Inhibition-mediating dopamine receptors and the control of intracranial reward.

A receptor selective agonist and antagonist of inhibition-mediating dopamine receptors (type II receptors) produced significant and dose-related alterations in bar-pressing for intracranial reward. Receptor inhibition by piribedil increased responding for reward while receptor activation by 3,4-dihydroxyphenylamino-2-imidazoline reduced responding. Inhibition-mediating receptors may therefore play a role opposite to classic excitation-mediating receptors in controlling reward.