Effects of ipsapirone and BAY R 1531 on learned helplessness

The effects of the 5-hydroxytryptamine-1A (5-HT1A) receptor agonists on the learned helplessness test were investigated. Rats were submitted to a single session of 60 uncontrollable shocks (10-s duration, 1.0 mA, every 60 +/- 40 s) and then treated twice daily with ip injections of either ipsapirone (13 mg/kg daily) or BAY R 1531 (0.375 mg/kg daily) for four consecutive days. On the last day, the animals were submitted to an escape test. The results showed that both drug treatments blocked the deficit in the escape learning (helplessness effect). These data suggest that drugs which stimulate 5-HT1A receptors have an antidepressant-like activity in this animal model of depression.