Intraventricular administration of antivasopressin serum inhibits retention in mice

Elevations and decrements in the levels of the posterior pituitary hormone vasopressin result in facilitations and deficits in retention, respectively, in rats. Despite the frequent use of mice in studies of pharmacological influences on retention, there is a paucity of information regarding the role of endogenous peptides, particularly vasopressin, in the memory processes of mice. In the present experiment, mice suffering from acute inactivation of central vasopressin, induced by an immediately posttraining, 2 microliters, intracerebroventricular injection of antivasopressin serum, displayed a retention deficit for passive avoidance training. The results of this experiment suggest that endogenous vasopressin modulates the memory processes of mice, as well as rats.