[Memory confinement versus generalization decrement on retrograde amnesia produced by cortical spreading depression]

An examination of memory confinement vs. generalization decrement under unilateral cortical spreading depression was undertaken using a licking suppression to a tone previously paired with a shock. In Experiment I, rats that were trained and tested under normal cortical conditions showed an impairment of memory when KCl-induced depression was given to an unilateral hemisphere within 15 min after the training. In Experiment II, where rats were trained under normal cortical conditions followed by unilateral depression and tested under unilateral cortical depression, the degree of impairment was more severe when the test was performed under depression shifted to the other hemisphere than under depression to the same hemisphere. The results taken together support the memory confinement theory.