XVI International Symposium on Olfaction and Taste - ecro

<strong>XVI</strong> <strong>International</strong> <strong>Symposium</strong> on Olfaction and Taste
Poster session I Poster #147
Pheromonal odour learning and brain activation in the newborn rabbit
Rachel Charra 1 , Gérard Coureaud 1 , Audrey Filezac de l'Etang 1 , Vincent Gigot 1 , Benoist Schaal 1 and Frédérique Datiche 1
1 CSGA, CNRS/INRA/UB, Dijon, France
gerard.coureaud@u-bourgogne.fr; frederique.datiche@u-bourgogne.fr
Mother-young relationship strongly depends on olfaction. Maternal odour cues contribute for instance to arousal,
attachment, and also directly to the mammae localization and sucking. European rabbit pups (Oryctolagus cuniculus)
display a typical orocephalic behaviour to locate and grasp the nipples during nursing. This behaviour is triggered, among
different cues, by the mammary pheromone (MP) emitted by lactating females. Besides its releasing role, the MP
efficiently promotes the learning of new, initially neutral odorants. In this form of associative conditioning, after single and
short pairing with the MP, the learned odorant becomes able to trigger the neonatal orocephalic behaviour as efficiently
as the MP. We previously used Fos neuroimaging to examine the brain network activated by the MP in 4-day- old pups. It
revealed a large activation of the main olfactory bulb (MOB) and a specific labeling of central structures (e.g., OVLT;
hypothalamic lateral preoptic area, LPO). Here, we investigated the activation generated by a neutral odorant (ethylacetoacetate;
EAA) learned by association with the MP or not learned, to highlight the reorganization of the neuronal
substrate that follows the conditioning and sustains the behavioural response. After conditioning/pseudo- conditioning to
EAA on day 3 and re-exposure to EAA on day 4, the brain of pups was processed by Fos immunocytochemistry. In
the MOB, the immunolabeling was higher in conditioned rabbits, and higher in their mitral+granule cells compared to
their glomerular layers, whatever the rostro-caudal level. Differences also appeared in regions and sectors of the
glomerular layer in both groups. Contrasted activation appeared also in higher brain regions of conditioned pups such as
the piriform cortex and the amygdala (i.e. "learning" structures) and in the LPO (implicated in osmoregulation). Thus, MPinduced
odour learning is followed by changes in the neonatal brain processing of EAA before/after acquisition.
Poster session II Poster #240
Heritability of enantioselectivity in human olfaction
Kepu Chen 1 , Xiaomeng Zhang 1 , Bin Zhou 1 and Wen Zhou 1
1Institution of Psychology, Chinese Academy of Science, Beijing, China
chenkp@psych.ac.cn
To the human nose, optical enantiomers could possess different smells. Here we probe the genetic contribution to such
enantioselectivity in the human olfactory system, where phenotypic diversity is widespread. In a four-trial three-
alternative forced choice test, we assessed the abilities of monozygotic and dizygotic twins to distinguish between the
enantiomers of carvone, limonene, as well as α-pinene, with one, one, and two chiral centers, respectively. We identified a
reliable genetic component in the chiral discriminations of carvone and limonene, but not α-pinene enantiomers.
Whereas the olfactory coding mechanism underlying the discrimination between enantiomers is scantily known, our
findings suggest that different chiral carbons are independently encoded in the nose.
Poster session I Poster #143
Detection of acidic pH in the mouse vomeronasal organ
Annika Cichy 1 , Jennifer Spehr 1 and Marc Spehr 1
1 RWTH Aachen, Dept. of Chemosensation, Institute of Biology II, Aachen, Germany
a.cichy@sensorik.rwth-aachen.de
The mouse vomeronasal organ (VNO) plays a key role in pheromone detection and recognition of other social signals.
However, the underlying mechanisms of signal detection in the VNO remain largely unknown.
Here, we describe activation of vomeronasal sensory neurons by extracellular protons. To investigate the mechanisms
involved, we performed whole-cell patch-clamp recordings from visually identified sensory neurons in acute tissue slices of
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