Central Monoamine Neurons and Pituitary—Adrenal Activity

Publisher Summary To elucidate the role of central monoamine neurons in the regulation of pituitary-adrenal activity, experiments have been started to study the amine turnover in central monoamine neurons in endocrine states with various degrees of adrenocorticotropic hormone (ACTH) secretion. NA neurons may exert an inhibitory influence that, at least in certain situations, could be of importance for the regulation of ACTH secretion. This interpretation is supported by the fact that steroid-sensitive neurons in the hypothalamus are, to a large extent, inhibited by NA. The central 5-hydroxytryptamine (5-HT) neurons probably do not directly participate in ACTH regulation with regard to stress responses. However, the 5-HT neurons may still play a role in the regulation of ACTH secretion, since 5-HT turnover is reduced by adrenalectomy and restored again to normal by subacute treatment with glycocorticoids. The increased 5-HT turnover caused by prolonged treatment with glycocorticoids may be of importance both for the negative feedback action on ACTH secretion caused by these steroids and for their actions on the affective state.