CLOBAZAM EXERTS AN ANTICONVULSANT ACTION IN IMMATURE RATS

The anticonvulsant action of 1,5-benzodiazepine clobazam was studied i n 12-, 18-, and 25-day-old rats. Cortical epileptic afterdischarges (A Ds) elicited by rhythmic electrical stimulation of the sensorimotor co rtical area were used as a model in animals with implanted electrodes. As far as the duration of ADs is concerned, clobazam in doses of 1 or 5 mg/kg i.p. blocked the progressive increase with repeated stimulati ons in all age groups and the higher dose significantly shortened ADs in 25-day-old rats. The intensity of movements accompanying stimulatio n was decreased only by the 5 mg/kg dose in 25-day-old animals, wherea s clonic seizures were less intense after both doses in 12- and 25-day -old rat pups. Clobazam exerted an anticonvulsant action at all the de velopmental stages studied; the lower efficacy in 18-day-old rats (des cribed also for clonazepam) remains to be analyzed.