Behavioral Effects of Peptides

Abstract

The pituitary—adrenal system plays an essential role in homeostatic functions. Numerous aspects of stress-induced pituitary—adrenal activation in relation to peripheral mechanisms of adaptation have been studied since Selye’s first observations on the general adaptation syndrome some 40 years ago (Selye, 1950). Little attention, however, has been paid to the brain as a target for these hormones. Clinical observations frequently commented on psychological changes in addition to electrophysiological alterations in hyper- as well as hypocorticism (Cleghorn, 1957; Von Zerssen, 1976). Many a laboratory experiment during the last decade, however, disclosed the implication of a number of pituitary and hypothalamic hormonal peptides on various brain functions. The importance of these entities was revealed by observations on behavioral disturbances following extirpation of the pituitary gland in rats (de Wied, 1969); in animals with hereditary diabetes insipidus, which lack the ability to synthesize vasopressin (de Wied et al., 1975a); or in rats in which the action of vasopressin in the brain is neutralized by intraventricular administration of specific vasopressin antiserum (van Wimersma Greidanus et al., 1975a).