic rebound. We conclude that there are
profound modifications in REM sleep chronobiology under Food Entrainment, supporting that the FEO
may compete with LEO in the circadian modulation of high rank integrative systems.
TU033
ATONIA DURING REM SLEEP
Morales Francisco R, Silveira V, Damián A, Higgie R. Pose I., School of Medicine (UDELAR) MontevideoUruguay.
Atonia during REM sleep The possible additional role of the Cystic Fibrosis Transmembrane Regulator to motoneuron inhibition produced by glycine neurotransmission. Francisco R. Morales, Valentina
Silveira, Andrés Damián, Ramón Higgie and Inés Pose. Facultad de Medicina, UDELAR, MontevideoUruguay. We study the choride channel of the Cystic Fibrosis Transmembrane Regulator (CFTR) in the
inhibition of somatic motoneurons during REM sleep. Inhibition is responsible for the atonia and is
mediated by glycine and, to a lesser extent, by GABA. Both neurotransmitters decrease the excitability
of motoneurons. “Disfacilitation”, which is produced by cessation of discharge of cathecolaminergic
and serotoninergic cells decreases motoneurons’ excitability. When we first studied the supression of
motoneurons many things were unknown. For example the existence of CFTR was ignored. We study the
actions of its antagonists, (i.e. glibenclamide) during the administration of glycine. First we examine
CFTR in motoneurons by immuno histochemistry. Motoneurons’ membrane shows a reaction to this
antibody, but not to its control. Then we study electrophysiologically in whole cells the effects of glycine
and glibenclamide. Glycine application produced the phenomena observed during REM, essentially an
increase in membrane conductance. Glibenclamide produced an increase in input resistance and a
shift in chloride ions equilibrium potential. Glycinergic effects were smaller in motoneurons treated
with glibenclamide. The fact that blocking of the CFTR chloride channel influences glycinergic actions
suggests that this channel plays a role in the inhibition that occurs during REM. The lower excitability
of motoneurons by multiple synergic mechanims indicates the importance of silencing these cells
during REM when the brain is alert. These results should be obtained in adult animals, not in slices.
How does CFTR became activated during REM? It is known that it is sensible to Nitric Oxide and we have
demonstrated nitrergic cells active during REM. CFTR could be active in behaviors different than REM,
everytime glycine acts on motoneurons.
TU034
PRENATAL NICOTINE EXPOSURE DIMINISHES THE
SEROTONINERGIC PROJECTION FROM RAPHE TO PREBÖTZINGER
AFFECTING MODULATION OF FICTIVE RESPIRATORY FIRING RATE
Eduardo Bravo(1), Veronica Cerpa(2), Isabel Llona(1), George Richerson(2), Jaime Eugenin(1), (1)
Laboratorio de Sistemas Neurales, Universidad de Santiago de Chile, Chile; (2)Neurology Departament,
University of Iowa, Iowa City, IA.
Nicotine, a main neuroteratogen and addictive component found in tobacco, would be responsible of
the epidemiological association between maternal cigarette smoking during pregnancy and Sudden
Infant Death Syndrome (SIDS). In previous work we have shown that mouse neonates prenatally exposed to nicotine had reduced ventilatory responses to hypercarbia and a depressed fictive respiratory
response to central chemoreceptors stimulation. Since serotonin receptor binding abnormalities have
been reported in SIDS, a possible target for nicotine actions is the chemosensitive medullary raphé
nuclei. In this work we evaluated the effect of prenatal nicotine exposure upon the raphé serotoninergic
neurons from raphe nucleus using the Pet-1 YFP transgenic mice. An osmotic minipump delivering
nicotine 60 mg Kg-1 was implanted s.c. into pregnant CF1 mice since 5th day of pregnancy until postnatal day 7th. In controls, the projections from raphé to preBötzinger (preBötC) are increased from P0
(0,5 ± 0.04 ROD) to P7 (1,36 ± 0.1 ROD). Prenatal nicotine exposure impairs the natural increase of
serotoninergic projections and diminishes the projections of serotoninergic neurons in P1, P3, P5, and
P7, by 52 ± 2 %, 48 ± 5 %, 80 ± 5 %, 81 ± 3 % respectively. Besides, the increase in respiratory frequency in response to exogenous 5-HT, evaluated in en bloc and slice brainstem preparations,
was higher than that in controls (600 % vs. 250%). The perfusion of 5-HT directly in preBötC increase
the firing rate in brainstem slice preparation in 58%, but perfusion of 5-HT directly in raphe nuclei do
not affect the firing rate on prenatal nicotine exposure mice. This increase is probably caused by over
expression of postsynaptic 5-HT1A receptors in pre-BötC nucleus at least in P1, P5 and P7. Our results
suggest that prenatal nicotine exposure affect the serotoninergic command of fictive respiration by a)
decreasing connectivity between raphé nuclei and pre-BötC nucleus and b) over expression of 5-HT1A
receptor in pre-BötC.
TU035
COULD THE CIRCADIAN RHYTHM
DISRUPTION CAUSE BIPOLAR DISEASE?
TU036
FEEDING TIME INDUCES DESINCRONIZATION BETWEEN CLOCK
AND METABOLIC GENES IN LIVER AND PREDISPOSE FOR OBESITY
Bruna Del Vechio Koike, João Miguel Ribeiro, Bruno S.B. Gonçalves, John Fontenele Araujo Laboratory
of Neurobiology and Circadian Rhythmicity, Department of Physiology, Universidade Federal do Rio
Grande do Norte, RN – Brazil.
Roberto Salgado-Delgado(1), Nadia Saderi(1,2), Elizabeth Sabath(2), Carolina Escobar(3) and Ruud
M.Buijs(2), 1. Facultad de Ciencias, Universidad Autónoma de San Luis Potosí, SLP, México. 2. Instituto
de Investigaciones Biomédicas, 3. Facultad de Medicina, Depto. de Anatomía, 2 y 3 Universidad Nacional Autónoma de México.
Alterations of circadian timing system have been associated with affective mood disorders such as
bipolar disorder. Our aim was to verify if rats with circadian rhythms disruption exhibit mania-like and
depression-like behaviour as well as bipolar patients. With this purpose we subjected Wistar rats to
forced desynchronization (FD) protocol (symmetric 22h light-dark cycle). Under FD protocol, there are
two rhythmic components of locomotor activity with different period lengths: one synchronized by the
LD cycle (T22h) and other as free running-like (T>24h). The FD generates different phases: aligned
phase when the subjective night (activity) is overlapped with objective night (T22-dark) and misaligned
phase when the objective night is overlapped with subjective day. Behavioral tests were applied to
assess affective state. Both desynchronized animals show atypical behavior such as diminished vertical exploration and risk assessment and increased grooming. Misaligned animals showed a great
anxiety in open field and elevated plus maze. Aligned animals showed less depressive-like behavior
in forced swimming test. Chronic lithium treatment abolishes the desynchronization and they present
only one activity rhythmic component longer than the free run period (T>24). The aligned animals
have decreased time awake compared to controls (T24) and hyperactivity in the darkness compared to
controls. The increase of SWS may be a homeostatic response to this raise in activity. The misaligned
animals have double awake time, but the locomotor activity increases only 10%, which might mean
hypoactivity, or suggest a depressive state. We observe a reverse pattern in misaligned sleep – SWS is
increased in the dark phase of misaligned animals and decreased in the light, compared with the other
groups. Altogether, our results suggest that aligned rats present a manic-like behaviour and misaligned
rats present depression-like behaviour. Furthermore, our data proposes an apparent validation of FD as
animal model to bipolar disorder. More studies are required to increase the knowledge of this model.
Studies of body weight regulation have focused almost entirely on caloric intake and energy expenditure. However, a number of recent studies in animals linking energy regulation and the circadian clock
at the molecular, physiological, and behavioral levels raise the possibility that the timing of food intake
itself may play a significant role in weight gain. The present study focused on the role of the circadian
phase of food consumption and its effect on the expression of clock and metabolic genes as well as the
consequences for body weight gain. In order to investigate the effect of feeding time, Wistar rats were
exposed to restricted food access for only 12-h in the light phase (FL) or for 12-h in the dark phase
(FD) for 3 weeks. The behavioral rhythms, core temperature, body weight gain and in the liver clock and
metabolic genes were analyzed. We show that when the nocturnal rat is fed only during the 12-h light
phase, the animals gain significantly more weight than rats fed only during the 12-h dark phase. In
the FL rats, clock genes such as BMAL1, PER1 and CLOCK completely invert their rhythm as compared
to FD rats and controls in ad libitum conditions. Their rhythms become dissociated from Per2 and the
metabolic genes Nampt, PGC1 and the PPARs that lose their rhythm and appear completely flattened.
No daily rhythm of SIRT was observed and the mean expression was significantly lower as was also
observed for PGC1 while the mean values of NAD+ were significantly higher. In the FD rats no any
change in clock and metabolic genes, was observed as compared to the control ad libitum animals.
These results demonstrate that feeding time desynchronizes the rhythm within the liver which might
be the basis for the association of metabolic disorders such as diabetes and obesity with circadian
desynchrony. This study was supported by the Fondo de Apoyo a la Investigación (FAI) de la UASLP,
PROMEP UASLP-PTC-421 and CONACyT 178810 and 82462, PAPIIT- UNAM IN209711
TU037
MORPHOLOGICAL CHARACTERIZATION OF INTRINSIC CARDIAC
NERVE SYSTEM IN RIGHT VENTRICULAR HYPERTROPHY INDUCED
BY MONOCROTALINE IN SPRAGUE DAWLEY RATS
TRUJILLO-CONDES V.E.(1),FLORES G(2), GOMEZ-VILLALOBOS M.J.(1), (1) Benemérita Universidad Autónoma de Puebla. Laboratorio de Investigación Cardiovascular. (2) Benemérita Universidad Autónoma de
Puebla. Laboratorio de Neuropsiquiatría.
The intrinsic cardiac nerve system (ICNS) is formed by intracardiac ganglia interconnected by a network
of nerve fibers distributed in the heart. It is unknown whether there are morphological changes in the
ICNS associated with right ventricular hypertrophy (RVH). Through Golgi-Cox method, acethylcholinesterase and histofluoresence stains, we characterized these changes in an experimental model of RVH.
METHOD. In male Sprague Dawley rats, with 150grs weight, pulmonary hypertension with secondary
RVH, was induced with monocrotaline (MCT, 60mg/kg, ip, n = 24; and 0.9% SSI 0.3ml ip, n = 24, as
control group). In one group right ventricular pressure and the RV thickness were recorded. In another
group, hearts were incubated for 1 month in Golgi-Cox stain, wall tissues were cut by vibratome (200
microns), processing and analyzed in light microscopy with Leica LAS-software. In relation to the cardiac ganglia, area (mm2) and density (ganglia number/mm2) were determined. Finally histochemistry
was performed on cryostat tissue sections (20 microns) with acetylcholinesterase and glyoxylic acid
stains. RESULTS In the MCT group RV systolic pressure (mmHg) was 62.68 ± 3.02 vs 26.21 ± 0.67
of control group (P <0.0001), RV wall thickness (mm) was 2,100 ± 0,189 ± 0,108 and 1,071
respectively (P <0.0001). Number and size of intracardiac ganglia were found reduced in the right
ventricle of rats with monocrotaline, in relation to the control group. Histochemestry studies shown
clear impregnation for acetylcholinesterase stain and a reduced histofluoresence with glyoxylic acid
in the MCT group compared with the control group. CONCLUSION. The ICNS in RVH has changes related
with a significant decrease in size and density of ganglia in the right ventricle, and are associated with
a reduced histofluorescence for amines, suggesting a myocardial sympathetic denervation.
TU038
FRUCTOSE INTAKE AND CORONARY RISK INCREASE
ZEPEDA I(1), AVENDAÑO D(1), and CORTES C(1), (1)Dpto. de Fisiología, Facultad de Medicina, BUAP,
Puebla, Puebla, México.
The changes in diet, along with genetic predisposition play an important role in the development of
metabolic disorders such as overweight, obesity and dyslipidemia. Particularly, the excessive consumption of high-fructose industrial products is related to lipid abnormalities in young adult population. The aim of our study was to determine the coronary risk in young people with high fructose intake
based on the measurement of plasma cholesterol, triglycerides, HDL, LDL and glucose. We performed
a descriptive study of a sample of 50 young people aged between 18-23. We included men and women
with unknown pathological conditions. We determined anthropometric and biochemical parameters.
The results in the control group (n=25) were: glucose: 80.24±5.32; Cholesterol: 158.24±12.16
mg/dl; Triglycerides: 137.64±6.33 mg/dl; Ch/HDL: 41.08±4.06 mg/dl; Ch/LDL: 89.632±9.67 mg/
dl; Coronary heart risk: 3.82±0.34 mg/dl. For the group at risk (n=25) glucose: 94.92±5.12; Cholesterol: 213.56±14.37 mg/dl; Triglycerides: 163.76±12.99 mg/dl; Ch/HDL: 35.96±3.23 mg/dl;
Ch/LDL: 144.848±12.51 mg/dl; Coronary heart risk: 6.0±0.44 mg/dl. From the obtained results, we
conclude that subjects with a high-fructose diet have a significantly higher coronary risk (p <0.001)
compared with the control group. In this work, we also noted that a sedentary lifestyle and related to
a BMI> 26.23 predispose the young adults in our study to the early development of cardiovascular
and metabolic diseases. The detection of risk factors, a change in lifestyle and a better diet should be
a strategy for the prevention of chronic health disorders.
TU039
ELECTROENCEPHALOGRAPHIC ALTERATIONS IN
CHILDREN WITH SEVERE CONGENITAL HEART DEFECTS
TU040
CONOCAP-A MODULATES THE ACTIVITY OF
RYANODINE RECEPTORS IN RAT CARDIOMYOCYTES
Otero GA(1), Mendieta GG (2), Pliego FB(1). (1)Facultad de Medicina, Univ Aut. del Estado de México,
México and (2) Hosp. para el Niño, IMIEM, Toluca, México
Luis A. Ciriaco-Rico(1), J. Antonio G. Arias-Montaño(2), Carolina Möller(3), and Angélica Rueda(1).
Departments of (1)Biochemistry and (2)Physiology, Biophysics and Neurosciences, Cinvestav-IPN.
México City, México. (3)Department of Chemistry and Biochemistry, Florida International University,
Miami FL, USA.
Introduction and objectives. Congenital cardiopathies (CC) are among the most common birth defects
and delays of neurodevelopment are among the most frequently observed diseases in school-age children presenting CC. The main objective of this study was to determine the possible impact of severe CC
on central nervous system (CNS) development as determined after EEG recording. Methods. Thirty children of ages between 15 days and 12 years presenting severe CC with haemodynamic consequences
and/or chronic hypoxia were studied (21 acyanogenic and 19 cyanogenic). Conventional EEGs were
performed on all cases. Results. In the whole sample we found abnormal EEGs in 43.3% of cases, these
mostly showing immature basal activity (slow for the age), and focal and multifocal paroxysmal activity
characterised by sharp waves and spikes/slow waves complexes. Abnormal EEG activity was determined in 42.8% of non-cyanogenic CC and 44.4% of cyanogenic CC. Conclusions. A high percentage of
children carrying severe CC showed epileptic-like EEG activity. It is possible that in afflicted children as
a result from haemodynamic disturbances present from foetal stages onwards, these alterations would
favour the development of ectopic growth of grey matter leading to epileptic-like activity.
Marine cone snails of the genus Conus are known to utilize venom to capture preys. The venom comprises small peptides (conopeptides) that specifically target ion channels. Recently, a Crustacean
Cardioactive-like peptide (CCAP-like) known as ConoCAP-a, (for cone snail CardioActive Peptide)
was isolated from Conus villepinii and its precursor was cloned; however, the molecular targets of
this conopeptide are not yet determined. Since ConoCAP-a permeates plasma membrane, decreases
the amplitude of intracellular Ca2+ ([Ca2+]i) transients and impairs contractile activity of Fluo3-loaded rat cardiomyocytes, our aim was to evaluate the cardiac ryanodine receptor (RyR2) and/or
the Sarcoplasmic Reticulum (SR) Ca2+ pump (SERCA2a) as possible molecular targets of ConoCAPa.
In-cell activity of RyR2 was monitored in Fluo-3-loaded rat cardiomyocytes by confocal microscopy
and ConoCAP-a effect was assessed by monitoring changes of Ca2+ spark properties in the presence
of the conopeptide. In addition, modifications of RyR in vitro activity by ConoCAP-a were monitored
with [3H]-ryanodine binding assay on cardiac SR vesicles, while modifications of SERCA2a activity
were measured by Ca2+ uptake with Fura-4F. Superfusion of ConoCAP-a (100 nM) onto Fluo-3-loaded
cardiomyocytes showed a very fast effect on RyR2 activity. After 5 min of ConoCAP-a application,
Ca2+ spark frequency and amplitude were reduced by 69 and 17%, respectively; while Ca2+ spark
duration and time-to-decay increased by 17 and 23%, respectively, without modifying Ca2+ spark
size. [3H]-ryanodine binding assays in the presence of ConoCAP-a (1 nM to 1 μM) showed increased
binding at pCa of 7 but not at pCa of 4. However, Ca2+ reuptake velocity in SR vesicles was not modified by ConoCAP-a. Our data suggest that ConoCAP-a alters Ca2+ handing in cardiomyocytes through
modifications of RyR2 activity during diastole and that SERCA2a pump is not involved. Funding: ICyTDF
Project 331/2010.
TU041
VASORELAXANT EFFECTS OF CANNABINOIDS THROUGH
THE ACTIVATION OF GPR55 RECEPTORS IN RAT AORTA
Osuna-Calleros, Z (1), Guzmán-Guadarrama, Y (1), Sánchez-Pastor, E (1), Andrade, MF (2) y Elizalde, A
(1), (1)Centro Universitario de Investigaciones Biomédicas. Colima, Colima, México. (2)Instituto Tecnológico de Colima. Villa de Álvarez, Colima, México.
TU042
EFFECTS OF H1 HISTAMINE RECEPTOR ANTAGONIST
ON SPATIAL LEARNING AND ELECTROPHYSIOLOGICAL
PROPERTIES OF CA1 NEURONS
Cristián Sánchez1 and José L. Valdés1, 1. Programa Disciplinario de fisiología y biofísica. Instituto de
Ciencias Biomédicas ICBM. Universidad de Chile.
Both the cannabinoids, derived from the plant “Cannabis sativa”, marijuana (phytocannabinoids),
synthetic cannabinoids and endocannabinoids (endogenous cannabinoids) act on the cardiovascular,
immune and central nervous systems. In the cardiovascular system particularly, there are reports that
chronic use of marijuana produces hypotension in humans and that they lower blood pressure due to
the vessel dilation and heart rate in experimental animals. These effects occur through the activation
of receptors to cannabinoid (CB1 and CB2), direct effects on ion channels and effects through other receptors as the TRPV1 (vanilloid receptor). In addition, there are data that reveal the existence of a third
type of cannabinoid receptor coupled to G proteins, GPR55, which in humans is encoded by the GPR55
gene. To date, although some of the mechanisms by which cannabinoids modulate the arterial tension,
there is still a lot of work to do to fully understand all the ways involved. In this respect, the goal of
this work was to determine the role of GPR55 in the modulation of the vascular tone by cannabinoids
in the rat aorta, using for this the agonist of these receptors, the AM251; as well as to determine by
confocal microscopy the presence and location of the receptors GPR55 in the rat aorta. The experiments were done with Wistar rat`s aorta rings (with and without endothelium). Our results show that
the GPR55 receptors are located both in the layer of smooth muscle as in the endothelial layer of the
aorta. Moreover, the activation of GPR55 receptors induces vasorelaxation in arteries with endothelium
but not in aorta without endothelium. Thus, we can conclude that the activation of endothelial GPR55
receptors leads to a relaxation of the rat aorta.
The role of histamine in learning and memory is still highly controversial. The histaminergic neurons
are characterized by high firing rate during wake and low activity during sleep. We hypothesize that
high levels of histamine in the hippocampus during wake, could be necessary for learning. In the present study we evaluated the behavioral and electrophysiological effects of blocking the histaminergic
neurotransmission in CA3, during a spatial learning task. In brief the task consisted of an open field
arena able with 21 equidistant wells, where only one of them was baited with food. The rat was challenged to find the reward during 15 consecutive trials. The number of successfully trials, the length
of the path walked by the animal and the number of approaches to non baited wells was considered
as learning index and all of them were negatively affected by H1 antagonist injection on CA3. Electrophysiological recording from CA1 were conducted during the exploration of a circular maze to evaluate
changes in the place fields properties, such as stability and changes in firing rate, when the H1 antagonist or vehicle was injected in CA3. We observed a significant reduction in the place fields stability
and a not significant changes in firing rate. These results suggest thatproperly levels of histamine in
the hippocampus during wake are necessary for spatial memory acquisition process and to maintain
the place fields properties when the animals navigated.
TU043
LONG-TERM SYNAPTIC PLASTICITY IN THE
STRIATOPALLIDAL SYNAPSE
TU044
FUNCTIONAL SIMULTANEOUS IMAGING AND
ELECTROPHYSIOLOGY IN NEURAL NETWORKS (FSIENN)
HERNÁNDEZ-MARTÍNEZ R, ARIAS-GARCÍA MA, PÉREZ-ORTEGA JE, GALARRAGA, E AND BARGAS J.
Instituto de Fisiología Celular, UNAM, Mexico.
Pérez-Ortega JE, Duhne M, Arias-García MA, Galarraga E, and Bargas J, División de Neurociencias,
Instituto de Fisiología Celular, Universidad Nacional Autónoma de México (UNAM). México. D.F., México
Long-term synaptic plasticity has been proposed as a mechanism for information storage and has
been described at both excitatory and inhibitory synapses; currently researching this is phenomena in
the basal ganglia, because they are involved in procedural memory; however the cortico-striatal has
been studied extensively but the other synapses in the basal ganglia are largely unknown. We study the
striatopallidal synapse the test is performing whole cell patch clamp recordings from GP neurons in
rat brain slices. We were found that the stiatopallidal synapse display long-term depression and it is
necessary of endocannabinoids synthesis for the initiation of this phenomenon.
A big challenge in current neuroscience is to unravel the operation modes and mechanisms that underlie the activity of neuronal microcircuits or cell assemblies. There are several techniques to record the
activity of these microcircuits. One of them is epifluorescence microscopy that allows the recording of
image series of neuronal electrical activity indirectly, through the calcium imaging of dozens of neurons
simultaneously. For instance, experiments in the neoestriatal microcircuit in vitro exhibit spontaneous
synchronization in the activity of neuronal groups, alternation of this activity among them, and recurrence, where the flow of activity shows a cyclical behavior. To elucidate the mechanisms underlying
such dynamics is a challenge given the different neuronal elements involved and their interactions.
We propose a methodology to approach the understanding of these microcircuits: “Functional Simultaneous Imaging and Electrophysiology in Neural Networks” (fSIENN). This methodology requires the
development and implementation of virtual instrumentation to analyze microcircuit dynamics during
the experiment while targeting specific neurons to record and manipulate by using electrophysiological
and optogenetic techniques. In the present work will show evidence that these recurrent microcircuits
exhibit the properties of free-scale networks
TU045
THE ROLE OF PROTEIN KINASE M ZETA IN THE PERSISTENCE
OF IN VIVO HIPPOCAMPAL MOSSY FIBERS SYNAPTIC PLASTICITY
TU046
INTRINSIC PROPERTIES OF NEOSTRIATAL NEURONS
SHAPE CORTICAL AND THALAMIC SYNAPTIC INTEGRATION
Cáceres A(1), and Escobar M.L(1), (1)División de Investigación y Estudios de Posgrado, Facultad de
Psicología, UNAM, México D.F., México.
Arias-García MA(1), Bargas J(1) and Galarraga E(1), (1)División de Neurociencias,Instituto de Fisiología
Celular,UNAM,México D.F. México.
Persistence is a characteristic attribute of long-term memories. However, little is known about the
molecular mechanisms that mediate this process. Recent experimental evidence shows that the persistence of some forms of long-term memory and long-term potentiation (LTP) requires the persistent action of the atypical protein kinase C isoform, protein kinase M zeta (PKM_). In these sense
it has been reported that the administration of the PKM_ selective inhibitor ZIP (_-pseudosubstrate
inhibitor protein) reverses the late-phase of hippocampal LTP on the perforant and Schaffer collaterals
pathways, but this effect has not been explored on the atypical hippocampal mossy fibers (MF)-CA3
pathway that exhibit an NMDA-receptor independent form of LTP. In a similar manner, the relationship
between PKM_ activity and morphological synaptic modifications that have been proposed to underlie
memory persistence has not been clearly observed in the adult brain. Our previous studies show that
in vivo delivery of highfrequency stimulation (HFS) sufficient to induce LTP at the MF pathway elicits
MF structural reorganization at the striatum oriens of CA3 area seven days after HFS. In the present
study we administrated acute microinfusions of ZIP in the hippocampal CA3 area during the late-phase
of in vivo MF-CA3 LTP with the purpose to evaluate the participation of PKM_ on the persistence of
this atypical form of LTP as well as on its concomitant structural reorganization. Our results show that
inhibition of PKM_ activity neither reverses MF potentiation nor modifies its concomitant structural reorganization, even when it is able to reverse the perforant pathway LTP in our own preparations. These
findings suggest that synaptic plasticity persistence on these atypical synapses does not requires of
PKM_ activity in the same degree as other expressions of synaptic plasticity.
Major glutamatergic afferents to the striatum come from the cerebral cortex and thalamus making
monosynaptic contacts with striatal neurons. Here, we compared corticostriatal and thalamostriatral
suprathreshold synaptic responses recorded in direct pathway spiny projection neurons (dSPN), indirect pathway spiny projection neurons (iSPN), fast spiking interneurons (FS), cholinergic interneurons
(TAN) and interneurons exhibiting low threshold spikes (LTS). Whole cell recordings in brain slices
where thalamostriatal and corticostriatal pathways were preserved were used. Evoked suprathreshold
synaptic responses after single or four field stimuli in the cortex or in the intralaminar nuclei of
the thalamus were compared with discharges evoked with direct somatic injections. It is shown here
that: 1) Corticostriatal responses in each class of striatal neuron are remarkably different so as to
shape an electrical profile that distinguish among them even if the inputs are the same, suggesting
that intrinsic properties shape synaptic responses, 2) Corticostriatal responses in d and iSPNs do
not change when stimulating different cortices (sensorimotor, temporal, frontal). 3) Suprathreshold
corticostriatal and talamostriatal responses were similar in different classes of striatal neurons.Both
contain intricate mixtures of monosynaptic, polysynaptic and intrinsic ionic currents. Thus, synaptic
integration depends on the postsynaptic neuron and their differences are largely independent of the
stimulated afferent (cortices or thalamus), reinforcing the view that each neuron class has particular
ways to process the same inputs.
TU047
DIFFERENT IM REGULATION OF SYNAPTIC EXCITABILITY IN STRIATAL
PROJECTION NEURONS OF THE DIRECT AND INDIRECT PATHWAYS
TU048
WHICH GABAA RECEPTOR SUBUNITS ARE NECESSARY
FOR TONIC INHIBITION IN MICE CENTRAL AMYGDALA?
Perez-Ramirez MB(1), Bargas J(1) and Galarraga E(1), (1)División de Neurociencias,Instituto de Fisiología Celular,UNAM,México D.F., México.
ROMO-PARRA H; KANISHKOVA T and PAPE HC, Institute of Physiology I, Westfälische Wilhelms-University,
Münster.
The voltage-activated K+ channels KCNQ which generate the M-current (IM), play a key role in the control of direct and indirect striatal spiny projection neurons (d and iSPNs). The source of acetylcholine
(ACh) that regulates these channels is the tonically firing cholinergic interneuron of the neostriatum
(TAN) via the activation of muscarinic M1 type receptors present in both d and iSPNs. Here, we show
the contribution of IM current in the synaptic integration of d and iSPNs using whole cell patch clamp
recordings in an in vitro corticostriatal slice preparation from D1 and D2 transgenic BAC mice. In the
controls, the corticostriatal synaptic responses in dSPNs is more prolonged and evoke more action
potentials than that in iSPNs, while iSPNs exhibit intrinsic autoregenerative calcium responses (FloresBarrera et al, 2010). We asked what happens with these suprathreshold corticostriatal responses after
the blockade of KCNQ channels with 20μM XE991. After KCNQ channels blockade the corticostriatal
response of dSPNs increased 20% the area under their response, elicited more action potentials and
exhibited spontaneous membrane potential oscillations (up and down states). When KCNQ channels
were blocked in iSPNs, their corticostriatal response increased 25% (area under) and autoregenerative
calcium potentials were facilitated. These potentials are dihydropyridine sensitive. Apparently, the contribution of the IM at subthreshold synaptic responses is more important in iSPNs. Surprisingly, despite
enhanced synaptically driven (dendritic) excitability in SPNs, evoked discharge via somatic current
injection was virtually unaffected during KCNQ channels blockade, suggesting that these channels are
mainly compartmentalized in the dendrites, were synaptic inputs arrive.
Aim: GABAA receptors can mediate both phasic (synaptic) and tonic (extrasynaptic) forms of inhibition.
It has been proposed that tonic inhibition plays a critical role in controlling neuronal and network
excitability. Modulation of tonic receptors represents a promising strategy for the development of new
anticonvulsant, anxiolytic, and anaesthetic drugs. Despite extensive research on the role of GABAA extrasynaptic receptors (GABA-ER), no evidence of a functional expression in the Central Amygdala (CeA)
was reported so far. Here we investigate i) the expression of GABA-ER in situ and ii) the functionality
of GABA-ER in the CeA by the application of GABAA agonists and antagonists in vitro. Methods: PCR
and immunostaining against _alpha5 and delta subunits were developed. Current- and voltage-clamp
(whole-cell) recordings in CeA neurons from adult BL6 mice were carried out. Gabazine (GBZ), Picrotoxin (PTX), GABAA_alpha5 subunit antagonist (L-655-708), delta agonist (THIP) and GABA transporter 1
(GAT-1) antagonist (NCC-711) effects on firing frequency and on holding voltage and current shift were
studied. Results: i) In situ, the presence of both GABAA subunits (alpha5 and delta __was confirmed
in CeA by PCR and immunoassays. ii) In vitro, PTX abolished the mIPSCs and evoked a large outward
shift in the holding current. In contrast, the high-affinity antagonist GBZ (10 and 50 μM) produced no
significant or small positive shift in the holding current, respectively. Nonetheless, GBZ (at both concentrations) completely abolished the mIPSCs. In current clamp mode it produced a depolarization with
an increase in excitability, seen by the increase in firing frequency. GBZ at low dose (0.5 μM) produced
small negative shift that was reversed by the further application of PTX. The GABAA _alpha5 subunit
antagonist (L-655-708 5-10μM) prevented the outward shift produced by PTX. The delta agonist (THIP,
1-10μM) induced a large inward shift on the holding current that was blocked by the posterior application of PTX (100μM). Finally, the GAT-1 transporter blocker (NNC-711; 5μM) induced a negative shift in
holding current and it did not prevent PTX effect. Conclusion: The present data demonstrate that GABAA
receptors subunits alpha5 and delta _mediate tonic inhibitory currents in mice central amygdala
neurons and they might represent a key role in the regulation of fear expression.
TU049
INDIVIDUAL DIFFERENCES AS AN APPROACH
FOR THE STUDY OF STRESS RESPONSE AND MOOD DISORDERS
SEQUEIRA A(1,2), MASÍS M(2), MORA A(2), and FORNAGUERA J(2,3), (1)Insituto de Investigaciones en
Salud, Universidad de Costa Rica; (2)Programa de Investigación en Neurociencias, Universidad de
Costa Rica, and (3)Escuela de Medicina, Universidad de Costa Rica.
The study of individual differences in animal models of human psychopathology has become an important area of research. By means of the classification of individuals according to the natural variation
of specific behaviors in a given population we are capable to study the mechanisms associated with
those behaviors. Moreover, when such behaviors are related to stress response and to disorders as
depression and anxiety, it is possible to identify and to understand key elements in the development
of such psychopathologies. Our group has developed two lines of research in this field: the study on
rats of natural variations in behaviors related to maternal care and in the immobility behavior in
the forced swimming test (FST). Regarding maternal care, our results suggest that differences in the
licking/grooming behavior by the mothers throughout the first six days of life modulate changes in
serotonergic neurotransmission and in the expression profile of the TrkB receptor in the nucleus accumbens (NAc), which might be related to the development of depression-like behaviors and high levels
of anxiety. On the other hand, differences in the time of immobility in the FST seem to be associated
with the differential accumbal expression of the receptor R1 of corticotropin-releasing factor (CRFR1),
suggesting that differences in the expression of this receptor might act as a susceptibility factor in the
development of depression-like behaviors. In general, our results offer convincing evidence to justify
the use of individual differences as an adequate approach in the study of the mechanisms underlying
psychopathological disorders and also point to several factors (e.g. TrkB and CRFR1 expression in the
NAc) that might play an important role in the function/dysfunction related to mood disorders.
TU050
THE LOGICAL EMPIRICISM AND THE CONSTRUCTION OF A
BEHAVIOR SCIENCE: DIFFICULTIES AND LIMITS TO THE
STUDIES OF MENTAL FUNCTIONS
SOARES E (1), (1) Sao Paulo State Univ, Marília, Brazil
The comprehension of the so called mental functions, defined as internal states have been one of the
greatest goals of Psychology and Philosophy and, nowadays, of the Neural Science. This essay intends
to, from an historical and epistemological approach, present and to discuss some theoretical and
methodological difficulties and limitations which come from the influence of some epistemological and
ontological positions about internal states and that influenced the construction of a behavior science.
Among those positions it will be highlightened the conceptions of the positivism, logical empiricism,
which is characteristic from the Vienna Circle and Ludwig Wittgenstein’s thought in relation to the
private language.
TU051
CLASSIFYING SCHIZOPHRENIC REPORTS
USING SPEECH GRAPHS MEASURES
TU052
HEMISPHERIC ASYMMETRY PROCESSING
SCALING HE SIZE OF CIRCLES
MOTA N(1,2), LEMOS N(1), RIBEIRO S(1) and COPELLI M(3) (1), (1) Brain Institute, UFRN, Natal, Brazil;
(2) Hospital Universitário Onofre Lopes, UFRN, Natal, Brazil; (3) Department of Physics, UFPE, Recife,
Brazil.
Costa MF(1,2), Lopes MCB(2), Martins CMG(2) and Nagy BV(1,2), (1)Dept. of Experimental Psychology,
Univ. of São Paulo, São Paulo, Brazil; (2)Nucleus for Neuroscience and Behavior and Nucleus for Applied
Neuroscience, Univ. of São Paulo, São Paulo, Brazil.
Schizophrenia is defined as psychotic syndrome and remains only clinically classified by subjective
and interpretative methods. Speech analyses based on graph theory distinguished schizophrenics from
maniacs, with good sensibility and specificity. The aim of the present study is to improve speech
graph analysis applied to psychotic reports. Oral interviews were recorded with 24 adult subjects, (8
schizophrenic, 8 manic and 8 controls). We applied SCID, PANSS and BPRS. Then, subjects were asked
to report on a recent dream. The reports were parsed into backbone speech elements. Each report was
represented by a directed multigraph in which each node corresponded to an element and the temporal
link between two elements was represented by an edge. We calculated nineteen measures divided
into general, connectivity-related, recurrence-related, hub-related and global-related categories. We
used the Bonferroni-corrected Kruskal-Wallis and Wilcoxon Ranksum tests to compare groups. Manics
scored significantly higher than schizophrenics in fifteen attributes. Psychopathological symptoms
such as logorrhea and poor speech were grasped by the analysis even when verbosity differences were
discounted. Schizophrenics were distinguish from controls using connectivity, recurrence, and hub
measures, remained different after normalizing for recurrence (L3, p = 0.0022) measures. Schizophrenics also showed denser graphs than controls (p=0.0051). Binary classifiers sorted schizophrenics from controls with up to 81% of sensitivity and specificity, with AUC of 0.91. Overall, the results
point to automated psychiatric diagnosis based not on what is said, but on how it is said.
Asymmetrical specialization of cognitive processes across the cerebral hemispheres is a hallmark of
healthy brain development and an important evolutionary trait underlying higher cognitio n in humans.
However, recent research has been shown assymetrical responses in electrophysiological recording of
primary visual areas. Our purpose is to quantify possible cortical assymetry in circle size judgment.
We used the magnitude estimation to obtain the apparent size of circles. Twenty-two subjects with
normal or corrected-to-normal visual acuity (mean age= 22yrs; SD= 1.4) were tested. The procedure
consisted of two gray circles luminance of 40 cd/m2, 10 degrees apart from each other. On one side
was the reference circle (visual angle of 1.1 cpd) in which was assigned an arbitrary value of 50. The
subjects’ task was to judge the size of the circles appearing in the right/left side of the monitor screen
assigning the number proportional to the changed size, relative to the reference circle. Seven different
sizes (0.6, 0.8, 1.0, 1.1, 1.3, 1.4, 1.5 cpd at 50 cm) between smaller and larger than the reference
circle were presented. Our results have shown a high correlation (R= 0.9987) between the logs of the
stimuli and the subject response for each hemisferical condition. The exponents obtained were 0.71
for the left visual field/right-hemisphere and 0.41 for the right visual field/left hemisphere, which
indicates a superiority of the right hemisphere to judging theapparent size of the circle. In conclusion,
we found a no-linear judgment in the apparent size of gray circles and a right-hemisphere superiority
in perform that task in a visually normal population of young adults.
TU053
INFLUENCE OF SUBITIZING, COUNTING AND NUMERICAL MAGNITUDE
COMPARISON IN LATER STAGES OF MATHEMATICAL KNOWLEDGE.
EVIDENCE FROM A LONGITUDINAL STUDY
González-Alemañy E(1), Reigosa-Crespo V(1), León T(2), Valdés-Sosa(1), (1)Centro de Neurociencias de
Cuba (2)Instituto Central de Ciencias Pedagógicas
The influence of basic numerical capacities (BNC) on later stages of mathematical competence has
not been systematically tested. To address this question, BNC measures were assessed in 3rd and 4th
graders. Mathematical and reading achievements were evaluated in the same children one year later.
The efficiencies in counting and comparing numerical magnitudes and, also the sizes of the subitizing
and counting effects individually explained between 5% to 9% of the variance in mental calculation
fluency and curriculum-based math competence above and beyond the influence of age and intelligence. However, the BNC failed to explain individual variability in reading competence. Whereas the
BNC explained overall 28% of the variance in math fluency, it only explained 7% of the variability in
math curriculum competence. These results demonstrate that BNC are not exclusively start-up tools for
the acquisition of early arithmetic skills; but they continue modulate later stages of mathematical cognition. Moreover, they are specific predictors for math achievement. On the other hand, the influence of
the BNC on all domains of mathematical cognition is not homogeneous. Fluency in mental computation
seems to be more susceptible to such influence than the performance in other domains. Finally, the
significant association between the individual differences in the size of the subitizing effect and the
math outcome measures found in this study constitutes a behavioral evidence of the influence of the
Small Numerosity System on the construction of symbolic numerical thinking. This finding challenges
the current theoretical approaches about the role of this inherited system.
TU055
NEURONAL ACTIVITY IN THE INSULAR
CORTEX DURING FEAR EXPRESSION
Contreras M.(1), Casanova J.P.(1), Valdés J.L.(2) and Torrealba F.(1), (1)Facultad de Ciencias Biológicas,
Pontificia Universidad Católica de Chile, Santiago, Chile;(2)Programa de Fisiología y Biofísica, Facultad
de Medicina, Universidad de Chile, Santiago, Chile.
Growing evidence suggests that the insular cortex is involved in the perception of emotions. The continuous processing of body information in the interoceptive insular cortex is believed to be important
for perception of emotions. However, how the body information is represented in the interoceptive insular cortex is unknown. Our preliminary behavioral study showed that fear behavior critically depends
on the function of the interoceptive insular cortex in the rat. We tested the idea that electrical activity
of the insular cortex is correlated with the freezing behavior, a commonly used measure of conditioned
fear in rodents. Using a high density electrophysiology recording system in behaving rats and auditory
fear conditioning, we observed that the activity of single neurons of the interoceptive insular cortex
showed excitatory responses that correlated with the time course of freezing behavior. Our results
suggest that the electrical activity of neurons of the insular cortex is associated to expression of
conditioned fear.
TU054
FUNCTIONAL DISSOCIATION OF DEFAULT MODE NETWORK
IN RESTING STATE AND RETRIEVAL OF EMOTIONAL EPISODES
Bado P. (1)(2), Angel A.(1)(3), Bramati I.E.(1)(2), Sato J.R.(1)(4), Paiva F.F.(1), Garrido, G.(1), de Oliveira-Souza R.(1)(5), Moll J.(1), (1)Cognitive and Behavioral Neuroscience Unit, D’Or Institute for Research
and Education, Rio de Janeiro, Brazil;(2)Instituto de Ciências Biomédicas (ICB), Universidade Federal
do Rio de Janeiro, Rio de Janeiro, Brazil;(3)Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany;(4)Center for Mathematics, Computation and Cognition, Universidade Federal
do ABC, Santo André, Brazil;(5)Gaffréee Guinle University Hospital, Federal University of the State of Rio
de Janeiro, Rio de Janeiro, Brazil.
Human beings spend great time of their lives mind-wandering and these spontaneous thoughts are usually
embedded with past experiences and self-reference components. During this “idle” or resting state of the
mind, it has been demonstrated that a specific brain “default mode” network (DMN) is engaged. Here we
investigated to which extent the activity in the DMN can be explained by emotional autobiographical components. Participants (n=15; F=7; age 26 ±3.5) engaged in emotional autobiographical memories, resting
state, or performed a mental calculation while their hemodynamic brain responses were recorded. Subjects
provided contextual information for each episode and chose a key word to recall each scenario during the
fMRI experiment. Functional images were acquired with a 3T Philips Achieva scanner with a gradient-echo,
echoplanar sequence (TR/TE =1650/22ms, Matrix/FOV =80/240mm, slice thickness=3mm, 29 slices),
in addition to reference anatomical images. Total scanning time was 1h19min. The data were analysed
with SPM8. We found shared brain activation in the DMN between emotional autobiographical and resting
conditions when contrasting them with the calculation task. More important, by directly contrasting autobiographical and resting conditions we observed a ventral-dorsal dissociation of DMN in which activation of
DMN core regions (medial prefrontal cortex and posterior cingulate cortex) appear to be driven by emotional
autobiographical retrieval, whereas subcortical regions such as ventral striatum, subgenual and ventral
anterior cingulate cortex were more robustly engaged in the resting state. In the functional connectivity
analysis, the medial prefrontal cortex and posterior cingulate cortex also presented a higher coupling in autobiographical conditions than during rest. In contrast, no change in connectivity was observed for subcortical
regions. Our findings suggest that a partial functional dissociation exists in the DMN and point to a novel
understanding on the default brain network and its relationships to emotional memories.
TU056
THE CAPACITY FOR OBJECT RECOGNITION MEMORY IN THE
DOMESTIC RABBIT (ORYCTOLAGUS CUNICULUS) IS NOT
SEXUALLY DIMORPHIC, BUT MALES EXHIBIT GREATER
BEHAVIORAL REACTIVITY TO NOVEL OBJECTS
Basurto E,Hoffman KL, Centro de Investigación en Reproducción Animal (CIRA), CINVESTAV – Universidad Autónoma de Tlaxcala.
We examined whether sex differences exist in object recognition memory (ORM) in the rabbit. We
designed a novel object recognition (NOR) task that took advantage of the rabbit’s natural tendency to
scent-mark novel objects. The NOR comprised a “sample phase”, in which the rabbit was introduced
into an open field arena containing two identical objects for 15 min. After a 5 min delay spent in its
home cage, the rabbit was returned to the arena for a “test phase”, in which the arena contained two
new objects: one similar to the original ones, and another of a different shape. During the test phase,
we registered the latency to scent-mark each object, the number of scent-marks during the rabbit’s
first encounter with each object, and the total number of scent-marks directed at each object. We calculated “discrimination ratios” (DR = # scent-marks on novel object – # scent-marks on familiar
object / total # scent-marks) to quantify ORM. We compared the performance males and females in
this task after having been given either saline or a sub-anesthetic dose of ketamine (sc), 5 min before
the sample phase. DR scores were similar for saline-treated males and females, indicating the sexes
did not differ in the capacity for ORM. However, males marked the novel (but not familiar) object significantly more than females, and approached and marked both objects sooner. In both sexes, ketamine
decreased the DR based on total number of chin marks, but discrimination at the first encounter was
diminished only in females. Unexpectedly, ketamine reduced the latency of females to mark the novel
object. These results indicate that (1) sexual dimorphisms in ORM are not present in rabbits, although
males are more reactive to novelty, and (2) in this paradigm, the effects of ketamine may be more
related to reactivity to novelty than to ORM.
TU057
NEURAL BASIS OF ARTISTIC PERCEPTION OF PAINTING´S
STYLE. EEG GAMMA BAND DIFFERENTIAL PATTERN ACTIVATION
Lazo Pastó Orlando Rafael (1), Montoya Pedrón Arquímedes (2), (1) West University of Cuba (2)Hospital
General Santiago.
Introduction: The visual characterizations of different styles in painting have been focus usually from
art and social sciences as anthropology, sociology and psychology. Few studies have been considering
the biological basis of artistic perception. Gamma Band synchronization EEG, has been reported in
association with high order brain analysis of visual complex images. The perception of formal (color,
shapes, luminance and contrasts) and conceptual characteristics of visual image for each painting´s
style could generate differential activation of EEG gamma band synchronization. Objective: Determine
the EEG pattern activation under perception of different painting styles. Methods: 15 healthy young
normal voluntaries aged between 25 – 35, no art specialist. EEG recorded in 32 channels (10/10
international system). EEG signal filtered between 0.5 to 100 Hz and sampled at 500 Hz . The stimulus
consists in aleatory presentation of 15 pictures, 5 per style (Renascence, Romanticisms and Surrealism). Gamma Band EEG quantitative analysis were calculated in two band, Gamma 1 (30-70 Hz) and
Gamma 2 (71-100 Hz). The source analyses for spectral peaks of the response were calculated using
LORETA system. Results: The Gamma Band synchronization was found in responses at the three artistic
painting styles. The magnitudes of activation were higher in responses at images form Romanticisms
in both gamma bands. Renascence and Romanticisms gamma response obtain higher energy in low
gamma 1 band, meanwhile surrealism evoked activations in higher gamma band frequencies. The
differences in topographical distribution and LORETA solutions for maximum energy peaks for each
gamma band, show wide cortical activations mainly at parietal, occipital, inferior temporal and frontal
lobes. Conclusions: Stimulus with painting of different styles evoked a differential pattern of activation
in Gamma Band EEG response and suggests that perception of painting styles has at least in part some
specific brain structures and functional network.
TU058
THE GLOBAL BRAIN ATROPHY SHOULD BE TAKEN INTO ACCOUNT IN
SPECT–NEUROPSYCHOLOGY CORRELATIONS: THE EXAMPLE OF VERBAL
LEARNING IN PATIENTS WITH MILD COGNITIVE IMPAIRMENT
CHONGO-ALMERALL D(1),SANCHEZ-CATASUS C(2),SAMPER J(3), àGUILA A(2), RODRIGUEZ R(2),and FERNANDEZ Y(7). (1)Department of Neuropsychology, Center for Neurological Restoration (CIREN), Havana,
Cuba (2)Department of Nuclear Medicine, Center for Neurological Restoration (CIREN), Havana, Cuba
(3) Department of Clinics, University Hospital “Carlos J. Finlay”, Havana, Cuba (4)Department of Cognitive Neuroscience, Cuban Neuroscience Center, Havana, Cuba.
Purpose: To examine the impact of global brain atrophy on SPECT–neuropsychology correlations.
We correlated a verbal learning test with brain perfusion in patients with Mild Cognitive Impairment
(MCI), taking into account the Brain Parenchymal Fraction (BPF), an indicator for global brain atrophy, expressed as the percentage of the ICV occupied by brain tissue. Methods: Twenty-nine patients
(between 50 and 73 years of age, CDR-0.5 and GDS-3) with MCI, underwent brain SPECT with 99mTcethylcysteinate dimer, Minimental State Examination (MMSE ) and Wechsler’s memory scale’s sub-test
of verbal learning of difficult words pairs. SPM2 was used for voxel-based correlation analysis after
normalization to average cerebellar counts (height threshold: p<0.01). In the first analysis, only age,
years of education and global cognitive impairment were inserted as nuisance covariates, while in a
second analysis the BPF measurement was inserted as together with the latter. Results: In the first
analysis, one cluster of significant correlation was found in both hemispheres in regions such as:
middle an superior occipital lobe, parietal and the posterior and middle cingulate and middle temporal
gyrus. The significant voxels were located in the superior parietal lobe of the right hemisphere (RH), and
in the posterior cingulate and angular gyrus of the left hemisphere(LH). After taking into consideration
the BPF, the cluster of signification correlation was smaller and the significants voxels were mainly
found in LH, including the parietal gyrus angularis, the posterior cingulate and the middle temporal
gyrus in the RH. Conclusion: The wide differences observed between the correlations achieved with
and without taking into account the BPF measurement indicate that the global brain atrophy should
be considered when searching for brain perfusion–neuropsychology correlations. In the present case,
this strategy resulted in correlations that closely matched neuropsychological models of verbal learning and memory deficit.
TU059
BRAIN MARKERS OF NEURODEGENERATION
IN SEPSIS SURVIVOR RATS
TU060
FK506-DEPENDENT NEUROREGENERATION RESEMBLES
THE EARLY STEPS OF NEURONAL DIFFERENTIATION
Francieli Vuolo MSc1,PhD1; Matheus Pasquali MSc2; Samantha Pereira Miguel BSc3; Daniel Pens Gelain
PhD2; Fabricia Petronilho PhD3; João Quevedo MD, PhD4; José Cláudio Fonseca Moreira PhD2, Felipe
Dal-Pizzol MD.
Quintá HR(1), Galigniana MD (2), (1)Departamento de Química Biológica Patológica, IQUIFIB, Facultad
de Farmacia y Bioquímica, UBA/Conicet. Argentina; (2) IBYME-Conicet Argentina.
Survivors from sepsis presented cognitive deficits associated with decreased quality of life and increased long-term morbidity. Some of these alterations resembled the pathophysiological mechanisms
of neurodegenerative diseases. The receptor for advanced glycation (RAGE) has been increasingly implicated in the progression of neuronal death in many neurodegenerative diseases, such as Alzheimer’s
Disease (AD), and is also an important pro-inflammatory mediator. For this reason, we analyzed biochemical parameters related to neurodegeneration in rats that survived sepsis, and their relation to
cognitive dysfunction. Rats were subjected to sepsis by cecal ligation and puncture (CLP), and thirty
days after surgery the hippocampus and pre-frontal cortex have been isolated just after cognitive
evaluation by the inhibitory avoidance test. The immunocontent of b-amyloid peptide (Ab), RAGE and
synaptophysin were analyzed by western blot. Ab was increased in septic animals the hippocampus,
but not in the pre-frontal cortex. RAGE was upregulated in both structures after sepsis, and the immunocontent of synaptophysin was decreased only in the pre-cortex, and inversely correlated to Ab
levels. Pre-frontal levels of synaptophysin correlated with performance in the inhibitory avoidance, as
well as hippocampus levels of Ab. In conclusion, brain from sepsis survivor animals presented several
markers of neurodegeneration and RAGE and this was related to cognitive performance suggesting that
this alterations could be responsible to long-term cognitive deficits in sepsis survivors.
BACKGROUND AND PURPOSE: The immunosuppressive macrolide FK506 (tacrolimus) shows neuroregenerative action by a mechanism that appears to involve the Hsp90-binding immunophilin FKBP52.
This study analyzes some aspects of the early steps of neuronal differentiation and neuroregeneration.
EXPERIMENTAL APPROACH : Undifferentiated murine neuroblastoma cells and hippocampal neurons
isolated from embryonic day-17 rat embryos were induced to differentiate with FK506. The subcellular
relocalization of FKBP52, Hsp90 and its cochaperone p23 was analyzed by indirect immunofluorescence confocal microscopy and by Western blots of axonal fractions isolated from cells grown on a
porous transwell cell culture chamber. Neuroregeneration was evaluated using a scratch-wound assay
and two photons microscopy. KEY RESULTS: In undifferentiated cells, FKBP52, Hsp90 and p23 are
located in the cell nucleus forming an annular structure that disassembles as soon as the differentiation process is triggered by the macrolide FK506. This observation is valid for the N2a cell line as well
as for hippocampal neurons, but not for astrocytic glial cells. Importantly, the annular structure of
chaperones is reassembled after damaging the neurons, whereas FK506 prompts their rapid regeneration, a process that is linked to the subcellular redistribution of the heterocomplex. CONCLUSIONS AND
IMPLICATIONS: There is a direct relationship between the disassembly of the chaperone complex and
the progression of neuronal differentiation upon stimulation with the immunophilin ligand FK506. Both
neuronal differentiation and neuroregeneration appear to be mechanistically linked, so the elucidation of one mechanism may lead to unravel the properties of the other. The study also implies that
the generation of FK506 derivatives devoid of immunosuppressive action would be therapeutically
significant for neurotrophic use.
TU061
OXIDATIVE DAMAGE ALTERS MEMORY CONSOLIDATION IN ADULT RATS
Mei-Li Díaz-Hung(1), María E González (1), Ivette Fernández (2), Irenia Horruitiner (2),Samuell Piedra
(1), (1)Departamento de Inmunoquímica, Centro Internacional de Restauración Neurológica (CIREN),
Cuba (2)Departamento de Neurofisiología Experimental, Centro Internacional de Restauración Neurológica (CIREN), Cuba.
Glutathione is an important cellular antioxidant whose depletion leads to oxidative damage and alters
short- and longterm synaptic interactions. Taking into account that the role of this molecule in learning and memory has been poorly studied, the present work evaluates the effect of the administration
of L-buthionine sulfoximine (BSO) on glutathione content and markers of cellular oxidative damage
(malondialdehyde, superoxide dismutase, glutathione peroxidase). BSO was delivered into the brain
by intraventricular injection in the frontal cortex, hippocampus and striatum, evaluating the effect of
the resulting glutathione depletion on learning and memory by means of the passive avoidance test,
performed 7 days after administration. The results suggest that injecting L-buthionine sulfoximine unbalances the antioxidant enzyme system, resulting in damage to cellular lipid components. In addition,
the data suggest the existence of a relationship between oxidative damage originated by glutathione
depletion and memory consolidation.
TU063
NEUROPROTECTIVE EFFECT OF FLAVONOIDS AND MONOTERPENS
EXTRACTED FROM PLANTS IN A TRIPLE TRANSGENIC ALZHEIMER’S
DISEASE MICE MODEL
SABOGAL-GUAQUETA AM(1),MUÑOZ-MANCO JI(1), CORTES-RENDON N(2), RAMIREZ-PINEDA J(3), OSORIODURANGO E.(2), CARDONA-GOMEZ GP, (1)Univ. of Antioquia, Área de Neurobiología Celular y Molecular.
Grupo de Neurociencias de Antioquia (2) Grupo de Sustancias Bioactivas(3)Grupo de Inmunomodulación. SIU, Universidad de Antioquia. Medellín, Colombia.
Alzheimer’s disease is the most common senile dementia in the world, which is characterized by
progressive loss of cognitive functions. For this disease, different treatments have been proposed to
prevent its progression including natural products, without any complete satisfactory results. In this
study, we evaluate the neuroprotective effect of some secondary metabolites extracts from Colombia, South America plants, such as: monoterpenos, Thymol (10mg/kg), Carvacrol (10mg/kg), Linalool
(25mg/kg) v.o. and flavonoids (Quercetin and Biflavonoide fraction (25mg / kg)) via ip., administered
each 48 hours during 3 months in old (22 months) triple transgenic Alzheimer’s mice model (3xTgAD). Neurodegeneration markers (Nissl staining, NeuN, GFAP) and histolopathological hallmarks of AD
(b- amyloid, and AT-8) were evaluated by immunohistochemistry. Also, learning and spatial memory
tasks were analyzed by Morris water maze test. Our data show that the treated animals with flavonoids
and Linalool present a significant reduction of extracellular b- amyloidosis and tauopathy in the CA1
region of the hippocampus and the amygdala. Besides, the old 3xtgAD mice treated with Biflavonoid
fraction (BF) and Linalool had the best and significant performance in the learning test compared
to the resting and respective treatments and controls (DMSO and saline). In addition, all treatments
presented preference by the platform quadrant respect to the controls. But, all treatments except the
BF showed a significant reduction of the latency finding the hidden platform in the memory test. In
summary, our data suggests that flavonoids (quercetin and biflavonoid fraction) and Linalool present
more complete effects reversing the main histological hallmarks and cognitive dysfunction in old triple
transgenic Alzheimer’s mice.
TU062
STUDY OF NRF2-DEPENDENT MODULATION OF CELLULAR
DEFENSES, AS A PUTATIVE MECHANISM INVOLVED
IN QUERCETIN NEURONAL PROTECTION
ARREDONDO F(1), ECHEVERRY C(1), CARVALHO D(1), ABIN-CARRIQUIRY JA(1), ANTUNEZ K(2), DAJAS F(1),
(1)Depto. Neuroquímica, IIBCE, Montevideo, Uruguay; (2)Depto. Microbiología, IIBCE, Montevideo, Uruguay.
The maintenance of cellular redox homeostasis appears as a clue to the correct functioning of redox
signaling and control, and the prevention of oxidative stress-related diseases. Numerous studies on the
Central Nervous System support the idea that the disturbance of redox homeostasis, often associated
with deficits in mitochondrial function, leads to oxidative stress events and neuronal death, thereby
contributing to the development of diverse neurodegenerative disorders. In this context, pharmacological interventions that regulate redox homeostasis could be an important strategy to promote cell
survival and deal against neurodegeneration. There’s a growing interest in dietary flavonoids as potential neuroprotective compounds, although the exact mechanisms by which they exert their benefits
are not fully understood. Previously we described the protective effects of the flavonoid quercetin
against oxidative injury in 24-h-pretreated neuronal cultures. Our results suggested that the longestablished free radical scavenging properties of quercetin wouldn’t be enough to provide it protective
effect. Interestingly, in this model quercetin caused nuclear translocation of the transcription factor
NF-E2-related factor 2 (Nrf2) and significantly increased total glutathione (GSH) levels. Thus, in the
present work we focused on the modulation of the Nrf2-dependent signaling pathway, as a putative
mechanism of neuronal protection by the flavonoid quercetin. Results of real-time PCR of a battery of
antioxidant and cytoprotective genes induced after Nrf2 activation, showed that quercetin treatment
significantly increased gene expression of _-glutamate–cysteine ligase catalytic subunit (GCLC), the
rate-limiting enzyme of GSH synthesis, and heme oxygenase (HO)-1 enzyme. Further western blot assays were performed in order to evidence changes in protein levels of HO-1 and Nrf2. We propose
that Nrf2-dependent modulation of endogenous antioxidant defense systems by quercetin could be a
beneficial response against several noxious stimuli, suggesting a potentially protective role in several
pathophysiological states including neurodegeneration.
TU064
DIENCEPHALIC DAMAGE ALTERS HIPPOCAMPAL ACETYLCHOLINE AND
GLUTAMATE RELEASE DURING SPONTANEOUS ALTERNATION TESTING
RESENDE LS (1), HALL JM (2), RIBEIRO AM (2), BISHOP C (2), SAVAGE LM (3), (1) Univ. of Minas Gerais,
Belo Horizonte, Brazil; (2) Dept. of Neuroscience, Univ. of State of New York at Binghamton, New York,
USA.
Investigation of the rodent model of diencephalic amnesia, pyrithiamine-induced thiamine deficiency
(PTD), has been vital in elucidating the critical brain regions involved in learning and memory. Although
the thalamus and mammillary bodies are the lesioned primary sites, functional deactivation of the
hippocampus also contributes to the cognitive dysfunction reported in the animal model. In the present
study, acetylcholine (ACh) and glutamate (Glut) release were measured in the hippocampus of PTDtreated and control rats prior to, during, and after behavioral test. Sixteen male Sprague-Dawley rats
aged 60 days old were divided in two groups: (i) thiamine deficient diet associated with daily thiamine
i.p. injections (Par Feed group, PF, n = 8); (ii) thiamine deficient diet associated with daily pyrithiamine i.p. injections (PTD, n = 8). The episode of TD was interrupted after 4.5 hours the appearance of
seizure activity, by the administration of two i.p. thiamine doses (100 mg/kg). Cognitive performance
was assessed using a spontaneous alternation task and ACh and Glut release before, during and after
behavioral testing were analyzed using microdialysis and high-performance liquid chromatography.
During behavioral testing, animals from both groups displayed an increase in ACh release. However,
both the rise in ACh release during spontaneous alternation testing (p=0.004) and the alternation
scores (p=0.003) were higher in control rats relative to PTD-treated rats. The Glut release during
spontaneous alternation testing was significantly decreased in PTD rats (p=0.02). There was a positive correlation between spontaneous alternation and ACh release (r=0.55, p=0.02), but not Glut
release (r = 0.29, p = 0.27). However, there was a tendency toward correlation (r= 0.45, p=0.07)
between behavioral stimulated ACh and Glut efflux. These data show that the hippocampus cholinergic
and glutamatergic system are involved in the spatial learning and memory processes. Furthermore, the
present results indicate that diencephalic damage affects the rats’ performance when the task involves
a spatial cognitive hippocampal demand.
TU065
EFFECT OF TRAUMATIC BRAIN INJURY AND DEPRIVATION
OF RAPID EYE MOVEMENT SLEEP OR TOTAL SLEEP IN
THE CB1 RECEPTOR EXPRESSION
TU066
DJ-1 PROTECTS AGAINST NEUROTOXIN-INDUCED
INHIBITION OF THE SURVIVAL PI3K/AKT PATHWAY IN
A MODEL OF MESENCEPHALIC NEURONS
Solis-Luna B, Tabla-Ramón E, Navarro-Argüelles H, Molina-Flores E, Ortiz-Lailzon N, Hernández-Castrejón B, Estrada-Rojo F, Martínez-Tapia R, Hernández-Chávez A, González-Rivera R, Martínez-Vargas
M, and Navarro L. Lab. de Neuroendocrinología, Depto. Fisiología Facultad de Medicina, UNAM, Ciudad
Universitaria, Coyoacán D.F. México.
JARAMILLO-GÓMEZ JA(1), ARBOLEDA H (2), ARBOLEDA GH (1), (1) Cell Death Research Group, Departament of Patology, and (2) Neuroscience-UN Research Group, Deparment of Pediatry, Faculty of Medicina, Universidad Nacional de Colombia, UN, Bogotá D.C.
Introduction: Worldwide, traumatic brain injury (TBI) is a serious public health contributes significantly
to the number of deaths and permanent disabilities. In Mexico, is the fourth leading cause of death
occurring more in men than in women and affect the population aged 15 to 45 years. Following TBI responses are activated to induce brain damage and / or cell death, but also induce protective responses
to maintain the integrity and functionality of the brain, known as neuroprotection. One of the neuroprotective pathways that are activated is cannabinergic system, which we have reported an increased
CB1 receptor expression by the effect of sleep deprivation. Methodology: We used male Wistar rats of
250 to 280 g of weight at the beginning of the experiment, maintained at constant temperature with
food and water ad libitum in a 12:12 light-dark cycle. Eleven groups were formed: Control, Sham, TBI
and experimental groups consisted of deprivation of rapid eye movement sleep (REMSD) and Total Sleep
(TSD), the minimum sample size for all groups was 8. We analyze changes in body weight water and
food intake and neurological damage 24 hours after TBI, then rats were killed to analyze the expression
of cannabinoid CB1 receptor in cerebral cortex by RT-PCR and Western blotting. Results: We found that
TBI induces weight loss, decreased food and water intake and neurological impairment. The TSD does
not modify the effect of TBI in losing weight or water intake and food, however, significantly reduces
neurological damage, correlating with increased RNAm of CB1 receptor expression in the cerebral
cortex, compared with PSMOR and the control groups. We are analyzing data from western blotting.
Supported by: PAPIIT IN222209 and PAPIIT IN221212.
TU067
PROTECTIVE EFFECTS OF DIPHENYL DISSELENIDE AGAINST
SEPSIS-INDUCED DAMAGE IN RAT BRAIN
Petronilho F (1), Silvestre F(1), Michels M (1), Danielski LG (1), Florentino D (1), Mendonça MG (1),
Tournier M (1), Vuolo F (2), da Rocha JB (3), Dal-Pizzol F (2), (1)Programa de Pos-graduaçao em Ciencias da Saúde, Universidade do Sul de Santa Catarina, Tubarão, Brazil; (2) Programa de Pos-graduaçao
em Ciencias da Saúde, Universidade do Extremo Sul Catarinense, Criciuma, Brazil;(3) Departamento
de Química, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria,
Brazil.
Introduction. The development of cognitive impairment in sepsis is associated with neurotoxic effects
caused by oxidative stress. We have assessed the effects of acute administration of diphenyl disselenide (DD) a selenium compound that present antioxidant activity on brain oxidative stress parameters
in rats submitted to sepsis by cecal ligation and perforation. Methods. Male Wistar rats underwent
either sham operation, CLP or CLP with DD. Rats subjected to CLP were treated with oral administration of DD (10, 50 and 100mg/kg after CLP) or vehicle. Twelve, 24h and 10 days after CLP, the rats
were sacrificed, and samples from brain (hippocampus, striatum, cerebellum, prefrontal cortex and
cortex) were obtained and assayed for thiobarbituric acid reactive species (TBARS) formation and
protein carbonyls and was followed for 10 days for evaluation of survival. Results. Our results indicate
a survival rate of 100% in sham animals with a decrease to 30% in CLP animals on the 5th day of
monitoring and DD was effective in increasing survival to 70% at a dose of 100mg/kg and while 10 and
50mg/kg had 40% survival. Since the effectiveness of the dose of 100mg/kg, we find this same dose
for a decrease in lipid damage in animals subjected to CLP in all brain structures in 12, 24 hours and
10 days and a decrease protein oxidation in the cerebellum, striatum and pre-frontal in same times.
Conclusion. Our data provide the first experimental demonstration that DD was able to reduce the
consequences of CLP-induced sepsis in rats, by decreasing oxidative stress parameters in the brain.
Introduction: Parkinson’s disease (PD) is a complex and chronic neurodegenerative disorder affecting ~1% of the population over 65 years, and reaching 4% of the population at the age 85. PD is
characterized by the progressive, chronic and selective loss of dopaminergic neurons in the substantia
nigra pars compacta, leading to deficit of dopamine, presence of Lewy bodies and motor dysfunction.
Recently, several genes have been associated with PD; however, their physiological and pathological
functions are not clear. Mutations of dj-1 (PARK7:1p36) usually lead to decreased stability and expression of the protein and causes a rare autosomal-recessive form of PD that accounts for approximately
1–2% of all early-onset forms of PD. The DJ-1’s function is not clear, although it has been suggested
that has a possible neuroprotective effect against the action of neurotoxins. Objective: In the present
study we aim to determinate the effect of overexpression of DJ-1 against the neurotoxic action of
rotenone, C2-ceramide and 6- hydroxydopamine (6-OHDA) and its relation with the survival PI3K/AKT
pathway in a model of cathecolaminergic neurons of murine mesencephalic origin (CAD cells). Materials and Methods: Initially, we evaluated the effect of rotenone, C2-ceramide and 6-OHDA in CAD cells
by MTT and LDH assays and its relationship with the survival PI3K/AKT pathway by western blot of
p-AKT (Ser473) and t-AKT. Subsequently, the cells CAD were transfected transiently with pCDNA3.1V5/
HIS (EV, empty vector) and pCDNA3.1V5/HIS DJ-1-WT (WT-DJ-1) by lipofection to overexpress the human
WT-DJ-1 protein. Results: We demonstrated that these neurotoxins induce cell death by dose-time
dependent effect and survival PI3K/AKT pathway inhibition (P<0.01). The results by western blot suggest that DJ-1 can enhance the survival PI3K/AKT pathway because CAD cells transfected with WT-DJ-1
present higher level of p-AKT (Ser473) respect to CAD cells transfected with EV (P<0.01), even under a
neurotoxic challenged with C2-ceramide and 6-OHDA (P<0.05). However, there are not significant differences between WT-DJ vs. EV in the levels of p-AKT (Ser473) when the cells are treated with rotenone.
Conclusion: DJ-1 could be suggested as therapeutic target for PD because it can enhance the PI3K/AKT
pathway front to neurotoxic damage in cathecolaminergic neurons.
TU068
POSSIBLE NEUROPROTECTIVE EFFECT OF TRAINING
PHYSICAL ON OXIDATIVE STRESS PARAMETERS IN CORTEX
OF RATS WITH PARKINSON’S DISEASE
Tuon T(1), Valvassori SS(2), Ferreira GK(2), Silva LA(1), Quevedo JL(2), De Souza CT and Pinho, RA(1),
(1)Laboratory of Exercise Biochemistry and Physiology (PPGCS/UNESC, Criciúma, Brasil (2)Laboratory
of Neurosciences and National Institute for Translational Medicine (PPGCS/UNESC, Criciúma, Brasil)
The beneficial effects of exercise on Parkinson’s disease (DP) has been suggested (Bloomer et al.,
2008; Elokda et al., 2010, Tajiri et al., 2010), but the mechanisms responsible for these effects are
poorly understood. The aim of this study was to evaluate the effect of training physical on oxidative stress markers in the cortex of rats with DP. Twentyfour 2-month-old male Wistar rats were divided into untrained+sham-operated (USO), untrained+DP (UPD), trained+Sham-operated (TSO),
trained+DP (TPD), n=6. The animals were submitted to training on the treadmill (8-week, 4 days/
week on alternate days, 50 min/day, 13-17 m/min). Twenty-four hours after training, DP was induced
by lesion unilateral on the left hemisphere with an injection of 6-OHDA (8 μ g in 1 μ l in 0.2% ascorbic
acid). Seven days after the lesion the animals underwent rotational test (rotameter) and euthanasia by
decapitation ensued. The cortex was homogenized in specific buffer for Western Blot and immunoblotting with anti-tyrosine hydroxylase (TH), antisuperoxide dismutase (SOD), anti-glutathione peroxidase
(GPX), and oxidative damage in lipid (TBARS) and protein (carbonyl and sulphydril content). The UPD
and TPD groups showed a clear rotational asymmetry when compared to sham groups and TPD group
showed less asymmetry in relation to UPD group, expression SOD and GPX as well as an increase in
TBARS and carbonyl content and sulphydril groups. The expression of TH was not significantly altered by
exercise, but the TPD group increased the expression of SOD and GPX as well as prevented the oxidative
damage in lipids and protein. The effects of exercise on DP observed in the present study indicate the
possibility that exercise, to a certain extent, modulates redox status in the cortex of rats, possibly by
improving the antioxidant defense system and electron transport chain.
TU069
CHARACTERIZATION OF MONOSODIUM GLUTAMATE ACTION
ON CORTICAL SPREADING DEPRESSION IN EXERCISED
AND SEDENTARY DEVELOPING RATS
MARTINS CBLB, Vitor SM, GUEDES RCA, Departamento de Nutrição, Universidade Federal de Pernambuco, Recife, Brasil.
Monosodium glutamate (MSG) is a flavoring agent that is also a neuroexcitatory amino acid harmful
to the central nervous system. In rats, the administration of MSG during the neonatal period results
in acute degeneration of some cephalic nuclei leading to sexual dysfunction, stunt, behavioral deficit,
damaged cardiovascular control and signs of neuroendocrine obesity that can be counteracted by
physical exercise. Here we investigated the electrophysiological effects of MSG-treated exercised and
sedentary developing rats, and control littermates, on the brain excitabilityrelated phenomenon, known
as cortical spreading depression (CSD). Wistar rat pups received MSG (4g/kg; n=24; group MSG-4,
or 2g/kg; n=22; group MSG-2), or saline (n=23), or no treatment (naïve group; n=11) every two
days in the first 14 days of postnatal life. After weaning, the four groups were subdivided in exercised
(treadmill running, 3 weeks, 5 days/week for 30 min; n=47), or sedentary (n =33). Two days after
training was completed, animals were anesthetized, CSD was elicited by KCl and electrophysiologically
recorded during 4h. The group MSG-4, but not MSG-2, presented mean CSD velocities (in mm/min) significantly higher, when compared with the saline or the naïve group. The CSD velocities for the saline,
naïve, MSG-2 and MSG-4 were respectively 3.84±0.20, 3.71±0.08, 3.75±0.10, and 4.59±0.34.
Physical exercise reduced CSD velocities in all groups (Saline Exercised: 3.27±0.26; Naïve Exercised:
3.25±0.19; MSG-2 Exercised: 3.49±0.19; MSG-4 exercised: 4.05±0.18 mm/min; P<0.05; ANOVA
plus Tukey test). MSG (4g/kg) administered to rats during brain development facilitates CSD propagation, which is decelerated by physical exercise. No MSG-exercise interaction could be demonstrated.
Our data suggest the cautious use of MSG as flavoring during development; also point to the beneficial
effects of physical exercise in the nervous system. Financial support: CAPES. CNPq, FACEPE. CBLBM is
a fellow of FACEPE.
TU071
THE OLFACTORY BULBECTOMY PROMOTES ALTERATIONS IN TOTAL
DENDRITIC LENGTH AND SPINE DENSITY OF PYRAMIDAL NEURONS:
ENTORRINAL CORTEX AND CA3 HIPPOCAMPUS
De la Luz-Torres H, Silva-Gómez AB Laboratorio de Neurofisiología Experimental, BUAP, Puebla, México.
Ablation of the lobes olfactory of the rat results in changes in behavior, in endocrine, immune and neurotransmitter systems. This model had been proposed as experimental model to study major depression however we think too, is an important tool to observe the large capacity of plasticity of pyramidal
neurons. Was of our interest know what happens with CA3 hippocampus and entorrinal cortex (EC)
neurons after bilateral ablation of olfactory bulbs since the latter have a direct projections to those
structures. We used male Wistar pups rats (7 PD); under cryoanesthesia the olfactory bulbs were
removed and the wound was sutured. Two colonies of three groups of rats were randomly prepared:
intact rats (CON); surgery sham (SHAM) and bilateral olfactory bulbectomy (OB). One colony of rats
was sacrificed (60 PD) to obtain the brains and these were processed by Golgi-Cox method. Draws of
pyramidal neurons of EC and CA3 dorsal hippocampus (CA3) were analyzed to determine total dendritic
length (TDL) and dendritic spine density (DSD) in basilar and apical dendritic arbors. The other colony
of experimental rats was introduced in Morris water maze and we calculated the escape latency with
present platform. In EC, the OB produced a decrease in DSD in both apical and basilar trees. The TDL
was modified with an increase at level of apical dendritic tree but a decrease was observed in basilar
arbor. Only apical dendrites in CA3 neurons were affected with spine density diminished. Like to EC,
apical dendritic trees in CA3 showed an increase in TDL while a decrease was observed in basilar tree.
Also, the sham surgery has similar effects on TDL and DSD than OB. In relation to spatial memory, the
OB rats showed an increase in escape latency compared with CON and SHAM rats but the memory was
unaffected.
TU070
PRENATAL STRESS AND ITS EFFECT IN THE NUMBER
OF APOPTOTIC CELLS OF RAT HIPPOCAMPUS DENTATE GYRUS
Alvarado JL(1), Ten -M(2), Valencia LC(1), Schulz E(1) and Magaña E(1), 1) Universidad Autónoma de
Baja California 2) Instituto Nacional de Neurología y Neurocirugía.
Introduction: Prenatal stress has been asociated with structurals, molecular and functionals changes
in the central nervous system with consequences in memory and apprenticeship. In this work our
interest is to learn about factors that influence memory and apprenticeship structural bases. This
work shows a relationship between prenatal stress and the number of cells with apoptosis in dentate
gyrus of rat hippocampal formation. Objetive: The purpose of this study was to investigate the effect
of prenatal stress on the number of cells with apoptosis in rat hippocampal formation dentate gyrus.
Methodology: We use 12 pregnants albino Sprague-Dawley rats. Animals were divided in two groups:
six rats were submited to stress with inmovilization and permanent light exposition during complete
pregnancy (experimental group) and the others six were treated with laboratory regulars conditions
(control group). Offsprings were sacrificed at 21 days of age. In deep anesthesia, the animals were
perfused intracardially 10% formaldehyde. The brains were collected and sent to pathology laboratory
without identifying the specimens group. Was determined the number of cells with apoptosis in hippocampus dentate gyrus. Results: Compared with control group more apoptotic cells were observed in
experimental group (p = 0.025, SPSS17). Conclusion: Prenatal stress can cause structural changes in
central nervous system. In this case in the hippocampus dentate gyrus. We can assume that prenatal
stress is possibly cause of memory and apprenticeship problems.
TU072
IDENTIFICATION OF VEHICLES TO CARRY NERVE
REGENERATION INDUCERS USING TUBULISATION
Nascimento-Elias AH(1); Fresnesdas BC(2); Schiavoni MCL(3); Almeida NFG(4); Santos AP(5); Ramos
JO(6); Marques WJr(7); Barreira AA(8)* 1-4, 6-8 Department of Neurosciences, School of Medicine of
Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto SP, Brazil, 5Federal University of Jequitinhonha and Mucuri Valleys (UFVJM), MG, Brazil.
For the study of nerve regeneration tubulisation is an alternative to research regenerative factors.
Agarose, collagen and Dulbecco’s Modified Eagle Medium (DMEM) can be used as vehicles. In this
study, we compared the ability of these vehicles to induce rat sciatic nerve regeneration with the
intent of finding the least active or inert substance. We used 47 female Wistar rats, divided into four
experimental groups (agarose 4%, agarose 0.4%, collagen, DMEM) and one normal control group. An
incision was made that created a 10mm gap in the right sciatic nerve. A silicone tube was grafted
onto each stump, and the tubes were filled with the respective media. After 70 days, we evaluated the
formation of a regeneration cable, nerve fiber growth (semi-thin sections), and the functional viability.
No connection was formed in 4% agarose group. In the 0.4% agarose group, DMEM and collagen
group there was regeneration cable in nine, six and seven rats, respectively. Six of the rats from the
0.4 % agarose group exhibited nerve fiber regeneration. In three of those animals, less than 30 fibers
reached the distal segment. The average number of fibers of collagen, DMEM and the control groups are
2241.0 (±4197.5), 3356.6 (±2868.3) and 7878.0 (±474.6), respectively. The average conduction
velocities of the collagen, DMEM and control groups were 40,0 (± 7.7), 33.3 (± 10.4) and 54.4 (±
13.0) m/s, respectively, and the average CMAP values were 3.0 (± 2.0), 3.3 (±7.0) and 32.5 (±
5.9) mv, respectively. Comparison among the three vehicles showed that 0.4% agarose gels had almost
no effect on provoking the regeneration of peripheral nerves and that 4% agarose gels completely
prevented fiber growth. In the appropriate concentration, agarose gel may be an important vehicle for
testing factors that induce regeneration with little or no interference with nerve growth.
TU073
NEUROPROTECTIVE ACTIONS OF PROLACTIN AND ITS PHOSPHORYLATED
MIMIC S179D-PRL IN THE HIPPOCAMPUS OF FEMALE RATS
TU074
EFFECT OF ALLIIN ON THE ADIPOKINES GENE EXPRESSION IN
AN INFLAMMATORY IN VITRO MODEL OF 3T3-L1 ADIPOCYTES
Eugenia Ramos(1), Ameae M. Walker(2), Mary Lorenson(2), and Teresa Morales(1), (1)Departamento de
Neurobiología Celular y Molecular, Instituto de Neurobiología, UNAM. Querétaro, México. (2)Division of
Biomedical Sciences, University of California, Riverside, CA, USA.
Quintero-Fabián MS(1,2), Ortuño–Sahagún D(2),Vázquez-Carrera M(3), López-Roa RI(1), (1) Departamento de Farmacobiología, Centro Universitario de Ciencias Exactas e Ingenierías; Universidad de Guadalajara. (2) Departamento de Biología Celular y Molecular, Centro Universitario de Ciencias Biológicas
y Agropecuarias; Universidad de Guadalajara. (3) Pharmacology Unit, Department of Pharmacology and
Therapeutic Chemistry and Institut de Biomedicina de la UB (IBUB), Faculty of Pharmacy, University of
Barcelona, Barcelona.
The neural prolactin (PRL) system is involved in many functions, including neurotransmission, maternal behavior, stress response, myelinization, neurogenesis, and neuroprotection. During lactation, the
hippocampus is protected from kainic acid (KA)-induced damage, and pretreatment with ovine-PRL
has similar protective effects in female rats. In this study, we questioned whether intracerebral human
PRL (hPRL) would have the same protective action. S179D PRL, a mimic of the naturally occurring
phosphorylated PRL and a selective PRL receptor modulator, that may have opposite biological actions
than PRL, was also tested. Female ovariectomized (OVX) rats were implanted with microosmotic pumps
connected to unilateral 28 gauge icv cannulae directed at the right lateral cerebral ventricle. The
osmotic pumps contained either 0.10 ng/h of hPRL, S179D PRL, a combination of hPRL+S179D PRL,
or saline vehicle, infused for 7 days previous to an acute dose of 7.5 mg/kg of KA. Neu-N immunolabel
revealed a significant KA-induced decrease in the cell number in CA1, CA3, and CA4 hippocampal areas
of rats previously treated with saline (~55% of control). In contrast, icv treatment with Hprl prevented
the damaging effect of KA in these hippocampal regions. S179D PRL, and the combination of both,
hPRL and S179D PRL had the same protective action than either one alone (~95% of corresponding
control). In vehicletreated rats, the progression of KA-induced seizure expression (behavioral epileptoid
markers registered at 4h after KA) included staring, wet dog shakes, hyperactivity and rearing and
falling, while those manifestations reached only to the early stages in hPRL- and S179D PRL-treated
rats. These data confirm that PRL exerts neuroprotective actions in this experimental model. Additionally, the mimic of phosphorylated PRL was also neuroprotective and, together with hPRL, results were
neither additive nor antagonistic. Supported by PAPIIT-UNAM IN202812 and CONACYT 128090.
TU075
CA2+ IMAGING OF CHROMAFFIN CELLS (CCS) IN ADRENAL SLICES
FROM SPONTANEOULSY HYPERTENSIVE RATS (SHR). DO ALTERATIONS
IN INTRACELLULAR CA2+ HANDLING MECHANISMS UNDERLIE
CATECHOLAMINE HYPERSECRETION IN SHR CCS?
JIMENEZ-PEREZ N, SEGURA-CHAMA P and HERNANDEZ-CRUZ A.
Departamento de Neurociencia Cognitiva. Instituto de Fisiologia Celular, UNAM, México D.F., México.
Spontaneously hypertensive rats (SHR) are widely used as model of essential hypertension, and normotensive Wistar Kyoto (WKY) rats are often used as controls. Elevated catecholamine plasma levels in
SHR compared to WKY rats might be associated with enhanced catecholamine release after exposure to
ACh or high K+ in intact adrenal glands and cultured adrenal chromaffin cells (CCs) from SHR. Acute
adrenal slices from 8-10 week old SHR and WKY rats were used. Confocal Ca2+ imaging was used to
examine Ca2+ signals from many individual CC simultaneously. CCs from both strains show spontaneous Ca2+ fluctuations, but they are more frequent in SHR (60.7%) than in WKY CCs (43.5%). CCs
with high frequency fluctuations were 42.3% in SHR compared to 23.2% in WKY slices. The percentage of CCs with low frequency fluctuations is similar in both strains. Also, the mean peak amplitude
(_F) of spontaneous Ca2+ fluctuations was larger in SHR compared to WKY. Depolarization-induced
Ca2+ transients were elicited in CCs in the slice with K+ 50mM, applied locally through a glass
pipette. From these Ca2+ signals, we measured peak amplitude, peak first derivative, area under the
curve, decay time constant and half-width. All these parameters gave values significantly larger in SHR
compared to WKY. That is, Ca2+ transients from SHR are larger and have faster rise time than in WKY.
They also decay more slowly. SHR CCs display more often spontaneous Ca2+ fluctuations and of larger
amplitude than WKY, suggesting that SHR could have an increased baseline catecholamine secretion.
Depolarization-induced Ca2+ transients in SHR are larger, have faster rise time and decay more slowly
than WKY CCs. Since the density of voltage-gated Ca2+ currents is the same, these results suggest
that Ca2+ handling properties of CCs differ between both strains. Supported by Grants: PICSA10-116
(ICyTDF), CONACyT 79763 and DGAPA-PAPIIT IN227910.
Adipose tissue was traditionally considered to be a long-term energy storage organ, but it is now
appreciated that it has a key role in the integration of systemic metabolism. This metabolic function
is mediated, in part, by its ability to secrete numerous adipokines. Over the last decade, a close link
between a state of chronic low-level inflammation and metabolic dysfunction has been proposed. In
fact, excessive nutrition consumption or storage has the capacity to activate both inflammatory and
metabolic signalling networks. Garlic (Allium sativum) has been used to treat a variety of problems
of health, due to its high content of organosulfur compounds and antioxidant activity. These isolated
compounds modulate leukocyte cell proliferation and cytokine production, as well as IFN-_, TNF-_ e
IL-12. The main active component in garlic is the S-allyl cysteine sulphoxide, commonly called alliin,
which present cardioprotective effect in a model of myocardial infarct. In addition, alliin reduce the
levels of TNF-_ in human umbilical vein endothelial cells and helps to decrease serum levels of glucose, insulin, triglycerides and uric acid, as well as insulin resistance, when compared with fructose
fed rats. To determine the effect of alliin in vitro in an inflammatory model, 3T3-L1 were differentiated
into adipocytes cells. On day 9 adipocytes were incubated for 24 h with 100 μ mol/L alliin and then
with 100 ng/mL LPS for 1 h. After the incubation, RNA was isolated from adipocytes. Pro-inflammatory
genes expression levels were assessed by the qRTPCR. Our data indicated that exposure of 3T3-L1
adipocytes to alliin caused a decrease the mRNA expression level of proinflammatory genes (IL-6,
MCP-1 and Egr-1), therefore alliin is able to suppresses the molecular inflammatory signals in this in
vitro mode of adipose tissue.
TU076
ALTERATIONS OF LXRS EXPRESSION IN THE
HYPOTHALAMUS OF GLUCOSE-INTOLERANT RATS
KRUSE MS(1), REY M(1), VEGA MC(1), and COIRINI1H(2,3)*, 1Laboratorio de Neurobiología, Instituto de
Biología y Medicina Experimental (IByME-CONICET), V. de Obligado 2490, (C1428ADN) Ciudad Autónoma
de Buenos Aires, Argentina. 2Departamento de Bioquímica Humana, Facultad de Medicina, Universidad
de Buenos Aires, Paraguay 2155, 5to Piso, (C1121ABG) Ciudad Autónoma de Buenos Aires, Argentina.
3Facultad de Ciencias Medicas, Universidad Católica de Cuyo, Rivadavia, Provincia de San Juan, Argentina.
Liver X receptor (LXR) a and b are nuclear receptors that are crucial for the regulation of the carbohydrate and lipid metabolisms. Activation of LXRs in the brain facilitates cholesterol clearance
and improves cognitive deficits, thus they are considered as promising drug targets to treat diseases
such as atherosclerosis and Alzheimer´s disease. Nevertheless, little is known about the function and
localization of LXRs in the brain. Here, we studied the expression of LXRs brain receptor in rats that
received free access to 10 % (w/v) fructose group (FG) in the beverages or water control drinks (CG).
After 6 weeks FG presented hypertriglyceridemia, hyperinsulinemia and became glucose intolerant,
suggesting a progression towards type 2 diabetes. We found that hypothalamic LXRs expression was
altered in fructose fed-rats. FG presented a decrease of LXRb levels while showing an increase in
LXRa expression in the hypothalamus but not in the hippocampus, cerebellum or neocortex. Moreover,
both LXRa and LXRb expression correlated negatively with insulin and triglyceride levels. Interestingly,
LXRb showed a negative correlation with the area under the curve (AUC) during glucose tolerance test
in CG, and a positive correlation in FG. Immunocytochemistry revealed that the paraventricular and
ventromedial nuclei express mainly LXRa meanwhile the arcuate nucleus express LXRb. Both LXRs
immunosignals were found in the median preoptic area. This is the first study showing a relationship
between glucose and lipid homeostasis and the expression of LXRs in the hypothalamus, suggesting
that LXRs may trigger neurochemical and neurophysiological responses for the control of food intake
and energy expenditure through these receptors.
TU077
HUMAN “MONOCLONAL ANTIBODIES” AGAINST NEISSERIA
MENINGITIDIS SEROGROUP B POLYSACCHARIDE
León-Toirac E(1), Camacho F(2), Sarmiento ME(2),González D(3), González H(3), Alerm A(4) and Acosta
A(2), (1)Immunology Lab – Neurobiology Department,Neurology and Neurosurgery Institute, Havana,
Cuba. (2)Department of Molecular Biology, Finlay Institute Vaccine Center,Havana, Cuba. (3)Department of Production, Finlay Institute Vaccine Center,Havana, Cuba. (4) Physiology Department of “Victoria de Girón” Medical University, Havana, Cuba.
Introduction: Neisseria meningitidis (Nm) as epidemic cerebroespinal meningitis causal agent produce
an increased morbidity and mortality. This bacterium has a capsular polysaccharide which particularly
in serogroup B shows chemical and physical structural homologies with human Sialic Acid and a poor
immunogenicity which make difficult the development of vaccines and monoclonal and polyclonal
antibodies against this antigen. Recently, it has been created a variety of artificial libraries of human
antibodies via the expression and selection of them in phages employing Molecular Biology technics.
Those antibodies can be used as recognizing molecules capable to join to almost any existent target
and as alternative to the conventional monoclonal antibodies, with the advantage of being obtained
in less time and without animal immunization. Taking into consideration these antecedents, the use
of human antibody libraries in phage is an attractive alternative for the production of monoclonal
antibodies against “difficult” antigens as Nm serogroup B polysaccharide. Materials and methods: This
was a basic experimental, prospective and descriptive piece of work, using a human scFv phage library
(Tomlinson J) in order to identify ligands with the capacity to recognize Nm serogroup B polysaccharide.
Results and Conclusions: The results obtained through Polyclonal ELISA screening against serogroup
B and C Nm capsular polysaccharides suggest the existence of linear fractions of human antibodies
(scFv) expressed in phages which recognized the antigen of interest. Preliminary phage monoclonal
screening suggested the presence of several clones showing specific recognition a result that should
be confirmed in future studies.
TU078
FURTHER EVIDENCE OF THE LACK OF ‘STRESS HORMONE’
RESPONSES FOLLOWING AVERSIVE ELECTRICAL STIMULATIONS
OF THE PERIAQUEDUCTAL GRAY MATTER OF RATS
ARMINI R.S(1),BERNABÉ C.S(1), ROSA C.A(1),SILLER C.A(1),TUFIK S(2) and SCHENBERG L.C(1), (1)Laboratory of Neurobiology of Mood disorders and Anxiety, Dept. of Physiological Science,Federal University of
Espírito Santo, Brazil; (2)Dept. of Psychobiology, Federal University of São Paulo, Brazil.
Previous studies from our laboratory showed that the ‘stress hormones’ corticotropin (ACTH), corticosterone (CORT) and prolactin (PRL) are not changed following the defensive behaviors induced
by electrical stimulation of the dorsal periaqueductal gray matter (DPAG) of rats. These results are
similar to the lack of stress hormone responses in human spontaneous and lactate-induced panic
attacks (PA). However, the CORT morning plasma levels of these rats were about 300 ng/ml, values
much higher than the expected 60-100 ng/ml. Although the CORT baseline level bears no relation with
PRL responses, they could but explain the lack of ACTH responses. Indeed, other researchers reported
significant increases in CORT plasma levels 30 min after DPAG-evoked escape responses. Nevertheless, it remains unclear whether the latter results were due to the muscular exertion or the emotional
response. Indeed, although the urge to escape is a cardinal symptom of PA, actual flight rarely occurs.
In turn, previous studies showed that the DPAG-evoked flight responses are completely suppressed if
rats were stimulated in a small diameter arena. Therefore, this study reexamined the stress hormone
responses to DPAG stimulations of same intensities in large (60 cm) and small (20 cm) diameter
arenas. Following surgery, rats were allowed to recover for 4 weeks in a emperaturecontrolled soundattenuated access-restricted room with water and food ad libitum. Thereafter, rats were stimulated in
either the small or large arena with previously recorded thresholds. Rats were then beheaded under
isoflurane anesthesia for blood sampling in EDTA. As expected, rats stimulated in the small arena
neither presented the flight responses, nor showed increases in lactate levels. More important, ACTH,
CORT and PRL plasma levels did not differ from sham-stimulated controls in either arena. Besides
being the first separation of DPAG-evoked motor and emotional responses, results support the DPAGevoked responses as a model of PA.
TU079
STUDY OF METHANOLIC EXTRACT EFFECT FROM MORINGA
OLEIFERA LEAF OVER BLOOD GLUCOSE LEVELS IN A
MOUSE MODEL OF DIABETES
TU080
GONADECTOMY INDUCES CHANGES IN GNRH-INDUCED [CA2+II
SIGNALING IN GONADOTROPHS RECORDED IN ACUTE PITUITARY
SLICES FROM MALE MICE
Eustaquio-Cruz, A(1), Mendoza-Pérez, J.A(2),and Fregoso-Aguilar T(1). (1)department of Physiology.
National School of Biological Sciences, National Polytechnic Institute. (2)department of Environmental
Systems Engineering.National School of Biological Sciences, National Polytechnic Institute.
DURÁN-PASTÉN ML(1), FIORDELISIO-COLL T(2) and HERNÁNDEZ-CRUZ A(1). (1) División de Neurociencias,
Instituto de Fisiología Celular and (2) Departamento de Biología, Facultad de Ciencias. Ciudad Universitaria, Universidad Nacional Autónoma de México, México City, DF, México, 04320.
Diabetes is a multifactorial chronic degenerative disease, with a high mortality rate in Mexico and the
world and whose main alteration is bad regulation of glucose. In the search for an effective treatment,
with low cost and few side effects, currently it has been used a broad variety of plants like an alternative to drug therapy. Moringa oleifera, has been used in traditional medicine for treating of diabetes. In
this work, we studied the hypoglycemic effect of this plant in a model of diabetes in mouse. Moringa
leaves were collected in Michoacan state. After drying them, the biological material was grinded and
extracted in methanol. The collected extract was concentrated under reduced pressure conditions. Also
with the extract was established the phytochemical composition and the antioxidant and hypoglycemic
activities. Moringa leaves showed an antioxidant activity with high dependence on concentration, assays were performed with extract concentrations of 50, 25, 12.5, 6.25 mg/mL. The higher concentrations displayed a 50% inhibition during the first minutes of reaction. 40 male mice (NIH, 25–30 g)
were divided in the following treatment groups: control, diabetic (streptozotocin, 120 mg/kg, ip.),
control + Moringa extract (500 mg/kg) and diabetic + Moringa extract. For all the animals were measured the blood glucose levels and body weight each week for 36 days. A significant decrease in blood
glucose was observed when comparing the control group of diabetic mice against the group of diabetic
mice treated with Moringa extract (Student-Newman-Keuls test; P <0.05). It also was confirmed a
tendency to prevent weight loss. Phenolic compounds and flavonoids were detected and both are
reported in the literature as responsible for the hypoglycemic effect due to their antioxidant capacity.
Therefore, M. oleifera is proposed that can be used as coadyuvant in diabetes treatment.
The acute pituitary slice is amenable for Ca2+ imaging studies since cells remain in their native
environment cell-cell interactions intact. GnRH-induced intracellular Ca2+ signals from dozens of
gonadotrophs were recorded simultaneously in slices from intact and 15 and 45 days post gonadectomized (GnX) adult male mice. Slices 130 μ m in thickness were incubated with fluo-4 AM (22 μ M;
30 min) and perfused with normal BBS saturated with O2 and CO2. Image sequences were obtained
while GnRH was bath-applied for 30 s (five doses, from 0.01 to 100 nM), and washed for >30 min
between applications. 15 and 45 days after castration, non-canonical Ca2+ signalling patterns increased from 58% to ~90%. Also, after 15 days post-GnX the number of cells responding increased
from 56.33±8.01 in intact mice to 82.56±11.15 in GnX mice (mean±SE) and the mean area size
increased, corroborating the proliferation and growth of gonadotrophs reported in anatomical studies.
Hypertrophied gonadotrophs display more vigorous GnRH-induced Ca2+ signals than intact gonadotrophs. GnRH dose-response curves in control mice gave ED50 = 0.174 nM, while 15 and 45 days
post GnX, ED50 was 0.069 and 0.064 nM, respectively, suggesting that castrated mice gonadotrophs
are more sensitive to GnRH. Gonadotroph Ca2+ responses comprise three components: oscillation,
plateau and hump. Gonadotrophs in vitro from castrated rat predominantly display Ca2+ oscillations, even at high [GnRH]. However, in gonadotrophs in situ from both intact and castrated mice,
the oscillatory component diminishes and the hump component increases with increasing [GnRH],
similarly to intact rat gonadotrophs in vitro, suggesting that Ca2+ signaling patterns in mice and rat
gonadotrophs do not respond in the same way to GnX. Also, 45-days after GnX, gonadotrophs lose the
ability to respond with different Ca2+ signaling patterns to [GnRH] from 1 to 100 nM. Suppoted by
CONACyT 79763, ICyTDF PICSA10-116 and IN227910 DGAPA-UNAM.
TU081
THE ARCUATE NUCLEUS MEDIATES GLUCOCORTICOD
FAST FEEDBACK THROUGH A NEURAL PATHWAY
LEON L.A(1), HERRERA D(1), BASUALDO M.C(1) and BUIJS R.M(1), (1)Dpto. de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, UNAM, México, DF 04510, México.
Several studies have demonstrated the variation of Glucocorticoids (GC) independently of the levels of
ACTH in the circulation, demonstrating a sympathetic route for the direct stimulation of corticosterone
from the adrenal. Thus two important pathways to control corticosterone secretion exist: a hormonal
one via ACTH and a neural one directly to the adrenal. Therefore we hypothesized two feedback routes
for GC to the hypothalamus: One acting on the CRH neurons in Paraventricular Nucleus of the Hypothalamus (PVN) to adjust the release of ACTH from the pituitary gland and the other mediated by the
autonomic output of the hypothalamus to modify the activity of the adrenal. Although the PVN is proposed to be involved directly in sensing and adjusting hormonal changes, its autonomic neurons do not
express the GC receptor (GR). Since the Arcuate Nucleus (ARC) has free access to GC in the circulation
and possesses both GR and mineralocorticoid receptors (MR), we hypothesized that the ARC can sense
hormonal levels and signal the changes to the PVN to adjust the endocrine output in a fast fashion. To
test this hypothesis we infused agonists and antagonists to GR and MR by means of microdialysis in
the area of the ARC and measured corticosterone in the blood after different time intervals during the
dialysis and the expression of genes related to the synthesis of steroid hormones and the response
to ACTH in the adrenal gland. Our results show fast changes in both the hormone levels in the blood
and gene expression in the adrenal glands, providing evidence for the participation of the ARC in the
neuronal regulation of hormone production.
TU083
ANTIOXIDANT ACTIVITY FROM THE LEAF OF NEEM TREE
(AZADIRACHTA INDICA) AND EVALUATION OF ITS HYPOGLYCEMIC
EFFECT IN A DIABETES MOUSE MODEL
Delgado L.E.(1), Mendoza-Pérez J.A.(2), Fregoso-Aguilar T.(1). (1) Department of Physiology, National
School of Biological Sciences, National Polytechnic Institute. (2)Department of Enviromental Sciences
Engineering, National School of Biological Sciences, National Polytechnic Institute.
Several compounds in human diet have antioxidant properties in addition to its nutritional characteristics that could provide an alternative for the treatment and prevention of chronic-degenerative
diseases that are aggravated by the formation of free radicals. Diabetes is a disease in which blood
glucose levels are high and represents a health problem for Mexico, since it involves treatments which
are for entirely life and very expensive. Therefore, there is a tendency to seek alternative treatments
based on the use of plants. The Neem tree (Azadirachta indica) has been used for the treatment of
diabetes since a short time ago. In this study it was performed the evaluation of the hypoglycemic
activity of methanolic extracts from the Neem leaf in mice treated with streptozotocin (120 mg / kg, ip).
Groups of diabetic mice treated with 10% and 15% extracts, showed a significant decrease in glucose
levels compared to the group of diabetic mice (Student-Newman-Keuls test, p <0.05). However, the
extract didn´t decreased glucose levels to values near to the control group. The antioxidant activity
was evaluated with the DPPH method over 1, 15, 30, 60 and 90 minutes and absorbance was read at
517 nm. Comparing this extract with a methanolic extract of passion fruit and a commercial product
that presents this activity, the methanol extract of Neem presented more than 50% inhibition during
the first 15 minutes of reaction compared with Passion fruit extract, which not displayed such an
effect.A qualitative phytochemical study of Neem extract was also performed. As results, it detected
the presence of phenols, alkaloids and flavonoids; metabolites that may be involved in antioxidant and
hypoglycemic activities.
TU082
ON THE PROESTRUS DAY, THE ROLE OF VASOACTIVE INTESTINAL
PEPTIDE (VIP) IN THE OVARIES ON ESTRADIOL SECRETION DEPENDS
FROM INTEGRITY OF THE SON
Rosas-Gavilán G(1), Linares C(1), Chavira R(2),Morales L (1) y Domínguez R (1). (1) Facultad de Estudios Superiores Zaragoza, UNAM, D.F, México. (2) Instituto Nacional de Ciencias Médicas y Nutrición
“Salvador Zubirán”, D.F, México.
The ovary receives vasoactive intestinal peptide (VIP) innervation mainly via the superior ovarian nerve
(SON). VIP stimulates progesterone, androgen and estradiol release from cultured rat granulosa cells
and whole ovaries in vitro. 24 hours after the VIP injection into the ovarian bursa (OB) of diestrus-2
animals resulted in an asymmetric estradiol secretion which is lost at proestrus day (P). The aims
of present study was to analyze if increase unilateral or bilateral of VIP ovarian levels on P, modifies
estradiol secretion; also, if the changes depend on the integrity of the SON. Sixty day-old female rats of
the CII-ZV strain, were subjected at 10.00 h of P to the unilateral or bilateral injection 20 μl of VIP (106M) or saline solution (SS) in the OB. In other groups, rats were submitted to the unilateral or bilateral
section of the SON [left (L-SON), right or bilateral] followed by the injection of VIP into the denervated or
inervated ovaries. All rats were sacrificed 60 minutes after treatment. Estradiol levels were measured
by RIA. Injection of VIP into the left ovary decreased estradiol levels (104.2±8.2 vs. 173.5±15.5
pg/ml, p<0.05). The injection of VIP into the ovaries of rats with L-SON resulted in higher estradiol
levels than animals injected with SS (VIP left ovary 288.6±21.5 vs. 130.5±8.8 pg/ml; VIP right ovary
142.2±13.2 vs. 97.2±10.8 pg/ml; p<0.05). Present results suggest that the sensitivity of the left
ovary to VIP overstimulation is different than the right ovary. Also, that the SON modify the sensitivity
of the ovary to VIP. Supported by DGAPA IN218911-3 and CONACyT225347.
TU084
ANDROGEN RESPONSE TO PRIMATE SOCIAL
PARADIGM OF DEPRESSION
GALVÃO-COELHO NL (1), SHIRAMIZU VKM (2), GALVÃO ACM (3), SILVA LMP (4), SOUSA MBC (5). 1 Department of Physiology, Federal University of the Rio Grande do Norte –UFRN. 2 Graduate Program in
Psychobiology-UFRN. 3 Undergraduate Course of Biological Sciences- UFRN. 4Undergraduate Course of
Pharmaceutical Sciences- UFRN
Testosterone has several biological purposes in addition to its gonadal function, including influencing
the continuous process of neuronal adaptation to new environmental demands. A number of recent
studies have concluded that testosterone levels are low in cases of depression and that this is strongly
associated with apathy levels. The aim of this study was to investigate the profile of fecal androgens
and cortisol levels in adult male common marmosets, a widely used animal model in studies ont stress
and depression. We used two primate social paradigms of depression: social privation and determination of social rank. At baseline (FB), males (n= 8) were paired in dyads for 28 days. Next, dyads were
separated and placed in new cages similar to baseline (FI- 7 days), and then reunited in the baseline
cage (FR- 7 days). At FB fecal samples were collected on alternate days and daily at FI and FR. At FI
androgen levels decreased significantly in relation to FB (ANOVA; F=3.44, p=0.03; LSD p=0.03),
whereas at FR androgen levels increased in relation to FI (ANOVA; F=3.44, p=0.03; LSD p=0.02).
Cortisol levels did not change over the course of the study (ANOVA; F=1.51, p=0.23), but a significant negative correlation was observed between this hormone and androgens (Sperman: rs= 0.33,
p< 0.05). These results show the interaction between HPA and HPG in the stress response of male
common marmosets.The finding of low androgens associated to isolation suggests the high potential
ofthese animals as a model of depression. It is recommended that sample size be increased and behavioral correlates in the FI condition be investigated to further reinforce the results of the present study.
TU085
TESTOSTERONE REPLACEMENT INDUCES PATERNAL
BEHAVIOUR IN VIRGIN MALES OF THE MEXICAN VOLCANO
MOUSE (NEOTOMODON ALSTONI)
TU086
TERRITORIAL AGGRESSION AND TESTOSTERONE IN
A SOCIAL CONTEXT IN THE MONGOLIAN GERBIL
(MERIONES UNGUICULATUS)
Ramos-Blancas G (1), Carmona A (2),Villalpando I (3), Delgado-Solís J (4), Luis J (1); (1) Lab. Biología
de la Reproducción, FES Iztacala UNAM, (2) Lab. Biología Experimental Facultad de Ciencias, UNAM,
(3) Instituto de Investigaciones Biomédicas, UNAM, (4) Psicología Experimental, FES Iztacala UNAM
Piña-Andrade S (1), Martínez-Torres M (1), Villalpando I (2), Luis J(1). (1) Biología de la Reproducción,
FES Iztacala, UNAM, (2) Instituto de Investigaciones Biomédicas, UNAM.
In the California mouse the testosterone exerts its effects on neurons of the medial area preoptic
(MPOA) to regulate paternal behavior in this rodent. In the Mexican volcano mouse the testosterone
induced paternal behaviour in males sexually experienced. The aim of this study was to determine
whether the testosterone is also able to induce the exhibition of parental care in virgin males and
compare the expression of androgen receptors in MPOA among males castrated with testosterone
implant that displayed paternal behaviour and these that showed aggression. Through screen test
paternal behaviour 41 mice aggressive or indifferent towards pups were chosen; 10 virgin mice were
castrated bilaterally (CVM), 10 virgin males underwent bilateral castration and testosterone replacement (TCVM), ten virgin males were utilized sham procedure (SVM), other 11 with sexual experience
were castrated and testosterone implant were placed (TCEM). After five days of the treatment each
male was submitted again to test paternal behavior and then blood sample was extracted for the
quantification of testosterone by RIA. Likewise, immediately of the tests of paternal behavior 2 males
(1 aggressive and 1 paternal) were sacrificed. The brains were processed for immunohistochemistry.
Testosterone replacement induced paternal behavior in virgin males as sexual experienced males. The
males TCVM and TCEM had testosterone concentrations in plasma higher than CVM and SVM males
(P< 0.01). Only it observed the expression of androgen receptor in MPOA in the mice that showed
paternal behavior. These results support the hypothesis, that the testosterone is involved in the mechanisms neuroendocrine that suppress the infanticide and that promote the expression of the paternal
behavior in the Mexican volcano mouse. Also suggests that testosterone exerts its effects via androgen
receptors in the MPOA.
TU087
ROLE OF RENIN ANGIOTENSIN SYSTEM ON THE
EARLY ALTERATIONS OF DIABETIC NEPHROPATHY
Vázquez-Cruz B1, Núñez-Ortiz A.R1, Segura-Cobos D1, López-Sánchez P2, Amato-D. 1Lab. de Farmacología, UIICSE, FES Iztacala UNAM, 2Sección de graduados, ESM, IPN. ROLE OF RENIN ANGIOTENSIN
SYSTEM ON THE EARLY ALTERATIONS OF DIABETIC NEPHROPATHY. Vázquez-Cruz B1, Núñez-Ortiz A.R1,
Segura-Cobos D1, López-Sánchez P2, Amato D1. 1Farmacología, UIICSE, FES Iztacala UNAM, 2Sección
de graduados, ESM, IPN.
Diabetic nephropathy (DN) starts with renal hypertrophy, thickening of the basement membrane and
glomerular hyperfiltration. Given that angiotensin-converting enzyme inhibitors and AT-1R antagonists
are effective in slowing the progression of DN, the renin angiotensin system (RAS) is associated with
DN development. Aim: Study the participation of the RAS on the early alterations of DN. Methods:
Diabetes mellitus was induced in male Wistar rats (230-250 g) by, streptozotocin injection (65 mg/
Kg, i.p) 48 h later diabetic rats were divided into 3 groups: untreated, treated with losartan (LOS) and
treated with captopril (CAP) (10mg/Kg). After two weeks, the kidneys were excised, decapsulated and
weighted. In order to determine the protein levels, half of the kidney was employed. After this, western
blot was used for determining the expression of receptors AT-1, AT-2 and Ang-(1-7)mas receptor. The
remaining excised kidneys were fixed in 10% formalin for histopathological studies. Results: There
was an increase in blood glucose of diabetic rats (DR) (358±15.11 mg/dL) as compared with control
rats (CR) (125±2.19 mg/dL). DR showed polyuria, polyphagia, polydipsia and weight loss, as well as
increased kidney weight (1.075±0.052g vs CR 0.82±0.036 g) and tubular area (120.98±8.08 μ2
vs CR 88.46±11.32 μ2). While renal protein expression of AT-IR was significantly increased in DR,
AT-2R and Ang 1-7mas receptor decreased. Due to CAP treatment, there was reduction of kidney weight
and tubular area. Following this, the expression of AT-IR decreased; and the expression of Ang 1- 7mas
receptor increased, though the AT-2R expression was not modified. LOS treatment only decreased the
AT-IR expression. Conclusion: These data suggest that Ang II plays a significant role in renal hypertrophy through AT-1R. Angiotensin 1-7 may partially protect against the renal injuries caused by diabetes
mellitus. Supported by PAPCA 2011 AND 2012.
The aggressive behavior in vertebrates is attributed to testicular androgens, like testosterone, the influence of this steroid hormone on this behavior has been demonstrated in several studies; castration
reduces the aggression and the subsequent administration of testosterone restores it. Social factors
such as cohabitation with a female, the mating and isolation affect the aggressive behavior. The aim of
this study was to determine the relationship among testosterone and territorial aggression, as well as
establish the effect of cohabitation with a female on this behavior in the Mongolian gerbil. In a first experiment were utilized 18 virgin males that cohabitated with other males; 6 castrated, 6 castrated with
testosterone implants and 6 sham-castration. In the second experiment 30 males that cohabitated
with a female were used; 10 castrated males, 10 castrated with testosterone implant and 10 shamoperated. Cohabitation in both experiments was of 15 days before surgeries. The aggression tests
resident-intruder were performed 5 days after testosterone implants were placed. In these tests 45
intact virgin males were utilized like intruder. The attack latency was used as measure of aggression.
After of aggression test was extracted each resident male a blood sample for quantify testosterone
in plasma by RIA. None of the males that cohabitated with other males showed aggression in any of
the experimental conditions. However, those males castrated with testosterone implant and shamcastrated males that cohabitated with a female exhibited aggression. Although we still do not measure
the plasma testosterone, these results suggest that territorial aggression is regulated by testosterone
but that factors such as the cohabitation with female have an important role in the activation of neural
circuit that regulate the territorial aggression in the Mongolian gerbil.
TU088
THE EFFECTS OF UNILATERAL SECTION OF THE SUPERIOR
OVARIAN NERVE ON SPONTANEOUS OVULATION DEPENDS ON
THE DAY OF THE CYCLE AND THE HOUR OF THE DAY WHEN
THE DENERVATION IS PRODUCED
Muñoz JC(1), Silva CC(1), Cruz MA(1), Flores A(1), and Domínguez R(1), (1)Lab. De Biología del Desarrollo de la Unidad de Investigación en Biología de la Reproducción, FES Zaragoza, UNAM.
Ovulation is regulated by hormonal signals arising from the pituitary and neural signals arising from
the hypothalamus and extrahypothalamic areas. There is evidence that the Superior Ovarian Nerve
(SON) modulates in a different way the effects of gonadotropin on the ovaries, depending on the day
and hour of the estrous cycle. The aims of present study was to compare the effects of unilateral
section of the SON performed at 09.00 or 13.00 h of each day of the estrous cycle on spontaneous
ovulation measured at the day of vaginal estrus. The results were compared with the effects of a ventral
laparotomy (sham operation) and control animals. Laparotomy at 09.00 of diestrus-2 resulted in lower
number of ova shed by the right ovary than control (4.3±0.6 vs. 7.1±0.7, p<0.05). The section of
the right SON resulted in lower ovulation rate than animals with laparotomy [diestrus-1:3/7 vs. 7/7;
diestrus-2: 3/7 vs. 7/7, proestrus 2/7 vs. 7/7, estrus 2/7 vs. 7/7, p<0.05]. The number of ova shed
by rats with the section of the right SON at diestrus-2 or proestrus was lower than laparotimized rats
(7.3±1.9 vs. 11.1±0.9; 7.4±1.2 vs. 11.4±0.7, p<0.05). At proestrus the section of left SON
resulted in a lower number of ova shed by rats with laparotomy (7.1±0.8 vs 11.4±0.7, p<0.05). In
rats treated at 13.00 h of proestrus the section of the right or left SON resulted in lower ovulation rate
than laparotomized animals (2/7 vs. 7/7; 3/7 vs. 7/7, p<0.05). Taken together, the results of present
study show that the neural information arriving to the ovaries through the SON plays an asymmetric role
in the regulation of the response of the ovaries to gonadotropin signals, which varies along the estrous
cycle. DGAPA-PAPIIT IN 209508-3, IN 218911- 3.
TU089
VAGUS NERVE STIMULATION AND VENTROMEDIAL PREFRONTAL
CORTEX KINDLING ON EMOTIONAL RESPONSES IN RATS
TU090
EXPRESSION CHANGES OF NEUROPEPTIDE Y IN A MODEL
OF PTZ-INDUCED CONVULSIONS IN RATS
Velázquez-Hernández LG(1), Magdaleno-Madrigal VM(1), López-Ruiz E(2), Fernández-Mas R(1),
Almazán-Alvarado S(1), Martínez-Mota L(3). (1)Lab. Neurofisiología del control y la regulación; (2)Lab.
Cronobiología; (3)Lab. Farmacología conductual. Instituto Nacional de Psiquiatría Ramón de la Fuente
Muñiz, México DF, México.
Andrade R(1), Pitot C(1), Falconi A(2), Chavez J(3)Coveñas R(4), Aguilar L(1,3), (1) Universidad Peruana
Cayetano Heredia, Laboratorio de Investigación y Desarrollo (LID), Area of Neuroscience and Behavior,
Lima, Perú; (2) Facultad de Medicina. Universidad de la Republica. Montevideo. Uruguay;(3) Institute
of Biochemistry and Molecular Biology, Universidad Nacional Agraria La Molina. Lima. Perú;(4) Incyl.
Universidad de Salamanca . Spain.
Vagus nerve stimulation (VNS) has been used in both treatment-resistant epilepsy and depression.
The ventromedial prefrontal cortex (vmPFC), and basolateral amygdaloid nucleus (BLA) are associated to emotional responses. The aims of present study were to analyze the effect of VNS on kindling
epileptogenesis of vmPFC, and analyze emotional changes of rats undergoing the forced swim test (FST)
and taste aversion (TA). Wistar male rats were used in this study. Tripolar stainless-steel electrodes
in vmPFC and BLA were stereotaxically implanted. Screw epidural electrodes were directed to parietal
cortex. On the first day of testing, rats have their pretest FST by a 15-min swimming session. Eight
hours after, as a measure of TA, quinine was added to sweet milk. During 1 hour per day VNS was
done (1 min on/5 min off). Kindling stimulation was applied at hourly intervals for five times per
day. Rats were classified as follows: 1) vmPFC, only kindling stimulation; 2) VNS, only VNS; 3) VNS/
vmPFC, VNS plus kindling stimulation. One day after the final vmPFC kindling stimulation, or VNS were
discontinued, rats had their second FST and TA sessions. The epileptogenesis in VNS/vmPFC shows a
progressive development, the kindling trials to reach generalized tonic-clonic seizure were minor that
vmPFC. Animals subjected to VNS/vmPFC showed a significant decrease in immobility behavior, and
quinine consumption. One remarkable finding was that some animals showed a penile erection. Our
results indicate that concomitant VNS plus vmPFC epileptogenesis regulate the emotional responses,
increasing the antidepressant-like effect produced by VNS alone or deep brain stimulation of vmPFC.
TU091
CLINIC AND ELECTROENCEPHALOGRAPHY
CHARACTERIZATION THE NEONATAL SEIZURES
Exposito Y, Contreras M. America America hospitals. Univ. of Calixto Garcia, La Havana, Cuba.
Objectives: To establish the incidence of the different types of clinical neonatal seizures and to evaluate the correspondence of them with the background EEG record and the epileptic activity, the underlying etiologic, the response to antiepileptic treatment and their prognosis. Methods: Retrospective
study of admitted 62 newborns with the diagnosis of neonatal seizures in “América Arias” Gynecologic
and Obstetric Hospital during the period included January 2004 to January 2012. Some of variables
collected were birth and gestational age, apgar, clinical pattern, duration of the convulsions, critical
and intercritical EEG traced, EEG background, etiological diagnosis, treatment used and response of the
same, evolution and neurological state at hospital discharge and at one year of age. Resulted: 83 children were admitted with neonatal seizures diagnosis, of these only 58 EEG convulsions were confirmed.
The most frequent seizure was generalized tonic seizure, the multifocal discharges (33,3 %) and the
infants having had EEG background moderately and markedly abnormal showed unfavourable outcome. Conclusions: The necessity to confirm by means of EEG record the neonatal clinical convulsions
before and after establish the anticonvulsive treatment, due to the control of electrical convulsions
improves their neurological outcomes. Relevance: There is increasing evidence that neonatal seizures
have an adverse effect on neurodevelopmental outcome, and predispose to cognitive, behavioural, or
epileptic complications in later life. Undetected and untreated seizure activity increases the insult to
the neonatal brain.
Epilepsy is a neurological disorder characterized primarily by spontaneous uncontrolled seizures due to generalized
electrical activity of brain neurons. Studies on central nervous system (CNS) functions in models of epilepsy have
determined that this condition affects severely neuroplasticity, memory and learning. Recent evidence shows that
neuromodulators like neuropeptide Y (NPY) are involved in regulation of interneuron excitability. Nevertheless, up
to now, it is not completely clear how its expression patterns are altered in epilepsy and its role in cognitive functions. Male Holtzman rats weighing 250-300 g were housed in cages in a room with light-dark cycle (12 h light/
l2 h dark) and temperature (22°C). The animals received daily injections of 30 mg/kg, i.p. PTZ over a period of 13
days. After each injection they were observed and recorded for 30 min and convulsions were classified according to
the McIntyre and Racine scale (1986). Furthermore, evaluation of spatial memory was performed in animals using
the T Maze 24 hours after the last PTZ injection for 5 days. The rats were sacrificed by decapitation on the sixth
day and the brains were immediately removed to immunohistochemistry for NPY was carried out using Vectastain
ABC Peroxidase-Kit. An increased of NPY inmunoreactivity in neuronal soma number and fibers was found in experimental animals in comparison to controls. Seven days after the last kindling session, a significant increment
(Kolmogorov Smirnov test) was observed in pyriform cortex (Pir), amygdalohippocampal area (AHiPM), basomedial
and basolateral amygdaloid nucleus (BMP and BLP), posterolateral cortical amygdaloid nucleus (PLCo), parietal
association cortex (PtA), primary somatosensory cortex (S1bf) and hippocampus. It was also observed an increase
in size and number of convulsions, and a significant difference in time regarding T Maze between experimental and
control animals. This last condition was gradually recovered after last treatment. In conclusion, PTZ-induced convulsions increase expression of NPY in areas related to association and motor system (PtA, S1bf), spatial memory
(hippocampus) and amygdaloid structures, which have been involved with seizure occurrences, since amygdaloid
kindling stimulation experimentally induces chronic epilepsy. Also, PTZ-induced kindling model affect memory but
this is recovered after treatment, probably due to any compensatory mechanisms.
TU092
ELECTROPHYSIOLOGICAL CONSEQUENCES OF
MORPHOLOGICAL CHANGES IN NEWLY BORN GRANULE CELLS
OF THE RAT DENTATE GYRUS AFTER PILOCARPINE-INDUCED
STATUS EPILEPTICUS: A COMPUTER MODELING STUDY
TEJADA J(1,2), GARCIA-CAIRASCO N(2), and ROQUE AC(1), (1) Depto. de Física, FFCLRP, Univ. de São Paulo, Ribeirão Preto, SP, Brazil; (2) Depto. de Fisiologia, FMRP, Univ. De São Paulo, Ribeirão Preto, SP, Brazil
Pilocarpine-induced status epilepticus produces morphological changes in granule cells (GCs) of the
rat dentate gyrus (DG), including mossy fiber sprouting and narrower arborizations. Previous DG models suggest that mossy fiber sprouting plays a critical role in DG hyperexcitability but the additional
effects of other morphological changes are yet unknown. The objective of this work was to evaluate
the effects of GC morphological changes on DG activity. We adapted a previous DG model by replacing
its simple GC models by morphologically reconstructed GC models. Our sample had 20 GC models
from pilocarpine-treated rats and 20 from control rats. The models were implemented in NEURON
and their ion channels and conductance densities were the same to allow an evaluation of the role of
morphological changes alone. The control DG model had 500 GCs with 10% sprouting as in previous
models. From this model we constructed models with different fractions (from 10% up to 50%) of the
GCs replaced by cells randomly chosen from the pilocarpine-treated sample. Models were submitted to
focal perforant-path stimulation and, for each model, 100 simulations were run to obtain averages. The
control model produced a response similar to the one of the model with simple GC models. In contrast,
the model with 10% of pilocarpine-treated GCs presented a significant increase in excitability. Models
with further increases in the fraction of pilocarpine-treated GCs had increasingly higher excitabilities.
However, the effect of the insertion of pilocarpine-treated GCs was only visible in combination with
mossy fiber sprouting. Our results suggest that changes in the dendritic morphology of GCs alone are
not enough to affect the DG hyperexcitability but when these changes occur in the presence of mossy
fiber sprouting they may enhance the DG hyperexcitability.
TU093
ANTIEPILEPTIC AND NEUROPROTECTIVE EFFECT OF
PARAWIXIN2, ISOLATED FROM PARAWIXIA BISTRIATA
SPIDER VENOM, IN LITHIUM-PILOCARPINE MODEL
OF TEMPORAL LOBE EPILEPSY
Godoy LD(1,2), Liberato JL(1,2), Gobbo-Neto L(3), Lopes NP(3), Coutinho-Netto J(4) and Santos WF(1,2)
(1)Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo (2)INeC Instituto de Neurociências e Comportamento (3)Departamento de Física
e Química, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo (4)
Departamento de Bioquímica, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo.
Among the adult patients that are diagnosed with epilepsy, 40% present the temporal lobe epilepsy
(TLE), and 30% do not respond to currently available treatments. Several studies demonstrate that
dysfunctions in GABAergic transmission may contribute to the onset of epileptic activity, as well as
other pathologies in the CNS. Therefore, the search for ligands that enhance GABA inhibitory activity
may reveal novel compounds to be used in the understanding and treatment of these pathologies.
Parawixin2, a novel compound isolated from Parawixia bistriata spider venom inhibits both GABA and
glycine uptake. Previous studies demonstrated that Parawixin2 is anticonvulsant when used before
systemic or central injection of a wide range of chemoconvulsants, with good therapeutic indexes.
In the present work, the neuroprotective activity of Parawixin2 was analyzed against cell damage in
chronic TLE model. Wistar rats (250g) were submitted to lithium-pilocarpine-induced Status Epilepticus
(SE). After 38 days from SE it was performed a stereotactic surgery to implant a cannulae in the lateral
ventricle. It was established a 7-day period for recovery and for starting treatment session, which was
carried through 15 consecutive days i.c.v. injections of Saline 0.9% or Parawixin2 (0.86 μM). It was
evaluated morfologic changes in the hippocampus after 60 days from SE by Nissl and Fluoro-Jade C
stainning. It was observed a significant reduction in neuronal loss in CA1, CA3 and Hilus regions of
Parawixin2 treated animals, but it was not observed neuroprotection in the dentate gyrus granular
layer, as compared with the group treated with saline. Unspecific blockade of GABA transporters is an
interesting alternative to the prospection of neuroprotective drugs. This work showed that Parawixin2
has a great potential to be used as tool to neuroscience research and as a probe to the identification
of novel GABAergic neuroprotective agents in epilepsy treatment.
TU095
NEUROPROTECTIVE AND MEMORY-SAVING EFFECTS OF PARAWIXIN10,
AFTER PILOCARPINE-INDUCED STATUS EPILEPTICUS IN WISTAR RATS
Liberato J.L(1,2), Godoy L.D(1,2), Mortari M.R (3), Gobbo-Neto L(4), Lopes N.P(4), Santos W.F(1,2), (1)
College of Philosophy Science and Literature of Ribeirao Preto, USP, Ribeirao Preto, Brazil; (2) Instituto
de Neurociencias e Comportamento,INeC, Ribeirao Preto, Brazil; (3)Institute of Biological Sciences,
Univ. of Brasilia, Brasilia, DF, Brazil.(4) College of Pharmaceutical Science of Ribeirão Preto, USP, Ribeirao Preto, Brazil.
Temporal lobe epilepsy (TLE) is the most common type of epileptic syndrome, and the one presenting
the highest refractoriness. Also, it is characterized by a progressive memory loss that is correlated to
hippocampal sclerosis. Previous data have shown that Parawixin10 (Pwx10), a new compound that
enhances glutamate uptake, prevented the onset of tonic-clonic seizures induced by KA, NMDA and PTZ
in Wistar rats. Continuing the study on Pwx10 potencialities, the aim of this study was to evaluate a
possible neuroprotective effect of Pwx10 on pilocarpine-induced status epilepticus (SE) model of TLE.
Wistar rats were submitted to SE by injecting pilocarpine (2.4 mg/uL, i.c.v.). The Sham group did not
undergo SE only receiving a saline injection instead. Three hours after the seizure activity onset, SE was
attenuated by injection of sodium thiopental (30 mg/kg, i.p) and rats were divided in groups (n=8)
treated with saline (SAL; 0.9%), carbamazepine (CBZ; 120 mg/Kg; i.p) or 3 different doses of Pwx10
(0.5, 1.0, 2.0 μg/μL). These compounds were administered for four consecutive days after interruption of SE. In order to evaluate the prolonged SE cognitive impairment, rats were submitted to MWM two
days after treatments. Subsequently, the rats were euthanized with sodium thiopental and the brains
were processed to obtain histological sections, for further quantitative analysis of the layers cells of
CA1, CA3, and DG by Nissl staining. Pwx10 had a significant improvement in learning in MWM task by
presenting better performance in escape latency and also in probe trial. Regarding the cell viability,
rats treated with all drugs showed lower cell loss as compared to SAL group. Notably those effects on
MWM and in Nissl staining revealed that Pwx10 surpassed carbamazepine efficacy. Pwx10 was efficient to reduce the cognitive deficits. Moreover, this molecule presents an important neuroprotective
preserving hippocampus from cell death.
TU094
PROTEOMIC PROFILING OF THE HIPPOCAMPUS OF
RATS SUBJECTED TO THE PILOCARPINE MODEL OF EPILEPSY
Persike DS (1); Lima ML (2); Amorim RP (1); Araújo MGL (1); Sierra LF (1); Cavalheiro EA (1); Schenkman S (2); Fernandes MJS (1). (1)Depto. de Neurologia e Neurocirurgia; (2)Depto. de Microbiologia,
Imunologia e Parasitologia; Universidade Federal de São Paulo, Unifesp.
The temporal lobe epilepsy (TLE) is the most common type of partial complex seizure in adulthood. The main features
of TLE are: a) seizures starts in the limbic system, particularly in the hippocampus, entorhinal cortex and amygdale,
b) frequently an “initial precipitating injury (IPI)” precedes the appearance of TLE; c) the IPI is followed by a “latent
period”; and d) high incidence of sclerosis (neuronal cell death and gliosis) occurs in the hippocampus (CA1, subiculum
and hilus). High doses of pilocarpine (i.p.) to rats induce status epilepticus (SE) and reproduce the main characteristics
of TLE. This model appears to be highly isomorphic with the human disease, so it has been used to elucidate the main
mechanisms involved with epileptogenesis. Here, we employed a two-dimensional gel electrophoresis (2-DE) technique
to study differential expression of proteins in the hippocampus of rats exhibiting SRS induced by pilocarpine. Methods
and Results: Male Wistar rats (weight ~250 g) were used. All procedures were approved by the Local Ethics Committee (CEP.1770/06). Experimental groups: PILO: animals treated with pilocarpine (360 mg/kg, N=2), and Control:
SALINE (N=2). Both groups were analyzed 90 days after SE onset. Hippocampi were dissected and homogenized in
a lysis buffer [20mM Tris, 7M urea, 2M thiourea, 4% CHAPS (w/v) and protease inhibitors]. Homogenates were used
to perform 2-DE. Protein spots were analyzed by PDQuest (7.3.1) software revealing forty proteins differentially expressed in the hippocampus of epileptic rat compared to control (p<0.05, Student’s test). These spots were excised
and digested overnight with trypsin (12.5μg/ml) generating a peptide finger print to each isolated protein. LC MS/
MS (Q-TOF Micro, Waters) results obtained from samples hydrolyzed with trypsin were analyzed with MASCOT search
engine (Matrix Science) against Swiss-Prot database. Thirty-one of the identified proteins were up-regulated in epileptic
rat, among them Dihydropyrimidinase-related protein 2, and V-type proton ATPase catalytic subunit A. Seven proteins
were down-regulated, i.e. Fructose-bisphosphate aldolase A, Phospholipase A2 gamma, ATP-binding cassette, Malate
dehydrogenase, Guanine nucleotide-binding protein, Factin-capping protein, Guanine nucleotide-binding protein. Two
proteins were expressed only in the control: L-lactate dehydrogenase, and Phosphatidylethanolamine-binding protein.
Now, commercially antibodies have been used to validate some of that proteins by Western blotting and imunohistochemistry. Conclusion: Some of the proteins differentially expressed in the hippocampus of rats with SRS were also
observed altered in the hippocampus of patients with TLE. In general such proteins are part of important metabolic
pathways responsible for the maintenance of vital functions for the cell. These data are partial and the study is in
progress. Financial support: Fapesp, INCT-MCT, CNPq and CAPES. We acknowledge the Laboratório Nacional de Luz
Sincrontron, LNLS, Campinas, Brazil for their support with the mass spectrometry analysis.
TU096
REGULATION OF POST SYNAPTIC CA2+ INFLUX IN HIPPOCAMPAL CA1
PYRAMIDAL NEURONS VIA EXTRACELLULAR CARBONIC ANHYDRASE
FEDIRKO NV (1) Lviv National University, Lviv, Ukraine.
Extracellular ionic shifts (ECA) associated with spreading depression (SD). Increasing significance has
been attributed to ionic changes during SD in view of their role in ischemic brain injury. The hallmarks
of these phenomena include a increase in interstitial K+ concentration, associated with a negative
shift in interstitial electric potential. The ionic displacements are typically accompanied by extracellular pH changes (pHo) consisting of a rapid interstitial alkaline shift. These endogenous shifts can
influence the propagation of SD. In the hippocampal CA1 area, activitydependent alkaline shifts are
large, whereas the mechanisms of their regulation are not clear. In this work we used concentric
pH- and Ca2+-selective microelectrodes , Fluo-5F imaging of [Ca2+]i transients, and current clamp
recording. Shifts in pHe, [Ca2+]e, and[Ca2+]i were elicited by stimulation of the Shaffer collateral
fibers with a train of ten 200 _s, constant current pulses. It was shown that stimulation of the Schaffer
collaterals elicited an alkaline pHe transient, a decrease in [Ca2+]e and in [Ca2+]i. Inhibition of ECA
with benzolamide caused an amplification and prolonged recovery of the pHe and [Ca2+]e responses,
as well as the dendritic [Ca2+]i transients. Addition of benzolamide increased the peak amplitude
of alkaline responses by 165 ± 41% and decay half time by 165 ± 19% (p < 0.01, n = 10);
increased the peak fall in [Ca2+]e by 53 ± 10% (p < 0.01, n = 9) and peak [Ca2+]i responses
in the dendrites by 43 ± 5% (p < 0.001; n=5). The increase in amplitude caused by benzolamide
did not occur in the presence of the NMDAR antagonist APV. Conclusion: Inhibition of ECA causes
amplification of alkaline pHe transients, NMDARs-dependent augmentation of [Ca2+]e, [Ca2+]i and
post-synaptic electrical responses. Data suggest that ECA acts to limit excitability and can shape the
amplitude and time course of dendritic Ca2+ responses.
TU097
ICL-SWELL CURRENTS AND THEIR ROLE ON
VOLUME REGULATION OF ARTICULAR CHONDROCYTES
TU098
SERTRALINE IS AN EFFECTIVE INHIBITOR OF PRE-SYNAPTIC
NA+ CHANNEL-MEDIATED RESPONSES IN HIPPOCAMPUS
TEJEDA C, JIMENEZ L, PONCE A Departamento de Fisiología, Biofisica y Neurociencias, CINVESTAV-IPN,
Mexico
ALDANA BI(1) and SITGES M(1), (1) Dpto. de Biología Celular y Fisiología, Instituto de Investigaciones
Biomédicas, Universidad Nacional Autónoma de México, Distrito Federal, México.
Articular chondrocytes dwell in an environment that is continuously changing its osmolarity as a consequence of mechanical loading, yet their volume regulation capabilities are not fully understood. After
sustained hyposmotic challenges, freshly isolated rat articular chondrocytes showed to be osmotically
sensitive and capable of regulatory volume decrease ( RVD). Whole cell patch clamp recordings showed
that RVD was accompanied by activation of outwardly rectifying chloride currents, featuring instant
activation and inactivation at most depolarizing voltage levels, with an anion selectivity sequence
of I->Br->Cl->Fl->> gluconate-> methanesulphonate-. They were also permeable to the nonessencial aminoacid taurine. These currents were significantly inhibited by chloride channel blockers
DIDS, SITS, 9-AC and NPPB and by drugs that has proven to be selective blockers of swelling activated
chloride currents ICl,swell such as fluoxetine, phloretin, DCPIB and tamoxifen. RT-PCR assays showed
the presence of mRNA for CLC-3 and TMEM16A, both possible molecular determinants of (ICl,swell)
currents. These all indicate that freshly isolated rat articular chondrocytes have ICl,swell. Further,
the finding that the ICl,swell blockers tamoxifen, fluoxetine and DCPIB also altered the RVD response
suggest that ICl,swell are involved in RVD of rat articular chondrocytes in response to hyposmotic
challenges.
Sertraline is a selective serotonin reuptake inhibitor widely prescribed for the treatment of depression. Interestingly, in cultured human embryonic kidney cells sertraline reduced hNav 1.3 channel
activity evoked by electrical _eld stimulation, and in rat pituitary GH3 cells endogenously expressing
neuronal Nav 1.1, 1.2, 1.3 and Nav 1.6 Na+ channel isoforms, sertraline also inhibited the persistent
Na+ currents. Since several of the most effective antiepileptic drugs reduce cerebral excitability
and stop the brain paroxysmal neuronal activity accompanying seizures by blocking Na+ channels,
a possible sertraline action on cerebral pre-synaptic Na+ channels was investigated in the present
study. For this purpose, the effect of sertraline on responses induced by the Na+ channel opener,
veratridine, namely the increase in Na+ (as judged by the Na+ selective indicator dye, SBFI) and in
neurotransmitter release in hippocampus-isolated nerve endings was investigated. Our results show
that sertraline in the low μ M range (1.5-25 μM) progressively inhibits the rise in Na+ and the release
of pre-loaded [3H]Glutamate as well as the release of endogenous serotonin, glutamate and GABA
(detected by HPLC) induced by veratridine depolarization either under external Ca2+ -free conditions
or in the presence of external Ca2+. In addition, under non-depolarized conditions, sertraline (25
μM) increased the external concentration of serotonin at expense of its internal concentration, and
unchanged the external and internal concentrations of the amino acid neurotransmitters and of the
serotonin main metabolite, 5-HIAA. This result is consistent with the sertraline inhibitory action of the
serotonin transporter. However, sertraline is unlikely to inhibit pre-synaptic Na+ channels permeability by increasing external serotonin. Because serotonin in a wide concentration range (1-1000 μM) did
not change the veratridine-induced increase in Na+. In summary, present findings demonstrate that
besides the inhibition of serotonin reuptake, sertraline is an effective inhibitor of pre-synaptic Na+
channels controlling neurotransmitter release.
TU099
VOLTAGE-GATED SODIUM CHANNEL _-SUBUNITS IN CERVICAL
CANCER CELLS: POTENTIAL ROLE IN CELLULAR MIGRATION
TU100
TAMOXIFEN IS AN INHIBITOR OF KV7.2/KV7.3 CHANNELS
Sánchez Sandoval AL, Hernández Plata E, Díaz Velásquez CE, Gómora JC. Departamento de Neuropatología Molecular, División de Neurociencias, Instituto de Fisiología Celular, UNAM. México, D.F.
Voltage-gated sodium channels (VGSCs) are heteromeric transmembrane proteins that consist of a
single poreforming _-subunit associated with one or two auxiliary _-subunits (VGSC_s). These channels are known to be responsible for action potential generation and propagation in excitable cells, but
they are also widely expressed and up regulated in a variety of human cancer types, including breast,
prostate, ovarian, lung, and uterine cervix, where the VGSC activity has been associated with cell motility and invasiveness. VGSC_s are multifunctional molecules that modulate VGSC _-subunit functions.
Additionally they possess a V-type immunoglobulin repeat in the extracellular domain similar to the
family of neural cell adhesion molecules. VGSC_s expression is also correlated with the metastatic
behavior in breast and prostate cancer cell lines. We have previously demonstrated that VGSCs are
over expressed in cervical cancer biopsies versus normal cervix. Furthermore, we reported the functional expression of VGSCs in primary cultures derived from human cervical cancer biopsies and their
contribution to cell migration and invasiveness. In the present work we investigated the electrophysiological activity of VGSCs and the expression of VGSC_s in several cervical cancer cell lines (CaSki,
SiHa, Hela, CaLo, and INBL), as well as their contribution to cell motility. Migration assays where done
in the presence and absence of small interference RNAs targeting VGSC_s in CaSki cells. Preliminary
experiments show a significant reduction in the migration index of CaSki cells when _- subunits are
down regulated, suggesting a potential role in cell migration for these molecules. Interestingly, this
novel effect of _-subunits in cervical cancer is independent of the VGSC _-subunits, as no evidence of
functional expression of these subunits was detected. These findings provide support for the potential
use of the VGSC_s as molecular targets to improve the treatment of cervical cancer.
Ferrer T; Sanchez-Chapula JA, Centro Universitario de Investigaciones Biomédicas. Universidad de Colima. Colima, Colima, México.
KCNQ genes encode five Kv7 K+ channel subunits (Kv7.1–Kv7.5). Four of these (Kv7.2–Kv7.5) are
expressed in the nervous system. Kv7.2 and Kv7.3 are the principal molecular components of the slow
voltage-gated M-channel, which regulates neuronal excitability. In this study, we demonstrate that
tamoxifen, an estrogen receptor antagonist used in the treatment of breast cancer, inhibits KCNQ2/
Q3 currents in human embryonic kidney HEK-293 cells. Current inhibition by tamoxifen was voltage
independent but concentration-dependent. The IC50 for current inhibition was 1.68 ± 0.44 μM. The
voltage dependence of channel activation was not affected by tamoxifen (the V1/2 and the slope were
-30.07 ± 0.72 mV and 8.89 ± 0.64 in control conditions and -31.48 ± 0.57 mV and 9.6 ± 0.51
respectively in presence of tamoxifen 1 μM). This is the first report in the literature about tamoxifen
inhibition KCNQ2/Q3 current. During breast cancer treatment, tamoxifen plasma levels yield 0.54 to
2.0 μM. However, tamoxifen plasma concentrations have been reported to reach up to 1.56 to 7.0
μM during high-dose therapy. Therefore, the concentrations of tamoxifen found to significantly inhibit
KCNQ2/Q3 current are clinically relevant, tamoxifen could increase neuronal excitability.
TU101
A NON-FUNCTIONAL TRUNCATED TRPV1 CHANNEL IS
EXPRESSED IN RAT PANCREATIC BETA CELLS
TU102
REGULATION OF THE M-CURRENT IN CULTURED NEURONS
FROM THE ARCUATE NUCLEUS OF HYPOTHALAMUS
Carlos Manlio Diaz-Garcia, Sara Morales-Lázaro, Carmen Sanchez-Soto, Tamara Rosenbaum and Marcia
Hiriart. Neural Development and Physiology, Instituto de Fisiología Celular, UNAM, Mexico.
LUPERCIO-CORONEL P (1), CASTRO-RODRIGUEZ E (1), and CRUZBLANCA H (1), (1) Centro Universitario de
Investigaciones Biomédicas, Universidad de Colima, Colima, México.
Thermosensitive channels from the transient receptor potential family have been associated with cation non-selectivecurrents in pancreatic beta cells. Although immnoreactivity for the vanilloid receptor
1 (TRPV1) channel has been observed in rodent and human islets, only insulinoma cells have been
shown to be responsive to the agonist capsaicin. In the present work, we explored the expression and
function of TRPV1 in the neonate and the adult rat pancreas. The full-length and a truncated form of
TRPV1 were detected by western blot analysis of native pancreatic beta cells, isolated from newborn
and adult rats. RT-PCR experiments suggest that Exon 7 is missing in the short TRPV1 subunit transcript, resembling a non-functional splice variant. To evaluate the function of TRPV1, we determined
whether capsaicin (16 μM) could increase the Ca2+-sensitive fluorescence of Fluo-4AM or activate
cationic non-selective currents measured using whole-cell patch clamp recordings. However, we found
no evidence of functional TRPV1 channels in these cells. Finally, isolated beta cells from newborn rats
were incubated during 2-3 days with NGF (50 ng/ml), which has been shown to potentiate TRPV1.
NGF did not change the expression and no currents from TRPV1 channels were observed. Our data
suggest that TRPV1 does not participate in the modulation of glucose-induced insulin secretion at
physiological conditions. Further research may identify possible roles for TRPV1 during the ontogenesis of pancreatic islet cells. This work was supported by Gobierno del Distrito Federal PICDS08-72,
CONACYT CB2009-131647, and DGAPAPAPIIT IN215611, Universidad Nacional Autónoma de México.
Carlos Manlio Díaz-García was supported by a doctoral fellowship from Consejo Nacional de Ciencia
y Tecnología (CONACyT).
The M-current (IKM) is an important regulator of excitability; for instance, in superior cervical ganglion
neurons (SCG), the cells where this K+ current was discovered, contributes to frequency dependent adaptation. Besides, IKM inhibition causes a slow membrane depolarization that increases the
probability of firing. M channels are heteromers from Kv7.2-Kv7.5 subunits, and evidence shows that
hypothalamic neurons from the arcuate nucleus (Arc) are endowed with these channel subunits. Serotonin (5-HT) is a relevant regulator of Arc neurons excitability because through the 5-HT2C receptor
enhances cell firing of POMC neurons. In this study we assess whether 5-HT modulates IKM. Rat SCG
or Arc neurons were cultured to: a) use confocal fluorescence microscopy to investigate the possible
co-localization between the Kv7.2 and 5-HT2C proteins; b) record the IKM deactivation with the patch
clamp technique. The immunostaining assays revealed the presence of the 5-HT2C and Kv7.2 proteins
both in SCG and a fraction of Arc neurons. Nevertheless in SCG neurons there was no overlapping of the
fluorescence signals becoming from the antibodies against the Kv7.2 and 5-HT2C proteins; indeed 5-HT
had no effect on IKM. In contrast, some Arc neurons revealed a degree of co-localization suggesting
a functional coupling between 5-HT and IKM. The Arc cells had the following biophysical parameters:
membrane capacitance of 16.9 ± 1.5 pF; input resistance of 750 ± 123 M Ω and; resting potential
of -46 ± 5.2 mV. The level of IKM in Arc cells was much lower (~ 20 pA) as compared with those
found in SCG neurons (~ 200 pA). Therefore before 5HT challenge, Arc cells were bathed with N-EthylMaleimide (50 μM), which increases the opening time of M channels. Under these conditions 5-HT
(20 μM) attenuated to IKM by 40- 50%. This suggests that 5-HT could be increasing the excitability of
these cells through inhibition of IKM.
TU103
FORSKOLIN SUPPRESSES DELAYED RECTIFIER K+ CURRENTS
AND ENHANCES SPIKE FREQUENCY DEPENDENT ADPATATION
OF SYMPATHETIC NEURONS
TU104
ROLE OF CRH R2 RECEPTORS ON FEEDING, GLUCOSE
AND TRIGLYCERIDES OF ADRENALECTOMIZED WISTAR RATS
ACOSTA-GOMEZ EI (1), ANGEL-CHAVEZ LI (2), MORALEZ-AVALOS M (2), IBARRA- RETANA B (1), and CRUZBLANCA H (2), (1) Instituto de Ciencias Biomédicas, UACJ, Ciudad Juárez, Chihuahua, México; (2)
Centro Universitario de Investigaciones Biomédicas, Universidad de Colima, Colima, México
In signal transduction research it is common that natural or synthetic drugs are used as pharmacological tools to activate, or to inhibit, a variety of signaling proteins. That is the case of forskolin (FSK), a
diterpene which directly activates the enzyme adenylate cyclase, thereby increasing the cellular cAMP
levels. However, it is well known that FSK inhibits some cloned K+ channels independently of the
cAMP signaling pathway, as well. Despite the growing evidence revealing that Kv _ subunits are directly
blocked by FSK, there are no studies in neurons exploring the impact on cell excitability upon the FSKinduced K+ channel blockade. Here, we find that FSK or its derivative inactive 1,9-Dideoxyforskolin
reversibly suppressed the delayed rectifier K+ current IKV generated by sympathetic neurons. Given
that IKV is partially generated by Kv2.1 channels, to characterize the action of FSK HEK-293 cells were
transiently transfected with cDNA encoding for Kv2.1 _ subunit. FSK suppressed the Kv2.1-mediated
K+ currents with an IC50 of 32 _M, besides the drug induced an apparent K+ current inactivation
and slowed-down current deactivation. To assess the physiological consequences of the FSK-mediated
suppression of IKV, current-clamp records of action potentials were taken from sympathetic neurons.
FSK markedly reduced the spike afterhyperpolarization and enhanced the spike frequency-dependent
adaptation. We suggest that FSK reduces the excitability of sympathetic neurons by enhancing the
spike frequency-dependent adaptation through a direct blockage of their native Kv2.1 channels.
Rito Domingo Melisa (1,2), Lopez Alonso Veronica Elsa(1), Díaz Urbina Daniel (1), Cruz Garcia Karina(1),
Ambrocio Segundo Gabriela(1), Reyes Santos Karla(1), Mancilla Díaz Juan Manuel(1). (1) Universidad
Nacional Autónoma de México-Fes Iztacala (2) Posgrado en Ciencias Biológicas-UNAM.
The hypothalamus pituitary adrenal (HPA) axis have a key roll in the homeostasis, and in the control for
feeding behavioral response, promoting neuropeptides release and behavioral changes that modulates
the food intake. The Corticotropin-Releasing Hormone (CRH), induced inhibition of feeding those effects
are mediated CRH receptor 2 (CRH-R2), it know that Urocortin II (Ucn II) is an agonist of CRH -R2 this
receptors are expressed in the Paraventricular nucleus of the hypothalamus (PVN). The aim of the present investigation was determinate the role of CRH-R2 receptors in feeding, glucose and triglycerides
serum concentrations of adrenalectomized rats. Experimental subjects, male rats of the Wistar strain
of 250 to 300 g were habituated to a diet of separate sources of protein, carbohydrate and fat, then
were implanted a cannula by stereotaxic procedure, on right PVN. Additionally underwent surgery
to remove the adrenal glands bilaterally (ADX rats) and sham surgery in the control group (sham
rats). After the postoperative recovery (5 days period), the rats were assigned to groups: control group
(Sham-saline), and experimental groups ADX-saline injecting CRH-R2 agonist (ADX-Ucn II), injection of
CRH-R2 antagonist Antisauvagine-30 (ADX+Asv-30). The results showed that administration of Ucn II
reduced carbohydrate and total food intake due to the interruption of the behavioral satiety sequence
(BSS), Glucose and triglycerides concentration decrease with the administration of the agonist and the
antagonist reverse this effect. In conclusion the results of this study suggest that CRH R2 receptors of
the PVN are important for the regulation of feeding, glucose and triglycerides in adrenalectomized rats.
Research support by DGAPA, PAPIIT IN306711.
TU105
INCREASED EXPRESSION OF TRYPTOPHAN-5-HYDROXYLASE 1, BUT
NOT 2, IN BRAINSTEM AS A RESULT OF INTRAUTERINE MALNUTRITION
MANJARREZ GG (1), MARTINEZ RK (1), BOYZO MOA (2), OROZCO SS (3), HERNÁNDEZ-R J (2), 1 Hospital
de Cardiología, and 3 Hospital de Especialidades, Centro Médico Nacional, Instituto Mexicano del
Seguro Social, México, D.F., Mexico. 2 Centro de Investigación y de Estudios Avanzados (CINVESTAV)
IPN, México, D.F., México.
The aim of this study was to determine whether intrauterine malnutrition (IUM) produces a change
in the expression of tryptophan-5-hydroxylase (TPH) 1 and/or 2 as the primary mechanism to explain
the observed chronic cerebral acceleration of the synthesis of 5-hydroxytryptamine (5-HT). We used
an IUM model and controls with ages of 1, 15 and 21 days. The brainstem was obtained to determine
L-tryptophan, 5-HT and TPH activity. Expression of TPH1 and TPH2 via specific antibodies for each was
also evaluated by immunocytochemistry and Western blot. Malnourished offspring had a significant elevation of L-Trp, TPH activity and 5-HT in the brainstem. Both isoforms (1 and 2) of TPH were expressed
from birth in both groups; however, TPH1 expression was significantly higher in offspring with IUM in
relation to the controls. Importantly, these malnourished offspring showed reduced expression of TPH2
compared to controls. It was confirmed that IUM produces an increase in 5-HT in the brainstem and
also showed increased expression of TPH1 at birth, with decreased expression of TPH2. These findings
together allow us to propose that chronic elevation of synthesis of 5-HT observed in the brain of the
offspring with IUM is probably due to a change in the expression and activity of TPH1 induced from
fetal life.
TU107
BDNF AND AMPA IN THE COMISSURAL NTS
MODULATE BRAIN GLUCOSE RETENTION AFTER
CAROTID CHEMORECEPTOR ANOXIC STIMULATION
CUÉLLAR R (1), MONTERO S (1.2), LEMUS M (1), LARA J (1), MELNIKOV V (2), ROCES DE ÁLVAREZ-BUYLLA
E (1), (1) CUIB and (2) Facultad de Medicina, Universidad de Colima, Colima, Col. México.
To test whether BDNF and glutamatergic agonist (AMPA) in comissural NTS (cNTS) modify hyperglycemic
reflex with an increase in glucose retained by the brain (HRBGR) after an anoxic stimulation of carotid
chemoreceptors (CCh), male Wistar rats (280-300g) anesthetized with sodium pentobarbital and artificially ventilated were subjected to the following protocol: a) control: aCSF infusion-100nL into cNTS 4
min before anoxic stimulus (NaCN-5 μg/100g into the isolated carotid sinus of general circulation-ICS)
(n=5); b) experimental 1: BDNF infusion (1 ng/100nL aCSF, as in “a”) (n=5); c) experimental 2: BDNF
antagonist infusion (K252a-25 ng/100nL aCSF, as in “a”) (n=5); d) experimental 3: AMPA infusion
(2 mM/50nL aCSF, as in “a”) (n=5). To analyze the activity of cNTS 2nd order neurons, anterograde
fluorescent labeling was performed in 4 male Wistar rats (150-200g) anesthetized with sodium pentobarbital; the left carotid body (CB) was dissected under aseptic conditions, crystals of anterograde
fluorescent tracer Dil (Molecular Probes) were applied into the CB and sealed with Kwik-Sil to visualize
neuronal activity. Rats were divided in two groups (with and without CCh- ICS stimulation). Twenty days
afterwards rats were anesthetized with pentobarbital, and brain stem was rapidly removed and placed
into a freezer (-70°C). Brain stem was cut into a 40 μm thick transverse sections with a cryostat,
and cNTS sections (Paxinos and Watson, Atlas) were mounted to observe the fluorescence by confocal
microscope. The results indicate that BDNF induced a HRBGR bigger than the one obtained in control
experiments, without BDNF. In the other hand, K252a infusion decreased the reflex. The HRBGR after
AMPA infusion was similar to that observed in the control group. These results suggest: 1)the CCh
anoxic stimulation increased cNTS 2nd order neurons activity as a result of afferent activity from the
reflexogenic carotid zone; 2)BDNF and AMPA modulate the HRBGR induced by anoxia.
TU106
DIFFERENTIAL EFFECTS OF 8-OH-DPAT ON FEEDING BEHAVIOR
López-Alonso VE(1), Mancilla-Díaz JM(1), Díaz-Urbina D(1), Rito-Domingo M(1), Escartín-Pérez RE(1).
(1)Universidad Nacional Autónoma de México, FES Iztacala, Laboratorio de Psicobiología de la Alimentación.
Previous research suggests that the stimulation of 5-HT1A receptor subtype induces biphasic effects
on food intake. But it is unknown the mechanism through which the hypophagic or hyperpagic effect
happen. In the present study we characterized the pattern of behavioral satiety sequence (BSS) by
stimulation of the 5-HT1A receptor subtype in the paraventricular nucleus (PVN) and ventromedial
nucleus (VMN) of the hypothalamus. The 5-HT1A agonist, 8-OHDPAT, was administered in hypothalamic
paraventricular nucleus (PVN) or in the ventromedial hypothalamic nucleus (VMN) of the rats. Experimental subjects were in a dietary self-selection feeding paradigm of protein, carbohydrate and fat.
Administration of 8-OH-DPAT into the PVN decreased carbohydrate intake, while in the VMN this agonist
increased carbohydrate consumption. The hypophagic effect of 8-OH-DPAT in the PVN was associated
to the normal development of the BSS while in the VMN, the 5-HT1A agonist inhibited the satiation
process. In conclusion, 5-HT1A receptors in the PVN and in the VMN modulate food intake by different
mechanism of action, producing hypophagic or hyperphagic effects. This work is the result of financed
projects by DGAPA, PAPIIT IN306711 and PAPIIT IN224811.
TU108
NEONATAL MANIPULATION OF THE SEROTONINERGIC SYSTEM
ALTERS FEEDING BEHAVIOR IN ADULT RATS
Galindo LCM1, de Matos RJB2, Pinheiro IL3, da Luz MDB3, Lívia LA3, Manhães de Castro R4, Lopes de
Souza S3. 1Doutoral Student, Dep Anatomy, Federal University of Pernambuco, Brazil 2 Federal University de Pernambuco, Academic Center of Vitória de Santo Antão 3 Dep Anatomy, Federal University of
Pernambuco 4 Dep Nutrition, Federal University of Pernambuco.
Introduction: Early-life pharmacological management may reflect on the expression of features in
adult organisms. Since serotonin is related to the control of feeding behavior, this study aimed to
evaluate the effects of neonatal pharmacological manipulation of the serotoninergic system on adult
rats feeding behavior. Method: The treatment was carry-out during the lactation time (21days) with
subcutaneous injection of fluoxetine (selective serotonin re-uptake inhibitor, 10mg/Kg) in male Wistar
rats (Fluoxetine Group – F). Control group (C) received saline (10ml/Kg) during the same period. At
180 days of life, after adaptation to individual boxes, the food intake was measured during three days.
On the fourth day, after three hours of fasting, was offered chow diet of animals for Behavioral Satiety
Sequence (BSS) analysis. Ninety minutes after receiving the diet the animals were anesthetized and
perfused. The brains were collected and submitted to immunohistochemistry against c-Fos protein.
Another group of animals with the same age were decapitated and quantitative real time PCR experiments were conducted on RNAs extracted from whole hypothalamus for analysis of gene expression of
Neuropeptide Y (NPY), proopiomelanocortin (POMC), 5-HT1B and 5-HT2C. Results: The fluoxetine group
had lower (p 0.05) daily food intake (C = 71.79 ± 5.64 vs. M = 58.73 ± 2.88) (n=10) and lower
intake on the BBS test (C= 4.8±0.4 vs F= 3.6±0.3) (n=10). This group also expressed more
c-Fos immunoreactive neurons at the nucleus of the solitary tract (C, 218.3 ± 6.6, n=3 vs F, 367
± 25.9, n=4) (p≤0.001) and had higher POMC expression in the hypothalamus (C= 0.82 ± 0.01
n=4 vs. F= 1.01 ± 0.03, n=5) (p≤0.001). Conclusion: Neonatal pharmacological manipulation
of serotonergic system may be associated with hypophagia by increasing activation of anorexigenic
neurons and peptides related to the feeding behavior control pathway in adult rats.
TU109
METABOLIC CHANGES IN A RAT MODEL OF NIGHT WORK
Vega B.(1), Rodríguez K.(2), Velasco M.(2), Hernández M.(2), Escobar C.(2), (1) Lic. Investigación Biomédica Básica, IIB; (2) Facultad de Medicina.
Introduction: Night workers have high propensity to develop obesity, metabolic syndrome, cardiovascular and gastric disorders and cancer. This study explored the changes in metabolism, activity and
feeding patterns in rats after four weeks of forced activity during the day. Method: male Wistar rats
(190g) were exposed to three different conditions of activity for eight hours per day: forced activity
during the day or sleep phase (A-SP), forced activity during the night or activity phase (A-AP) and a
group control not exposed to forced activity. Forced activity was induced by placing rats slow rotating
wheel, where food and water were available in fixed in the center axis of the wheel. All the rats were
housed in individual cages in a 12/12 cycle, fed with chow and water ad libitum. Rats were weighed
every Friday and ingested food was monitored once every week. The values of glucose, triglycerides,
cholesterol were determined the last week. To analyze the circadian rhythmicity of locomotive activity
we analyzed the number of 24h of activity counts for the weekends from baseline to end of the experiment. Results: we did not find significant differences in triglycerides, cholesterol and glucose between
the groups, but we found a significant difference in the results of glucose tolerance test, where the
A-SP exhibited higher values than the other two groups. The locomotive and feeding pattern did not
change. Conclusions: The force activity during the day does not change the metabolic variables, because the rats continue synchronized to the L/D cycle and conserved their feeding pattern. Supported
by PAPIIT IN-203907 Y CONACYT 82462 .
TU111
AUTOMATIC RECORDING OF RODENT
BEHAVIORS IN EXPERIMENTAL SETTINGS
JULIAN TEJADA(1), DAVID NASCIMENTO DOS SANTOS RODRIGUES(2), DANILO SCAVACINI GONÇALVES(2),
FABIO OCTAVIANO(2), ANDRE DI THOMMAZO(2), SILVIO MORATO(1). (1) Univ. of São Paulo, Ribeirão Preto,
Brazil. (2) Instituto Federal de Educação, Ciência e Tecnologia de São Paulo (IFSP) – Brazil .
The detailed record of the animal behavior is an important source of information in different areas,
from neuroscience to psychology behavioral analysis in general, including many different areas such
as ethology and psychopharmacology. The data are usually recorded in experimental sessions and
later submitted to visual inspection and manual codification. This process, depending on human decisions, is subject to errors and takes time. Our main objective was to develop a software able to assist
behavioral recording. In a first stage, we focused on the elaboration of a software (X-Plo-Rat) allowing
manual recording in which, through a computer keyboard, it is possible to track a set of behaviors, record their duration and localization. The software contains a set of preprogrammed apparatuses (such
as the elevated plus-maze and the open-field) and it permits to create new ones. The software output
includes a set of different analyses, arranging the information by places in the apparatus or by time
of behavior occurrence in the session (summarized or detailed), and can be easily export to different
statistic packages. Examples of analyses will be presented. In the second stage, we are including a
module to perform automatic recording and first level analysis by using image recognition. An assistant
wizard to help in the process of defining experimental designs is also being included. Examples of the
software use will be presented. Acknowledgments PIBIC – CNPq.
TU110
EFFECTS OF EARLY LIFE INTERVENTIONS AND
PALATABLE DIET ON OXIDATIVE STRESS IN YOUNG RATS
Marcolin ML(1), Benitz AND(1), Arcego DM(1), Noschang C(2), Krolow R(2)and Dalmaz C(1,2), (1) PPG
Neurociências and (2) PPG Bioquímica, Instituto de Ciências Básicas da Saúde, Univ. Federal do Rio
Grande do Sul, Porto Alegre, RS, Brasil.
Aim: to investigate the effects of stress exposure by isolation in childhood (pre-puberty) in male Wistar
rats handled or not in the neonatal period on oxidative stress in the hippocampus and prefrontal cortex.
Additionally, we aimed to verify whether the access to a high palatable diet, concomitant to stress, affects
these parameters. Methods: Fourteen litters of rats were non-handled or handled 10 min/day, days 1-10
after birth. Weaning was on postnatal day 21; the rats were stressed (isolation) or not and they received
a high palatable (made with condensed milk and rich in simple carbohydrates) or standard lab diet for
seven days. At day 28 after birth, the animals were killed by decapitation, the brain was removed and
dissected the prefrontal cortex and hippocampus. Superoxide dismutase (SOD), glutathione peroxidase
(GPx) and catalase (CAT) activities and total thiol content were determined. Results were analyzed using
three-way ANOVA, using handling, stress and diet as factors; p<0.05 was considered significant and
the results were expressed as mean±standard error of mean. Results: in the prefrontal cortex, it was
found an interaction between handling and diet on SOD activity (p<0.01), a diet effect on CAT activity
(p<0.05), an interaction between stress and diet on GPx activity (p<0.05), an interaction between handling and diet on SOD/GPx ratio (p<0.005), no difference in SOD/CAT ratio (p>0.05) and a handling and
a diet effect on total thiol content (p<0.05 and p<0.001, respectively). In hippocampus, it was found
a significant effect of handling and diet on SOD activity (both p<0.01), an interaction between handling
and diet and another interaction between the three variables on CAT activity (p<0.005 and p<0.01,
respectively), a diet effect and an interaction between handling and diet on GPx activity (p<0.005 and
p<0.05 respectively), a significant effect of diet and an interaction between handling and diet on SOD/
CAT ratio (both p<0.05), a handling effect on SOD/GPx ratio (p<0.05) and no difference in thiol content
(p>0.05). Conclusions: in the prefrontal cortex, handling reduced thiol content and appears to imbalance
the antioxidant enzymes system, which is counteracted by a palatable diet. Hippocampus seems to be
more sensitive than the prefrontal cortex to early interventions, especially to the highly palatable diet, and
both handling and diet appear to imbalance the antioxidant enzyme system.
TU112
A NEW METHOD AND DEVICE TO MEASURE GLUTAMATE
CONCENTRATION WITH HIGH TEMPORAL RESOLUTION:
AN ALTERNATIVE BASED ON THE USE OF ENZYMATIC REACTORS
MORALES-VILLAGRAN A, PALOMERA-ÁVALOS V and LÓPEZ-PÉREZ SJ.
University of Guadalajara, Mexico.
Glutamate (Glu) is the main excitatory neurotransmitter in the brain. Glu appears to play an important
role in neurological disorders such as Alzheimer’s disease, epilepsy or stroke. To understand better its
function, we need sensitive methods with high temporal resolution. This feature will allow correlating
Glu brain concentrations with behavior and electrophysiological activities. Unfortunately, available
methodologies do not have the needed temporal resolution for such correlation. The microdialysis
technique is the most used method to measure the extracellular Glu. In this procedure, the samples
are collected periodically (minutes resolution) and quantified mainly by High Performance Liquid Chromatography (HPLC). To overcome this limitation, we have developed a new method with high temporal
resolution to measure Glu. Our new approach uses glutamate oxidase and Amplex Red, generating a
fluorescent derivate (resorufin) that can be optically detected and measured. Microdialysate coming
from a probe is mixed with a similar volume of an enzymatic reactor prepared to measure Glu concentration. The mixture is introduced into a fused silica tubing inside of an incubation chamber at 37 oC
to carry out the reaction. A fluorescence cell, located at the end of this tubing, measure fluorescence at
590 nm every two hundred milliseconds. Resorufin isn excited at 561 nm by a laser beam. Calibration
curves are carried out immersing the probe in different Glu concentrations. To validate this method
a probe was placed into the frontal cortex in adult awake rats. Our preliminary results show changes
in Glu concentration after infusing 4-aminopyridine by reverse microdialysis procedure in animals
that were previously underwent an asphyxia process around postnatal age. Our results show that our
method has the appropriate sensitivity and temporal resolution to measure this neurotransmitter during brain altered function. This project was supported by CONACyT grant: 105 807.
TU113
MECHANICAL STIMULATION SYSTEM FOR HAND MOVEMENT
LIMA M(1), CANTILLO J(1), RUIZ E(1), and ELÍAS D(1), (1)Sec. Bioelectrónica, Dpto. Ingeniería Eléctrica,
CINVESTAV, D.F., México.
Project Scope: To analyze the brain signal that is delivered with hand movement. This will be attained
through the construction of a mechanical system for stimulation of hand movement. The system is
attached to the patients hand in order to understand the executing movements & brain signal patterns involved in the opening and closing of the hand by the user. Description: The system consists of
three parts: the orthopaedic attachment, the actuator unit and the controller unit. 1) The orthopaedic
attachment consists of a Velcro strap around the hand. On the back of the hand are 5 separate channels, one above each finger. 2) The actuator unit consists of 5 separate servomotors, each servomotor
controls the movement of each individual finger. The movement is transmitted through a series of 2
Bowden cables for each servomotor; one cable for the flexing and another cable for the extension of
the finger. Limit switches, for sensing the presence of the fingers and to constrain the system to move
the hand within these limits, are located near the ends of the Bowden sheaths. 3) The control unit has
a graphical interface by Labview, in which the start command is sent to a micro controller by USB communication. This generates the signal required to control the servomotors. Summary: The system can
be used for recording EEG activity during passive & active hand grasping with the purpose of simplifying
the training of a BCI for rehabilitation of the movement of a hand. This uses a system of classification
of imagined movement of the hand. This is based on the sole premise that the EEG signals in active,
passive & imagined movements are similar enough to be classified in the same way.
TU115
CONSTRUCTION OF A LOW COST SYSTEM FOR RECORDING
EEG AND EMG ELECTRICAL SIGNALS AND ANALYSIS SOFTWARE
FOR CEREBRAL STATE DETERMINATION OF SLEEP AND
AWAKE IN RATS SECOND BY SECOND
Ruiz E.(1), Villavicencio M. (2), Gutierrez R. (2), Camacho A. (1), Elias D. (1), (1) Seccion de Bioelectronica, CINVESTAV Zacatenco, Mexico D.F. (2) Departamento de Farmacologia y Toxicologia, CINVESTAV
Zacatenco, Mexico D.F.
Sleep is a very important physiological process for the proper function of the organism. Sleeping patterns alterations can modulate several physiological processes such as: memory, learning, attention
and even alimentation, sleeping privation increases fat rich food preference which could favor obesity
development. In order to understand the involved physiological processes, sleep study is fundamental
as well as for the research in our country. A low cost electromyograph and electroencephalograph were
developed so as to encourage the sleep study in Mexico. The electromyograph records the electrical signals generated by muscle contractions, the magnitude of these signals varies between -5 millivots and
+5 millivots, the frequency lies between 6 and 10000 Hz (500 Hz for surface emg, 2000 Hz for needle
recordings and 10000 Hz for single motor units), according to these characteristics, a variable gain
amplifier was designed (1v/mv to 5v/mv in 1v/mv steps), the bandwidth goes from 1 Hz to 2100Hz. On
the other hand, electroencephalography is the brain electrical activity recording, the signal bandwidth
is divided in bands that include near dc signals and reach about 100 Hz, the signal amplitude varies
between 0.001 millivolts and 1 millivolt, in order to record the eeg signal, a variable gain amplifier was
designed (2v/mv to 10v/mv in 2v/mv steps), the bandwidth for this amplifier was established between
0.1 Hz and 100 Hz. A matlab software was developed, it decodes the signals every second to determine
the cerebral state of a rat, it also allows external devices activation through TTL levels when an specific
state is reached (e.g. the rat is in slow wave sleep), this characteristic allows the researcher to activate
an electrical stimulator (or a laser for optogenetics studies). We consider that this configuration (the
recording systems and the software) will be helpful to promote sleep studies in Mexican laboratories.
TU114
DEVELOPMENT OF A COMPUTERIZED SYSTEM FOR THE ANALYSIS
OF FORCES GENERATED BETWEEN UPPER AND LOWER TEETH
DURING OCCLUSION
EMMANUEL ORTEGA(2), LUIS GARCÍA(2), FERNANDO ÁNGELES(1), NICOLÁS PACHECO(1), ESTEBAN RUIZ(2),
ALBERTO NUÑO(2), JULIO MORALES(1), ARACELI GALICIA(1), PATRICIA ALFARO(3), HAROLDO ELORZA(1),
DAVID ELÍAS(2), (1) Lab. de Fisiología, Div. de Estudios de Posgrado e Investigación, Facultad de Odontología, UNAM, D.F., México; (2) Secc. de Bioelectrónica, Depto. Ingeniería Eléctrica, CINVESTAV, D.F.,
México and; (3) Depto. de Atención a la Salud, UNAM–Xochimilco, D.F., México.
If it is true that mandibular disorders are not a problem which put at risk patient’s life, they do become
a serious difficulty that can decrease people’s life quality. That’s why in the search of more economic
and less invasive diagnostic and follow-up methods for these diseases, the design and construction of
an instrument which can measure dynamically the force distribution produced between superior and
inferior teeth along the dental arc is proposed.To that end, Tekscan’s T-Scan pressure sensor was used,
and data acquisition electronics and human interface software were built. Single sensor characterization was done in order to relate its output with a pressure unit, and consequently force unit, as well,
as to study its linearity, drift, repeatability and dynamic response. The whole system characterization
was also performed proving to be a high spatial and temporal resolution measurement instrument. The
T-Scan sensor is composed of about 1400 sensing elements which makes it have a spatial resolution
of about 1.6 mm2. The developed system scans the whole sensor with a sample time of 60 ms with a
12-bit resolution and 48 ms in 7-bit resolution. It is connected to a personal computer by the Universal
Serial Bus-Human Interface Device protocol (USB-HID) that gives the possibility to make it portable to
other operating systems than Windows (on which it runs by the time) as the HID support is available in
all platforms. It has a reduced size and it is USB powered which makes it easy to manage. The software
designed acquires and processes data sent by the device and presents it graphically as a map of the
dental arc in which colors represent different intensities of force. Other calculations are also made
such as center of force, area of contact, maximum force, etc. and other odontological information of
interest. PAPIIT-IN227511-DGAPA-UNAM.
TU116
FIRST FAMILIES DIAGNOSED WITH MACHADO JOSEPH
DISEASE/SCA3 IN CUBAN POPULATION
GONZALEZ-ZALDIVAR Y (1), ALMAGUER-MEDEROS L.E (1), LAFFITA-MESA J.M (1), SANCHEZ-CRUZ G (1),
CRUZ-MARIÑO T (1), CUELLO-ALMARALES D (1), ALMAGUER-GOTAY D (1), AGUILERA-RODRIGUEZ R (1),
RODRIGUEZ-LABRADA R (1), CANALES-OCHOA N (1), VELAZQUEZ-PEREZ L (1).1 Center for Research and
Rehabilitation of Hereditary Ataxias.
Objectives: To assess the frequency of MJD/SCA3 among Cuban families with autosomal dominant
ataxia different from SCA2 and to identify the main molecular features of affected individuals. Background: Machado-Joseph disease (MJD/SCA3) is an inherited neurodegenerative disease due to the
expansion of CAG repeats in the ATXN3 gene. It is the most prevalent spinocerebellar ataxia worldwide,
but so far no cases had been diagnosed in Cuba. Methods: In a nationwide genetic survey for SCAs, 95
patients with a clinical diagnosis of autosomal dominant ataxia different from SCA2 were recruited. All
subjects underwent molecular analysis to assess the (CAG)n expansion size in the ATXN3 gene, they
were clinically evaluated through an standardized neurological examination and a genealogical study.
Results: Fourteen (15%) out 95 patients belonging to 7 unrelated families carried an expanded ATXN3
allele. National prevalence rate was estimated near to 0.39/100 000 inhabitants. Normal allele’s size
ranged from 13 to 37 CAG repeats, whereas the expanded alleles ranged from 63 to 77 CAG repeats. No
significant differences in both the size of the paternally versus maternally inherited expanded alleles
or between affected males and females were observed. Mosaicism index for mutant alleles ranged
from 2.22 to 4.76 with a mean of 3.3±0.58. There was no significant correlation between mosaicism
index and age (r=0.11; p=0.34) or CAG repeat expansion (r=0.18; p=0.25). Age at onset showed a
mean of 39.7±9.18 and correlated significantly with the CAG repeat number at expanded alleles (r=
-0.77; p<0.001). Conclusions: The low prevalence rate of MJD/SCA3 together ith its low frequency
among the group of no-SCA2 autosomal dominant ataxias are new clues about the ethnic particularities of Cuban population. Through our work the molecular diagnosis of no-SCA2 ataxias started in the
country, at the same time the basis for the beginning of predictive diagnosis testing in families at risk
were established.
TU117
BUCCAL CELL MICRONUCLEUS FREQUENCY IS
SIGNIFICANTLY INCREASED IN CUBAN PATIENTS
WITH SPINOCEREBELLAR ATAXIA TYPE 2
TU118
EFFECT OF EXPOSURE TO EXTREMELY LOW FREQUENCY
ELECTROMAGNETIC FIELDS ON STRESS AND MOTOR BEHAVIOR
IN AN ANIMAL MODEL OF PARKINSON’S DISEASE
CUELLO-ALMARALES D.A (1), ALMAGUER-MEDEROS L.E (1), VÁZQUEZ-MOJENA Y (1), ALMAGUER-GOTAY D,
(1), LAFFITA-MESA J.M (1), AGUILERA-RODRÍGUEZ R (1), ZAYAS-FERIA P (1), GONZÁLEZ-ZALDÍVAR Y (1),
RODRÍGUEZ-ESTUPIÑÁN A (1). (1) Center for Research and Rehabilitation of Hereditary Ataxias.
BAEZA-MORALES C. E, BECERRIL-LEDEZMA K, MEDINA-SALAZAR I, VERDUGO-DÍAZ L. Depto. de Fisiología,
Facultad de Medicina, Universidad Nacional Autónoma de México, UNAM, México, D.F. MEXICO.
Background: Pathogenic CAG expansions are associated with Spinocerebellar ataxia type 2 (SCA2).
Little is known about the behavior of the cytome in SCA2. In polyQ pathologies has been found morphological markers of nuclear damage which suggest an association between pathological CAG tracts
and genetic instabilities. Objective: To evaluate whether genome instability, cell proliferation and cell
death markers are associated to the SCA2 pathological process. Methods: In a case-control setting
that included 24 affected individuals and 25 age and sex matched controls, a test for micronuclei,
binucleated, condensed chromatin, pyknotic and karyolitic cells was applied in exfoliated buccal
cells. Results: There was a highly significant increase of cells with MNs in SCA2 affected individuals
(p<0.001); the increment was 44.5% related to controls. The frequencies of binucleated, karyolytic,
pyknotic and condensed chromatin cells were no associated to SCA2. None of the studied cell proliferation or cell death markers, neither micronuclei, showed significant associations with the CAG repeat
number at ATXN2 expanded alleles or clinical markers, with the only exception for binucleated cells
that showed a significant association with disease duration (r=0.46; p=0.027). Conclusions: It was
revealed an association between SCA2 and micronuclei unveiling the occurrence of genome instability
as a component of the pathological process.
TU119
TARGETING THE UPR TRANSCRIPTION FACTOR XBP1
PROTECTS AGAINST HUNTINGTON’S DISEASE THROUGH
THE REGULATION OF FOXO1 AND AUTOPHAGY
Rene L. Vidal (1,2), Alicia Figueroa (1,2), Felipe A. Court (3), Peter Thielen (4), Ana Maria Cuervo (5),
Laurie H. Glimcher (4,6), and Claudio Hetz (1,2,4). (1) Center for Molecular Studies of the Cell, Institute
of Biomedical Sciences, University of Chile, (2) Biomedical Neuroscience Institute, Faculty of Medicine,
University of Chile, Santiago, Chile, (3) Millennium Nucleus for Regenerative Biology, Faculty of Biology,
P. Catholic University of Chile, Santiago, Chile, (4) Department of Immunology and Infectious diseases,
Harvard School of Public Health, Boston MA, USA, (5) Department of Developmental and Molecular
Biology Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, New York, USA, and (6)
Department of Medicine, Harvard Medical School, Boston, MA, USA.
Mutations leading to expansion of a poly-glutamine track in Huntingtin cause Huntington’s disease
(HD). Signs of endoplasmic reticulum (ER) stress have been recently reported in animal models of HD,
associated with the activation of the unfolded protein response (UPR). Here we have investigated the
functional contribution of ER stress to Huntington’s disease by targeting the expression of two main
UPR transcription factors, XBP1 and ATF4, in full-length mutant Huntingtin transgenic mice. XBP1
deficient mice were more resistant to developing disease features, associated with improved neuronal
survival and motor performance, and a drastic decrease in mutant Huntingtin levels. The protective
effects of XBP1 deficiency were associated with enhanced macroautophagy in both cellular and animal
models of HD. In contrast, ATF4 deficiency did not alter mutant Huntingtin levels. Although, XBP1 mRNA
splicing was observed in the striatum of HD transgenic brains, no changes in the levels of classical
ER stress markers were detected in symptomatic animals. At the mechanistic level, we observed that
XBP1 deficiency led to augmented expression of Forkhead box O1 (FoxO1), a key transcription factor
regulating autophagy in neurons. In agreement with this finding, ectopic expression of FoxO1 enhanced
autophagy and mutant Huntingtin clearance in vitro. Our results provide strong evidence supporting an
involvement of XBP1 in HD pathogenesis probably due to an ER stressindependent mechanism involving
the control of FoxO1 and autophagy levels.
Recent studies have demonstrated that extremely low frequency electromagnetic fields (ELF-EMF)
produced effects on nervous system function, brain activity and cognition. There is evidence that
transcranial electromagnetic fields are an alternative therapeutic non-invasive for use in patients
with Parkinson’s disease (PD). Treatment with electromagnetic fields has been reported to decreased
difficulty to initiate movements in patients PD. The aim of the study was to determinate the effect
exposure to ELF-EMF on motor and stress behaviors of rats with 6-OHDA lesions. Adult male Wistar
rats (200-220 g) were lesioned unilaterally in the nigrostriatal via injection of 6-OHDA. To evaluate the
degeneration, rotational motor behavior were induced with apomorphine each two weeks. After two
evaluations the animals were divided into three groups (n=8): Group A: lesioned, Group B: lesioned
with ELF-EMF stimulation and Group C: control. ELF-EMF stimulation was applied for two hours daily
(10:00-12:00) during 60 days with a pair of circular Helmholtz coils located above and below the
acrylic cages. The coils produce a vertical sinusoidal 60 Hz magnetic field at 2.4 mT. Each 15 days
before and after the stimulation the animals were evaluated for: open field activity (immobility time,
wall touch and locomotor activity), induced rotational behavior, balance beam test, elevated plus maze
and curling. The results showed that the animals with ELF-EMF stimulation improve their performance
on the balance beam test and that electromagnetic stimulation induces a reduction on the anxietyrelated behaviors. Changes on motor and anxiety-related behaviors in the animal model of PD induced
by ELF-EMF could be produced by alterations in the brain activity and neuroendocrine, in particular the
reduction in the stress hormones. This work was supported in part by PAPIIT grant IN-217812 from the
Universidad Nacional Autónoma de México.
TU120
AMYLOID BETA (42) INDUCED MRI CHANGES
IN AGED RABBIT BRAIN RESEMBLES AD BRAIN
(1)Monica Florence S, (2)Ramesh BN, (1)Ruben Berrocal, (1)Rao KS, (1)INDICASAT-AIP, City of knowledge, Republic Panama, (2)CFTRI, Mysore, India.
Alzheimer’s disease is the most common form of dementia and is structurally characterized by brain
atrophy and loss of brain volume. Amyloid beta is one of the widely accepted causative factors of
AD. Amyloid beta deposition is positively correlated with brain atrophy in AD. In the present study,
structural brain imaging techniques such as Magnetic Resonance Imaging (MRI) were used to measure
neuroanatomical alterations in Alzheimer’s disease brain. MRI is a non-invasive method to study brain
structure. The objective of the present study was to elucidate the role of Amyloid beta on brain structure in the aged rabbit brain. Among 20 aged rabbits, one batch (n = 10) rabbits was injected chronically with Ab(1–42) and another batch (n = 10) with saline. The MRI was conducted before Amyloid
beta (1–42)/saline injection and after 45 days of Amyloid beta (1–42)/saline injection. All the aged
rabbits underwent MRI analysis and were euthanized after 45 days. The MRI results showed a significant reduction in thickness of frontal lobe, hippocampus, midbrain, temporal lobe and increases in the
lateral ventricle volume. We also conducted an MRI study on AD (n = 10) and normal (n = 10) cases
and analyzed for the thicknesses of frontal lobe, hippocampus, midbrain, temporal lobe and lateral
ventricle lobe. We found significant reductions in thickness of the frontal lobe and the hippocampus.
However, no significant reduction in the thickness of midbrain, temporal lobe or increase in the lateral
ventricle volume was observed compared to normal. Correlations in brain atrophy changes between
rabbit brain and human AD brain were found for frontal lobe and hippocampal regions. In contrast,
other regions such as midbrain, temporal lobe, and lateral ventricles were not correlated with rabbit
brain atrophy changes in the corresponding regions. The relevance of these changes in AD is discussed.
TU121
CANNABIDIOL ADD-ON TO TREATMENT AS USUAL IMPROVES
THE OUTCOME OF PATIENTS WITH PARKINSON’S DISEASE
TU122
ANTIPSYCHOTIC PROPERTIES OF CANNABIDIOL ON BEHAVIORAL
CHANGES INDUCED BY REPEATED TREATMENT WITH MK-801 IN MICE
ZUARDI AW; CHAGAS MHN; TUMAS V; PENNA-PEREIRA M; SOBREIRA-NETO M; SOBREIRA ET; ECKELI AL; HALLAK JEC; DOS SANTOS AC; CRIPPA JAS. University of Sao Paulo, Ribeirão Preto, Brazil; INCT Translational
Medicine (CNPq).
GOMES FV(1), ISSY AC(2), DEL-BEL(2), and GUIMARÃES FS (1), (1)Dept. of Pharmacology, School of Medicine, Univ. of Sao Paulo, Ribeirao Preto, Brazil and (2) Dept. of Morphology, Stomatology and Physiology,
Faculty of Dentistry, Univ. of Sao Paulo, Ribeirao Preto, Brazil.
In a recent open-label pilot study, we observed that patients diagnosed with Parkinson’s disease (PD)
who had psychosis for at least 3 months showed a significantly decrease in psychotic symptoms under
Cannabidiol (CBD) treatment. We also observed a decrease in the total scores of the Unified Parkinson’s Disease Rating Scale, suggesting that CBD also improved other symptoms of PD. We conducted
a double-blind, placebo-controlled trial of CBD added to treatment as usual in Parkinson’s symptoms.
Twenty patients with a confirmed diagnosis of idiopathic PD without dementia and on stable doses of
anti-Parkinson drugs for at least 30 days were enrolled. The patients were randomly allocated into
three groups treated for six weeks with daily doses of placebo (n=7), CBD 75 mg (n=6) or CBD 300
mg (n=7) added to usual treatment in a double-blind procedure. Before the beginning and at the end
of the study, the patients were evaluated with the Parkinson’s disease Questionnaire - 39 (PDQ-39) and
the UKU Side Effects Rating Scale. The repeated measures analysis of variance (rmANOVA) of the PDQ39 scores showed significant effects of time, treatment, and time x treatment interaction. Duncan’s
post-hoc test showed that the group treated with CBD 300 mg had a significantly greater decrease in
PDQ-39 scores from baseline (-25.6) than patients treated with CBD 75 mg (-6.5) or placebo (-10.0).
No adverse effects were observed with the introduction of CBD. These preliminary results suggest that
300 mg of CBD added to the usual treatment of PD is safe and capable to improve patients’ outcomes.
Preclinical and clinical studies have shown that cannabidiol (CBD), a major non-pychotomimetic constituent of Cannabis sativa, has a similar effect to drugs with antipsychotic profile. However, the
antipsychotic properties of repeated treatment with CBD have not been investigated. Thus, we investigated if the repeated treatment with CBD would be able to attenuate the behavioral changes induced
by chronic administration of MK-801, a NMDA receptor antagonist. Male C57BL/6J mice (6 weeks of
age when experiment began) received daily ip injection of MK-801 (0.1, 0.5 or 1 mg/kg) for 14, 21 or
28 days. Twenty-four h after the last injection the animals were submitted to prepulse inhibition test
(PPI; pulse: 105dB/20ms; prepulse: 75, 80 and 85dB/10ms, noise: 65 dB). After that, we investigated
if repeated treatment with CBD (15, 30 and 60 mg/kg) would attenuate the impairments induced by
chronic treatment (28 days) with MK-801 (1mg/kg) in PPI. This experiment was similar to the first one
except that the treatment with CBD started on the 6th day after the start of treatment with MK-801
and continued until the end of treatment. In a third experiment, we investigated if CBD would attenuate
the MK-801-induced behavioral changes in social interaction and object recognition test. We observed
impairment in PPI (prepulse: 75 and 80dB) only after the treatment with MK-801 at a dose of 1 mg/
kg for 28 days. In addition, CBD (30 and 60 mg/kg) was able to attenuate the behavioral changes in
the PPI induced by repeated treatment with MK-801 (1 mg/kg). Repeated treatment with MK-801 also
impaired the social interaction and object recognition, an effect attenuated by CBD. Moreover, CBD by
itself did not change the PPI, social interaction and object recognition. These results indicate that the
repeated treatment with CBD was able to reverse the psychotomimetic effects observed after chronic
administration of NMDA receptor antagonists, a model that seems to better represent the changes
observed in patients with schizophrenia, supporting the evidence indicating antipsychotic properties
of CBD. FAPESP and CNPq.
TU123
NEUROPROTECTIVE EFFECT OF CURCUMA LONGA ADMINISTRATED
WITH PEPPER NIGRUM AGAINST ALUMINIUM NEUROTOXICITY AND
ALZHEIMER’S DISEASE (EXPERIMENTAL STUDIES IN MICE)
TU124
TOXIC EFFECT OF A HYPERICUM POLYANTHEMUM CYCLOHEXANE
EXTRACT IN AN ANIMAL MODEL OF PARKINSON DISEASE INDUCED
BY 6-HYDROXYDOPAMINE
ZERROUKI Khayra, DJEBLI Noureddine, Department of biology, Faculty of natural and life science, University of Mostaganem, MOSTAGANEM-ALGERIA
SOUZA TM(1,2), BORSOI M(2), BATASSINI C(3), LAZZARETTI C(2), SILVESTRIN RB(2), BETTI AH(4), ANTONIO,
CB(4), VON POSER GL(4), RATES SMK(4,5), (1) Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil; (2) Programa
de Pós-Graduação em Neurociências, UFRGS; (3) Programa de Pós-Graduação em Bioquímica, UFRGS;
(4) Programa de Pós-Graduação em Ciências Farmacêuticas, UFRGS; (5) Faculdade de Farmácia, UFRGS
Chemicals with neurotoxic effects are found to be very different, citing the aluminum which can cause
serious consequences, not only on the nervous system but also on other organs (liver, kidneys, bones
...) The presence of aluminum in the internal medium (blood) can take only a few hours, but with subacute exposure to chronic, this metal can be stored in several tissues (liver, bone, cartilage, nervous
... ) causing serious complications can go to the molecular level and resulted in tumor diseases and
irreversible damages. Currently, the toxicity of aluminum is well established in the animal laboratory,
and the neurotoxic effect is studied by means of behavioral tests, memory tests, histological and
biological analysis. Several means were considered to fight against this severe health problem, including, herbal medicine which is based on the effectiveness of the antioxidant effect on lesions induced
by metals. Curcuma longa is a powerful antioxidant used to reduce the damage causes by aluminum;
it shows a protective effect against neurotoxicity, a large effect against antioxidative stress inhibiting
the reactions cascade of neurofibrillary tangles, it’s classed between therapeutic agents fight against
neurodegenerative disorders and Alzheimer’s disease induced by AlCl3 on the pyramidal cells in cerebral cortex and hippocampus of albino mice; but it’s less bioavailability and it’s fast eliminated by
the liver detoxification pathways, obliged there administration with piperine exist in Pepper nigrum,
inhibitor of the key enzyme involved in detoxification, which helps maintain a high rate of curcumin
(Curcuma longa) longer. Our aim is realized by means of two experiences with a different exposition of
albino mice; sub acute and chronic exposure with a different manner (Oral and IP) on Curcumin with a
Pepper as a fixative of absorption and AlCl3.
Introduction: Parkinson´s Disease (PD) is a neurodegenerative disorder characterized by a loss of
dopaminergic neurons in the Substantia nigra pars compacta (SNpc). New therapies for this disease
are required. Since a Hypericum polyanthemum extract inhibited monoamine reuptake and modulated
GTP binding in activated striatal dopamine receptors, the aim of this study was to evaluate, in rats, the
effect of an extract from this plant in a PD model induced by 6-hydroxydopamine (6-OHDA). Methods:
Wistar rats received two infusions of 6-OHDA (5.5 mL, 3 mg/mL) into the right medial forebrain bundle.
A cyclohexane extract (90 mg/kg) was orally administered three times spaced in 8 hours either on
the second day following the 6-OHDA infusion (treatment 1) or prior to each testing (from 25 to 1 h,
treatment 2). Methylphenidate (MP, 20 mg/kg, i.p.) induced ipsilateral rotations on post-infusion days
10, 45, and 85, and the sticky tape test was carried out on day 62. Tyrosine hydroxylase (TH) content
was analyzed only in animals under treatment 1. Results and Discussion: Animals under treatment 1
rotated more ipsilaterally (384±65; mean±SE) than controls (212±37; repeated measures ANOVA
group effect, F(1,23)=6.43, p<0.02). In the sticky tape test, there was no difference between groups
(Mann-Whitney test, p>0.05), which showed higher latencies to notice the tape on the contralateral
paw (Wilcoxon test, p<0.01). SNpc lesion level was higher in the treated group [99.6%, 99.5-99.9%
(median, IR); controls: 83%, 34-97%; Mann-Whitney test, p<0.01). No behavioral alteration was
observed in the animals under treatment 2 (p>0.05). Therefore, the cyclohexane extract has a toxic
effect in an animal PD model when administered on the second day following the 6-OHDA infusion,
underlying molecular mechanisms of which remain to be clarified. Financial support: CNPq and Rede
Instituto Brasileiro de Neurociência (IBN-Net) # 01.06.0842-00, FINEP
TU125
HIPPOCAMPAL DISTRIBUTION OF NEUROPEPTIDE Y IN RAT
MODEL OF STREPTOZOTOCIN-INDUCED EXPERIMENTAL
DEMENTIA OF ALZHEIMER’S TYPE
Ariza A(1)*, Andrade R(1),Romero K (1,2), Ruiz C (2) ,Campos A (2), Aguilar L.A (1,2), (1)Laboratorio de
Neurociencia y Comportamiento, Facultad de Medicina “Alberto Hurtado’’, Universidad Peruana Cayetano Heredia, Lima, Perú. (2)Centro Iberoamericano de Neurociencias Educación y Desarrollo Humano,
CEREBRUM. Lima Perú. *[email protected]
TU126
SILENCING OF PINK1 INHIBITS IGF1 AND EGF
MEDIATED AKT PHOSPHORYLATION
CONTRERAS-ZARATE MJ(1), NIÑO A(1), ROJAS L(1), ARBOLEDA H(1), ARBOLEDA G (1), (1) Universidad
Nacional de Colombia
Distribution of numerous neuropeptides in the human brain suggests that peptidergic systems may
contribute to the pathogenesis of cognitive impairment in pathological aging such as dementia disorders. Neuropeptide Y (NPY) is a 36-amino acid peptide and it is the most abundant neuropeptide
presently known in the mammalian brain. The primary structure of NPY has been well preserved during
evolution making this peptide one of the most conserved among species. Although some divergent data
are available, the bulk of evidence suggests that NPY levels in cortex, hippocampus, basal ganglia and
cerebrospinal fluid are contradictory. Intracerebroventricular-streptozotocin (ICVSTZ) in rats causes
impairment of brain glucose and energy metabolism along with oxidative damage and cholinergic
dysfunction, and provides a relevant model for Alzheimer’s disease (AD). The present study examined
the presence of inmmunoreactive cell bodies containing NPY in a rat model of AD. Male rats were
injected bilaterally with ICV-STZ (0.5mg/kg), while sham rats received the same volume of vehicle, then
rats were sacrificed for immunocytochemical assays. One month after STZ injection a high density of
NPY-immunoreactive perikarya was found in the hippocampal CA1 region, CA2 region, CA3 region and
dentate gyrus (DG). In addition, activated astrocytes were seen in the hippocampus and in the cortex.
This NPY distribution indicates that the neuropeptide studied might be involved in multiple functions
like neuroprotection in the rat brain. These finding suggest that NPY may have important roles in the
progression of AD.
Introduction: The etiology of Parkinson’s disease (PD) remains unknown. Mutations in PINK1 have
provided an understanding of the molecular mechanisms of this pathology. Approximately 40 clinical
mutations PINK1 are associated with mitochondrial dysfunction. However, the role of PINK1 in the regulation of neuronal survival pathways is not clear. Aim: was to analyze the role of PINK1 in the control of
the PI3K/AKT survival pathway mediated by IGF-1 and EGF. Methods: we used a model of mesencephalic
neurons (CAD cells) permanently transfected with lentiviral PINK1 shRNA or Control shRNA constructs,
and they were treated with IGF-1, EGF or C2-ceramide, a know AKT inhibitor. Silencing of PINK1 was determined by RT-PCR and inmunoblot. Cell viability was analyzed by MTT and LDH assays. AKT and GSK3B
phosphorylation were analyzed by inmunoblot. Results: PINK1 shRNA transfected cells show a remarkable decrease in the expression level of PINK1 and a reduction in cell survival compared to Control
shRNA cells (p<0,05). Exposure to IGF-1 and EGF (100 ng/ml) induces a increase in phosphorylation
level of AKT in untransfected cells and Control shRNA transfected cells, while exposure to C2-ceramide
significantly inhibits the phosphorylation. However, silencing of PINK1 decreases the basal level of
phosphorylation of AKT (p<0,05) and blocks its increase upon both IGF-1 and EGF treatment and
downstream, there is a lower phosphorylation level of GSK3B in serine 9 (p<0,05). Conclusions: PINK1
confers neuroprotection by modulating the response of the PI3K/AKT cell survival pathway upon growth
factor treatment. We suggest that PINK1 and its impact on the PI3K/AKT cell survival pathway could be
appropriate therapeutic targets in PD. However, further studies are needed in order to understand the
biochemical mechanisms through which PINK1 regulates AKT phosphorylation. Funded by: Colciencias
(110145221189) and DIB-Universidad Nacional de Colombia (20101007590 and 20201009689).
TU127
ACTIVATION OF LIVER X RECEPTORSRESTORES COGNITIVE DECLINE IN
THE TRIPLE TRANSGENIC MOUSE MODEL OF ALZHEIMER´S DISEASE
TU128
THE ANTIMANIC-LIKE EFFECT OF PHENYTOIN: ROLE
OF VOLTAGE-ACTIVATED SODIUM CHANNELS
Sandoval-Hernandez Adrián1, Munoz- Juan Ignacio2, Arboleda Gonzalo1,*, Cardona-Gomez Gloria Patricia2
Martynhak BJ(1), Tonelli DG(1), Pereira M(1), Correia D(1), Casarotto PC(2), Biojone C(2), Guimarães
FS(2), Joca SRL(3), Andreatini R(1) (1) Dept. of Pharmacology, Federal Univ. of Paraná, Brazil; (2) Depat
of Pharmacology, Univ. of São Paulo, Ribeirão Preto, Brazil and (3) Dept of Pharmaceutical Sciences,
Univ. of São Paulo, Ribeirão Preto.
Introduction:The activation of Liver X Receptors(LXR) has become in an important target for treatment of Alzheimer disease (AD). LXR activation up-regulates apolipoprotein E (APOE) that promotes
the proteolytic degradation of A_, reduces amyloid plaque pathology, neuroinflammation and improve
memory inamyloid models of AD (APP and PS1 mutantions). However the capacity of LXR agonist to
improve the pathological characteristics in the triple AD models (APP, PS-1 and tau mutations: 3xtg)
that form neurofibrillary tangleremains unclear. Aims: to analyze the potential of activation of LXR to
improve the cognitive behavior in 3xtg model of AD. Methodology: We used de LXR activator GW3965 in
the 3xtg model of AD which replicates more closely pathologic characteristics of AD including plaques,
tangles, and synaptic dysfunction. We used two groups of animals: Group 1, short-term (ST) treatment
for 6 days (50mg/kg/day) in 24-months old mice; Group 2, long-term (LT) treatment for 12 weeks
(33mg/kg/day) in 12-months old mice. Cognitive performance was evaluated by using hippocampal
dependent spatial memory: Morris water maze. Initially, learning tests were performed for 5 days, two
trials for day; retention test were performed 48 hour after learning test; and transference test were
performed for 2 days, two trials for day, 24 hour after retention test. Results: LT Litermates animals
perform significantly better than 3xtg mice on 5 days of trials (p<0.001: learning, retentionand transference), as untreated 3xtg mice did not show any significant decrease in escape of latency over 5
days of trials. When 3xtg mice were treated with LT GW3965 there was no significant difference with
litermates in these tasks. ST GW3965 treated 3xtg mice perform significant better than untreated
3xtg mice on learning and 4x retention tests in 5 days of trials (p<0.01). Conclusion: Both ST and
LT GW3965 treatment restored memory functions in the 3xtg of AD. Further studies are underway to
analyze the molecular mechanism associated to these cognitive changes, is pending the biochemical
and immunohistochemical analysis of plaques, tangles and lipidomics.
Some anticonvulsants are effective antimanic drugs and, despite some pharmacological differences,
all share the common effect of blocking of voltage-gated sodium channels. In add-on studies, phenytoin, a low cost anticonvulsivant drug, reduced the mania relapse in patients. Interestingly, phenytoin
also reduced the immobility time in mice exposed to the forced swimming test, an effect that was
blocked by veratrine, an opener of voltage-gated Na+ channels. Thus, the objective of the present study was to verify whether phenytoin prevents hyperlocomotion induced by methylphenidate,
an animal model useful for screening antimanic-like drugs and, additionally, whether this effect is
reversible by veratrine pre-treatment. It was also evaluated the effects of repeated administration (21
days) of phenytoin (10 mg/kg, i.p) on BDNF, TrkB and pTrkB levels. Carbamazepine, an anticonvulsivant
drug with approval use for bipolar disorder, was used as a positive control. Methylphenidate (5 mg/kg,
s.c.) increased the locomotion in the open-field and phenytoin (5-10 mg/kg, i.p.) and carbamazepine
(20 mg/kg, i.p.) blocked this effect. Veratrine (0.4 mg/kg, s.c.) pre-treatment reversed the effects
of phenytoin (10 mg/kg i.p.) and carbamazepine (20 mg/kg i.p.). Phenytoin (1-50 mg/kg i.p.) and
carbamazepine (10-20 mg/kg i.p.) did not change spontaneous locomotor activity. Repeated administration of carbamazepine (20 mg/kg) and phenytoin (10 mg/kg) did not change BDNF levels in mice,
but increased the phosphorylation of the BDNF receptor, TrkB. Our results indicate that phenytoin and
carbamazepine might display antimanic properties through the blockade of voltage-gated Na+ channels and that both drugs promote the same effects on the BDNF cascade. Therefore, phenytoin may be
an alternative to other mood stabilizers.
TU129
NEW EVIDENCE ON _-SYNUCLEIN AND TAU BINDING TO
CONFORMATION AND SEQUENCE SPECIFIC GC* RICH
DNA: RELEVANCE TO NEUROLOGICAL DISORDERS
TU130
STUDY OF SPATIAL MEMORY AND EXPRESSION OF
NEUROPEPTIDES IN THE CENTRAL NERVOUS SYSTEM
OF AN ANIMAL MODEL OF PARKINSON´S DISEASE
Guerrero E(2),Vasudevaraju P(1), Muralidhar H(3), Collen T(4), Britton G(2), and Rao K.S.(2), (1)Dept.
of Neuroscience, Medical University of South Carolina, Charleston, USA;(2)Dept. of Neuroscience, Institute for Scientific Research and Technological Services (INDICASAT-AIP), City of Knowledge, Republic
Panama;(3)Dept. of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston,
USA; (4) Dept. of Clinical Biochemistry, Columbus Medical School, Panama.
Pitot C1.,Andrade R1.,Salazar H3 Aguilar L1,2,3. 1 Universidad Peruana Cayetano Heredia, Laboratorio de Investigación y Desarrollo (LID), Area of Neuroscience and Behavior, Lima, Perú. 2 Centro
Iberoamericano de Neurociecias, Educacion y Desarrollo Humano, CEREBRUM. Lima. Perú. 3 Facultad
de Psicologia. Universidad Peruana Cayetano Heredia.
DNA changes in conformation and structural dynamics in the brain have been associated with various neurological disorders; the precise role in the pathogenesis is unclear. Previous studies from our
laboratory have shown a conformational change in the genomic DNA of Parkinson’s disease (PD) (B to
altered B-DNA) and Alzheimer’s disease (AD) brain (B to Z-DNA). There is limited information on the
mechanism on DNA dynamics changes in brain. In the present study, we investigate the DNA conformation and sequence specific binding ability of a-Synuclein and Tau with reference to B-DNA and Z-DNA
using oligonucleotide (CGCGCGCG) as a novel model DNA system. This sequence is predominantly present in the promoter region of genes with biological relevance. Natively, (CGCGCGCG) sequence exists in
B-DNA conformation, but in the presence of high sodium concentration (4 M NaCl) the oligo converts
into Z-DNA form. We used circular dichroism(CD), melting temperature and fluorescence studies to
understand protein-DNA interactions. CD studies indicated that both a-Synuclein and Tau bind to B-DNA
conformation of (CGCGCGCG) and induce altered B-form. Further, these proteins increased the melting
temperature and decreased the number of EtBr molecules bound per base pair of DNA in B-form indicating that DNA stability is favored to alter B-DNA conformation, which could be an intermediate form
favoring Z-DNA conformation. Moreover, both a- Synuclein and Tau also bound to disease-linked Z-DNA
conformation of (CGCGCGCG) and further stabilized the Zconformation. The present study provides vital
mechanistic information on synuclein and tau binding to DNA in a conformation-specific manner causing conformational transition. Furthermore, both the proteins stabilize Z-DNA conformation. These have
altered minor and major groove patterns and thus may have significant biological implications in relevance to gene expression pattern in neurodegeneration. We discuss the implications of _- Synuclein/
Tau binding to DNA and stabilizing the altered conformations of DNA in neuronal cell dysfunction.
Parkinson’s disease (PD) is the second most common neurodegenerative disorder, following Alzheimer’s disease, and it is considered to be an important cause of chronic disability in the population
over age 60. Clinically, PD is characterized by the expression of motor symptoms such as akinesia,
muscle rigidity, decrease of postural re_ex, and distinctive resting tremor. This disorder is characterized by progressive degeneration of dopaminergic neurons from the substantia nigra pars compacta
(SNpc), and to a lesser extent, from the ventral tegmental area (VTA), what causes an intense reduction
of dopamine (DA) concentration in the striatum. Although PD etiology is still not completely known,
neuronal degeneration can result from the convergence of different pathogenic factors, including disturbs of calcium homeostasis, apoptosis, excitoxicity, oxidative stress or even genetic mutation. In the
present study we evaluated changes in motor behavior, spatial memory, for thistest was used Morris
water maze. The areas involved in spatial memory are the hippocampus, hypothalamus, striatum.
Moreover we studied the distribution of neuropeptides ( neuropeptide Y, ß- enkephalyn, sustance P) in
areas associated with motor function which are involved in PD and the variation in the expression of
theseneuropeptides in the substantia nigra, hippocampus and striatum. Results showed the presence
of both fibers and TH immunoreactive cell bodies and NPYin some areas of brains of control rats and
those with Parkinson induced by injection of6-OHDA, suggesting an important function of NPY in the
regulation of the dopaminergic pathway in this animal model.
TU131
NEUROPROTECTIVE EFFECTS OF AGMATINE AGAINST BEHAVIORAL
AND NEUROCHEMICAL IMPAIRMENTS IN MICE SUBMITTED TO THE
INTRANASAL MPTP MODEL OF PARKINSON’S DISEASE
TU132
EFFECT OF FLUOXETINE, BUPROPION AND
YOHIMBINE ON PROCEPTIVITY AND RECEPTIVITY
IN NATURALLY CYCLING FEMALE RAT
MATHEUS FC(1),AGUIAR Jr AS(1),CASTRO AA(2),FIGUEIREDO CP(3),SANTOS ARS(4), FERREIRA J(5),TASCA
CI(2)PREDIGER RD(1), (1)Department of Pharmacology, Federal University of Santa Catarina, Florianópolis, Brazil; (2)Department of Biochemistry, Federal University of Santa Catarina, Florianópolis,
Brazil; (4)Department of Clinical and Toxicological Analysis, Federal University of Rio de Janeiro, Rio
de Janeiro, Brazil; (4)Department of Physiological Sciences, Federal University of Santa Catarina, Florianópolis, Brazil; (5)Department of Chemistry, Federal University of Santa Maria, Santa Maria, Brazil.
Ventura-Aquino E, Fernández-Guasti A
Agmatine is an endogenous substance that has been characterized as a neuroprotective neuromodulator.
In the present study we investigated the potential neuroprotective effects of the systemic treatment with
agmatine (30 mg/kg, i.p.) during 5 consecutive days on the behavioral and neurochemical changes induced by
the intranasal (i.n.) infusion of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP, 1 mg/nostril) in C57BL/6
aged mice, an experimental model of Parkinson’s disease. Fifteen-month-old female C57BL/6 mice were chosen since they are more susceptible to the neurotoxic effects of MPTP and were divided in four groups: control/
control, agmatine/control, control/MPTP and agmatine/MPTP. Animals were evaluated in activity chamber,
social recognition, neurological severity score (NSS) and open field tasks, respectively, 3, 7, 13 and 19 days
after intranasal MPTP infusion to assessed the motor, cognitive, neurological and motor functions. After the
behavioral experiments, the animals were sacrificed and the brains were dissected for the evaluation of the
hippocampal glutamate uptake and imunohistochemistry for tyrosine hidroxylase (TH) in substantia nigra pars
compacta (SNpc). The agmatine capacity to inhibit monoamino oxidase B (MAO-B) activity was also evaluated in vitro. The accepted level of significance for all tests was P < 0.05. CEUA-UFSC: PP00358. Agmatine
increased about 40% the survival rate of the animals infused with MPTP. The treatment prevented the development of cognitive and the neurological impairments caused by i.n. MPTP. The neurotoxin caused a decrease in
the number of crossings and rearings evaluated in the open field test and agmatine was able to prevent such
deficits. These behavioral effects of agmatine were accompanied by a protection against the MPTPinduced
decrease of hippocampal glutamate uptake and loss of dopaminergic neurons in the substantia nigra pars
compacta without altering brain monoamine oxidase B (MAO-B) activity. Repeated treatment with agmatine
prevent, at least in part, the behavioral and neurochemical alterations induced by i.n. MPTP administration.
INTRODUCTION: Some drugs have effects on sexual behavior in animals and humans, for instance, fluoxetine (FLX) produces hypoactive sexual disorder and anorgasmia in men and women, and impairs sexual
behavior in male and female rats. Yohimbine (YOH) has been used for treating erectile dysfunction with
a modest efficacy; while has no effect on women´s sexuality. However, in male rats, YOH has a profound
stimulant effect on sexual motivation, including the reversal of sexual satiety, but its effects in females is
little known. Finally, bupropion (BUP) has revealed pro-sexual effects in humans but there is scarce data
in preclinical studies. The female rat sexual behavior is composed by two main elements: receptivity:
lordosis –a reflex which allows the penis to enter the vagina- and proceptivity: various behaviors intended
to arouse, and solicit the male to mate, considered a measure of sexual motivation. Recently we found
that after continuous mating there is a decrease in proceptivity unaccompanied by changes in receptivity.
OBJECTIVES: To characterize the effect of FLX (1.25mg/kg/s.c./14 days), BUP (5mg/kg/i.p./14 days), YOH
(1mg/kg/i.p./single dose) on proceptivity and receptivity under continuous mating test in naturally cycling
female rats tested in proestrus. RESULTS: FLX inhibited proceptivity; without affecting receptivity; YOH
inhibited receptivity, with no effect on proceptivity. BUP showed a tendency to increase proceptivity without
modifying receptivity. CONCLUSIONS: a) serotonin inhibits sexual motivation females. B) noradrenaline
does not seem to participate in sexual motivation in female´s sexual motivation, but it has an important
inhibitory effect on receptivity. C) BUP at this dose/treatment had an unclear action on female sexual
behavior, inviting to do more research in this regard.
TU133
ANTIHYPERTENSIVE AND TRIGLYCERIDES-LOWERING
EFFECTS OF SALVIA HISPANICA SEED EXTRACT IN
HYPERTENSIVE RATS INDUCED BY L-NAME
GONZALEZ MARTINEZ BE(1), GONZALEZ RAMOS V(1), GUZMAN DE LA GARZA FJ(2), IBARRA HERNANDEZ
JM(2), FERNANDEZ GARZA NE (2), (1) Universidad Autónoma de Nuevo León, Centro de Investigación en
Nutrición y Salud Pública. Laboratorio de Alimentos. Facultad de Salud Pública y Nutrición, Monterrey,
Nuevo León, México. (2) Universidad Autónoma de Nuevo León, Departamento de Fisiología, Facultad
de Medicina. Monterrey, Nuevo León, México.
In Mexico, the chia (Salvia hispanica l.), was a basic food in pre-Columbian times. It is a good source
of alphalinolenic acid, fiber and antioxidant compounds. Traditionally used for therapeutic purposes.
Methodology: 38 Rats with hypertension induced by L-NAME were divided into 4 groups (n=8): negative control (Sham); hypertensive control (CH); hypertensive + captopril (HCA); and hypertensive +
extract (HE). The group HE received P.O. 400 mg/kg/day of methanolic extract of Chia (EM) during the
experiment. We monitored for 5 weeks the systolic blood pressure (SBP); at the beginning and at the
end of the test, blood was collected to quantify the serum levels of C-reactive protein (CRP), total cholesterol (ColT), (Col-LDL) cholesterol-LDL, triglycerides (TG), and liver enzymes (AST, ALT, LDH). Results:
We avoided the increase in SBP with the administration of the methanolic extract in the HE group. There
were no significant differences in serum levels of ColT, LDL-Col ni PCR. The TG of the HE group at the
end were smaller than in the CH group. No substantial changes in the levels of AST, ALT, LDH became
apparent. Conclusion: The methanolic extract of Salvia hispanica l., administered orally, lowers the
SBP and the serum triglyceride levels. These results and the ancient use of the Chia as food; suggest to
use safely chia in the treatment of high blood pressure, however, more studies are needed to find the
dose with the desired effect and to be recommended
TU134
D4 RECEPTORS MODULATE STIMULATORY EFFECTS
OF D1 RECEPTOR ACTIVATION ON MOTOR BEHAVIOR
Campos-Campos B (3), Acosta J (1), Sierra A (1), Aceves J (1), Erlij D (2), Floran B (1). (1) Physiology,
Biophysics and Neurosciences, CINVESTAV, México. (2) Sunny Downstate Medical Center. Brooklyn N.Y.
USA. (3) Pharmacology, CINVESTAV, México.
D4 receptors are involved in several neuropsychiatric disorders with alteration of motor behavior like
Attention Deficit Disorder (ADH), but their role on motor control is still controversial since activation or
blockade by systemic administration of drugs modifying D4 activity, has modest effects on behavior. D4
receptors are located at cortical and pallidal projection neurons, application of this location to current
basal ganglia circuit model predicts that D4 receptors decrease motor behavior having an opposite role
to D1/D2 receptors probably modulating their effects. Now we study the effect of D4 receptor activation
or blockade on motor behavior elicited by activation of D1 receptors. We study the effect of D4 receptor
blockade on amphetamine treated rats and activation of D4 receptor in SKF 38393 effects on reserpine
treated rats. Amphetamine (1mgr./kg i.p.) increase locomotor activity in rats with respect to vehicle.
Blockade of D4 receptor with L 745,870 (0.1 mgr/kg i.p.) 10 minutes before amphetamine, potentiates
amphetamine effect in about 40%, indicating the activation of D4 receptors during amphetamine
treatment. Blockade of D1 receptors with the selective agonist SCH 23390 (0.1 mgr/kg i.p.) prevent
all the stimulatory effect of amphetamine on motor behavior. Also blockade of D1 receptors prevent
the potentiation of D4 receptor blockade in amphetamine treated animals. In reserpine treated rats D1
receptor stimulation with the selective agonist SKF 38393 (2 mgr./kg i.p.) increases locomotor activity.
The effect of SKF 38393 on reserpine treated rats was decrease in 50% by D4 receptor activation with
PD 168,077 (0.5 mgr./kg i.p). This data suggested an antagonist interaction between D1 and D4 receptors on motor behavior and that motor effects of D4 receptor requires increased activity of D1 receptors
to modulate locomotor activity. Support by CONACYT México 152326
TU135
ANTIDEPRESSANTS PREVENT HIERARCHY DESTABILIZATION INDUCED
BY LIPOPOLYSACCHARIDE ADMINISTRATION IN MALE MICE
TU136
THE EFFECT OF METHYLPHENIDATE ON PALATABLE FOOD INTAKE IN
PRENATALLY ALCOHOL TREATED RATS
COHN DW(1), KINOSHITA D(1), PALERMO-NETO J(1) Univ. of São Paulo, School of Veterinary Medicine,
Neuroimmunomodulation Research Group
BARRIOS DE TOMASI E (1), DE LA PARRA J (2) and JUÁREZ J (1), (1)Laboratorio de Farmacología y
Conducta, Instituto de Neurociencias, CUCBA, Universidad de Guadalajara (2) Universidad de Especialidades, Universidad Autónoma de Guadalajara
Depression research needs new animal models in order to increase knowledge of the disease and
search for new therapies. This work aims at providing a neurobiologically validated model to investigate the relationship between sickness behavior, antidepressants treatment and social dominance
behavior in mice. For this purpose, dominant individuals from dyads of male swiss mice were treated
with the bacterial endotoxin LPS (400 μg/ kg i.p. for three consecutive days) to induce social hierarchy
destabilization. There were five groups. One was treated only with LPS. Two other groups were treated
with the antidepressants imipramine or fluoxetine (20 mg/kg 1 hour prior to LPS administration). Another two groups were treated only with imipramine or fluoxetine. Antidepressant treatment prevented
the occurrence of social destabilization. These results indicate that this model could be useful to
provide new insights on the understanding of the brain systems involved in depression.
Palatable food intake increases dopamine (DA) release in dorsal striatum in proportion to the level of
pleasure derived from standard food (SF). Studies show that the consumption of foods rich in sugar
and fat release DA in the accumbens nucleus. It has been reported that prenatal ethanol exposure
can impair the function of midbrain DA system. On this basis, we consider important to study the
effect of dopaminergic activation by methylphenidate (MP) treatment on palatable food consumption
in rats prenatally treated with alcohol. We used 40 female rats exposed prenatally to either, alcohol
(PA) or an isocaloric solution (ISO). At 75 days of age, food consumption was measured every 24 hrs
and body weight every other day. These parameters were evaluated during four periods: 12 days of
base line with access to 24hrs/12 days to macadamia nut (MN) as palatable food and SF ad libitum
(free-choice condition). Afterwards, the animals were injected with either, MP i.p. 3mg/kg or saline
solution for 6 days every other day, and 30 min after injection they had access only to MN for 3hrs
and then to SF in the rest of the day; afterwards, rats were exposed again to the free-choice between
NM and SF for 12 days, posttreatment (PT1), and finally a post-treatment period with only access to
SF (PT2). Methylphenidate treatment reduced total food consumption only in PA group. Preference for
MN decreased significantly in PA group in the free-choice condition in PT1 after MP treatment. In PT2
(only access to SF), food consumption trended to increase in PA group and body weight in this group
was significantly higher than ISO group in this same period. Dopaminergic and noradrenergic activation
seems to reduce the rewarding value of food in rats with DA dysfunction, which affects the preference
for palatable food after MP treatment.
TU137
ANTIDEPRESSANT-LIKE EFFECT OF THE COMBINATION
OF ETHINYL ESTRADIOL AND CITALOPRAM IS DEPENDENT
OF POSTOVARIECTOMY TIME FRAME
Estrada-Camarena E(1), Mejia Mauries S (1). (1)Laboratorio de Neuropsicofarmacología, Dirección de
Neurociencias, Instituto Mexicano de Psiquiatría “Ramón de la Fuente”. México, México.
Several reports indicate that estrogen replacement therapy (ERT) has a therapeutic window for intervention and it is suggested that ERT should be initiated closely to perimenopause. In fact, the
antidepressant-like action of estrogens is absent if hormone restitution started several weeks after
estrogen decline. In addition, estrogens facilitate the antidepressant-like effect of several antidepressants in ovariectomized (OVX) rats in the forced swimming test (FST), an animal model for the
screening of antidepressant drugs. However, it is unknown if this effect could be affected by post-OVX
time frame. Then, present study is focused to evaluate whether post-OVX time affects the synergism
between ethinyl-estradiol (EE2) and citalopram in the FST in middle age rats. Independent groups of
OVX Wistar rats (13-15 months old) received several doses of EE2 (1.25, 2.5 and 5.0 μg/rat; -48h, s.c)
or citalopram (1.25, 2.5, 5.0 and 10 mg/kg, -23.5, 4 and 1 h; s.c) after one or three weeks post-OVX
and were subjected to the FST. In a second experiment, a lower dose of EE2 (1.25 μg/rat,-48h) was
combined with a lower dose of citalopram (2.5 mg/kg, -23,-4, -1h) and rats were tested in the FST after
one or three weeks post-OVX. EE2 is able to induce an antidepressant-like action at one but not three
weeks post-OVX. In contrast, any dose of citalopram induced antidepressant-like effect neither one
nor three weeks post-OVX. In relation to the effect of the combination of EE2 with citalopram, it was
observed an antidepressant-like effect only one week post-OVX. Results suggest that post-OVX time
frame is critical to observe a synergism between EE2 and citalopram to produce an antidepressant-like
effect in middle aged rats. Supported by Fundación Miguel Alemán and CONACyT 104659.
TU138
DIFFERENTIAL EFFECTS OF AN OPIOID ANTAGONIST ON
PALATABLE FOOD CONSUMPTION IN RATS PREVIOUSLY
CLASSIFIED AS LOW, MEDIUM OR HIGH PREFERENCE
CONSUMERS FOR THIS INCENTIVE
Alvarado Bañuelos M., Barrios De Tomasi E. y Juárez J. Laboratorio de Farmacología y Conducta, Instituto de Neurociencias, CUCBA, Universidad de Guadalajara, Guadalajara, Jal., México.
It has been described that endogenous opioid system plays a role in the rewarding value of food
intake; Opioid antagonists administration can reduce consumption of several incentives such as water,
alcohol and food; food intake reduction by opioid antagonists administration seems to be greater for
the preferred or the highly palatable food. On the other hand, it is known that chronic opioid antagonist
treatment increases opioid receptors density, this upregulation may lead to an opioid activity sensitization which could facilitate the rewarding experience of relevant incentives mainly on the firsts days
after treatment. On this base, we studied the changes in palatable food intake after a chronic opioid
antagonist treatment, naltrexone (NTX), in rats with low, medium or high preference for this incentive.
Male rats were exposed to two kinds of food: standard food (SF) and palatable food (chocolate taste),
(PF) for 9 days, then, subjects were classified according to their preference level for this PF as: high
medium or low consumers; afterwards, animals were injected either with NTX s.c. 2mg/kg/day or
vehicle for 6 days in two doses/day, following this period animals were re-exposed to SF and PF in a
free-choice condition. ,There was an increase on PF preference after the NTX treatment, specially in
rats with medium preference; PF preference in low preference rats increased regardless of treatment
with NTX or vehicle; no significant change was observed in animals with previous high preference. The
rewarding degree given by a novelty PF seems depends on individual features in which opioid system
seems to play a key role, once the incentive-reward relationship has been established, the opioid system activation seems to modulate the later incentive consumption on the basis of previous experience.
TU139
NMDA PRECONDITIONING INCREASES AFFINITY AND REDUCES
EXPRESSION OF ADENOSINE A1 RECEPTOR IN MICE HIPPOCAMPUS
TU140
MOLECULAR BASIS OF GABA RESPONSES
IN CRAYFISH X-ORGAN NEURONS
Constantino, L.C.*(1), Ludka, F.K. (1,3), Pamplona, F.A. (2), Tasca, C.I. (1), (1) Departamento de Bioquímica, Laboratório Neuroquímica-4, Universidade Federal de Santa Catarina (UFSC), Florianópolis/
SC; (2) Instituto D’Or de Pesquisa e Ensino, Rio de Janeiro/RJ, 3Curso de Farmácia, Universidade do
Contestado (UnC), Canoinhas/SC.
Jiménez-Vázquez E (1), Arias JM (2) and García U (1). (1)Department of Physiology, Biophysics and
Neuroscience, CINVESTAV-IPN. (2)Faculty for Advanced Studies Iztacala, UNAM
Introduction/Aim: Subtoxic concentrations of N-methyl D-aspartate (NMDA) plays a neuroprotective
role in neuronalexcitotoxicity, a mechanism described as preconditioning. As, adenosinergic receptors
functionally influence NMDA reconditioning in the hippocampus (Boeck et al., 2004), we aimed at
evaluating binding properties and expression of adenosine A1 (A1R) and A2A receptors (A2AR) in the
hippocampus of mice subjected to NMDA preconditioning Methods: Male adult Swiss mice received
saline (NaCl 0.9%g, i.p.) or a nonconvulsant dose of NMDA (75 mg/kg, i.p.) and were observed for 30
minutes for the absence of convulsions. After 24 hours the animals were killed and hippocampi were
collected to perform binding of [3H]DPCPX (to A1R) and [3H]CGS21680 (to A2AR). Adenosine receptors
expression was analyzed by western blot. In addition, functional evaluation of glutamate uptake in
hippocampal slices obtained from preconditioned mice was performed after in vivo treatment with the
selective A1R agonist, CCPA (0.2 mg/kg, i.p.). Statistical analysis was evaluated by one-way analysis of
variance (ANOVA) followed by Tukey’s post hoc test or unpaired t-test. (CEUA/UFSC-PP0549). Results:
NMDA preconditioning increases the affinity of A1R by the ligand DPCPX (Saline: Kd= 38.4 ± 8.88nM,
NMDA: Kd=12.0 ± 3.7 nM, n = 4) and reduces binding maximum (Saline: Bmax= 24.4 ± 2.3
fmol/ug, NMDA: Bmax= 18.0 ± 2.0 fmol/ug, n = 4). These alterations were paralleled by a 30%
decrease in the immunodetection of A1R in hippocampus of preconditioned mice (p <0.05, n = 5).
Furthermore, activation of A1R by the selective agonist CCPA blocked the increased of glutamate uptake
induced by preconditining (control: 0.03 ± 0.022, NMDA: 0.19 ± 0.20, control + CCPA: 0.05 ±
0.04, NMDA + CCPA: 0.025 ± 0.018 nmol/mg protein/min, p <0.05, n = 8). Conclusion: NMDA
preconditioning increases the affinitiy and reduces the number of binding sites and expression of A1R.
Treatment with the A1R agonist (CCPA) functionally overcomes the receptor down-regulation induced by
NMDA preconditioning, bringing hippocampal glutamate uptake back to its regular level.
In the Central Nervous System, _-aminobutyric acid (GABA) acts as an inhibitory transmitter by activating ligand –gated GABAA receptor channels and G protein-coupled GABAB receptors. Both of these
receptors mediate inhibitory post-synaptic transmission. For GABAA receptors, this inhibitory action
is associated with a hyperpolarization due to an increase in conductance to chloride ions. However, it
has been observed that GABAA receptor activation in spinal cord neurons and neonatal neurons can
be excitatory. In all these neurons, the reversal potential for GABA responses is more depolarized than
the resting membrane potential; this means that the equilibrium potential for chloride (ECl-) is less
negative than the resting membrane potential, onsidering that several cation-chloride co-transporters
(NKCC and KCC) controls the chloride gradient across neurons. Interestingly, these GABA excitatory
actions, at least in invertebrates, have shown that this neurotransmitter is also able to mediate excitation via cation currents (Beg and Jorgensen, 2003). The first evidence was described in the nematode
Caenorhabditis elegans, where it was described a homo-oligomeric receptor with high homology to
subunits that comprise ionotropic GABA receptor, but with amino acid residues in the region of the
selectivity filter corresponding to cationic receptors. Another evidence of these receptors type was
described in the fruit fly Drosophila melanogaster through a systematic expression analysis, where
the combination of two ligand-gated cationic channels subunits (LCCH3 and GRD) form a heteromultimeric GABA-gated cation channel (Gisselmann, et al. 2004). Similarly, in xorgan neurons of crayfish
Procambarus clarkii we isolated transient GABA-gated currents showing sodium dependence. However,
so far no characterization at the molecular level has been achieved in this species. In the present
study, using RACE technique we described for the first time a sequence corresponding to an anionic
GABA receptor subunit.
TU141
DYNAMIN-2 REGULATES EXOCYTOSIS IN AN
ACTIVITY-DEPENDENT MANNER, THROUGH A MECHANISM
THAT INVOLVES ACTIN POLYMERIZATION
González-Jamett A(1), Guerra MJ(1),Momboisse F(1),Baez-Matus X(1),Ory S (2), Martínez A(1), Gasman S(2), Cárdenas AM(1). (1)Centro Interdisciplinario de Neurociencia de Valparaíso. Universidad
de Valparaíso. Gran Bretaña 1111, Playa Ancha. Valparaíso, Chile. (2)Institute des Neurosciences Cellulaires et Intégratives, Université de Strasbourg. Centre de Neurochimie- 5, rue Blaise Pascal-67084.
Strasbourg, France.
Dynamin is a multimodular GTPase required for the vesicle pinching off from the plasma membrane
during endocytosis. Although there is evidence that dynamin could also participates during regulated
exocytosis, its specific contribution is still unclear. Here, we show that the disruption of dynamin-2
affects both endo/and exocytosis in bovine chromaffin cells. The inhibition of the GTP-ase activity of
dynamin-2, by the over-expression of a dominant negative mutant (Dyn2K44A), or the knock-down of
endogenous dynamin-2 with small interfering RNA (iRNADyn2) blocked the compensatory endocytosis
of chromaffin granules. The expression of Dyn2K44A or iRNADyn2 also affected the catecholamine
release events in a stimulus-dependent way. Thus, in response to a low concentration of the nicotinic
agonist 1,1-dimethyl-4-phenyl-piperazinium (DMPP) (10 uM), but not in response to a higher concentration (50 uM), Dyn2K44A or iRNADyn2 expression increased fusion pore lifetime, catecholamine
qua

november 5 - Sociedad Mexicana de Ciencias Fisiológicas

Transcription

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