Changes in the sensitivity of dopamine receptors in the nucleus accumbens and in the striatum induced by chronic ethanol administration.

Rats of the Sprague-Dawley strain were maintained on ad libitum food and a forced-intake regimen of ethanol for up to 270 days. Bilateral application of dapamine (DA) into the nucleus accumbens of both chronic ethanol rats and rats undergoing withdrawal produced a pronounced increase in coordinated locomotor activity which was 8--10 times higher than that of untreated water control rats. This phenomenon was first observed after 5 months of ethanol treatment and lasted for about 4 weeks after cessation of the treatment. It is concluded that prolonged ethanol administration produces an increased sensitivity of the DA-receptors in the nucleus accumbens and further supports the contention that central catecholamine mechanisms are involved in the mediation of the withdrawal syndrome observed after chronic treatment with ethanol.