ACQUISITION OF 2-WAY SHUTTLE-BOX AVOIDANCE AFTER HIPPOCAMPAL LESIONS

Rats with lesions in both the anterior and posterior hippocampus (APH) acquired shuttle-box avoidance in fewer trials, with fewer shocks and with a larger proportion of avoidance responses than control animals. Their escape, but not avoidance, latencies were shorter than control latencies throughout training. Although not hyperactive on a jiggle-platform, they showed somewhat greater tendency to spontaneous activity in the shuttle-box than controls. However, neither the shorter escape latencies nor the increased spontaneous activity could account for their superior avoidance learning. Rats with lesions restricted to only the anterior (AH) or the posterior (PH) hippocampus showed no facilitation of avoidance learning over controls. A cortical lesion group was statistically indistinguishable from any other group on any of the measures. © 1969.