El Olfato, el Sentido Intimo

El Olfato,
el Sentido Intimo
Fernando J. Lopez-Malpica,MD
6 de octubre de 2009
Restaurant Pelayo
Objetivos
Reconocer la importancia del sentido del olfato,
el mas ancestral de los sentidos, en nuestras
mas primitivas y sofisticadas comunicaciones
Identificar circunstancias que pueden afectar el
funcionamiento fisiologico de este sistema y sus
posibles consecuencias
Definir la dualidad del sistema olfactorio y el
posible rol de la feromonas en nuestro diario
quehacer
Reconocer la interaccion del olfato, la memoria
y experiencias vividas
Life Pleasures and Smells
…y el aroma del café te hace cosquillas,
seguro suenas que estas en Puerto Rico,…
Rhinitis
DNA double
helix
Nature and Nurture
Concept
“Tainos”
“Africans”
“Spanish”
“Puerto Ricans”
Caribbean Weather Systems
Sahara Dust
Air Pollution
Cigarette smoke
Smoking, Pregnancy and Breast
Feeding
Public Health Policies and
Cigarette Smoking
Smoking ban in pubs
Pubs, smoking and sexual encounters?
Cocaine Use
Septal perforation
Damage to the olfactory system can occur
by traumatic brain injury, cancer,
inhalation of toxic fumes, or
neurodegenerative diseases such as
Parkinson's disease and Alzheimer's
disease.
Olfactory Bulb
• The piriform cortex is probably the area
most closely associated with identifying
the odor.
• The medial amygdala is involved
in social functions such as mating and the
recognition of animals of the same species.
• The entorhinal cortex is associated with
memory, e.g. to pair odors with proper memories.
• The exact functions of these higher areas are a
matter of scientific research and debate.
Olfactory
receptor proteins
The cloning of olfactory receptor proteins by
Linda B. Buck and Richard Axel (who were
awarded the Nobel Prize in 2004), and
subsequent pairing of odor molecules to specific
receptor proteins.
Each odor receptor molecule recognizes only a
particular molecular feature or class of odor
molecules.
Mammals have about a thousand genes
expressing for odor reception. Of these genes,
only a portion are functional odor receptors.
Linda B. Buck and Richard Axel
Humans have far fewer active odor receptor genes than
other primates and other mammal
In their landmark paper published in 1991, Buck and
Axel cloned olfactory receptors, showing that they
belong to the family of G protein-coupled receptors. By
analyzing rat DNA, they estimated that there were
approximately one thousand different genes for olfactory
receptors in the mammalian genome.
This research opened the door to the genetic and
molecular analysis of the mechanisms of olfaction
Buck and Axel have shown that each olfactory receptor
neuron remarkably only expresses one kind of olfactory
receptor protein and that the input from all neurons
expressing the same receptor is collected by a single
dedicated glomerulus of the olfactory bulb.
Olfactory Bulb Functions
enhancing discrimination between odors.
enhancing sensitivity of odor detection.
filtering out many background odors to
enhance the transmission of a few select
odors.
permitting higher brain areas involved in
arousal and attention to modify the
detection or the discrimination of odors.
Olfactory System
The main olfactory system detects volatile,
airborne substances, while the accessory
olfactory system senses fluid-phase
stimuli.
Behavioral evidence indicates that most
often, the stimuli detected by the
accessory olfactory system are
pheromones.
Olfaction, the act or process of smelling,
is a dog's primary special sense. A dog's
sense of smell is thousand times more
sensitive than that of humans. A dog has
more than 220 million olfactory receptors
in its nose, while humans have only 5
million.
Kobi achieved high marks in a
cancer-detection experiment
conducted at the Pine Street Clinic
in San Anselmo, Calif.
The sense of smell plays a vital role in
our sense of well-being and quality of
life.
The sense of smell brings us into harmony
with nature, warns us of dangers and
sharpens our awareness of other people,
places and things. It helps us to respond
to those we meet, can influence our mood,
how long we stay in a room, who we talk
to and who we want to see again.
Firsts Encounters with Smells
Numerous studies have shown that smell memory is
long and resilient, and that the earliest odor associations
we make often stick.
When you first smell a new scent, you link it to an event,
a person, a thing or even a moment. Your brain forges a
link between the smell and a memory -- associating the
smell of chlorine with summers at the pool or lilies with a
funeral.
Because we encounter most new odors in our youth,
smells often call up childhood memories.
But we actually begin making associations between
smell and emotion before we're even born. Infants who
were exposed to alcohol, cigarette smoke or garlic in the
womb show a preference for the smells. To them, the
smells that might upset other babies seem normal or
even comforting.
Olfaction is our quickest sense
New signals detected by our eyes and our
ears must first be assimilated by a
structural way station called the thalamus
before reaching the brain’s interpretive
regions, odiferous messages barrel along
dedicated pathways straight from the nose
and right into the brain’s olfactory cortex,
for instant processing.
Everyone has his or her own unique
odor-identity or “smell fingerprint.
No two people have the exact same odoridentity or “smell fingerprint” which is
determined by many factors including: our
genes, skin type, diet, medicine, mood
state and even the weather.
A woman’s sense of smell is
keener than a man’s.
However, her sensitivity does change over
the menstrual cycle. These changes are
influenced by estrogen, which increases
smell acuity in the first half of a woman’s
cycle. It peaks at a time when women are
most fertile and most sexually responsive.
People recall smells with a 65% accuracy after
a year, while the visual recall of photos sinks
to about 50% after only three months.
Our odor memories frequently have strong emotional
qualities and are associated with the good or bad
experiences in which they occurred. Olfaction is handled
by the same part of the brain (the limbic system) that
handles memories and emotions. Therefore, we often
find that we can immediately recognize and respond to
smells from childhood such as the smell of clean sheets,
cookies baking in the oven, the smell of new books or a
musty room in Grandma’s house. Very often we cannot
put a name to these odors yet they have a strong
emotive association even if they cannot be specifically
identified.
Scent Marketing
Advertisers are eager to cash in on the
close link between smell, memory and
mood.
Scent marketing is the latest trick to stand
out from the visual and auditory barrage
that dominates advertising.
Stink Bomb
“Biological Warfare’
While retailers and developers turn to positive
smells for advertising and marketing, the U.S.
Department of Defense has realized the value of bad
smells -- really bad smells. Unlike pepper spray or
tear gas, which irritate pain receptors and can cause
serious damage, stink bombs just reek and make
unruly crowds disperse in a flash.
The idea of using smell as a weapon has been
around for some time, however. The Office of
Strategic Services for the French Resistance
considered using a horrific garbagelike smell called
"Who Me?" against German soldiers in World War II.
The only problem? The sulfur that made the scent so
pungent had a nasty habit of escaping on its own
and lingering on everything it touched.
Odors, sounds and images
Studying groups of Swedes whose
average age was 75, the researchers
offered three different sets of the same 20
memory cues — the cue as a word, as a
picture and as a smell. The scientists
found that while the word and visual cues
elicited associations largely from subjects’
adolescence and young adulthood, the
smell cues evoked thoughts of early
childhood, under the age of 10.
Smells, feelings and memory
A smell can bring on a flood of memories,
influence people's moods and even affect their
work performance.
The olfactory cortex is embedded within the
brain’s limbic system and amygdala, where
emotions are born and emotional memories
stored.
That’s why smells, feelings and memories
become so easily and intimately entangled,
calling up memories and powerful responses
almost instantaneously.
Structure-Function
Olfactory and Vemoronasal
System
Vomeronasal organ
Detects other compounds in addition to
pheromones and that some pheromones
are detected by the main olfactory system
Vomeronasal organ
Hormones vs pheromones
They can be the same chemical element.
A hormone is defined as a molecule which is
secreted internally from a gland or a tissue that
makes hormones that circulates in the blood
stream of that same individual and then acts
upon other parts of that individual's
neuroendocrine system.
A pheromone, in contrast, is a molecule which is
excreted, that is rather than secreted. It acts at a
distance from the individual who excretes it and
has its actions on another individual, a very
important distinction.
Behavioral Studies
Rats with extirpated VNO’s were significantly different from
both control groups of rats. Removal of the VNO removed the
experimental rats from important social information. This is
seen in the reduced exploratory activity in the experimental
animal and the lower number of species-specific reactions.
In another study, half of the guinea pigs vomeronasal systems
were removed, while the other half were put under fake
surgeries with their vomeronasal systems left intact. The
findings suggested that the VNO in the male domestic guinea
pig is necessary for the maintenance of normal responsiveness
to sex odors.
These behavioral studies show the importance of the
vomeronasal system in animals’ social networks and everyday
activities. The importance of the vomeronasal system to the
role of reproduction and social networking has been shown in
many studies.
VNO In human Beings
regresses during fetal development
persist as a vestige in adults
The human embryonic VNO possesses bipolar cells and
luteinizing hormone releasing hormone (LHRH)
producing cells
Won (2000) found evidence of a VNO in 13 of his 22
cadavers (59.1%) and in 22 of his 78 living patients
(28.2%). Given these findings, some scientists have
argued that there is a VNO in adult human beings.
However there is no reported evidence that human
beings have active sensory neurons like those in working
vomeronasal systems of other animals.
Pheromones
"excreted chemical substances which trigger
reproductive behavior within the same species“,
1. Mother-Infant Recognition
2. Territorial Repellants
3. Sexual Attractants
4. Menstrual Synchrony and Timing Influence
"Pheromones are chemical molecules
expressed by a species aimed at other members
of the species to induce stereotyped behavior or
hormonal changes"
Primer encuentro (3:30 pm)
Mis primeros
50 minutos…
Chemical communication and mother-infant recognition
Stefano Vaglio
Laboratory of Anthropology; Department of Evolutionary Biology “Leo
Pardi”; University of Florence; Florence
Fifty years after the term “pheromone” was coined by Peter Karlson
and Martin Lüsher the search for these semiochemicals is still an
elusive goal of chemical ecology and communication studies.
Contrary to what appears in the popular press, the race is still on to
capture and define human scents. Over the last several years, it
became increasingly clear that pheromone-like chemical signals
probably play a role in offspring identification and mother
recognition. Recently, we analyzed the volatile compounds in sweat
patch samples collected from the para-axillary and nipple-areola
regions of women during pregnancy and after childbirth. We
hypothesized that, at the time of birth and during the first weeks of
life, the distinctive olfactory pattern of the para-axillary area is
probably useful to newborns for recognizing and distinguishing their
own mother, whereas the characteristic pattern of the nipple-areola
region is probably useful as a guide to nourishment.
Commun Integr Biol. 2009 May–Jun; 2(3): 279–281.
Mother-infant skin-to-skin contact after delivery results
in early recognition of own mother's milk odour
Authors: K. Mizuno a; N. Mizuno b; T. Shinohara b; M. Noda b
Division of Neonatology Chiba Children's Hospital Chiba Japan.b
Department of Obstetrics Maeda Women's Hospital Maeda Japan.
Conclusion: Our study provides evidence
that mother-infant skin-to-skin contact for
more than 50 min immediately after birth
results in enhanced infant recognition of
their own mother's milk odour and longer
breastfeeding duration
Mother-infant communication
Three-day-old babies will orient their head
toward a brassiere of their own mother
when the nurse wafts the brassiere over
the baby's head, but will ignore other
nursing mothers' brassieres.
Mothers in the animal world recognize
their own infants and will permit their own
infant to nurse, and knock off from them
other infants who try to nurse.
Territorial repellants
Urine marking that male dogs do to repel
other males from the females of their
interest. It's a repelling form of pheromone.
The smell of sex…
Pheromones
Double-Blind Placebo-Controlled trial in 38 men testing
male sex attractant formula applied topically to face
Winnifred Cutler, ARCHIVES OF SEXUAL BEHAVIOR (Feb.1998).
For Gay Men, Different Scents of
Attracttion
An article in The New York Times (2005) reports on a
study done by a team of Swedish researchers that used
a brain imaging technique to explore how homosexual
and heterosexual men respond differently to odors
(pheromones) that may be involved in sexual arousal.
They found that gay men respond in the same way as
women to these chemicals, which are produced by
individuals. This research may open the way to studying
human pheromones, as well as the biological basis of
sexual preference.
In mammals, each olfactory receptor neuron expresses
only one functional odor receptor
sexypheromones.com
Menstrual Synchrony and Timing
Influence
Wine Tasting
The results of the four recognized stages to wine tasting:
appearance
"in glass" the aroma of the wine
"in mouth" sensations
"finish" (aftertaste)
– are combined in order to establish the following
properties of a wine:
complexity and character
potential (suitability for aging or drinking)
possible faults
Bouquet or Aroma,
The “nose” of the
wine
Pausing to experience a wine's bouquet aids the
wine taster in anticipating the wine's flavors.
The "nose" of a wine - its bouquet or aroma - is
the major determinate of perceived flavor in the
mouth.
Once inside the mouth, the aromatics are further
liberated by exposure to body heat, and
transferred retronasally to the olfactory receptor
site.
It is here that the complex taste experience
characteristic of a wine actually commences.
Classic “disproven” tongue map.
Thoroughly tasting a wine involves
perception of its array of taste and
mouthfeel attributes, which involve the
combination of textures, flavors, weight,
and overall "structure".
Following appreciation of its olfactory
characteristics, the wine taster savors a
wine by holding it in the mouth for a few
seconds to saturate the taste buds.
By pursing ones lips and breathing
through that small opening oxygen will
pass over the wine and release even
more esters.
When the wine is allowed to pass
slowly through the mouth it presents the
connoisseur with the fullest gustatory
profile available to the human palate
Main areas associated with
four basic tastes:
-1-bitter tastes.
-2-sour tastes.
-3-salty tastes.
-4-sweet tastes.
Our sense of taste is greatly
influenced by our sense of smell.
Our sense of smell in responsible for about 80%
of what we taste. Without our sense of smell, our
sense of taste is limited to only five distinct
sensations: sweet, salty, sour, bitter and the
newly discovered “umami” or savory sensation.
All other flavors that we experience come from
smell.
This is why, when our nose is blocked, as by
allergies or a cold, most foods seem bland or
tasteless.
Our sense of smell becomes stronger when we
are hungry.