5-HT3 antagonists decreased the immobility time of mice in FST and TST.
NMDA antagonists potentiated the effect of 5-HT3 antagonists in behavioral tests.
NMDA receptor agonist prevented the anti-immobility effect of 5-HT3 antagonists.
Antidepressant effect of 5-HT3 antagonists is mediated by NMDA receptor blockade.