[New evidence for a GABA-ergic component in the mechanism of action of benzodiazepine tranquilizers].

Studies of impulse summation in the rabbit central nervous system have shown that valproate, an agent potentiating GABA-ergic inhibition, reduces while thiosemicarbazide and bicuculline that lower GABA inhibitory effects increase impulse summation. It has been also discovered that the action of phenazepam and diazepam is potentiated by valproate and reduced by thiosemicarbazide and bicuculline. According to the authors' data, diphenylhydantoin, an anticonvulsant having no GABA-positive effect fails to produce selective reduction of impulse summation. The data presented may be regarded as new evidence gained in the whole body for participation of the GABA-ergic mechanisms in the development of benzodiazepine effects.