Table 1.

Factors that influence glucocorticoid secretion (cortisol in primates and corticosterone in rodents)

Hypothalamus

SCN

Neuronal input to the adrenal gland via the splanchnic nerve

PVN

Support of production via CRH secretion

Initiation of pulses via CRH and AVP

CRH secretion (and possibly production) is modulated by slow glucocorticoid feedback

Pituitary gland

POMC production and post-translational cleavage into ACTH, endorphins, etc

Glucocorticoid mediated fast feedback to terminate pulses

Glucocorticoid mediated slow feedback to reduce transcription of POMC and POMC regulators

Adrenal gland

Production and secretion of glucocorticoid in response to ACTH

Production is modulated by neuronal input from SCN

Abbreviations: AVP, arginine vasopressin; CRH, corticotropin-releasing hormone; POMC, proopiomelanocortin; PVN, paraventricular neuron of the hypothalamus; SCN, suprachiasmatic neuron of the hypothalamus.