The Distribution and Mechanism of Action of Ghrelin in the CNS Demonstrates a Novel Hypothalamic Circuit Regulating Energy Homeostasis

摘要: The gastrointestinal peptide hormone ghrelin stimulates appetite in rodents and humans via hypothalamic actions. We discovered expression of a previously uncharacterized group neurons adjacent to the third ventricle between dorsal, ventral, paraventricular, arcuate nuclei. These send efferents onto key circuits, including those producing neuropeptide Y (NPY), Agouti-related protein (AGRP), proopiomelanocortin (POMC) products, corticotropin-releasing (CRH). Within hypothalamus, bound mostly on presynaptic terminals NPY neurons. Using electrophysiological recordings, we found that stimulated activity mimicked effect paraventricular nucleus hypothalamus (PVH). propose at these sites, release may stimulate orexigenic peptides neurotransmitters, thus representing novel regulatory circuit controlling energy homeostasis.