Anticonvulsant effects of calcium channel blockers in partial and generalized model epilepsies

The calcium channel blockers D890 and verapamil reduced neuronal calcium currents in single snail neurons with intra- and extracellular applications, respectively. Epileptic discharges of single neurons in the rat's motor cortex (in vivo) were depressed in amplitude by intracellular injection of D890. Focal seizure discharges and generalized tonic-clonic seizure activity in the cerebral cortex of the rat were reduced by intracerebroventricular perfusion of verapamil. In non-epileptic rats verapamil failed to exert a depressive effect on somatosensory evoked potentials and on the waves of the spontaneous EEG.