Description
Ghrelin is an endogenous peptide hormone that regulates feeding behavior, energy homeostasis, and secretion of growth hormone, growth hormone-releasing factor (GHRF/GHRH), and somatostatin. Ghrelin counteracts the effects of leptin, exhibiting orexigenic activity and increasing feeding behavior such as food intake and body weight. Ghrelin activates eNOS in endothelial cells, stimulating activation of AMPK and Akt. Ghrelin also enhances stress-induced fear responding in vivo and increases long-term potentiation (LTP) and dendritic spine synapse formation; it also exhibits cognition enhancing activity, improving spatial learning and memory in other in vivo models.