Membrane potential of cerebral cortical cells during spreading depression and asphyxia

Changes in membrane potential were recorded intracellularly from cortical cells during spreading depression (SD) and asphyxiation and a correction was made in a few instances for the effects of the slow potential change accompanying spreading depression on the membrane potential recorded between an intrACEllular and indifferent electrode.

Abstract

Changes in membrane potential were recorded intracellularly from cortical cells during spreading depression (SD) and asphyxiation. In fourteen cells with a mean membrane potential of 67 mv, SD caused a moderate to severe transient depolarization of about 2-min duration. The depolarization was relatively fast, the repolarization much slower. The mean value of the membrane potential at the maximum of depolarization was 35% of the original, with a range of 74 to 6%. A correction was made in a few instances for the effects of the slow potential change accompanying spreading depression on the membrane potential recorded between an intracellular and indifferent electrode. In one of these cases the corrected membrane potential approached zero. Asphyxiation caused, after a latency of 2 to 3 min, a fast depolarization to a low value of the membrane potential, preceded by a slow decline of the potential (6 mv/min) which started after a short latency (fraction of a minute).