ORAL ETHANOL SELF-ADMINISTRATION IN RATS IS REDUCED BY THE ADMINISTRATION OF DOPAMINE AND GLUTAMATE RECEPTOR ANTAGONISTS INTO THE NUCLEUS-ACCUMBENS

The purpose of this study was to assess the role of endogenous dopamine and glutamate systems within the nucleus accumbens in modulating responses for oral ethanol reinforcements (10% w/v) in a free-choice operant task. Pretreatment with both systemic (100 mug/kg) and intra-nucleus accumbens microinjection of fluphenazine (2 and 4 mug), a dopamine receptor antagonist, significantly decreased responding for ethanol, without significantly affecting responses for water. Ethanol self-administration was also attenuated by microinjection into the nucleus accumbens of 2-amino-5-phosphopentanoic acid (AP-5, 3 and 6 mug), a competitive NMDA receptor antagonist. These results suggest that dopamine and glutamate neurotransmission in the nucleus accumbens may regulate ethanol self-administration and its reinforcing effects.