IS THE SITE OF ACTION OF ETHOSUXIMIDE IN THE HINDBRAIN

The action of ethosuximide, valproate and clonazepam against pentylene tetrazol-induced epileptic EEG phenomena was studied in acute experime nts in rats with intercollicular brainstem transection. Ethosuximide l ost its action against both rhythmic metrazol activity (model of human absences) and EEG seizures. On the contrary, the action of valproate and clonazepam in cerveau isole rats was the same as in intact animals . The site of anticonvulsant action of ethosuximide may be localized i n hindbrain structures, whereas the actions of both valproate and clon azepam may be demonstrated even if hindbrain structures had been elimi nated.