Effects of ketanserin and mianserin on delayed neuronal death induced by cerebral ischemia in Mongolian gerbils.

We examined whether ketanserin and mianserin, drugs with 5-HT2 receptor antagonistic effects, would have protective effects in Mongolian gerbils on delayed neuronal death induced by cerebral ischemia. When training and test sessions in the passive avoidance task were carried out 6 and 7 days after 3 min of ischemia, passive avoidance impairment was apparent. Destruction and disappearance was apparent in the hippocampal CA1 neurons at 7 days after the induced ischemia. Administration of ketanserin (5-20 mg/kg) and mianserin (5-20 mg/kg) led to better passive avoidance and prevented the delayed neuronal death induced by the ischemia. These effects of ketanserin and mianserin were not inhibited by treatment with the cholinergic blocker scopolamine (5 mg/kg). Thus, ketanserin and mianserin have a protective effect on delayed neuronal death in gerbils and the effects of these drugs are not mediated by serotonergic and cholinergic systems.