Claude Colard

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The recent identification of two peptides named hypocretins (Hcrt), and expressed in neurons of the rat tuberal lateral hypothalamus (LHA) previously detected by an ovine prolactin antiserum, led us to revisit some experimental procedures intented to understand the physiological roles of these neurons. In the present study, rats received intraperitoneal(More)
Sub-populations of neurons producing melanin-concentrating hormone (MCH) are characterized by distinct projection patterns, birthdates and CART/NK3 expression in rat. Evidence for such sub-populations has not been reported in other species. However, given that genetically engineered mouse lines are now commonly used as experimental models, a better(More)
Following an i.p. injection of 2-deoxyglucose (2DG), a nonmetabolizable analogue of glucose known to induce intracellular glucopenia, a progressive decrease in the level of hypocretin (Hcrt)/orexin mRNA was observed in the rat lateral hypothalamus while the melanin-concentrating hormone (MCH) expression in neighbouring neurons remained unaffected. This(More)
The birth date of hypocretin-containing neurons was analysed using the bromodeoxyuridine method in the rat. The results indicate that these neurons are generated between embryonic days 11 (E11) and E14, with a sharp peak on E12. This spatiotemporal pattern of genesis contrasts with that of the co-distributed neurons producing the melanin-concentrating(More)
Prepro-RFRP-containing neurons have recently been described in the mammalian brain. These neurons are only found in the tuberal hypothalamus. In this work, we have provided a detailed analysis of the distribution of cells expressing the RFRP mRNA, and found them in seven anatomical structures of the tuberal hypothalamus. No co-expression with(More)
The distribution of substances related to the tetrapeptide APGWa was investigated in the central nervous system (CNS) and the reproductive apparatus of Helix aspersa by immunocytochemistry. In the CNS, APGWa immunoreactive neurons were detected in all ganglia except the pedal ganglia. Concerning the mesocerebrum of the cerebral ganglia, only neurons of the(More)
1. The presence of insulin-like substances has been demonstrated by immunocytochemistry in the central nervous system of the snail Helix aspersa. 2. The immunopositivity has been observed especially in the large perikarya of the mesocerebral green cells [the cerebral green cells (CeGC) stained in green by the alcian blue:alcian yellow technique]. 3. The(More)
The occurrence of secretogranin II in a neuron population of the rat lateral hypothalamus specifically detected by an anti-serum to ovine prolactin was examined. As this population was previously reported to synthesize dynorphin, the distribution of neurons recognized by ovine prolactin-, dynorphin B- and secretogranin II anti-sera was investigated on(More)
Two prominent neuron populations of the rat lateral hypothalamus express genes encoding respectively the prepromelanin-concentrating hormone (MCH) or dynorphin (DYN) and secretogranin II (SGII). Their roles remain hypothetical in mammals. In the present study, we examined the changes in MCH, DYN and SGII gene expression in dehydrated rats compared to(More)
Double immunostaining for oxytocin (OT) and Fos was used to study the oxytocinergic system of the rat hypothalamic paraventricular nucleus (PVN) following intraperitoneal insulin injections. The expression of c-fos in the PVN appeared about 3 h after insulin treatment and was very high after 5 h while no labelling was observed in isotonic saline-injected(More)