Transient N-methyl-D-aspartate receptor blockade in early development causes lasting cognitive deficits relevant to schizophrenia

Background: Aberrant N-methyl-D-aspartate (NMDA) receptor-mediated glutamatergic transmission has been implicated in schizophrenia. We studied whether transient inhibition of NMDA receptor activity during early postnatal development would produce a behavioral phenotype resembling that of individuals who are susceptible to develop schizophrenia. Methods: Rat pups were given injections of the NMDA channel blocker MK801 on postnatal days 7 through 10. This period is akin to the prenatal second trimester of primate development. Cognitive function was tested in adulthood. Results: Treatment with MK801 impaired cognitive flexibility and working memory. The impairment in cognitive flexibility was due to increased perseverative behavior. Treatment did not affect locomotor activity or recognition memory. Conclusions. These results suggest that a brief disruption of NMDA receptors during a sensitive period of cortical development is sufficient to produce selective cognitive deficits that are relevant to schizophrenia.