Pharmacopsychiatry 2008; 41(4): 138-145
DOI: 10.1055/s-2008-1058107
Original Paper

© Georg Thieme Verlag KG Stuttgart · New York

Behavioural Alterations in Rats Following Neonatal Hypoxia and Effects of Clozapine: Implications for Schizophrenia

M. Fendt 1 , 4 , A. Lex 1 , 5 , P. Falkai 2 , F. A. Henn 3 , 6 , A. Schmitt 2 , 3
  • 1Animal Physiology, Zoological Institute, Faculty of Biology, University of Tübingen, Tübingen, Germany
  • 2Department of Psychiatry, University of Göttingen, Göttingen, Germany
  • 3Central Institute of Mental Health, Mannheim, Germany
  • 4Present address: Novartis Institutes for BioMedical Research, Neuroscience DA, Basel, Switzerland
  • 5Present address: Animal Physiology, Biological Institute, University of Stuttgart, Stuttgart, Germany
  • 6Present address: Life Sciences, Brookhaven National Laboratory, Upton, NY, USA
Further Information

Publication History

received 08.10.2007 revised 02.01.2008

accepted 14.01.2008

Publication Date:
23 July 2008 (online)

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Abstract

Introduction: As a consequence of obstetric complications hypoxia has been discussed as a possible factor in the pathophysiology of schizophrenia. The present study investigated the effects of weak chronic neonatal hypoxia in rats on different behavioural animal models of schizophrenia.

Methods: (1) After neonatal hypoxia, half of the pups were fostered by normally treated nurse animals to control for possible maternal effects. (2) The animals were tested on postnatal days (PD) 36, 86, 120 and 150 by applying three different behavioural tests: prepulse inhibition (PPI), social interaction and recognition, and motor activity in an open field. (3) Before the PD 150 test, half of the animals had been chronically treated with the antipsychotic drug clozapine (45 mg/kg/day).

Results: Rats exposed to hypoxia as neonates exhibited a deficit in locomotor activity on PD 86, 120, and 150, as well as a PPI deficit on PD 120 and 150 but not before. Chronic treatment with clozapine reverses the hypoxia induced PPI deficit, but not the decreased locomotor activity. In a second experiment, clozapine was chronically administered before PD 120 and blocked the development of the PPI deficit in the animals exposed to hypoxia.

Discussion: The time course of the hypoxia-induced PPI deficit and reversibility by clozapine supports the validity of our animal model and the hypothesis that hypoxia as an obstetric complication is an important factor in the pathophysiology of schizophrenia.

References

Correspondence

Dr. M. Fendt

Novartis Institutes of BioMedical Research

DA Neuroscience

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Email: markus.fendt@novartis.com