Phencyclidine-induced cognitive deficits in mice are improved by subsequent subchronic administration of tropisetron: Role of α7 nicotinic receptors

We examined the effects of tropisetron, a 5-hydroxytryptamine (5-HT3) receptor antagonist and α7 nicotinic receptor agonist, on cognitive deficits in mice after repeated administration of the NMDA receptor antagonist phencyclidine (PCP). PCP (10 mg/kg/day for 10 days)-induced cognitive deficits were significantly improved by subsequent subchronic (2 weeks) administration of tropisetron, but not ondansetron. Effects of tropisetron were significantly antagonized by co-administration of the α7 nicotinic receptor antagonist methyllycaconitine, suggesting the role of α7 nicotinic receptors in the active mechanisms of tropisetron. These findings suggest that tropisetron could be a potential therapeutic drug for cognitive deficits in schizophrenic patients.