6533b7ddfe1ef96bd1273b62

RESEARCH PRODUCT

Processus sensoriels cognitifs et comportementaux impliqués dans la perception des mélanges odorants alimentaires complexes chez le lapin nouveau-né et l'Homme

subject

description

Within each breath, a large diversity of volatiles molecules of the surrounding reaches our olfactory receptors. Despite the chemical complexity of the natural environment, the organisms succeed to represent their world using relevant information carried by single odorants or mixtures. Focusing on the perception of these stimuli, we explored the processes involved in the treatment of this complex information, sometimes supported by mixtures or sub-mixtures. The treatment is based on two processes: the elemental mode, which allows extracting the odor quality of all or some of the elements, or the configural mode which allows the holistic representation of the mixture. In this doctoral thesis, we evaluated the influence of several parameters involved in elemental and configural odor processing of more or less complex mixtures. We addressed similar questions on two models, the rabbit and the Human, in order to optimize the knowledge of processes engaged in the perception of odor mixtures at different developmental periods: mainly the neonatal one in rabbit and the adult one in humans. The manuscript is organized in three main axes. The first one focused on the physicochemical properties of mixtures in the elemental and configural perception. Furthermore, as the number of odorants contained in mixture may overstep the elemental limits of perception, we assessed, in the second axis, whether the perception switches to the configural perception from a defined complexity level. Then, as the perception is supposed to depend on individual factors, we addressed the question of the influence of development on the modulation of odor mixture perception. The results confirm that the perception of configurations is shared by the two models even if the modality of their emergence can be distinct, at least in part. Our findings support the idea that in mixture, several elements or association of elements can carry a perceptual weight leading to the elemental, or configural perception, respectively. These weights can be influenced by several mixture physicochemical parameters, especially their complexity, but can also be partially modified by experience and development. Finally, these works brings original results allowing to better understand how an organism, at different period of its individual life, achieves the extraction of biologically significant odorants or mixtures of odorants from the highly chemical environment