gamma aminobutyrate (gaba) is a non-protein amino acid that is thought to play an important role in the modulation of the central response to stress. mechanisms by which gaba may facilitate these responses to stress are metabolic and/or mechanical disruptions. environmental stresses increase gaba accumulation through cytosolic acidification, induce an acidic ph-dependent activation of glutamate...

Inflammation and renin-angiotensin system activity in the brain contribute to hypertension through effects on fluid intake, vasopressin release, and sympathetic nerve activity. We recently reported that activation of brain peroxisome proliferator-activated receptor (PPAR)-γ in heart failure rats reduced inflammation and renin-angiotensin system activity in the hypothalamic paraventricular nucle...

Ghrelin is a stomach-derived hormone that regulates food intake and neuroendocrine function by acting on its receptor, GHSR (Growth Hormone Secretagogue Receptor). Recent evidence indicates that a key function of ghrelin is to signal stress to the brain. It has been suggested that one of the potential stress-related ghrelin targets is the CRF (Corticotropin-Releasing Factor)-producing neurons o...

Aldosterone stimulates the sympathetic nervous system by binding to a select population of brain mineralocorticoid receptors (MR). These MR have an equal affinity for corticosterone that is present in substantially higher concentrations, but are held in reserve for aldosterone by activity of the enzyme 11 -hydroxysteroid dehydrogenase type 2 (11 -HSD-2), which converts corticosterone to an inac...

Salter-Venzon D, Watts AG. The role of hypothalamic ingestive behavior controllers in generating dehydration anorexia: a Fos mapping study. Am J Physiol Regul Integr Comp Physiol 295: R1009–R1019, 2008. First published July 30, 2008; doi:10.1152/ajpregu.90425.2008.— Giving rats 2.5% saline to drink for 3–5 days simply and reliably generates anorexia. Despite having the neurochemical and hormona...

When injected into specific rat brain regions, the neurotransmitter candidate L-proline produces various cardiovascular changes through ionotropic excitatory amino acid receptors. The present study used an immunohistochemical double-labeling approach to determine whether intracisternally injected L-proline in freely moving rats, which increases blood pressure, activates hypothalamic vasopressin...

Orexins, also called hypocretins, are newly discovered hypothalamic peptides that are thought to be involved in various physiological functions. In spite of the fact that orexin receptors, especially orexin receptor 2, are abundant in the hypothalamic paraventricular nucleus (PVN), the effects of orexins on PVN neurons remain unknown. Using a whole cell patch-clamp recording technique, we inves...

Long term use of sugars can induce excess caloric intake and/or obesity. To evaluate the effects of sugar intake on different regions of the hypothalamus (the brain’s control center for energy homeostasis) we first developed and then evaluated a microscope-assisted dissection method. Because of the small size of the paraventricular nucleus, we validated the samples by measuring several hormones...

Pregnancy increases sympathetic nerve activity (SNA), but the mechanisms are unknown. Here, we investigated the contributions of the hypothalamic paraventricular and arcuate nuclei in α-chloralose-anesthetized pregnant and nonpregnant rats. Baseline arterial pressure (AP) was lower, and heart rate (HR), lumbar sympathetic activity, and splanchnic SNA were higher in pregnant rats compared with n...