Schedule-induced polydipsia in rats: adrenocortical and hippocampal modulation.

Onset of schedule-induced polydipsia (SIP) is related to adrenal gland weight. Adrenalectomy, but not demedullation, hastened the emergence of SIP, and exogenous corticosterone administration tended to reverse this effect. Hippocampal lesions were followed by a rapid and uniform release of SIP. None of the above manipulations influenced normal (home-cage) drinking. A synthesis of present findings with the literature suggests that the hippocampus and the adrenal cortex interact and that the equilibrium established within this system is reflected, for any particular rat, in its adjunctive behavior.