Pharmacology and neurochemistry of buspirone

Biochemically, buspirone is unlike the benzodiazepines in that it neither stimulates nor inhibits 3H-benzodiazepine binding, does not affect the influence of GABA or halide anion on 3H-benzodiazepine binding, and does not interfere with GABA binding or uptake. Buspirone lacks anticonvulsant activity, interacts minimally with CNS depressants, and does not cause muscle relaxation. Its tranquilizing activity is characterized by the ability to (1) tame aggressive rhesus monkeys, (2) block conditioned avoidance responding in the rat, (3) inhibit shock-induced fighting in the mouse, and (4) attenuate shock-induced suppression of drinking in the rat. In vitro binding experiments indicate that buspirone lacks significant activity at several binding sites. It appears to interact only with the dopaminergic system and possesses properties that are similar to both dopamine agonists and dopamine antagonists.