EFFECT OF DOPAMINE AGONISTS AND ANTAGONISTS ON ETHANOL-REINFORCED BEHAVIOR - THE INVOLVEMENT OF THE NUCLEUS-ACCUMBENS

Rats initiated to self-administer 10% ethanol (v/v) in an operant situation using the sucrose-substitution technique received bilateral n. accumbens or caudate nucleus microinjections of d-amphetamine (4, 10, and 20 mug/brain), quinpirole (4 mug/brain), and/or raclopride (0.1, 0.5, and 1.0 mug/brain). Only microinjections into the n. accumbens produced changes in rate and pattern of responding. With d-amphetamine, an increase in total responding and a slowing of initial response rate was seen, whereas with raclopride administration a dose-related decrease in total responding was observed with no alteration in momentary response rates. Drug-dependent behavioral rate and pattern differences suggest that DA activity in the n. accumbens influences ethanol reinforced behavior.