Search results for "olfaction"
showing 10 items of 251 documents
Rapid odorant release in mammalian odour binding proteins facilitates their temporal coupling to odorant signals.
2010
; We have measured the effect of rat odorant-binding protein 1 on the rates of ligand uptake and liquid-to-air transfer rates with a set of defined odorous compounds. Comparison of observed rate constants (k(obs)) with data simulated over a wide range of different kinetic and thermodynamic regimes shows that the data do not agree with the previously held view of a slow off-rate regime (k(off) <0.0004 s(-1)). We propose that a rapid koff would be a necessary requirement for such a system, since slow odorant-release rates would result in significant decorrelation between the olfactory world and odour perception. (c) 2010 Elsevier Ltd. All rights reserved.
Unconscious odour conditioning 25 years later: Revisiting and extending ‘Kirk-Smith, Van Toller and Dodd’
2009
International audience; The pioneering work by Kirk-Smith, Van Toller, and Dodd [Kirk-Smith, M. D., Van Toller, C., & Dodd, G. H. (1983). Unconscious odour conditioning in human subjects. Biological Psychology, 17, 221–231], established that an unnoticed odorant paired with an emotionally meaningful task can influence mood and attitudes when the odorant alone is re-encountered subsequently. This study was particularly important in highlighting unconscious odour learning processes as they may happen in everyday life. However, it was severely criticized by Black and Smith [Black, S. L., & Smith, D. G. (1994). Has odor conditioning been demonstrated? A critique of “Unconscious odour conditioni…
Olfaction and gustation
2017
International audience
Structural and enzymatic characterization of a Drosophila melanogaster glutathione transferase overexpressed in the sensory organs after exposure to …
2016
Glutathione transferases (GSTs) are ubiquitous key detoxification enzymes that catalyze the conjugation of glutathione to a large variety of xenobiotic chemical including odorants and sapid molecules. A previous study in Drosophila melanogaster demonstrated the existence of a GST specifically expressed in the antenna and involved in signal termination by catalyzing biotransformation of odorant molecules. Genomic analysis allows identifying forty GSTs in Drosophila melanogaster but their biochemistry is poorly documented. Here we demonstrated that among the GSTs, dmelGSTD2-2 was strongly and preferentially overexpressed in the sensory organs (antennae, proboscis, legs, wings) after an exposu…
Les comportements préalables à la prise lactée chez le souriceau : caractérisation de sécrétions maternelles réactogènes et implication de l'expérien…
2012
Birth is one of the most delicate periods mammalian infants have to deal with. Newborns have then to adapt physiologically and behaviorally to the aerial environment, and one of their first challenges is to ingest colostrum and milk. It is paradoxical that the survival of pups is conditioned by the success of this first suckling, and that we have so little understanding of the stimuli that underlie and promote it. Thus, the present work aims to contribute to answer how immature and naïve newborns do manage to orient to a nipple, to grasp it, and to suckle efficiently? This general issue will be addressed in the mouse in focusing on: i) the nature of the chemical substrates that newborn mice…
Olfactory neurons plasticity : environment effects during development
2012
In order to investigate the consequences of postnatal odorant exposure on a specific population of olfactory sensory neurons (OSNs), we have taken the following experimental approach. MOR23-GFP mice were daily exposed to Lyral for 21 days starting at birth and three lines of investigations were carried out. Using anatomical analysis we observe that the density of OSNs expressing MOR23 decreases after odorant exposure. This decrease concerns primarily matures OSN (MOR23-OMP+). In order to study molecular changes within individual OSNs, mRNA levels for olfactory signaling pathway components were quantitatively analyzed using qPCR on GFP-labeled neurons (7 per mouse). mRNAs for CNGA2, PDE1C an…
Hedonic sensations implicated in the control of human food intake : alimentary alliesthesia and sensory-specific satiety
2011
The control of food intake is a complex and multifactorial process controlled by the CNS. It is implicated in the regulation of body weight and the supply of energy substrates, as well as the supply of a panoply of nutrients to cover the specific needs of the organism. Among all the factors involved, hedonic sensations play an important role in guiding food selection and limitation of intake. The theoretical section of this thesis takes into account the physio-anatomical aspects of the control of food intake, in particular sensory pleasure and its evaluation, within the framework of the three principal hedonic phenomena: Conditioned Satiety (CS), Alimentary alliesthesia (AA) and sensory-spe…
Olfactory neurons plasticity : environment effects during development
2012
In order to investigate the consequences of postnatal odorant exposure on a specific population of olfactory sensory neurons (OSNs), we have taken the following experimental approach. MOR23-GFP mice were daily exposed to Lyral for 21 days starting at birth and three lines of investigations were carried out. Using anatomical analysis we observe that the density of OSNs expressing MOR23 decreases after odorant exposure. This decrease concerns primarily matures OSN (MOR23-OMP+). In order to study molecular changes within individual OSNs, mRNA levels for olfactory signaling pathway components were quantitatively analyzed using qPCR on GFP-labeled neurons (7 per mouse). mRNAs for CNGA2, PDE1C an…
Hedonic sensations implicated in the control of human food intake : alimentary alliesthesia and sensory-specific satiety
2011
The control of food intake is a complex and multifactorial process controlled by the CNS. It is implicated in the regulation of body weight and the supply of energy substrates, as well as the supply of a panoply of nutrients to cover the specific needs of the organism. Among all the factors involved, hedonic sensations play an important role in guiding food selection and limitation of intake. The theoretical section of this thesis takes into account the physio-anatomical aspects of the control of food intake, in particular sensory pleasure and its evaluation, within the framework of the three principal hedonic phenomena: Conditioned Satiety (CS), Alimentary alliesthesia (AA) and sensory-spe…
Variability in olfactory reactivity in 7-8 month-old infants
2006
To determine the origin of early food preference variability, an Observatory of Food Preference in Infants and Children (Opaline) was set up. One of its objectives is to relate hedonic reaction to odours to previous exposures (via amniotic fluid and/or breast milk) and to understand the role of hedonic reaction to odours on food rejections or preferences. To answer this question, we developed an instrument to measure and to compare olfactory reactivity in 7-8 month-old infants.