AMPA RECEPTOR-BINDING AND SUBUNIT MESSENGER-RNA EXPRESSION IN PREFRONTAL CORTEX AND STRIATUM OF ELDERLY SCHIZOPHRENICS

The dopamine hypothesis of schizophrenia has recently evolved into a m odel of dysfunctional integration between cortical ann subcortical dop aminergic activity. Anatomical data suggest that regional alterations in dopaminergic activity may be linked by means of the rich glutamater gic innervation of the striatum by corticostriatal projections, sugges ting a potential role for glutamatergic dysfunction in schizophrenia. Although pharmacological data have implicated the NMDA subtype of glut amate receptor in this illness, disturbance in AMPA receptor expressio n could potentially lead to the NMDA receptor hypoactivity hypothesize d in schizophrenia. To address this possibility, toe examined AMPA rec eptor binding and subunit mRNA levels in prefrontal cortex and striatu m of schizophrenics and matched controls. There were ilo significant d ifferences in AMPA receptor binding or subunit mRNA levels in either p refrontal cortical or striatal regions of schizophrenics. Furthermore, AMPA receptor expression did not seem to be regulated by chronic anti psychotic drug exposure, when neuroleptic treated and drug-free schizo phrenics were analyzed separately. These data do not support a role fo r altered AMPA receptor expression ill cortex and striatum in schizoph renia. (C) 1998 American College of Neuropsychopharmacology. Published by Elsevier Science Inc.