Bài giảng Odor perception (Cảm nhận mùi) ĐHBK TPHCM

Odor Perception

• Overview
➜ Olfaction: a "bad" Sense?
➜ The Olfactory System

ODOR PERCEPTION

➜ The Nature of Smell
➜ Odor and Behavior

Claire Sulmont-Rossé

➜ General Conclusion

Claire Sulmont-Rossé

Updated April 10, 2008

Olfaction: a "bad" Sense?

Olfaction: a "bad" Sense?

• Some philosophical points of view

• Some philosophical points of view

➜ Olfaction is associated with sex

➜ Olfaction is associated with animality

Freud: since humans walks upright, they
can "see" what is happening around
them. As many odors are heavier than
air, smelling implies lying on the ground,
like animals.

Antiquity: perfumes are associated with
physical pleasure and prostitution.
Plato, Kent, Freud: olfaction is a sense of
lust, desire and impulse. Its carries the
sense of animality.

Humans are unable to express odors in
language,
a
capacity
which
is
quintessentially human and testifies to
civilization.
Claire Sulmont-Rossé

Updated April 10, 2008

Claire Sulmont-Rossé

Updated April 10, 2008

Olfaction: a "bad" Sense?

Olfaction: a "bad" Sense?

• Some performance data

• Some performance data

➜ Sensitivity

Dogs are from 300 to 10,000 times more
sensitive to odors than humans.
➜ Discrimination ability

Humans could distinguish thousands of
different types of odorants.
➜ Identification ability
When asked to identify familiar odors,
people were successful only about half the
time.
Claire Sulmont-Rossé

Updated April 10, 2008

➜ Macrosmates (good smellers)
Many mammals (rodents, herbivores, many
predators), fishes, amphibians, reptiles,
insects
➜ Microsmates (poor smellers)

Birds, Humans
➜ Anosmates (non-smellers)

Whale
Claire Sulmont-Rossé

Updated April 10, 2008


Olfaction: a "bad" Sense?

Olfaction: a "bad" Sense?

• odorants

• Olfaction: a "bad" sense?

➜ Chemical compounds

➜ Protection against harmful subtances

not every chemical is odorant

Olfaction allows us to detect rotten food,
leaking gas…

➜ In order to be smelled:

➜ Attraction to edible substances

molecule must be

Olfaction allows us to enjoy our meals.

volatile, small, and hydrophobic

➜ Chemical communication

Olfaction might influence physiology and
behavior of conspecific.
Claire Sulmont-Rossé

Updated April 10, 2008

Claire Sulmont-Rossé

Olfaction: a "bad" Sense?

Odor Perception

• Olfaction: a "bad" sense?

• Overview

« Sense of smell? I never gave it a thought. You
don't normaly give it a thought. But when I lost it –
it was like being struck blind. Life lost a good deal
of its savour – one doesn't realise how much
"savour" is smell. You smell people, you smell
books, you smell the city, you smell the spring –
maybe not consciously, but as a rich unconscious
background to everything else. My whole world was
suddenly radically poorer… »

Updated April 10, 2008

➜ Olfaction: a "bad" Sense?
➜ The Olfactory System
➜ The Nature of Smell
➜ Odor and Behavior
➜ General Conclusion

The Man who Mistook his Wife for a Hat, Sacks, 1985
Claire Sulmont-Rossé

Updated April 10, 2008

Olfactory Physiology (cont’d)

Claire Sulmont-Rossé

Updated April 10, 2008

The Nose

• The human olfactory apparatus:
➜ Primary purpose of nose:

to filter, warm, humidify air we breathe
➜ Nose:

Small ridges,
epithelium

Claire Sulmont-Rossé

olfactory

cleft,

olfactory

Updated April 10, 2008

Claire Sulmont-Rossé

Updated April 10, 2008


The Olfactory System

The Olfactory System

• Location
• Odor pathways
➜ Orthonasal

• Odor pathways

Olfactory
mucosa

Nasal cavity

➜ Through the retronasal pathway, olfaction

has a strong influence on perception and
appreciation of food

Nostril

pathway

Septum

« There is a good reason not to talk
with one's mouth full: it means a
loss of precious smells making
their way to the organ of olfaction. »

➜ Retronasal

pathway
Tongue

Smell, the Secret Seducer, Vroon, 1994

Oral cavity

Claire Sulmont-Rossé

Updated April 10, 2008

The Olfactory System

• Odor pathways
% subjects identifying each food:
- with nostril open (blue bars)
- nostrils pinched shut (red bars)

Claire Sulmont-Rossé

Updated April 10, 2008

The Olfactory System

• Odor pathways

Chocolate

➜ Odors

perceived via the retronasal
pathway could be different from odors
perceived via the orthonasal pathway

Grape juice
Cinnamon
Pineapple

Mozell et al., 1969

Difference in concentration

Action of chewing and saliva

Onion
Lemon
Wine
Coffee
0

20

40

60

80

100

Percentage of subjects
Claire Sulmont-Rossé

Updated April 10, 2008

Claire Sulmont-Rossé

Updated April 10, 2008

The Olfactory System

The Olfactory System

• Vocabulary conventions

• The olfactory organ

➜ Odor

Brain 

Perceived through the orthonasal pathway
➜ Aroma

Olfactory tract
Olfactory bulb



Perceived through the retronasal pathway
➜ Taste
Perceived by the tongue (gustation)

Mitral cell

Cribiform
ethmoid bone

Glomerulus
Axons

Supporting layer

➜ Flavor

Olfactory
mucosa

Aroma + taste of a food

Olfactory
cortex

Olfactory
epithelium

Olfactory cell

Mucous layer
 Nasal cavity

Claire Sulmont-Rossé

Updated April 10, 2008

Claire Sulmont-Rossé

Updated April 10, 2008


The Olfactory System

The Olfactory System

• The mucous layer

• location & structure

➜ Odorant Binding Protein (OBP)

Transportation of the lipophilic odorants
across the hydrophilic mucous
Protection of the olfactory
preventing an oversaturation

cells

Brain 

by

Transportation of the odorants across the
membrane of the olfactory cells ???

Olfactory cell
Dendrite

Support cell

Removal of the odorants from the olfactory
cells ???
Claire Sulmont-Rossé

Axons

Basal cell

Updated April 10, 2008

Olfactory Physiology (cont’d)

Cilias
Mucous
 Nasal cavity

Claire Sulmont-Rossé

Updated April 10, 2008

Olfactory Sensory Neuron

• olfactory epithelium “retina of the nose”:
➜ types of cells:

1. Supporting cells
2. Basal cells
3. Olfactory sensory neurons (OSNs)—cilia
protruding into mucus covering olfactory
epithelium
Olfactory receptors (ORs):
on tips
Interaction between these and odorant

stimulates cascade of biochemical events
Claire Sulmont-Rossé

Updated April 10, 2008

Claire Sulmont-Rossé

Updated April 10, 2008

Updated April 10, 2008

Claire Sulmont-Rossé

Updated April 10, 2008

Olfactory Perception
Pathway

Claire Sulmont-Rossé


The Olfactory System

The Olfactory System

• olfactory receptor cells

• The olfactory cell
➜ Olfactory receptor

➜ Statistics

30,000 cells per mm2

Brain 

20 million cells
➜ Peculiar facts

The olfactory cell is a neuron in direct
contact with inhaled substances.
The olfactory cell is replaced after 4 to 8
weeks by a new neuron (neurogenesis).
Claire Sulmont-Rossé

Updated April 10, 2008

 Nasa lcavity

Claire Sulmont-Rossé

Updated April 10, 2008

The Olfactory System

The Olfactory System

• The olfactory cell

• The olfactory cell

➜ Mechanism of transduction
Odor

➜ Receptor specificity

++

Ca

Odor
receptor

+

The number of discriminable odorants is far
larger than the number of receptors.

Ca++

Na+

NH2

Na+

cAMP-dependant
cation channel

Some odorants are perceived as having

different odors at different concentration.

Odor

-

Adenylyl
cyclase

Protein
G
COOH

Na+

cAMP


A receptor recognizes several odorants
and an odorant is recognized by several receptors

Ca++

Ca++

Na+

ATP
Claire Sulmont-Rossé

Updated April 10, 2008

Claire Sulmont-Rossé

Updated April 10, 2008

The Olfactory System

The Olfactory System

• The olfactory cell

• The olfactory cell

➜ Receptor specificity: Sicard & Holley, 1984
ANI
ACE
PHO
PYR
PHE
IVA
MEN
THY
CIN
CAM
CDN
HEP
BUT
MAC
ISO

XON
XOL
DCI
LIM
CYM

Claire Sulmont-Rossé

➜ Odor coding

Different odorants are recognized
different combination of receptors.

3 4 5 52 5 4 1 4 1 1 3
1 1 5 5 4 2 3 3 4 2 4 1 4 6 5 3 3 3 4 4 2 2 2 3 5 2 3 1 2 5 5 11 3 5 2 2 4 1
6 1 1 2 5 7 8 3 9 7 0 9 2 6 7 8 7 2 5 6 1 5 5 3 8 3 4 4 8 1 0 9 9 6 5 7 4 6 3 2 1 5 0 8 6 2 0 9 7 0 2 43 4 4 0 9 8 3 1

by

Each olfactory cell expresses only one type
of receptor.


Odor quality is coded by the combination
of fired olfactory cells
Updated April 10, 2008

Claire Sulmont-Rossé

Updated April 10, 2008

Olfactory Physiology (cont’d)

The Olfactory System

• genetics of olfactory receptors:

• The olfactory bulb
➜ Location & structure

➜ Buck and Axel (91)

human genome contains about 1000
different olfactory receptor genes, each
codes for single type of OR

Granule cell

➜ Pseudogenes – 60-70% in humans

Mitral or tufted cell

➜ Trade-off between vision and olfaction
Peri-glomerular cell
Glomerulus
Olfactory cell axon
Claire Sulmont-Rossé

Updated April 10, 2008

Claire Sulmont-Rossé

Updated April 10, 2008

The Olfactory System

• The olfactory bulb

• All neurons expressing a particular OR
type converge onto one glomerulus pair
in the olfactory bulb

➜ Glomerulus specificity
Pattern of labeling of a 35S-labeled
receptor gene M50 probe in a mouse
olfactory bulb: the axons of the
olfactory cell that express the
receptor gene M50 converge on the
same glomerulus.

➜ No matter where they are on the nasal

epithelium
➜ However, each glomerulus pair receives

axons from several different receptor
types

Ressler et al., 1994

Claire Sulmont-Rossé

Updated April 10, 2008

Claire Sulmont-Rossé

Updated April 10, 2008

The Olfactory System

The Olfactory System

• The olfactory bulb

• The olfactory bulb
➜ Odor coding

➜ Odor coding

Different odorants fire different combination
of olfactory cells.
Each glomerulus receives input from the
olfactory cells that express the same
receptor.

Pattern of labeling of a 35Slabeled c-fos probe in a rat
olfactory bulb exposed to
peppermint: a single odorant
stimulates multiple glomeruli.

Guthrie et al., 1993


Odor quality is coded by the combination
of fired glomeruli
Claire Sulmont-Rossé

Updated April 10, 2008

Claire Sulmont-Rossé

Updated April 10, 2008


The Olfactory System

The Olfactory System

• The olfactory cortex

• The olfactory cortex
Olfactory bulb

Anterior commissure
Anterior olfactory nucleus
& olfactory tubercle

Thalamus

Olfactory

tubercle

Pyriform
cortex

Amygdala

Entorhinal
cortex

Hypothalamus
Orbitofrontal cortex

Thalamus

Amygdala

Olfactory tract
Olfactory bulb

Frontal cortex
Hypothalamus
Orbitofrontal
cortex

Toward the
entorhinal cortex
Pyriform cortex

Claire Sulmont-Rossé

Updated April 10, 2008

AssociationEmotion
?
Perception & discrimination
Claire Sulmont-Rossé

Odor Perception

• Conclusion

• Overview

with stimuli.
➜ Olfactory information does not relay in the

thalamus before reaching the cortex.
➜ Olfactory process is slow (seconds rather

Memorisation ?
Updated April 10, 2008

The Olfactory System

➜ Sensory cells are neurons in direct contact

Hippocampus

➜ Olfaction: a "bad" Sense?

➜ The Olfactory System
➜ The Nature of Smell
➜ Odor and Behavior
➜ General Conclusion

than milliseconds).

From an evolutionary point of view,
the olfactory system is an "old" system
Claire Sulmont-Rossé

Updated April 10, 2008

Claire Sulmont-Rossé

Updated April 10, 2008

The Nature of Smell

The Nature of Smell

• What factors determine the olfactory
quality of a molecule?

• Ascending approach

Ascending approach
Odorous molecule

➜ Molecules

with different physical and
chemical properties elicit different odor
sensations
Key-lock model

Odor perception

Descending approach
Claire Sulmont-Rossé

Updated April 10, 2008

Claire Sulmont-Rossé

Updated April 10, 2008


From Chemicals to Smells

Presumed Odorant-Receptor Binding

• Theories of olfactory perception:
➜ Shape-pattern theory:
Match between shapes of odorants and odor
receptors; dominant biochemical theory
➜ Molecular research:
Scents detected by means of combinatorial codes
➜ Vibration theory:
different vibrational frequency for every perceived

smell, molecules that produce same vibrational
frequencies will produce same smell

Claire Sulmont-Rossé

Updated April 10, 2008

Claire Sulmont-Rossé

Updated April 10, 2008

The Nature of Smell

From Chemicals to Smells (cont’d)

• Ascending approach

• Specific anosmia:

➜ Theory of Amoore, 1970

➜ inability to smell one specific compound

with otherwise normal smell perception

Existence of specific anosmia

➜ 50% of population has specific anosmia

to androstenone

➜ repeated exposure can sometimes enable

detection
➜ not consistent with vibration theory

Claire Sulmont-Rossé

Updated April 10, 2008

Claire Sulmont-Rossé

Updated April 10, 2008

The Nature of Smell

The Nature of Smell

• Ascending approach

• Ascending approach

➜ Theory of Amoore, 1970
Concept of primary odors
PRIMARY ODORANT

PRIMARY ODOR

ANOSMIC OCCURRENCE

Isovaleric acid

Sweaty

1-Pyrroline

Spermous

Trimethylamine

Fishy

6%

Isobutyraldehyde

Malty

36%

5α-Androst-16-en-3-one

Urinous

47%

ω-Pentadecalactone

Musky

12%

l-Carvone

Minty

1,8-Cineole

Camphorous

Claire Sulmont-Rossé

3%
16%

➜ Theory of Amoore, 1970
Determination of the physical and chemical
properties which elicit each primary odor
sensation
Trimethylamine

1,8-cineole

ω-pentadecalactone
Isovaleric acid

8%
33%
Updated April 10, 2008

Claire Sulmont-Rossé

Updated April 10, 2008


The Nature of Smell

The Nature of Smell

• Ascending approach

• Ascending approach

➜ Limits

➜ Limits

An odorant is recognized by several receptors.

(Amoore, 1991)

Specific
Specific
hyposmics
anosmics

30

Number of subjects

Bimodal distribution of

olfactory thresholds of
222 subjects to
isobutyraldehyde.

Normal
subjects

Some similar odorants
have
very different odors.
α-ionone
violet

20

Some very different
odorants have
similar odors.
Isoamyl-acetate
banana

β-ionone
berries

Hept-4-en-2-ol
banana

10

0

8

12

16

20

24

28

32

Dilution step
Updated April 10, 2008

Claire Sulmont-Rossé

Updated April 10, 2008

The Nature of Smell

The Nature of Smell

• Ascending approach

• Descending approach

➜ Molecules

with different physical and
chemical properties elicit different odor
sensations.

➜ Systems of odor classification
Linné, 1756
• Aromatic

• Descending approach
➜ Molecules

sensation
property.

• Scented or perfumed
• Ambrosia or musk-like

that elicit the same odor
should have a common

• Sharp or garlic-like
• Stinking or goat-like, sweaty
• Repulsive

 Pleasantness

Claire Sulmont-Rossé

• Disgusting
Claire Sulmont-Rossé

Updated April 10, 2008

Claire Sulmont-Rossé

Updated April 10, 2008

The Nature of Smell

The Nature of Smell

• Descending approach

• Descending approach

➜ Systems of odor classification
Zwaardemaker, 1895

➜ Systems of odor classification
Henning's odor prism, 1915

• Ethereal: acetone, ether

Putrid

• Aromatic: camphor, lavender, menthol, lemon
• Balsamic: musk, androstenol

Fragrant

• Alliaceous: garlic, rotten eggs
• Empyreumatic: coffee, toasted bread, tobacco smoke

Ethereal
Lemon

Thyme

• Hircine: cheese, sweet, urine

Burned

• Repulsive or suffocating: tomato, pepper, narcotic substances
• Disgusting: cadaverous odor, feces
Claire Sulmont-Rossé

Spicy
Updated April 10, 2008

Claire Sulmont-Rossé

Resinous
Updated April 10, 2008


The Nature of Smell

The Nature of Smell

• Descending approach

• Descending approach

➜ Systems of odor classification
Jaubert, 1987: the Field of Odors

Claire Sulmont-Rossé

➜ Limits

Odor classification is culturally determined?

Updated April 10, 2008

Claire Sulmont-Rossé

The Nature of Smell

The Nature of Smell

• Descending approach

3D representation
of the olfactory
space

➜ Limits

Continuum of odors rather than discrete
classes of odors: Laffort et al., 2000

Updated April 10, 2008

Laffort et al. , 2000

Dravniek's atlas: profile of 141 molecules × 146 descriptors
Multidimensional scaling: 3 dimensions = 88% of variance
3D representation of the olfactory space
Claire Sulmont-Rossé

Updated April 10, 2008

Claire Sulmont-Rossé

The Nature of Smell

The Nature of the Smell

• Odor mixtures

• Odor mixtures

➜ The perceived intensity of a mixture is

almost never the sum of the intensity of its
ingredients.
Odor A
intensity = 5

+
Odor B
intensity =7
Claire Sulmont-Rossé

Updated April 10, 2008

➜ We are scarcely able to identify the

different ingredients of a mixture
➜ We are scarcely able to predict the odor of

a mixture from its ingredients

Summation: AB = 12
Partial summation: 5 > AB > 12
Neutralization: 0 > AB > 5
Synergy: AB > 12
Updated April 10, 2008

Claire Sulmont-Rossé

Updated April 10, 2008


Odor Perception

Olfactory Psychophysics, Identification, and
Adaptation

• Overview

• Detection, discrimination, recognition

➜ Olfaction: a "bad" Sense?

➜ How much stimulation is required before

we perceive something to be there?

➜ The Olfactory System

➜ Olfactory detection thresholds:

➜ The Nature of Smell

Depend on several factors

➜ Odor and Behavior
➜ General Conclusion

Claire Sulmont-Rossé

Updated April 10, 2008

Olfactory Psychophysics, Identification, and
Adaptation
➜ Women:

Updated April 10, 2008

Olfactory Psychophysics, Identification, and
Adaptation (cont’d)

• Identification:

Generally lower thresholds than men,
especially during ovulatory period of
menstrual cycles, but sensitivity is not
heightened during pregnancy
➜ Professionals can distinguish up to

100,000 odors (e.g., professional
perfumers, wine tasters)

Claire Sulmont-Rossé

Claire Sulmont-Rossé

➜ attaching verbal label to smell is not easy

“Tip-of-the-nose phenomenon”
➜ Anthropologists found that there are fewer

words for experience of smells as
opposed to other sensations

Updated April 10, 2008

Claire Sulmont-Rossé

Updated April 10, 2008

Olfactory Psychophysics, Identification, and
Adaptation (cont’d)

Olfactory Psychophysics, Identification, and
Adaptation (cont’d)

• Sense of smell and language:
Disconnected, possibly because:

• Adaptation:

Olfactory information is not integrated in
thalamus prior to processing in cortex
Majority of olfactory processing occurs in
right side of brain while language
processing occurs in left side of brain

➜ Sense of smell a “change detector”
➜ Examples:

Walking into bakery, smelling
perfume that person cannot smell

strong

➜ Receptor adaptation
➜ Cross adaptation

Claire Sulmont-Rossé

Updated April 10, 2008

Claire Sulmont-Rossé

Updated April 10, 2008


Pathway for Odorant Molecule-Odorant Receptor
Binding (1)

Claire Sulmont-Rossé

Updated April 10, 2008

Pathway for Odorant Molecule-Odorant Receptor
Binding (2)

Claire Sulmont-Rossé

Updated April 10, 2008

Olfactory Psychophysics, Identification, and
Adaptation (cont’d)

Olfactory Psychophysics, Identification, and
Adaptation (cont’d)

• Cognitive habituation

• mechanisms of cognitive habituation:

➜ After long-term exposure to an odorant,

one is no longer able to detect that
odorant or has very diminished detection
ability
➜ Example: Going out of town, coming back

to house with smell

Olfactory receptors internalized into cell
bodies during odor adaptation may be
hindered after continuous exposure, take
longer to recycle
Odorant molecules may be absorbed into
bloodstream
causing
adaptation
to
continue
Cognitive-emotional factors

Claire Sulmont-Rossé

Updated April 10, 2008

Claire Sulmont-Rossé

Updated April 10, 2008

Olfactory Hedonics

Olfactory Hedonics (cont’d)

• Odor hedonics:

• Familiarity and intensity:

➜ The liking dimension of odor perception;

typically measured with scales pertaining
to an odorant’s perceived pleasantness,
familiarity, and intensity

Claire Sulmont-Rossé

Updated April 10, 2008

➜ We tend to like odors we’ve smelled many

times before
➜ Intensity:

Interesting relationship to odor liking

Claire Sulmont-Rossé

Updated April 10, 2008


Olfactory Hedonics (cont’d)

Odorant Pleasantness vs. Intensity

• Nature or nurture?
➜ Are hedonic responses to odors innate or

learned? controversial
Evidence from infants
Cross-cultural data -> associative learning
An evolutionary argument
Learned taste aversions

Claire Sulmont-Rossé

Updated April 10, 2008

Claire Sulmont-Rossé

Olfactory Hedonics (cont’d)

Olfaction, Memory, and Emotion

• 2 caveats for “learned odor hedonics:

• Are odors really the best cues to
memory?

➜ Trigeminally irritating odors may elicit

pain responses, and all humans have
innate drive to avoid pain

Updated April 10, 2008

➜ Other modalities can elicit memory as well

(e.g., vision, touch, taste)
➜ Memories triggered by odor cues are

➜ There is potential variability in receptor

genes and pseudogenes that are
expressed across individuals

Claire Sulmont-Rossé

distinctive in their emotionality
➜ Emotion and evocativeness of odor-

elicited memories lead to false impression
that such memories are especially
accurate
Updated April 10, 2008

Claire Sulmont-Rossé

Updated April 10, 2008

Olfaction, Memory, and Emotion (cont’d)

Memory Cues

• Orbitofrontal cortex:
➜ Olfaction is processed there
➜ Also the cortical area for assigning

affective value, (i.e., hedonic judgment)

Claire Sulmont-Rossé

Updated April 10, 2008

Claire Sulmont-Rossé

Updated April 10, 2008


Odor and Behavior

Odor and Behavior

• Some definitions…

• Some definitions…
➜ Primer pheromone

➜ Kairomone
Attracts individuals of other species

Triggers a long-lasting
change in the target animal

➜ Allomone

➜ Releaser pheromone

Repels individuals of other species

Triggers an immediate behavioral response
in the target animal

➜ Pheromone
Affects individuals of the same species

Claire Sulmont-Rossé

physiological

Updated April 10, 2008

Claire Sulmont-Rossé

Updated April 10, 2008

Odor and Behavior

Odor and Behavior

• Insects and pheromones

• Insects and pheromones

➜ Trail pheromone

➜ Identification pheromone

Ants, as they return to the nest with food,
lay down a trail pheromone, which attracts
and guides other ants to the food.
➜ Alarm pheromone
When honeybees are disturbed,
they release a pheromone which
attracts other bees to attack the
disturber.
Claire Sulmont-Rossé

Honeybee queen releases from her
mandibular glands a pheromone which
attracts workers.
➜ Sex pheromone
The female silkworm moth
releases a pheromone, the
bombikol,
which
can
attract the male from over

3 km.

Updated April 10, 2008

Claire Sulmont-Rossé

Updated April 10, 2008

Odor and Behavior

Odor and Behavior

• Mammals and pheromones

• Mammals and pheromones

➜ The vomeronasal organ

➜ The vomeronasal organ
Accessory olfactory bulb
Nasal septum

Main olfactory bulb
Vomeronal nerves
Nasal cavity

Vomer bone
Brain

Sensory epithelium

Vomeronasal organ

Lumen

Opening of the
vomeronasal organ

Nasal cavity
Oral cavity

Claire Sulmont-Rossé

Updated April 10, 2008

Claire Sulmont-Rossé

Updated April 10, 2008


Odor and Behavior

Odor and Behavior

• Mammals and pheromones

• Mammals and pheromones
➜ Primer effect

➜ The vomeronasal organ

Male mice produce chemosignals that
accelerate puberty in immature females.

Accessory olfactory bulb
Main olfactory bulb

Female mice housed in groups produce a
urinary chemosignal that supresses estrus
in other females.

Vomeronal nerves
Nasal cavity

Brain

Vomeronasal organ

If a just-mated female mouse is exposed to
the smell of a strange male (i.e. different
from the mating male), this smell prevents
the female from becoming pregnant.

Opening of the
vomeronasal organ
Oral cavity

Claire Sulmont-Rossé

Updated April 10, 2008

Claire Sulmont-Rossé

Updated April 10, 2008

Odor and Behavior

Odor and Behavior

• Mammals and pheromones

• Mammals and pheromones

➜ Releaser effect

A vaginal discharge of the female golden
hamster causes males to mate.

➜ Territorial behavior
Many mammals deposit chemicals in and/or
around their "territory".

When a sow in estrus
smells the boar odor, she
become motionless, rounds
her back and pricks up her
ears (lordosis).

Claire Sulmont-Rossé

Updated April 10, 2008

Claire Sulmont-Rossé

Updated April 10, 2008

Odor and Behavior

Odor and Behavior

• Human and pheromones

• Humans and pheromones

➜ The vomeronasal organ

➜ Female "pheromones"

No rigid tube of bone or cartilage

Russell, 1983: female sweat of a "donor"
woman affected the cycles of other women
➜ menstrual synchronization.

No blood pumping mechanism
Few bipolar neurons

Köster, 1986: Under the influence of a
vaginal odor, men and women found the
pictures of girls more sexy.

No accessory olfactory bulb - no projection
to the brain


No evidence for a functional
vomeronasal organ in humans
Claire Sulmont-Rossé

Updated April 10, 2008

Claire Sulmont-Rossé

Updated April 10, 2008


Odor and Behavior

Odor and Behavior

• Humans and pheromones

• Conclusion

➜ Male "pheromones"

➜ Chemical communication plays a role in

Kirk-Smith & Booth, 1980: chairs sprayed
with androstenone were used more often

by women, but were avoided by men.

many mammals, and vomeronasal organ
plays a role in chemical communication.
BUT…
➜ The main olfactory system also plays a

role in chemical communication.

Claire Sulmont-Rossé

Updated April 10, 2008

Claire Sulmont-Rossé

Odor Perception

Odor Perception

• Overview

• General conclusion

➜ Olfaction: a "bad" Sense?

Updated April 10, 2008

➜ The olfactory system is likely to encounter

a great variety of odorants during life

course.

➜ The Olfactory System
➜ The Nature of Smell

➜ The olfactory system should be able to

➜ Odor and Behavior

develop specific receptors / neural
networks in response of those stimuli.

➜ General Conclusion


Impact of learning on odor perception ?
Claire Sulmont-Rossé

Updated April 10, 2008

Claire Sulmont-Rossé

Odor Perception

Odor Perception

• Bibliography

• Bibliography

Updated April 10, 2008

Agosta W. (1992). Chemical communication: the language
of pheromones. W. H. Freeman & Company, New-York,
USA.

➜ Patrick Süskind (1986):

Perfume: the Story of a
Murderer.

Amoore J. (1991). Specific anosmias. In Smell and Taste
in Health and Disease, edited by Getchell et al., Raven
Press, New-York, USA.
Buck L. (2000). Smell and taste: the chemical senses. In
Principles of Neural Science, 4th edition, edited by Kandel
E et al., McGraw-Hill Companies.
Cain W. (1979). To know with the nose: keys to odor
identification. Science, 203, 467-470.

Claire Sulmont-Rossé

Updated April 10, 2008

Claire Sulmont-Rossé

Updated April 10, 2008


Odor Perception

Odor Perception

Carter R. (1998). Mapping the Mind. University of
California Press, London England.

Hanaway J., Woolsey T., Gado M., Roberts M. (1998). The
Brain Atlas. Fitzgerald Science Press, Bethesda, USA.

Doving K. and Trotier D. (1998). Structure and function of
the vomeronasal organ. The Journal of Experimental
Biology, 201, 2913-2925.

Hatt H. (1999). Follow your nose: mechanisms of signal
transduction. Zoology, 102, 120-126.

Fantino M. (1999). Neurophysiologie du goût et de
l'olfaction. OCL, 6, 306-310.
Goldstein E. B. (1996). Sensation & Perception, 4th
edition. Brooks/Cole Publishing Company, Pacific Grove,
USA.
Hudson R. (1999). From molecule to mind: the role of
experience in shaping olfactory function. J. Comp.
Physiol. A., 185, 297-304.
Claire Sulmont-Rossé

Updated April 10, 2008

Odor Perception
Sicard G. and Holley A. (1984). Receptor cell responses to

odorants: similarities and differences among odorants.
Brain Research, 292, 283-296.
Vroon P. (1997). Smell. Farrar, Straus and Giroux, NewYork, USA.

Claire Sulmont-Rossé

Updated April 10, 2008

Holley A. (1999). Recent advances in mechanisms of odor
perception. Wat. Sci. Tech., 40, 79-84.
Restak R. (1984). The Brain. Bantam Books, New-York,
USA.
Sacks O. (1985). The Man Who Mistook his Whife for a
Hat. HarperCollins Publisher, New-York, USA.
Santrock J. (1991). Psychology: the Science of Mind and
Behavior, 3rd edition. Wm. C. Brown Publishers,
Dubuque, USA.
Claire Sulmont-Rossé

Updated April 10, 2008