title: Increased drinking following social isolation rearing: implications for polydipsia associated with schizophrenia.
abstract: 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.
authors: Centre for Neuroscience Studies, Queen's University, Kingston, Canada.
authors: Emily R
authors: ER
authors: Hawken
authors: Nicholas J
authors: NJ
authors: Delva
authors: Richard J
authors: RJ
authors: Beninger
mesh_terms: D000818:Animals; D016291:Dizocilpine Maleate / Q000008:administration & dosage / Q000494:pharmacology; D004326:Drinking / Q000187:drug effects; D008297:Male; D059606:Polydipsia / Q000209:etiology; D051381:Rats; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors; D012559:Schizophrenia / Q000150:complications; D012934:Social Isolation / Q000523:psychology*
chemical_list: D016194:Receptors, N-Methyl-D-Aspartate; D016291:Dizocilpine Maleate