STEROID EFFECTS ON BRAIN FUNCTIONS - AN EXAMPLE OF THE ACTION OF GLUCOCORTICOIDS ON CENTRAL DOPAMINERGIC AND NEUROTENSINERGIC SYSTEMS

It is now clearly established that steroid hormones released from peri pheral endocrine glands may, through specific receptors in the brain, directly regulate brain function, These effects may be rapid or involv e long-term modifications at the genomic level. Concerning the glucoco rticoids, their receptors are found in most neuronal cells, an observa tion which can be related to their widespread effects on neuronal meta bolism. Furthermore, glucocorticoids are often related to stress. We h ave previously demonstrated that neonatal handling of the rat prevente d excessive endocrine response to stress. In adults, this action appea red to protect the animal from potential damaging effects of glucocort icoids and from related impairment of cognitive functions. The effects of glucocorticoids are thought to involve an interaction of several c entral neurotransmitter systems. One such neurotransmitter is neuroten sin, a neuropeptide which was reported to be closely related to centra l dopaminergic system regulation. This paper presents a rapid overview of the central effects of glucocorticoids and possible evidence far t he interrelationship between these steroids, dopamine and neurotensin systems in the regulation of the hypothalamo-pituitary renal axis. It provides a new way to approach stress responses and to develop new sub stances that may become potential drugs in the treatment of some psych iatric disorders.