Role of dopamine D₃ receptors in the addictive properties of ethanol

After the cloning of the dopamine D₁ and D₂ receptors (1-3), several additional dopamine receptors were identified. These new subtypes included the D₃ and D₄ receptors, which are similar to D₂, and the D₅ receptor, which is similar to D₁ (4-6). Although most studies have focused on the role of dopamine D₁ and D₂ receptors in mediating the addictive liability of drugs, the lack of selective pharmacological tools has significantly hampered this particular field of research. In contrast, recent studies using selective competitive antagonists have shown that the dopamine D₃ receptor is involved in drug-seeking behavior. The present review is intended to highlight a new, promising area in alcohol research that focuses on the role of the dopamine D₃ receptor in the addictive properties of ethanol.