Abstract
Interhemispheric synchrony of spike and wave discharges in feline generalized penicillin epilepsy, a possible model for human general corticoreticular epilepsy, was studied. Four groups of cats were treated. Group A underwent complete section of the corpus callosum and anterior commissure; group B underwent division of the massa intermedia alone; group C underwent partial section of the corpus callosum; and in group D, a slab of the cortex on 1 side, comprising the middle parts of the lateral and suprasylvian gyri, was severed from all its subcortical inputs without disturbing its connections with the opposite hemisphere through the corpus callosum. Two weeks after surgery or later the cats received an i.m. injection of penicillin. Bilateral synchrony of the epileptic discharges was abolished in group A but not in group B. In group C bilateral synchrony of the epileptic bursts was impaired, but not abolished. In group D epileptic bursts synchronous with those occurring in the intact hemisphere continued to occur in the slab, at lower amplitude. The corpus callosum is the main, if not the exclusive, pathway ensuring bilateral synchrony of the epileptic discharges of feline generalized penicillin epilepsy.