Treatment of spontaneous and chemically induced EEG paroxysms in the Fischer-344 rat with traditional antiepileptic drugs or AED+CGP 35348 polytherapy.

Twenty-four Fischer-344 rats implanted with cortical electroencephalograph (EEG) electrodes were evaluated for frequency, duration, and mean duration (duration/frequency) of both spontaneous and chemically induced spike-and-wave discharges (SWDs) during earlier and later adulthood. Fischer-344 rats, exhibiting a low level of spontaneous SWDs during earlier adulthood, progressed to exhibit a significantly larger number and duration of SWDs during later adulthood. The convulsant trimethylolpropane phosphate (TMPP), known to antagonize the GABAA inhibitory system through blockade of the chloride channel, induced or increased SWDs in every rat tested.