Opposite modulation of cocaine-seeking behavior by D1- and D2-like dopamine receptor agonists.

Activation of the mesolimbic dopamine system is known to trigger relapse in animal models of cocaine-seeking behavior. We found that this "priming" effect was selectively induced by D2-like, and not by D1-like, dopamine receptor agonists in rats. Moreover, D1-like receptor agonists prevented cocaine-seeking behavior induced by cocaine itself, whereas D2-like receptor agonists enhanced this behavior. These results demonstrate an important dissociation between D1- and D2-like receptor processes in cocaine-seeking behavior and support further evaluation of D1-like receptor agonists as a possible pharmacotherapy for cocaine addiction.