Pharmacological studies of recurrent cortical inhibition and facilitation

Abstract

Injection of tetanus toxin into the pericruciate cortex reduced or abolished cortical recurrent inhibition produced by medullary conditioning stimulation. These changes occurred when the electrocorticogram began to show small spikes and bursts, but before onset of large seizure discharges. Intravenous injections of subconvulsive doses of strychnine or of picrotoxin reduced recurrent inhibition slightly and reversibly; convulsive doses precluded such measurements. Intravenous injections of dihydro-beta-erythroidin or of atropine had no specific effects on recurrent inhibition, although in some cases there were slight increases or decreases.