AN INVESTIGATION OF CENTERS SUSCEPTIBLE TO MECHANICALLY AND ELECTRICALLY INDUCED AFTERDISCHARGE IN THE CAT BRAIN

Abstract

The cat's brain was mapped for centers susceptible to mechanically and electrically elicited afterdischarges. The observation that certain regions of the cortex were highly susceptible to mechanical injury by compression may be of fundamental importance in an understanding of the genesis of cortical epileptic foci. Highly electrically sensitive centers were found in the cortex, amygdala, and the hippocampus. These areas did not present a uniform sensitivity for this activity. The existence of gradients of threshold voltage between and around the sensitive centers could well explain the marked variations in threshold for afterdischarges, reported by numerous investigators. All of the highly susceptible centers in the different areas responded to similar threshold stimuli. The results, when compared with data obtained from other species, indicated that there was no reason to postulate the existence of different sensitivities between species for the afterdischarge response. The existence of highly susceptible centers might provide a basis from which the ultimate mechanisms underlying clinical epilepsy may be elucidated.