dizocilpine-maleate and Polydipsia

Primary polydipsia, excessive drinking without known medical cause, is especially associated with a diagnosis of schizophrenia. We used animal models of schizophrenia-like symptoms to examine the effects on schedule-induced polydipsia: post-weaning social isolation rearing, subchronic MK-801 treatment (an NMDA-receptor antagonist) or the two combined. Male, Sprague-Dawley rats reared in groups or in isolation beginning at postnatal day 21 were further divided to receive subchronic MK-801 (0.5 mg/kg twice daily) or saline for 7 days beginning on postnatal day 62. Following a 4-day withdrawal period, all groups were trained on a schedule-induced polydipsia paradigm. Under food-restriction, animals reared in isolation and receiving food pellets at 1-min intervals developed significantly more drinking behavior than those reared with others. The addition of subchronic MK-801 treatment did not significantly augment the amount of water consumed. These findings suggest a predisposition to polydipsia is a schizophrenia-like behavioral effect of post-weaning social isolation.

Topics: Animals; Dizocilpine Maleate; Drinking; Male; Polydipsia; Rats; Receptors, N-Methyl-D-Aspartate; Schizophrenia; Social Isolation

Topics: Age Factors; Amphetamine; Animals; Animals, Newborn; Body Weight; Central Nervous System Stimulants; Cognition Disorders; Cohort Studies; Disease Models, Animal; Dizocilpine Maleate; Drinking; Drug Administration Schedule; Excitatory Amino Acid Antagonists; Food Deprivation; Male; Motor Activity; Polydipsia; Random Allocation; Rats; Rats, Sprague-Dawley