The spontaneous activity of hypothalamic units was studied in chronic awake and ketamine-anesthetized rats. Ketamine appeared to decrease significantly the spontaneous firing of neurons in the ventromedial hypothalamic nucleus (VMH) but did not influence the activity in either the dorsomedial hypothalamic nucleus (DMH) or the lateral hypothalamic area (LHA). The responses obtained in the medial...

Neuropeptide Y (NPY) is one of the important endogenous orexigenic peptides. In these studies we employed c-Fos immunostaining and a selective NPY Y1 receptor antagonist to identify the site of action of NPY in the hypothalamus. The results showed that intracerebroventricular administration of NPY stimulated feeding and increased immunostaining of c-Fos, a product of the immediate early gene c-...

introduction: gonadotropin inhibitory hormone (gnih) is believed to be an inhibitor of gonadotropin releasing hormone (gnrh) secretion. the role of gnih in lactational inhibition of gonadotropin secretion is not well known therefore, the aim of the present study was to evaluate the effect of lactation on expression of gnih in these nuclei of lactating and non-lactating rats. methods: ten postpa...

The dorsomedial hypothalamic nucleus (DMH) output pathways are revealed by using autoradiographic tracing of tritium labeled Leucine and by the recently introduced Phaseolus vulgaris leuco-agglutinin immunocytochemical method. Terminal labeling appears in the dorsal motor nucleus of the vagus, nucleus ambiguus and in the parvocellular reticular formation at the lower medullary level. Mesencepha...

The prolactin receptor (PRL-R) has recently been identified in various hypothalamic nuclei of female rats. In this study, expression of both the short- and long-forms of PRL-R mRNA was investigated in 11 microdissected hypothalamic nuclei of ovariectomized, estrogen-treated rats. Specific nuclei were micropunched from 300-micrometer thick frozen coronal sections with autoclaved stainless steel ...

Activation of central 5-hydroxytryptamine 1A receptors powerfully inhibits stress-evoked cardiovascular responses mediated by the dorsomedial hypothalamus, as well as responses evoked by direct activation of neurons within the dorsomedial hypothalamus. The hypothalamic paraventricular nucleus also has a crucial role in cardiovascular regulation, and is believed to regulate heart rate and renal ...

Several lines of evidence suggest that the hypothalamus is involved in trigeminal pain processing. However, the organization of descending hypothalamic projections to the spinal trigeminal nucleus caudalis (Sp5C) remains poorly understood. Microinjections of the retrograde tracer, fluorogold (FG), into the Sp5C, in rats, reveal that five hypothalamic nuclei project to the Sp5C: the paraventricu...

Neurocircuit inhibition of hypothalamic paraventricular nucleus (PVN) neurons controlling hypothalamo-pituitary-adrenocortical (HPA) activity prominently involves GABAergic cell groups of the hypothalamus and basal forebrain. In the present study, stress responsiveness of GABAergic regions implicated in HPA inhibition was assessed by in situ hybridization, using probes recognizing the GABA-synt...