Studied the synergistic effect between the serotonergic agonist ipsapirone and the calcium channel antagonist, nifedipine, in animal models of anxiety and depression using male rats. Ipsapirone (1.5, 3.0, and 6.0 mg/kg) dose dependently potentiated the behavioral effects of a small and ineffective dose of nifedipine (2.0 mg/kg) in 2 experimental paradigms. This potentiation was revealed by a decrease in immobilization time in the forced swim test (antidepressant-like effect) and by an increase in water-consumption in a novel environment (anxiolytic-like effect).