Effects of ondansetron on short-term memory retrieval in mice.

Behavioral studies have shown cognitive improvements in various animal models of learning and memory using 5-HT3 receptor antagonists. The present study investigated the cognitive role of ondansetron, a selective 5-HT3 antagonist, in naive and scopolamine-treated mice. Ondansetron attenuated the performance deficits induced by scopolamine (0.3 mg/kg) with both doses employed, although 1.0 mg/kg ondansetron was more effective in ameliorating the deficits as compared to 0.1 mg/kg. However, none of the ondansetron doses (0.01, 0.1 and 1 mg/kg) influenced the performance of naive mice in the passive avoidance step-down paradigm. These results suggest that the 5-HT receptor system, particularly the 5-HT3 receptor, may play a modulating role in learning and memory phenomena in animals.