CARBAMAZEPINE ATTENUATES COCAINE-INDUCED INCREASES IN DOPAMINE IN THENUCLEUS-ACCUMBENS - AN INVIVO DIALYSIS STUDY

Carbamazepine's effects on cocaine-induced increases in dopamine overf low in the nucleus accumbens were studied using in vivo microdialysis in anesthetized rats. Rats were chronically treated with a diet contai ning carbamazepine or no drug for one week prior to microdialysis proc edures. The basal levels of dopamine in the nucleus accumbens did not differ between groups; however, the increases in dopamine following co caine administration (4 mg/kg i.v.) were significantly reduced by carb amazepine. In addition, basal levels of dihydroxyphenyl acetic acid (D OPAC) were significantly diminished in the carbamazepine group and a t rend in the same direction was observed for homovanilic acid (HVA). Th ese results are consistent with reports that carbamazepine might decre ase dopamine synthesis. Further studies are required to determine the mechanism of carbamazepine's inhibition of cocaine-induced dopamine ov erflow and its potential clinical implications.