MEDIAL PREFRONTAL CORTICAL D-2 AND STRIATOLIMBIC D-4 DOPAMINE-RECEPTORS - COMMON TARGETS FOR TYPICAL AND ATYPICAL ANTIPSYCHOTIC-DRUGS

1. In vitro receptor autoradiography was used to examine the long-term effects of a typical (fluphenazine), atypical (clozapine), or potenti al atypical antipsychotic (S[+]-N-n-propylnorapomorphine; [+]-NPA) on different dopamine (DA) receptor subtypes. 2. D(?)1-Like and D-3 recep tor levels were not changed with any treatment in any brain region exa mined. 3. D-2 Receptors in caudate-putamen (CPu), nucleus accumbens (N Ac) and olfactory tubercle (OT) were significantly increased by long-t erm treatment with fluphenazine, but not with clozapine or S[+]-NPA. 4 . D-2 Receptor levels in medial prefrontal cortex (MPC), but not dorso lateral frontal cortex (DFC), were elevated after repeated daily admin istration of fluphenazine, clozapine, and S [+]-NPA. 5. D-4-Like recep tors, assayed under D-4-selective conditions, were increased by fluphe nazine, clozapine and S(+)-NPA in both NAc and CPu, but by none of the se treatments in OT, DFC or MPC. 6. These results support a common rol e for medial prefrontal cortical D-2 and striatolimbic D-4 receptors i n mediating the clinical actions of typical and atypical antipsychotic drugs.