Contemporary Neuroendocrine Research Strategies and Methodologies in Psychiatry

Abstract

As a consequence of the pioneering work of Scharrer and Scharrer (1940) and Harris (1960), it is now appreciated that the secretion of anterior pituitary hormones is prominently regulated by the central nervous system (CNS). Small polypeptide and catecholamine hormones are secreted into the portal vessels of the pituitary stalk from neurosecretory cells in the external layer of the median eminence of the basal hypothalamus and carried to the anterior pituitary to stimulate or inhibit the synthesis of pituitary hormones and their release into the systemic circulation (Guillemin, 1978; Schally, 1978). Various putative neurotransmitters such as dopamine, norepinephrine, serotonin, acetylcholine, GABA and histamine (Weiner and Ganong, 1978), as well as some of the recently described CNS peptides such as endorphins, bombesin, substance P and vasoactive intestinal peptide, appear to be involved in the regulation of hypothalamic neuropeptide release (Hokfelt et al., 1978). These neurotransmitters and/or neuromodulators may act singly to increase or decrease the secretion of a specific pituitary hormone, but more likely a number of different transmitters are involved in a complex web of interactions, with the final response of the pituitary being determined by their net influence on the secretion of hypothalamic releasing and inhibiting factors into the hypophysial portal blood.