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Accueil du site > Equipes de recherche > Equipe CMO (N.Ravel, N.Buonviso) > Annuaire > Pages personnelles > Patricia VIRET


par Philippe Litaudon - 14 mai 2014


  • Duchamp-Viret P, Chaput M. In Vivo Electrophysiological Recordings of Olfactory Receptor Neuron Units and Electro-olfactograms in Anesthetized Rats. Methods in Molecular Biology (Clifton, N.J.). 2018;1820:123-135.
    Résumé : In vivo recordings of single olfactory receptor neurons and electro-olfactograms (EOG, field potentials from the olfactory mucosa) provide insights into the olfactory processing properties of the olfactory peripheral stage. Because the olfactory receptor neurons are very small electrical generators, it is not easy to unitarily record them in amphibians, reptilians, and fishes. In mammals such recordings are even more difficult to obtain: primarily due to the anatomical configuration in complex turbinates of the olfactory mucosa and its propensity to hemorrhage during surgery; secondarily due to the fact that olfactory receptor neurons are held in closely packed clusters in the olfactory mucosa and are difficult to isolate, from the electrophysiological recording point of view. Here we describe the material and methods we used in vivo, in rats-occasionally, also tested in mice-to get simultaneously receptor neuron single and electro-olfactogram recordings, from septal region or the endoturbinate II, in freely breathing or tracheotomized anesthetized animals. Recording EOG in parallel with receptor neuron units provide, by reflecting the population response to the olfactory stimulus, the continuous assurance of the good physiological state and reactivity of the olfactory epithelium. This configuration will ensure that when a single ORN does not respond to a stimulus it resulted from its qualitative selectivity and not from the olfactory mucosa damaged status.
    Mots-clés : Electro-olfactograms (EOG), In vivo anesthetized animals, Olfactory receptor neurons, Single unit electrophysiological recordings.

  • Estrade L, Cassel J-C, Parrot S, Duchamp-Viret P, Ferry B. Microdialysis Unveils the Role of the α2-Adrenergic System in the Basolateral Amygdala during Acquisition of Conditioned Odor Aversion in the Rat. ACS chemical neuroscience. 2018.
    Résumé : Previous work has shown that β-adrenergic and GABAergic systems in the basolateral amygdala (BLA) are involved in the acquisition of conditioned odor aversion (COA) learning. The involvement of α2-adrenoreceptors, however, is poorly documented. In a first experiment, male Long-Evans rats received infusions of 0.1 μg of the selective α2-antagonist dexefaroxan (Dex) in the BLA before being exposed to COA learning. In a second experiment, levels of norepinephrine (NE) were analyzed following Dex retrodialysis into the BLA. While microdialysis data showed a significant enhancement of NE release in the BLA with Dex, behavioral results showed that pre-CS infusion of Dex impaired, rather than facilitated, the acquisition of COA. Our results show that the NE system in the BLA is involved in the acquisition of COA, including a strong α2-receptor modulation until now unsuspected. Supported by the recent literature, the present data suggest moreover that the processes underlying this learning are probably mediated by the balanced effects of NE excitatory/inhibitory signaling in the BLA, in which interneurons are highly involved.
    Mots-clés : acquisition, basolateral amygdala, conditioned odor aversion, memory, microdialysis, norepinephrine, trace conditioning, α2-Adrenoceptors.


  • Hanser H-I, Faure P, Robert-Hazotte A, et al. Odorant-odorant metabolic interaction, a novel actor in olfactory perception and behavioral responsiveness. Scientific Reports. 7(1):10219.
    Résumé : In the nasal olfactory epithelium, olfactory metabolic enzymes ensure odorant clearance from the olfactory receptor environment. This biotransformation of odorants into deactivated polar metabolites is critical to maintaining peripheral sensitivity and perception. Olfactory stimuli consist of complex mixtures of odorants, so binding interactions likely occur at the enzyme level and may impact odor processing. Here, we used the well-described model of mammary pheromone-induced sucking-related behavior in rabbit neonates. It allowed to demonstrate how the presence of different aldehydic odorants efficiently affects the olfactory metabolism of this pheromone (an aldehyde too: 2-methylbut-2-enal). Indeed, according to in vitro and ex vivo measures, this metabolic interaction enhances the pheromone availability in the epithelium. Furthermore, in vivo presentation of the mammary pheromone at subthreshold concentrations efficiently triggers behavioral responsiveness in neonates when the pheromone is in mixture with a metabolic challenger odorant. These findings reveal that the periphery of the olfactory system is the place of metabolic interaction between odorants that may lead, in the context of odor mixture processing, to pertinent signal detection and corresponding behavioral effect.