Long-lasting Changes in the Level of the Electrical Activity of the Cerebral Cortex produced by Polarizing Currents

Abstract

THE passage of direct current produces changes in the electrical activity of nervous tissue. For example, the polarization of nerve terminals in muscle spindles gives rise to alterations in the membrane potential; a depolarization produces an increased rate of discharge of nerve impulses while hyperpolarization decreases the discharge frequency¹. A similar effect can be produced by polarization of the spinal cord²; the discharge in the ventral roots is altered by the passage of small currents across the thickness of the cord.