Recent Advances in the Development of Dopamine D3 Receptor Agonists and Antagonists

Advances in molecular cloning techniques have allowed the characterization of five subtypes (D1 -D5 ) of dopamine (DA) receptors. The limbic location of the D3 receptor has led to speculation about its possible role in schizophrenia and drug abuse. Since the D 3 receptor is localized in the limbic region rather than the striatum, antipsychotics with D 3 receptor selectivity could be devoid of extrapyramidal side effects commonly seen with D 2 receptor antagonists. Recent work in our laboratory revealed that the benz(e)indole cis-(±)-44b demonstrated high selectivity for the D 3 receptor. This compound exhibits a typical antipsychotic profile without the motor effects found in commonly used antipsychotic agents. This mini-review will give a brief introduction on D 3 receptors and a detailed description of selectively-acting D 3 agonists and antagonists which have recently appeared in the literature.