Growth hormone secretagogue receptor Growth hormone secretagogue receptor Growth hormone secretagogue receptor(GHS-R), also known as ghrelin receptor, is a G protein-coupled receptor that binds growth hormone secretagogues (GHSs), such as ghrelin, the "hunger hormone". The role of GHS-R is thought to be in regulating energy homeostasis and body weight. In the brain, they are most highly expressed in the hypothalamus, specifically the ventromedial nucleus and arcuate nucleus. GSH-Rs are also expressed in other areas of the brain, including the ventral tegmental area, hippocampus, and substantia nigra. Outside the central nervous system, too, GSH-Rs are also found in the liver, in skeletal muscle, and even
Ghrelin increase fear learning. Ghrelin was found to be upregulated by stress even in the absence of adrenal hormones. Blocking the ghrelin receptor during stress abolished stress-related enhancement of fear memory without blunting other markers of stress. These results suggest that ghrelin is a novel branch of the stress response. Human studies are needed to translate the use of anti-ghrelin treatments to prevent stress-induced psychiatric disorders. Ghrelin, through its receptor increases the concentration of dopamine in the substantia nigra. Ghrelin has inhibitory effects on gonadotropin-releasing hormone (GnRH) secretion. It may cause decreased fertility. Gastric bypass surgery not only reduces the gut's