Interhemispheric transfer of a passive avoidance reaction.

Abstract

Passive avoidance reactions elaborated during cortical spreading depression (CSD) in the left hemisphere were partly transferred to the right hemisphere, as shown by retention tests during functional decortication of the right hemisphere. This partial transfer of memory traces was preserved in split-brain animals (section of corpus callosum 1 week before learning) and even in rats in which CSD in the right hemisphere was evoked prior to recovery of the left hemisphere. By modification of learning and testing procedure it was demonstrated that the main sensory cues transferred are visual and tactile ones. Transfer is probably due to nonlateralized sub-cortical memory traces formed during unilateral aquisition and available during contralateral retrieval.