Serotonergic mechanisms in anxiety.

1. Anatomical, behavioral, neurochemical and electrophysiological evidence collectively support a role for central 5-HT in the modulation of anxiety and the anti-anxiety action of the benzodiazepines. 2. The advent of selective agonists and antagonists for 5-HT receptor subtypes (5-HT1, 5-HT2, 5-HT3) has rekindled investigation of the role of 5-HT in anxiety mechanisms. 3. The azapirones represent a new class of agent which possesses affinity for 5-HT1A receptors (partial agonists) and is active in anxiolytic animal models as well as in the clinic (buspirone) 4. While preclinical data supporting the anxiolytic potential of 5-HT2 antagonists remains controversial, a recent clinical study supports ritanserin's anxiolytic effects. 5. Several animal models support the anxiolytic potential of the 5-HT3 antagonist odansetron (GR38032F). Confirmation of it's therapeutic utility awaits clinical results.