G protein-mediated signal transduction as a target of antidepressant and antibipolar drug action: evidence from model systems.

While the molecular locus of antidepressant and antibipolar drug action has not yet been established, it has become increasingly likely that the targets of such drugs lie distal to neurotransmitter receptors along the signal transduction pathway. These targets are likely to involve G protein-mediated signal transduction systems such as adenylyl cyclase and phospholipase C. This article will demonstrate model systems that have been developed in an attempt to determine how and where these drugs work. It appears that these model systems not only represent good experimental paradigms for studying the mechanisms of antibipolar and antimanic drugs, but are useful as simplified, yet realistic venues in which to test the speed and efficacy of suspected therapeutic agents.