[Pharmacological studies on Y-8894. (III). Its effect on the abnormal electrocorticogram induced by destruction of the internal capsule].

The effect of Y-8894 on the abnormal electrocorticogram (ECoG) of alcuronium-immobilized rats, induced by destruction of the internal capsule with heat, was compared with that produced by imipramine, amantadine and Ca-hopantenate. ECoG power in the delta + theta (1-7 Hz), alpha (7.5-12.5 Hz) and beta (13-30 Hz) bands was used as an index. Delta + theta power increased following destruction of the internal capsule with heat. The increased delta + theta power (abnormal ECoG) lasted for 60 min following the injection of saline at 60 degrees C for 3 min. Y-8894 (0.1-1 mg/kg, i.v.) apparently improved the abnormal ECoG dose-dependently by significantly reducing the increased delta + theta power. Similar results were obtained with amantadine (10 mg/kg, i.v.), but its potency was weaker than that of Y-8894. Imipramine (1 mg/kg, i.v.) and Ca-hopantenate (30 mg/kg, i.v.), however, both failed to modify the abnormal ECoG. All drugs, except Ca-hopantenate, decreased the magnitudes of the alpha and beta bands. The above results suggest that Y-8894 may be effective in ameliorating cerebral dysfunction induced experimentally by the lesion of the internal capsule.