Search results for "HYPOTHALAMUS"
showing 10 items of 164 documents
Fasting enhances the response of arcuate neuropeptide Y-glucose-inhibited neurons to decreased extracellular glucose
2009
0363-6143 (Print) Comparative Study In Vitro Journal Article Research Support, N.I.H., Extramural; Fasting increases neuropeptide Y (NPY) expression, peptide levels, and the excitability of NPY-expressing neurons in the hypothalamic arcuate (ARC) nucleus. A subpopulation of ARC-NPY neurons ( approximately 40%) are glucose-inhibited (GI)-type glucose-sensing neurons. Hence, they depolarize in response to decreased glucose. Because fasting enhances NPY neurotransmission, we propose that during fasting, GI neurons depolarize in response to smaller decreases in glucose. This increased excitation in response to glucose decreases would increase NPY-GI neuronal excitability and enhance NPY neurotr…
Hypothalamic CB1 cannabinoid receptors regulate energy balance in mice.
2012
Cannabinoid type 1 (CB(1)) receptor activation is generally considered a powerful orexigenic signal and inhibition of the endocannabinoid system is beneficial for the treatment of obesity and related metabolic diseases. The hypothalamus plays a critical role in regulating energy balance by modulating both food intake and energy expenditure. Although CB(1) receptor signaling has been implicated in the modulation of both these mechanisms, a complete understanding of its role in the hypothalamus is still lacking. Here we combined a genetic approach with the use of adeno-associated viral vectors to delete the CB(1) receptor gene in the adult mouse hypothalamus and assessed the impact of such ma…
How many sites of action for endocannabinoids to control energy metabolism?
2006
The promising results obtained by clinical trials using Rimonabant to tackle visceral obesity and related disorders recently promoted a remarkable impulse to carry out detailed investigations into the mechanisms of action of endocannabinoids in regulating food intake and energy metabolism. The endocannabinoid system has been known for many years to play an important role in the modulation of the neuronal pathways mediating the rewarding properties of food. However, in the last few years, with the advanced understanding of the crucial role of the hypothalamic neuronal network in the regulation of appetite, several studies have also directed attention to the orexigenic role of the endocannabi…
Synergistic interaction between CCK and leptin to regulate food intake.
2000
Abstract Leptin administered (either intracerebroventricularly, icv, or intraperitoneally, ip) acts in synergy with CCK to suppress food intake and body weight in lean mice or rats. The potentiating effect induced by the co-injection of ip CCK and leptin to inhibit food consumption in mice is mediated by the CCK-A receptor and capsaicin sensitive afferents. In vitro, studies in rats showed that a subset of gastric vagal afferent fibers responded to leptin injected directly into the gastric artery only after a prior intra-arterial CCK injection. Moreover, the tonic activity of gastric-related neurons in the nucleus tractus solitarius (NTS) increased when leptin was delivered into the gastric…
Inactivation of Socs3 in the Hypothalamus Enhances the Hindbrain Response to Endogenous Satiety Signals via Oxytocin Signaling.
2012
Leptin is an adipocyte-derived hormone that controls energy balance by acting primarily in the CNS, but its action is lost in common forms of obesity due to central leptin resistance. One potential mechanism for such leptin resistance is an increased hypothalamic expression of Suppressor of cytokine signaling 3 (Socs3), a feedback inhibitor of the Jak-Stat pathway that prevents Stat3 activation. Ample studies have confirmed the important role of Socs3 in leptin resistance and obesity. However, the degree to which Socs3 participates in the regulation of energy homeostasis in nonobese conditions remains largely undetermined. In this study, using adult mice maintained under standard diet, we d…
Simultaneous pituitary–gonadal recrudescence in two Corsican populations of male blue tits with asynchronous breeding dates
2006
Animal populations living in geographically variable environments respond to different selection pressures. The adaptive character of the responses to environmental information determines the degree of synchrony of the breeding period with local optimal conditions. An example is provided by two populations of Mediterranean blue tits (Parus caeruleus) in Corsica, breeding in different habitats, with a 1-month difference in the onset of egg laying. This difference in the onset of lay is supposed to be adaptive because, although chicks from both populations are raised mostly on caterpillars, the timing of the appearance of caterpillars is earlier for populations of tits associated with deciduo…
Serine/threonine-kinase 33 (Stk33) – Component of the neuroendocrine network?
2016
The present study was conducted to investigate the expression of serine/threonine-kinase 33 (Stk33) in neuronal structures of the central nervous system in rat and hamster as well as the presence of the protein in the brain of higher mammals, using a polyclonal antibody on cryosections of fixed brains. We found a distinct immunostaining pattern that included intense fluorescence of the ependymal lining of cerebral ventricles, and of hypothalamic tanycytes and their processes. We further observed intense staining of magnocellular neurons in the hypothalamic paraventricular, supraoptic and accessory neurosecretory nuclei, in particular the circular nuclei, and less intense stained neurons in …
A moderate diet restriction during pregnancy alters the levels of endocannabinoids and endocannabinoid-related lipids in the hypothalamus, hippocampu…
2017
Existe para su consulta material suplementario aportado por el editor. Undernutrition during pregnancy has been associated to increased vulnerability to develop metabolic and behavior alterations later in life. The endocannabinoid system might play an important role in these processes. Therefore, we investigated the effects of a moderate maternal calorie-restricted diet on the levels of the endocannabinoid 2-arachidonoyl glycerol (2-AG), arachidonic acid (AA) and the N-acylethanolamines (NAEs) anandamide (AEA), oleoylethanolamide (OEA) and palmitoylethanolamide (PEA) in the brain of newborn rat offspring. We focused on brain structures involved in metabolism, feeding behavior, as well as em…
Transient Receptor Potential Canonical 3 (TRPC3) Channels Are Required for Hypothalamic Glucose Detection and Energy Homeostasis
2017
Fil: Chrétien, Chloé. University of Bourgogne Franche-Comté. Institut National de la Recherche Agronomique. Centre des Sciences du Goût et de l’Alimentation; France Fil: Fenech, Claire. University of Bourgogne Franche-Comté. Institut National de la Recherche Agronomique. Centre des Sciences du Goût et de l’Alimentation; France Fil: Liénard, Fabienne. University of Bourgogne Franche-Comté. Institut National de la Recherche Agronomique. Centre des Sciences du Goût et de l’Alimentation; France Fil: Grall, Sylvie. University of Bourgogne Franche-Comté. Institut National de la Recherche Agronomique. Centre des Sciences du Goût et de l’Alimentation; France Fil: Chevalier, Charlène. University of …
Functional Inactivation of the Genome-Wide Association Study Obesity Gene Neuronal Growth Regulator 1 in Mice Causes a Body Mass Phenotype
2012
To date, genome-wide association studies (GWAS) have identified at least 32 novel loci for obesity and body mass-related traits. However, the causal genetic variant and molecular mechanisms of specific susceptibility genes in relation to obesity are yet to be fully confirmed and characterised. Here, we examined whether the candidate gene NEGR1 encoding the neuronal growth regulator 1, also termed neurotractin or Kilon, accounts for the obesity association. To characterise the function of NEGR1 for body weight control in vivo, we generated two novel mutant mouse lines, including a constitutive NEGR1-deficient mouse line as well as an ENU-mutagenised line carrying a loss-of-function mutation …