ANTIANXIETY PROFILE OF ONDANSETRON, A SELECTIVE 5-HT3 ANTAGONIST, IN A NOVEL ANIMAL-MODEL

The profile of action of ondansetron ondansetron was assessed in a nov el animal model of anxiety. The mirrored chamber is a nonpunishing qua ntitative model of anxiety which measures approach-conflict behavior. Ondansetron in all the doses tested (0.01, 0.1 and 1 mg/kg i.p.) showe d significant anxiolytic action as compared to naive mice, but it was less potent as compared to a well-known anxiolytic, diazepam (1 mg/kg) . These results suggest that ondansetron has anxiolytic efficacy in no nconflict paradigms of anxiety, a response not mediated by the convent ional neurotransmitter receptors, GABA-benzodiazepine as flumazenil (4 mg/kg), a benzodiazepine receptor antagonist, failed to reverse the b ehavioral parameters evoked by ondansetron.