A5049405982- Circadian rhythm and melatonin
- Sleep and Wakefulness Research
- Photoreceptor and optogenetics research
- Neurobiology and Insect Physiology Research
- Neuroendocrine regulation and behavior
- Spaceflight effects on biology
- Dietary Effects on Health
- Adipose Tissue and Metabolism
- Bat Biology and Ecology Studies
- Light effects on plants
- Stress Responses and Cortisol
- Receptor Mechanisms and Signaling
- Genetics, Aging, and Longevity in Model Organisms
- Birth, Development, and Health
- Neuroscience of respiration and sleep
- Regulation of Appetite and Obesity
- Nitric Oxide and Endothelin Effects
- Physiological and biochemical adaptations
- Electromagnetic Fields and Biological Effects
- Neuroscience and Neuropharmacology Research
- Neuropeptides and Animal Physiology
- Hypothalamic control of reproductive hormones
- Neurotransmitter Receptor Influence on Behavior
- Retinal Development and Disorders
- Diet and metabolism studies
Université de Strasbourg
2013-2024
Centre National de la Recherche Scientifique
2015-2024
Institut des Neurosciences Cellulaires et Intégratives
2015-2024
Hôpital Militaire Moulay Ismail
2023
Mohammed V University
1997-2023
Laboratoire Analyse et Modélisation pour la Biologie et l'Environnement
2010
Laboratoire de Psychologie et NeuroCognition
2002-2006
Universidad Nacional Autónoma de México
2005
McGill University
2005
Douglas Mental Health University Institute
2005
Mutations of clock genes can lead to diabetes and obesity. REV-ERBα, a nuclear receptor involved in the circadian clockwork, has been shown control lipid metabolism. To gain insight into role REV-ERBα energy homeostasis vivo, we explored daily metabolism carbohydrates lipids chow-fed, unfed, or high-fat-fed Rev-erbα−/− mice their wild-type littermates. Chow-fed displayed increased adiposity (2.5-fold) mild hyperglycemia (∼10%) without insulin resistance. Indirect calorimetry indicates that...
The suprachiasmatic nuclei (SCN) of the hypothalamus contain master mammalian circadian clock, which is mainly reset by light. Temporal restricted feeding, a potent synchronizer peripheral oscillators, has only weak influence on light-entrained rhythms via SCN, unless feeding coupled with calorie restriction, thereby altering phase angle photic synchronization. Effects daytime were investigated mouse system. Normocaloric at midday led to predominantly diurnal (60%) food intake and decreased...
High-fat feeding in rodents leads to metabolic abnormalities mimicking the human syndrome, including obesity and insulin resistance. These diseases are associated with altered temporal organization of many physiological functions. The master circadian clock located suprachiasmatic nuclei controls most functions processes. Furthermore, under certain conditions (hypocaloric diet), cues capable altering clock's responses light. To determine whether high-fat (hypercaloric diet) can also affect...
Abstract The suprachiasmatic nucleus (SCN) controls the circadian rhythm of melatonin synthesis in mammalian pineal gland by a multisynaptic pathway including, successively, preautonomic neurons paraventricular (PVN), sympathetic preganglionic spinal cord and noradrenergic superior cervical ganglion (SCG). In order to clarify role each these structures generation rhythm, we first investigated day‐ night‐time capacity rat produce after bilateral SCN lesions, PVN lesions or SCG removal,...
Abstract Despite a pronounced inhibitory effect of light on pineal melatonin synthesis, usually the daily rhythm is not passive response to surrounding world. In mammals, and almost every other vertebrate species studied so far, coupled an endogenous pacemaker, i.e. circadian clock. mammals principal pacemaker located in suprachiasmatic nuclei (SCN), bilateral cluster neurons anterior hypothalamus. present paper we show rat that abolition γ‐aminobutyric acid (GABA), but vasopressin,...
In seasonal species, various physiological processes including reproduction are organized by photoperiod via melatonin, but the mechanisms of melatonin action still unknown. birds, peptide gonadotropin-inhibiting hormone (GnIH) has been shown to have inhibitory effects on reproductive activity and displays changes expression. Here we present evidence in mammals that gene orthologous GnIH, RFamide-related (RFRP) gene, expressed mediobasal hypothalamus, is strongly regulated length...
Melatonin (MLT) exerts its physiological effects principally through two high-affinity membrane receptors MT1 and MT2. Understanding the exact mechanism of MLT action necessitates use highly selective agonists/antagonists to stimulate/inhibit a given receptor. The respective distribution MT2 within CNS elsewhere is controversial, here we used "knock-in" strategy replacing or coding sequences with LacZ reporter. data show striking differences in mouse brain: whereas subtype was expressed very...
Abstract Melatonin is a neurohormone synthesized from dietary tryptophan in various organs, including the pineal gland and retina. In gland, melatonin produced at night under control of master clock located suprachiasmatic nuclei hypothalamus. Under physiological conditions, seems to constitute unique source circulating melatonin. involved cellular metabolism different ways. First, circadian rhythm helps maintenance proper internal timing, disruption which has deleterious effects on...
Using quantitative autoradiography, the density of melatonin binding sites has been measured in rat pars tuberalis (PT) and suprachiasmatic nuclei (SCN) every 4 h throughout a 24-hour period animals kept light regime 12L/12D (with lights on at 07.00 h). Slices PT SCN were incubated presence 180 172 pM, respectively, 2-125I-melatonin. In both structures investigated, specific 2-125I-melatonin showed similar rhythms with maximum 16.00 (PT: 46.9 +/- 2.8 fmol/mg protein, n = 5 SCN: 5.12 0.30 5)...
The hippocampal formation is a highly plastic brain structure that undergoes structural remodeling in response to internal and external challenges such as metabolic imbalance repeated stress. We investigated whether the extreme alterations status occur during course of hibernation European hamsters cause changes dendritic arborizations CA3 pyramidal neurons their main excitatory afferents, mossy fiber terminals (MFT), originate dentate gyrus. report apical, but not basal, trees...