Search results for "OLFACTORY"
showing 10 items of 319 documents
Comprehensive Anatomic Assessment of Ipsilateral Pterional Versus Contralateral Subfrontal Approaches to the Internal Carotid Ophthalmic Segment: A C…
2019
Objective Medially pointing aneurysms of the ophthalmic segment of the internal carotid artery (oICA) represent a neurosurgical challenge. Conventional ipsilateral approaches require internal carotid artery and optic nerve (ON) mobilization as well as anterior clinoidectomy (AC), all associated with increased surgical risk. Contralateral approaches could provide a better exposure of the superomedial aspect of the oICA, ophthalmic artery, and superior hypophyseal artery, sparing AC and internal carotid artery or ON mobilization. However, the microsurgical anatomy of this approach has not been systematically studied. In the present work, we exhaustibly analyzed the anatomic and morphometric c…
Just noticeable differences in component concentrations modify the odor quality of a blending mixture.
2008
International audience; The odors we perceive are mainly the result of mixtures of odorants that, however, are commonly perceived as single undivided entities; nevertheless, the processes involved remain poorly explored. It has been recently reported that perceptual blending based on configural olfactory processing can cause odorant mixtures to give rise to an emergent odor not present in the components. The present study examined whether specific component proportions are required to elicit an emergent odor. Starting from the composition of a ternary target mixture in which an emergent pineapple odor was perceived, 4 concentration levels of each component were chosen to elicit just noticea…
Age differences in olfactory affective responses: evidence for a positivity effect and an emotional dedifferentiation
2021
International audience; Studies on aging and hedonic judgment of odors have never been addressed within the empirical frameworks of age-related changes in emotion which state that advancing age is associated with a reduced negativity bias and a less pronounced differentiation between hedonic valence and emotional intensity judgments. Our aim was to examine and extend these age-related effects into the field of odors. Thirty-eight younger adults and 40 older adults were asked to evaluate the hedonic valence, emotional intensity, and familiarity of 50 odors controlled for their pleasantness. Compared to younger adults, older adults rated unpleasant odorants as less unpleasant and showed an in…
Gaining deeper insight into aroma perception: An integrative study of the oral processing of breads with different structures
2017
WOS:000394071900015; International audience; The objective of this study was to investigate for the first time the influence of bread structure, volatile compounds, and oral processing on aroma perception. 3 types of French baguette were created using the same raw ingredients but different bread-making processes; they consequently varied in their crumb and crust structures. We characterized the initial volatile profiles of two bread structural subtypes-namely bread crumb and bread crumb with crust-using proton transfer reaction-mass spectrometry (PTR-MS) headspace analysis. Three types of bread were characterized by thirty-nine ion fragments from m/z 45 to 139. We then conducted a study in …
Neonatal representation of odour objects: distinct memories of the whole and its parts
2014
Extraction of relevant information from highly complex environments is a prerequisite to survival. Within odour mixtures, such information is contained in the odours of specific elements or in the mixture configuration perceived as a whole unique odour. For instance, an AB mixture of the element A (ethyl isobutyrate) and the element B (ethyl maltol) generates a configural AB percept in humans and apparently in another species, the rabbit. Here, we examined whether the memory of such a configuration is distinct from the memory of the individual odorants. Taking advantage of the newborn rabbit's ability to learn odour mixtures, we combined behavioural and pharmacological tools to specifically…
Physico-Chemical Interactions in the Flavor-Release Process
2017
The perception of flavor is induced by the release of aroma compounds in the vapor phase. The olfactory perception is not only related to the nature of aroma compounds initially present in the food, but also to their distribution between the different phases. After a description of the interactions established between the aroma compounds and different constituents of food, this chapter looks at physico-chemical characteristics of aroma compounds and at the composition and properties of food matrices. Then, in order to understand the behavior of aroma compounds in the matrices, study methods of interactions are described. The assessment of the release is done by determining the partition coe…
Physiological responses and central nervous projections of antennal olfactory receptor neurons in the adult desert locust, Schistocerca gregaria (Ort…
1996
Olfactory receptor neurons present in two morphological sensillum types on the male Schistocerca gregaria antenna were for the first time investigated physiologically when stimulated with behaviourally relevant odours. Neurons present in trichoid/basiconic sensilla showed clear excitatory responses to compounds present in the male-produced aggregation pheromone and also to a plant produced compound. Sensilla could be categorised physiologically according to the responses of their receptor neurons to the tested stimuli. Also receptor neurons present in sensilla coeloconica responded to aggregation pheromone components, but always in an inhibitory fashion. These neurons could, however, be exc…
Ontogenesis of the Extra-Bulbar Olfactory Pathway inXenopus laevis
2013
Although the development, anatomy, and physiology of the vertebrate olfactory system are fairly well understood, there is still no clear definition of the terminal nerve complex acknowledged by all. Among the most debated matters is whether or not the extrabulbar projections found in anamniotes should or should not be considered part of the terminal nerve complex. In this context, we investigated the early development of the extrabulbar pathway in Xenopus larvae from placodal differentiation to postmetamorphic stages. We showed that the extrabulbar fibers become visible around Stage 42 and are conserved throughout metamorphosis. We confirmed previous reports concerning their central project…
Interactions of odorants with olfactory receptors and receptor neurons match the perceptual dynamics observed for woody and fruity odorant mixtures
2012
The present study aimed to create a direct bridge between observations on peripheral and central responses to odorant mixtures and their components. Three experiments were performed using mixtures of fruity (isoamyl acetate; ISO) and woody (whiskey lactone; WL) odorants known to contribute to some of the major notes in Burgundy red wine. These experiments consisted of (i) calcium imaging of human embryonic kidney cells (HEK293T) transfected with olfactory receptors (ORs); (ii) single-unit electrophysiological recordings from olfactory receptor neurons (ORNs) and analyses of electro-olfactogram (EOG) responses in the rat nose in vivo; and (iii) psychophysical measurements of the perceived in…
Acute effects of 1,1,1-trichloroethane on human olfactory functioning.
2004
Background Animal experiments indicate that 1,1,1-trichloroethane can cause degeneration of the olfactory epithelium. The effects of 1,1,1-trichloroethane on human odor perception still have not been investigated. The goal of this study was to learn more about acute effects of 1,1,1-trichloroethane. Methods Twelve healthy, nonsmoking students were exposed to 200 and 20 ppm (control) 1,1,1-trichloroethane in an exposure chamber for 4 hours according to a crossover design. Olfactory functioning was investigated with the Sniffin’ Sticks. The test includes the determination of the detection threshold for n-butanol and an odor identification test. Results After 1 hour of exposure to 200 ppm 1,1,…