Fig. 38.Schematic drawing showing an integrated view of the mammalian circadian timing system and the main neuroendocrine responses, physiological functions and behaviors under its control. AII = angiotensin II; APv = anterior periventricular nucleus of the hypothalamus; AVP = arginine vasopressin; BNST = bed nucleus of the stria terminalis; CAL = calretinin; ENK = enkephalin; GABA = aminobutiric acid; GRP = gastrin-releasing peptide; GLU = glutamic acid; 5-HT = 5-hydroxytryptamine or serotonin; HYP = hypothalamus, IGL = intergeniculate leaflet; NO = nitric oxide; NPY = neuropeptide Y; PACAP = pituitary adenylyl cyclase-activating peptide; PTA = pretectal area; PVN = hypothalamic paraventricular nucleus; rht = retinohypothalamic tract; SCN = suprachiasmatic nucleus; SP = substance P; SPVZ = hypothalamic subparaventricular zone; SRIF = somatostatin; VIP = vasoactive intestinal polypeptide.