Discovery of Novel Hypothalamic Neuropeptides Related to Stress

Abstract

G-protein coupled receptors (GPCRs) for unknown endogenous ligands are called as orphan receptors. Recently novel biologically active substances including peptides have been discovered as unknown ligands of orphan GPCRs. Some of them are neuropeptides that are expressed in the hypothalamic areas that are known to be important sites to integrate the autonomic, neuroendocrine and immune responses to the stress. In this review we focused on novel neuropeptides that are orexins, neuromedin U and galanin-like peptide as candidates of mediators of the stress responses via the hypothalamus.