Search results for "hypothalamu"
showing 10 items of 164 documents
Involvement of reactive oxygen species and TRP channels in glucose sensitivity of hypothalamic neuron
2013
Vers un lien entre plasticité du cerveau et satiété
2021
Vous venez de terminer un bon repas et vous vous sentez repu ?Des chercheurs (1) viennent de comprendre des mécanismes qui, dans votre cerveau, ont contribué à cet état. Il s’agit d’une cascade de réactions déclenchée par l’élévation du taux de glucose dans le sang.Dans une nouvelle étude menée chez la souris, l’équipe dirigée par Alexandre Benani, chercheur CNRS au Centre des Sciences du Goût et de l’Alimentation (2) montre que les circuits de neurones qui freinent la prise alimentaire sont activés après un repas et cette activation implique des mouvements de cellules dans le cerveau.Cette étude a été publiée dans Cell Reports le 3 mars 2020.Lire le communiqué de presse : https://bit.ly/3j…
Dual role of acyl-coa binding protein in the hypothalamus: regulator of astrocyte fatty acid metabolism and gliotransmitter targeting pomc neurons
2013
La liste des auteurs est incomplète.; absent
Implication de la plasticité cérébrale hypothalamique dans la régulation de l'homéostasie énergétique chez la souris : effet d'un régime gras
2012
The hypothalamus plays a crucial role in the control of energy balance. In adult brain, this area remain plastic and the cellular network can be rapidly modified under environmental pressures. Studies show than hypothalamic remodeling are disturbed when metabolic diseases such as obesity or type II diabetes are declared. In this study we hypothesized that a high fat diet (HFD) inducing obesity could rapidly causes cell modifications in the adult hypothalamus network. To answer this question, we have established a one week HFD mouse model, and evaluated to type of hypothalamic plasticity which are synaptic plasticity and neurogenesis. Our results show that HFD leads to an increase of the exc…
Topography of somatostatin gene expression relative to molecular progenitor domains during ontogeny of the mouse hypothalamus
2010
The hypothalamus comprises alar, basal, and floor plate developmental compartments. Recent molecular data support a rostrocaudal subdivision into rostral (terminal) and caudal (peduncular) halves. In this context, the distribution of neuronal populations expressing somatostatin (Sst) mRNA was analyzed in the developing mouse hypothalamus, comparing with the expression pattern of the genes Orthopedia (Otp), Distal-less 5 (Dlx5), Sonic Hedgehog (Shh), and Nk2 homeobox 1 (Nkx2.1). At embryonic day 10.5 (E10.5), Sst mRNA was first detectable in the anterobasal nucleus, a Nkx2.1-, Shh-, and Otp-positive basal domain. By E13.5, nascent Sst expression was also related to two additional Otp-positiv…
A CRF-Producing and -Secreting Tumor of the Lung
1986
Corticotropin-releasing factor (CRF) has recently been isolated from ovine hypothalamus, characterized chemically, and synthesized. Upton and Amatruda (1971) first suggested that CRF-like activity occurred in neoplastic tissues, and Hashimoto et al. (1980) subsequently detected CRF-like activity in an extract of an ACTHproducing nephroblastoma. Recently, Carey et al. (1984) and Asa et al. (1984) used immunocytochemical techniques to demonstrate CRF in postmortem tumor material obtained from patients with a carcinoma of the prostate and an intrasellar gangliocytoma.
Heterogeneous responses of nucleus incertus neurons to corticotrophin-releasing factor and coherent activity with hippocampal theta rhythm in the rat
2013
The nucleus incertus (NI) of the rat hindbrain is a putative node in the ascending control of the septohippocampal system and hippocampal theta rhythm and is stress and arousal responsive. NI contains GABA neurons that express multiple neuropeptides, including relaxin-3 (RLN3) and neuropeptide receptors, including corticotrophin-releasing factor receptor-1 (CRF-R1), but the precise anatomical and physiological characteristics of NI neurons are unclear. Therefore, we examined the firing properties of NI neurons and their responses to CRF, the correlation of these responses with occurrence of relaxin-3, and NI neuron morphology in the rat. Most NI neurons excited by intracerebroventricular CR…
Expression and regulation of mPer1 in immortalized GnRH neurons.
2003
Hypothalamic GnRH (gonadotropin-releasing hormone) neurons play a critical role in the initiation and maintenance of reproduction competence. Using the mouse GnRH neuronal cell line, GT1-7, we have characterized the expression of the gene mPer1, a recognized key element of the mammalian circadian clockwork. Both mPer1 transcripts and the 136 kDa mPER1 gene product could be detected in these cells. Immunocytochemical analysis also confirmed expression of mPER1 both in vitro and in vivo in GnRH neurons. Activation of cyclic AMP signalling pathways in vitro elevated GnRH secretion as well as mPer1 expression and nuclear mPER1 immunoreactivity. As mPER1 is known to feedback on transcriptional a…
Depressive effect of LHRH on the numbers of "synaptic" ribbons and spherules in the pineal gland of diestrous rats.
1983
Previous studies have shown that LHRH or LHRH-like substances are present in the pineal gland. In order to investigate whether exogenous LHRH may affect the pineal gland, in the present study the effects of a single dose of LHRH (1 microgram, i.p.) on pineal "synaptic" ribbons and spherules as well as serum melatonin levels were examined in diestrous Wistar rats. One hour after the injection both ribbons and spherules exhibited a statistically significant decrease in number. Serum melatonin levels were not affected. It is concluded that humoral feedback mechanisms may exist between the hypothalamus and the pineal gland.
Circadian rhythm and effects of light on cAMP content of the dwarf hamster suprachiasmatic nucleus
1998
The present study was conducted in the dwarf hamster (Phodopus sungorus) to investigate whether a circadian rhythm is present in the content of the second messenger cyclic adenosine 3',5'-monophosphate (cAMP) in the suprachiasmatic nucleus (SCN), the endogenous clock in mammals. In animals held under light/dark conditions (LD), we observed high levels at the end of the light phase and low levels during the night in frozen SCN punches. In animals held in continuous dark, a similar rhythm was seen although a second peak was present in the subjective day. In senile hamsters under LD, the decrease of cAMP levels at the light transition was not seen. These data, obtained for the first time from …