Search results for "Alimentation"

Hypothalamic eIF2 alpha signaling regulates food intake

2014

International audience; The reversible phosphorylation of the a subunit of eukaryotic initiation factor 2 (eIF2 alpha) is a highly conserved signal implicated in the cellular adaptation to numerous stresses such as the one caused by amino acid limitation. In response to dietary amino acid deficiency, the brain-specific activation of the eIF2 alpha kinase GCN2 leads to food intake inhibition. We report here that GCN2 is rapidly activated in the mediobasal hypothalamus (MBH) after consumption of a leucine-deficient diet. Furthermore, knockdown of GCN2 in this particular area shows that MBH GCN2 activity controls the onset of the aversive response. Importantly, pharmacological experiments demo…

Whey proteins are more efficient than casein in the recovery of muscle functional properties following a casting induced muscle atrophy.

2013

International audience; The purpose of this study was to investigate the effect of whey supplementation, as compared to the standard casein diet, on the recovery of muscle functional properties after a casting-induced immobilization period. After an initial (I0) evaluation of the contractile properties of the plantarflexors (isometric torque-frequency relationship, concentric power-velocity relationship and a fatigability test), the ankle of 20 male adult rats was immobilized by casting for 8 days. During this period, rats were fed a standard diet with 13% of casein (CAS). After cast removal, rats received either the same diet or a diet with 13% of whey proteins (WHEY). A control group (n =…

Associations between weight status and liking scores for sweet, salt and fat according to the gender in adults(The Nutrinet-Santé study)

2015

BACKGROUND/OBJECTIVES: As taste preferences may be associated with obesity, the present study investigated whether obese subjects presented heightened liking for the sensations of sweet, salt and fat.SUBJECTS/METHODS: Liking scores were determined by a questionnaire including 83 items on liking for sweet or fatty foods, and the preferred extent of seasoning with salt, sweet or fat. Data from 46 909 adults included in the French web-based observational cohort of the Nutrinet-Santé study were collected and weighted according to the national population census. Relationships between liking scores and body mass index (BMI) as categorical or linear explanatory variable were assessed separately by…

Transient and Permanent Experience with Fatty Acids Changes Drosophila melanogaster Preference and Fitness

2013

Food and host-preference relies on genetic adaptation and sensory experience. In vertebrates, experience with food-related cues during early development can change adult preference. This is also true in holometabolous insects, which undergo a drastic nervous system remodelling during their complete metamorphosis, but remains uncertain in Drosophila melanogaster. We have conditioned D. melanogaster with oleic (C18:1) and stearic (C18:0) acids, two common dietary fatty acids, respectively preferred by larvae and adult. Wild-type individuals exposed either during a transient period of development-from embryo to adult-or more permanently-during one to ten generation cycles-were affected by such…

Involvement of plasmalogens in post-natal retinal vascular development

2014

Objective: Proper development of retinal blood vessels is essential to ensure sufficient oxygen and nutrient supplies to the retina. It was shown that polyunsaturated fatty acids (PUFAs) could modulate factors involved in tissue vascularization. A congenital deficiency in ether-phospholipids, also termed "plasmalogens'', was shown to lead to abnormal ocular vascularization. Because plasmalogens are considered to be reservoirs of PUFAs, we wished to improve our understanding of the mechanisms by which plasmalogens regulate retinal vascular development and whether the release of PUFAs by calcium-independent phospholipase A2 (iPLA2) could be involved. [br/] Methods and Results: By characterizi…

Une nouvelle démarche à la pratique des têtes coupées chez les Gaulois : premiers résultats isotopiques d'un dépôt exceptionnel d'armes et de restes …

2016

Cross-cultural differences in consumer quality perception of rice

2014

International audience; Most aspects of food product quality perception are culture-bound. We present a cross-cultural study aiming at understandinghow consumers from four countries (French, Japanese, Korean and Thai) perceive, describe and appreciate rice and ricequality. Marked differences were found in participants' motivation to consume rice: sensory and commodity in France; sensoryand health in Japan; nutrition and commodity in Thailand; and nutrition, health and safety in Korea. For the description of ricequalities, despite a few cultural differences, especially between Korean and Thai descriptions of white and brown rice samples,similar sensory profiles were obtained in the four coun…

Retro-nasal aroma release is correlated with variations in the in-mouth air cavity volume after empty deglutition.

2012

International audience; We hypothesized that interindividual differences in motor activities during chewing and/or swallowing were determining factors for the transfer of volatile aroma from the in-mouth air cavity (IMAC) toward the olfactory mucosa. In our first experiment, we looked for changes in IMAC volume after saliva deglutition in 12 healthy subjects. The mean IMAC volume was measured after empty deglutition using an acoustic pharyngometer device. Based on the time course of the IMAC volume after swallowing, we discerned two groups of subjects. The first group displayed a small, constant IMAC volume (2.26 mL ±0.62) that corresponded to a high tongue position. The second group displa…

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…

Hypothalamus-olfactory system crosstalk: orexin a immunostaining in mice

2012

It is well known that olfaction influences food intake, and conversely, that an individual’s nutritional status modulates olfactory sensitivity. However, what is still poorly understood is the neuronal correlate of this relationship, as well as the connections between the olfactory bulb and the hypothalamus. The goal of this report is to analyze the relationship between the olfactory bulb and hypothalamus, focusing on orexin A immunostaining, a hypothalamic neuropeptide that is thought to play a role in states of sleep/wakefulness. Interestingly, orexin A has also been described as a food intake stimulator. Such an effect may be due in part to the stimulation of the olfactory bulbar pathway…