Conditioned reflexes and Leão's spreading cortical depression.

Abstract

The effect of spreading cortical depression on simple alimentary and avoidance conditional reflexes (CRs) was studied in unanesthesized, unrestrained rats. Increasing precentages of KC1 applied on occipital areas of both hemispheres lead to disappearance of both Crs for increasing periods of time. A close correlation between electrophysiological changes and the disturbance of CRs was found. Use of KC1 on frontal and temporal lobes gave similar results. Spreading depression is considered as deep but completely reversible cortical inhibition which may be used for its well defined electrical signs as a new approach to electrophysiological study of cortical mechanisms of conditioning. 24 refs.