Search results for "OLFACTORY PERCEPTION"
showing 10 items of 41 documents
Neurovascular EGFL7 regulates adult neurogenesis in the subventricular zone and thereby affects olfactory perception
2016
Adult neural stem cells reside in a specialized niche in the subventricular zone (SVZ). Throughout life they give rise to adult-born neurons in the olfactory bulb (OB), thus contributing to neural plasticity and pattern discrimination. Here, we show that the neurovascular protein EGFL7 is secreted by endothelial cells and neural stem cells (NSCs) of the SVZ to shape the vascular stem-cell niche. Loss of EGFL7 causes an accumulation of activated NSCs, which display enhanced activity and re-entry into the cell cycle. EGFL7 pushes activated NSCs towards quiescence and neuronal progeny towards differentiation. This is achieved by promoting Dll4-induced Notch signalling at the blood vessel-stem …
Perceptual blending in odor mixtures depends on the nature of odorants and human olfactory expertise.
2012
International audience; Our olfactory system is confronted with complex mixtures of odorants, often recognized as single entities due to odor blending (e.g., coffee). In contrast, we are also able to discriminate odors from complex mixtures (e.g., off-odors). Therefore, the olfactory system is able to engage either configural or elemental processes when confronted with mixtures. However, the rules that govern the involvement of these processes during odor perception remain poorly understood. In our first experiment, we examined whether simple odorant mixtures (binary/ternary) could elicit configural perception. Twenty untrained subjects were asked to evaluate the odor typicality of mixtures…
Modelling analysis of centroid curves of olfactory habituation in humans
2020
Indexation en cours.; International audience; Previously published experiments established the time-course of olfactory habituation in humans, and extracted 3 centroid curves from clustering analysis that reflected high, middle and low habituation. The aim of the current theoretical study was to further analyse these previous experimental data by developing a mathematical modelling analysis designed for fitting the 3 curves from a general equation. After adjusting equation parameters for each curve, fitting equation outcomes on experimental data yielded high correlation coefficients of 0.9997 – 0.9995 – 0.9962, respectively. A model-based interpretation of olfactory-habituation centroid cur…
Impact of olfactory and auditory priming on the attraction towards foods with high energy density
2015
\]\Recent research suggests that non-attentively perceived stimuli may significantly influence consumers' food choices. The main objective of the present study was to determine whether an olfactory prime (a sweet-fatty odour) and a semantic auditory prime (a nutritional prevention message), both presented incidentally, either alone or in combination can influence subsequent food choices. The experiment included 147 participants who were assigned to four different conditions: a control condition, a scented condition, an auditory condition or an auditory-scented condition. All participants remained in the waiting room during15 min while they performed a 'lure' task. For the scented condition,…
Synergy and masking in odor mixtures: an electrophysiological study of orthonasal vs. retronasal perception
2008
Perceptual interactions in a model of wine woody–fruity binary mixtures were previously reported in a psychophysical study performed through orthonasal stimulation only. However, recent studies suggested that the perception of food-like and nonfood-like odors may depend on the route of stimulation. The aim of the present study was two-fold: first to examine the neural correlates of perceptual interactions using electroencephalogram (EEG)-derived event-related potentials (ERPs) and second to test the influence of the stimulation route on quality perception. Therefore, we designed an experiment with 30 subjects to study perceptual interactions in woody–fruity mixtures and compared ortho- vs. …
Ligand binding study revealing a human olfactory receptor involved in waxy-floral odor perception
2006
International audience
Olfactory Dysfunction After Head Injury
2008
Objective: To determine the incidence of olfactory dysfunction after head trauma using clinical and radiologic findings, quantitative assessment, and electro-physiologic methods. Participants: A total of 190 patients with head trauma of different severity (n = 32 with mild traumatic brain injury (TBI), n = 94 with signs of moderate TBI, and n = 64 with severe TBI) 6 to 32 months prior to the study. Design: Patients were selected retrospectively, surveyed by telephone (n = 190), and screened for olfactory function with Brief Smell Identification Test (n = 82). Those with olfactory dysfunction were assessed as outpatients using the Sniffin' Sticks (n = 19) and olfactory-evoked potential recor…
The endocannabinoid system controls food intake via olfactory processes
2014
Comment in Sensory systems: the hungry sense. [Nat Rev Neurosci. 2014] Inhaling: endocannabinoids and food intake. [Nat Neurosci. 2014]; International audience; Hunger arouses sensory perception, eventually leading to an increase in food intake, but the underlying mechanisms remain poorly understood. We found that cannabinoid type-1 (CB1) receptors promote food intake in fasted mice by increasing odor detection. CB1 receptors were abundantly expressed on axon terminals of centrifugal cortical glutamatergic neurons that project to inhibitory granule cells of the main olfactory bulb (MOB). Local pharmacological and genetic manipulations revealed that endocannabinoids and exogenous cannabinoid…
Early-blind individuals show impaired performance in wine odor categorization
2018
International audience; Blind individuals display superior sensory abilities in other modalities, yet results remain contradictory regarding their performance on olfactory tasks. Using complex ecological olfactory tasks, we evaluated the impact of blindness on olfactory performance. We tested 12 early-blind individuals (M = 49, SD = 13.09) and 12 sighted controls (M = 49, SD = 14.31) who were all blindfolded. Based solely on the wine odors, participants evaluated 24 pairs of wine and determined if both samples belonged to the same category (red wine, white wine, or rosé wine) or not (odor categorization), and if so, whether they were identical or not (odor differentiation). Then, they had t…
Independence of first- and second-order memories in newborn rabbits
2011
WOS:000291649400006; International audience; The mammary pheromone promotes the acquisition of novel odorants (CS1) in newborn rabbits. Here, experiments pinpoint that CS1 becomes able to support neonatal learning of other odorants (CS2). We therefore evaluated whether these first- and second-order memories remained dependent after reactivation. Amnesia induced after CS2 recall selectively blocked this memory, when recall and amnesia of CS1 left the souvenir of CS2 safe; this finding partially differed from results obtained in adult mammals. Thus, in this model of neonatal appetitive odor learning, second-order memory seems to depend on first-order memory for its formation but not for its m…