Function in the adrenocortical system is markedly altered by availability of food. Basal activity is lowest and stress responsivity highest in the morning when nocturnal rats eat approximately 90% of their daily calories during the dark. After an overnight fast, basal corticotrophin and corticosteroid levels are elevated, and responsivity to stressors is decreased. Central neural sites that con...

Title: Insulin blunts the response of glucose-excited (GE) neurons in the ventrolateralventromedial hypothalamic nucleus (VL-VMN) to decreased glucose. Abbreviated Title: Insulin modulated glucose responses in VL-VMN GE neurons Authors: Victoria E. Cotero and Vanessa H Routh Addresses: New Jersey Medical School (UMDNJ), Newark, NJ Running Head: Insulin modulated glucose responses in VL-VMN GE n...

Our past microdialysis studies in ventromedial hypothalamic nucleus (VMN) and lateral hypothalamic area (LHA) of changes in dopamine concentrations in response to changes in food intake [characterized as feeding pattern (changes in meal number and size)] in anorexia of cancer show abnormal presynaptic dopaminergic neurotransmission. To determine postsynaptic receptor status, studies were done i...

Hyperphagia and weight gain to acquire energy stores for development and growth of the fetus and to prepare for the demands of lactation are important adaptations to support a healthy pregnancy. As a consequence, hypothalamic leptin resistance develops to enable maintenance of a positive energy state. During pregnancy there is a decrease in leptin receptor expression and reduced leptin-induced ...

Rats selectively bred to develop diet-induced obesity (DIO) have an early onset reduction in the sensitivity of their ventromedial hypothalamic nucleus (VMN) neurons to leptin compared with diet-resistant (DR) rats. This reduced sensitivity includes decreased leptin receptor (Lepr-b) mRNA expression, leptin receptor binding, leptin-induced phosphorylation of STAT3 (pSTAT3), and impaired leptin ...

In the rat, sex differences in behavioral responsiveness to progesterone have been correlated with a sex difference in estrogen-induced progestin receptor induction in the ventromedial nucleus (VMN). It has recently been suggested that this sex difference in progestin receptor induction may only be present after treatment with large doses of estrogen. We have evaluated the sex difference in hyp...

Many hypothalamic nuclei are involved in the regulation of food intake and energy homeostasis. An ultrastructural investigation of the hypothalamic ventromedial nucleus (VMN), a hypothetical "satiety centre" was performed to explore the morphological basis of altered feeding behaviour of old rats in an experimental model of fasting/refeeding. Young (5 months old, n=12) and old (24 months old, n...

Synthetic GH secretagogues (GHSs) act via a receptor (GHS-R) distinct from that for GH-releasing hormone (GHRH). We have studied the hypothalamic expression and regulation of this receptor by in situ hybridization using a homologous riboprobe for rat GHS-R. GHS-R mRNA is prominently expressed in arcuate (ARC) and ventromedial nuclei (VMN) and in hippocampus, but not in the periventricular nucle...

Central oxytocin reduces food intake and increases energy expenditure. The ventromedial hypothalamic nucleus (VMN) is associated with energy balance and contains a high density of oxytocin receptors. We hypothesized that oxytocin in the VMN is a negative regulator of energy balance acting to reduce feeding and increase energy expenditure. To test this idea, oxytocin or vehicle was injected dire...