ANTICONFLICT EFFECT OF 5-HT1A AGONISTS IN RATS - A NEW MODEL FOR EVALUATING ANXIOLYTIC-LIKE ACTIVITY

A new conflict procedure was developed to study the potential anti-pun ishment effects of 5-HT1A agonists as compared to diazepam. In this pa radigm, the opportunity existed for rats to choose during punished per iods between immediate, punished reinforcement and delayed, non-punish ed reinforcement. The results confirm that, for non-sedative doses (1 mg/kg), diazepam increases the number of punished responses. Furthermo re, the present paradigm seems sensitive for the detection of 5-HT1A a ctivity. Buspirone, gepirone, ipsapirone, zalospirone and 8-OH-DPAT in creased responding for immediate but punished reinforcement. 1-(2-pyri midinyl)piperazine, the common metabolite of the azapirones, does not participate in their anti-conflict effect. NAN 190, a 5-HGT(1A) antago nist, was shown to block the 5-HT1A agonists. The findings of the pres ent study suggest that benzodiazepines and 5-HT1A agonists reduce the capacity to tolerate delays in reward. Abnormality in serotonin system s may be associated with poor impulse control.