Early postnatal depletion of NMDA receptor development affects behaviour and NMDA receptor expression until later adulthood in rats--a possible model for schizophrenia.

There is increasing evidence that a dysfunction of the N-methyl-d-aspartate (NMDA) receptor system plays a key role in the pathophysiology of schizophrenia. Non-competitive NMDA-antagonists induce schizophrenia-like symptoms and cognitive impairment in healthy humans as well as rodents. As receptor dysfunction precedes clinical disorder manifestation, the present study investigated whether transient perinatal NMDA antagonism constitutes a suitable long-term animal model for schizophrenia. Male Wistar rats were treated from postnatal days 6-21 with the NMDA receptor antagonist MK-801, and then subjected to behavioural analysis up to an age of 180d. Alterations in cortical NMDA receptor expression and lymphocyte cAMP-response-element-binding-protein (CREB) were assessed. In comparison to controls, MK-801-treated animals showed differences in behaviour up to an age of 180d. Western blot analysis revealed that transient perinatal application of MK-801 caused a persistent increase in cortical NMDA-R1 protein in combination with a persistent disturbance of CREB phosphorylation, a downstream target of NMDA signalling. This animal model demonstrates that early postnatal NMDA receptor blockade leads to schizophrenia-like symptoms with persistent behavioural and neurochemical disturbances throughout life. Therefore, it might provide a basis for further understanding of the disease and evaluation of new therapeutic strategies.