Facilitation of cortical cell activity during spreading depression

Publisher Website
Google Scholar
Abstract
The steady potential changes which develops together with spreading depression of the cat sensoriomotor cortex were recorded at several cortical depths and related with concomitant modifications in cell firing rates.In most cases, it was found that the slow negative wave which spreads on the cortical surface does not invade the deep cortical layers. In these cases only a slow positive wave was recorded at the deep layers.At each layer the cell firing rates modification of PT and non‐identified neurons consisted of an initial acceleration followed by a depression. The deeper the recorded cells, the more prolonged the acceleration and shorter lasting the depression. At layers invaded by the slow negative wave, acceleration occurred during a part or all the temporal course of such wave. At layers not invaded by the slow negative wave, acceleration occurred coinciding with the slow positive wave.Acceleration of cell firing is believed to result from an adequate “local” active or “remote” passive depolarization of the cortical cells. Depression could result from excessive depolarization of the cortical cells. Depression could result from excessive depolarization of cortical neurons and presynaptic fibers.