Quantitative and qualitative automatic evaluation of afterdischarges in the study of antiepileptic drugs.

An automatic analysis of bioelectrical activity in some structures of the rabbit's brain was performed after i.v. administration of diazepam, phenytoin or phenobarbital. It was found that diazepam raised the ratio of fast activity in the afterdischarges pattern but paralelly decreased the total energy involved in the production of after-discharges in the cortex and midbrain reticular formation. Phenobarbital caused a significant shift in frequencies, increasing the ratio of slow activities (in the exception of hippocampus) and decreased the power spectra of afterdischarges in all structures (in the exception of midbrain reticular formation). Phenytoin, similarly to phenobarbital, decreased the ratio of fast activities. This effect was significant only in thalamus and midbrain reticular formation. At the same time it increased the total power of signal from hippocampus and midbrain reticular formation.