Early maternal deprivation as an animal model for schizophrenia

Since the aetiology and the neuropathology of schizophrenia still largely eludes us, the development of animal models for this severe psychiatric disease has remained a difficult undertaking. As a consequence of this, there is no 'best' animal model for schizophrenia. Nonetheless, the models which focus on the neurodevelopmental hypothesis have so far been the most successful. One of these is the maternal deprivation (MD) model in which young rats are separated from their mothers for a single period of 24 hr. The present paper gives an overview of the current knowledge on this model. It appears that MD at postnatal day 9 leads to a large variety of behavioural changes (such as a disruption in prepulse inhibition, latent inhibition, acoustic sensory gating and startle habituation) which closely resemble the symptoms of schizophrenia. Moreover, MD leads to neurochemical changes, predominantly in the hippocampal formation, suggestive of a reduced plasticity. Overall it appears that MD represents an interesting animal model for investigating the deleterious effects of early stressful life events, with special emphasis on possible schizophrenia-like characteristics. (C) 2003 Elsevier B.V. All rights reserved.