les sens chimiques - unige.ch
TRANSCRIPT
Les sens chimiquesProf. Alan Carleton
UNIGE, Faculté de médecine, Département de Neurosciences Fondamentales
• Le système olfactif principal
• Organe voméronasal et détection des phéromones
• La perception des goûts
Les sens chimiques
GUSTATION
Une expérience multisensorielle
FLAVEUR: Ensemble des
sensations olfactives,
gustatives et tactiles ressenties lors
de la
dégustation d'un produit
alimentaire.
Les cinq composantes du goût
AmerSucré UmamiSalé Acide
Organisation anatomique
Epiglotte
Langue
Palais
Cavité nasale
Les bourgeons du goût et papilles gustatives
Organisation des bourgeons du goût
20 mm
Bourgeons du goût:
Homme (10000)
Rat (1000)
500 CV
Caffeine
Quinine
Glucose
Aspartame
GlutamateNaCl
KCl
Acide acétique
Des molécules induisant la perception d’un goût
Guanosine
monophosphate
AmerSucré UmamiSalé Acide
Acide citrique
Récepteurs gustatifs
ENAC PKD2L1
Récepteurs du salé et de l’acide
Salé Acide
Canaux ioniques
Récepteurs du sucré, umami et amer
40 T2RsT1R2/T1R3 T1R1/T1R3
AmerSucré Umami
Perte de la perception sucré chez
des animaux carnivores
T1R2/T1R3 T1R1/T1R3
Sucré Umami
X
?
Perte de la perception sucré chez
des animaux carnivores
The cell biology of taste. Chaudhari and Roper (2010) JCB
Transduction
ATP
5-HT
T1R2-T1R3 T1R1-T1R3 ENACEpithelial Na Chan.
PKD2L1TRP channel
Transduction (Taste GPCR)
The cell biology of taste. Chaudhari and Roper (2010) JCB
Representation sensorielle sur la langue
Codage des goûts au niveau de la langue
Vers le cerveau
Gustatoray pathways in the human brain
Noyau du
tractus solitaire
Représentation corticale des goûts
La perception des goûts
La représentation cérébrale des goûts
Accolla et al. (2008) Journal of Neuroscience
Marella et al. (2006) Neuron
Schoenfeld et al. (2004) Neuroscience
Gilbertson et al. J Neurosci (2001)
Codage de l’information sensorielle
Codage de l’information sensorielle
Mouse behaviour
Mueller et al. Nature (2005)
Codage de l’information sensorielle
Cortical neurons
Stapleton et al. J Neurosci (2006)
Représentation sensorielle dans le cortex
Vision Audition
Location of the gustatory cortex in the rodent brain
mca
rhv
S1BF
GC
S1
Pir
lot
GC
rs
IC
• Changes in Reflectance upon activation
• Functional Population Activity
• Successfully used to establish spatial organization of other sensory areas
• Good Spatial Resolution
Methods – Intrinsic imaging
Functional localization of the gustatory cortex
Accolla, Bathellier, Petersen and Carleton. Journal of Neuroscience (2007) 27:1396-1404
Signals are taste specific
Represention des goûts dans le cortex
B
Pleasant
Unpleasant
A
SweetSalty
BitterSour
mca
rhv
Somatosenrory
Gustotopic map in the taste cortex
Gustotopic map in the taste cortex
Une représentation corticale gustotopique
Carleton et al. (2010) Trends in Neurosciences
Accolla et Carleton. (2008) PNAS
Accolla et al. (2007) Journal of Neuroscience
Chen et al. (2011) Science
Valeur hédonique des goûts
Apprentissage gustatif: exemple de l’aversion
d’un aliment
Control AVERSION à
La saccharine
Extinction
Carleton et al. (2010) Trends in Neurosciences
Accolla et Carleton. (2008) PNAS
Changement de la représentation gustotopique après
apprentissage
Accolla et al. (2008) Journal of Neuroscience
saccharinequinine
CORTEX après
OLFACTION
Organization of the human olfactory system
Organization of the olfactory systems
Photo: courtesy of Prof. Rodriguez (UNIGE)(Omp-TauLacZ) Tg mouse
Grueneberg
Ganglion (GG)
Vomeronasal
Organ (VNO)Main olfactory
Epithelium (MOE)
Olfactory
Bulb (OB)
Grueneberg ganglion
Grueneberg ganglion
Control lesion
Grueneberg ganglion
Chemical senses receptors
Organization of the olfactory systems
V2R
V1R
OR
Transduction in the VNO
Sexual behavior controlled by the vomeronasal organ
Sexual behavior controlled by the vomeronasal organ
Male normal et
Male castré
Male normal et
Male castré
(plus urine male
normal)
Male Trpc2-/- et
Male castré
(plus urine male
normal)
Sexual behavior controlled by the vomeronasal organ
A functional circuit underlying male sexual behaviour in the female mouse brain
Tali Kimchi, Jennings Xu & Catherine Dulac
Nature 448, 1009-1014 (2007)
Organization of the olfactory system
Organization of the main olfactory system
Organization of the main olfactory system
The main olfactory epithelium
Sensory neurons in the main olfactory epithelium
Sensory neurons in the main olfactory epithelium
Organization of the main olfactory epithelium
Transduction in the MOE
Transduction in the MOE
Transduction in the MOE
Organization of the olfactory system
The Nobel Prize in Physiology
or Medicine 2004
L. Buck R. Axel
(M50-TauLacZ) Tg mouse
~1000 olfactory
receptors in mice
Simplex and complex odors
Odor detection in mammals
cyclohexanol
CH3
O
O
O O
CH2OH
OH
OOCH3
O
anisole
acétophenone
1,8 cinéole
dl-camphre
cyclodecanone
heptanol
cyclohexanone2-heptanone
Sicard, G. and Holley, A. (1984). Receptor cell
responses to odorants: similarities and differences
among odorants. Brain Research, 292, (2), 283-96.
• One receptor is not
specific of a single
molecule
• Different odors are
detected by different
sets of receptors
Olfactory epithelium
Sensory neuron
Chemodetection
Imaging odor maps
Blood vessels
pattern
Functional Map
Different odorants evoked different glomeruli patterns
Ethyl
Butyrate
Amyl
acetate
Functional organization of cortical regions
Odor maps
Methyl BenzoateWater
Amylacetate Benzaldehyde
Hexanal
Carvone + (1) Carvone + (2)
Odor evoked glomeruli maps
A m y l a c e t a t e
M e t h y l B e n z o a t e
B e n z a l d e h y d e
Mouse C57Bl6- Odor maps from 03525
5 10 25 50 100 200
5 10 25 50 100 200
5 10 25 50 100 200
Amylacetate
Methyl Benzoate
5 10 25 50 100 200
5 10 25 50 100 200
Odor coding = Combinatorial coding
Anosmia: loss of the sense of smell
Anosmia: loss of the sense of smell
Mouse
Human
Anosmia: loss of the sense of smell
Sensory neurons Mitral cells
Olfactory bulb circuitry
Analysis of OB projections: electroporation in a single
glomerulus
Sosulski et al. Nature (2011) 472:213-216
Divergent projections towards the cortex
Sosulski et al. Nature (2011) 472:213-216
Piriform cortex organization
Temporal code and summation
Odor representation in the olfactory cortex
Stettler and Richard Axel. Neuron (2009) 63, 854-64
Lack of chemotopy and organization in the olfactory cortex
Stettler and Richard Axel. Neuron (2009) 63, 854-64
Optogenetic control of neuronal firing: Channelrhodopsin
http://www.biophys.mpg.de/en/bamberg.html
Optogenetic control of neuronal firing
http://channelrhodopsin.wikia.com/wiki/Bioengineering
http://allthingscensored.blogspot.it/2012/01/birth-of-optogenetics.html
Ensembles of piriform neurons can drive opposite behavior
Choi et al. Cell (2011) 146:1004-15