EFFECT OF ETHANOL ON EXTRACELLULAR DOPAMINE IN NUCLEUS-ACCUMBENS - COMPARISON BETWEEN LEWIS AND FISCHER-344 RAT STRAINS

The purpose of this study was to examine the differential effects of i ntraperitoneal ethanol on the mesoaccumbens dopamine (DA) system in Fi scher 344 and Lewis rat strains, utilizing microdialysis in awake anim als. At the lowest dose tested (0.5 g/kg), there were no changes in ex tracellular DA in the nucleus accumbens in either strain. There was a differential response to the intermediate dose of 1 g/kg ethanol, with an 84% increase in extracellular DA in the Fischer, but no change in Lewis rats. The highest dose administered (2 g/kg) did not induce sign ificant increases in DA in either strain. These data demonstrate that the mesoaccumbens DA systems of Fischer and Lewis rat strains differ i n their susceptibility to activation by ethanol, and suggest that the higher alcohol preference of Lewis rats is not associated with an enha nced DAergic response to acute experimental administration of ethanol.