Involvement of D2 dopamine receptors in the nucleus accumbens in the opiate withdrawal syndrome

THE nucleus accumbens is prominently implicated in the reinforc-ing effects of abused drugs^1-4, and is an important site for mediat-ing aversive stimulus properties of opiate withdrawal⁵. It is generally thought, however, that the role of the accumbens is negli-gible in the somatic signs of opiate withdrawal^5-7. Contrary to this assumption, we now report that D2 dopaminergic receptor activity in the accumbens area potently regulates somatic symptoms of opiate withdrawal. We find that activation of D2 receptors within the accumbens prevents somatic signs of naloxone-induced opiate withdrawal and, conversely, that blockade of accumbal D2 recep-tors in opiate-dependent animals elicits somatic withdrawal symptoms. These data indicate that dopamine in the accumbens not only is important in the rewarding effects of abused drugs, but also (via D2 receptors) plays a pivotal role in opiate withdrawal.