Epileptiform activity induced in single cells of the sensorimotor cortex of the cat by intracellularly applied scorpion venom.

Oscillations of 5 to 15 mV in the membrane potentials of neurons of the sensorimotor cortex of normal, awake cats were produced within 15 to 45 s after intracellular injection of Centruroides sculpturatus (c.s.) venom, but not after control injections of KCl. In every cell injected with c.s. venom, the oscillations eventually gave way to paroxysmal depolarizing shifts of appearance similar to that seen in epileptic cells. The results suggest that cortical epileptiform activity can be produced by the local action of c.s. venom, an agent known to alter the gating mechanism of sodium channels. Disruption of sodium gating may represent an intrinsic cellular mechanism involved in epileptogenesis.