A hypothalamic circuit for circadian regulation of corticosterone secretion.

There is a strong circadian rhythm of corticosteroid secretion in animals and humans, but the circuit for translating the suprachiasmatic (SCN) clock light-dark cycle rhythm into an increase in corticosteroid secretion beginning several hours before the active period is not known. We show here that in male mice, this rhythm depends upon input from the SCN to the subparaventricular zone (SPZ), and then to the dorsomedial nucleus of the hypothalamus (DMH). Both glutamatergic and GABAergic DMH neur...