Place Navigation Impaired in Rats with Hippocampal Lesions

Place Navigation Impaired in Rats with Hippocampal Lesions

Morris, Richard GM, Paul Garrud, JNP al Rawlins, and John O'Keefe
Nature 297, no. 5868 (1982): 681-683
https://doi.org/10.1038/297681a0

“If rats are placed in a large circular pool of opaque water, they will quickly learn to escape by finding and climbing on to a small platform hidden beneath the water surface, provided it remains in a fixed location over a series of trials. They cannot learn to find it when its position varies randomly from trial to trial. Although they can never see, hear or smell the platform, rats require only a few trials in order to learn to swim directly towards it, using the shortest route, even from a novel starting place. That is, the rats learn not only to recognize the vicinity of the safe place when they reach it, but also to swim towards it from a distance despite the absence of cues from the platform itself. The deleterious effects of cue-response separation apparent in visual discrimination do not, in this case, prevent extremely rapid learning. By comparing the performance of normal and brain-lesioned animals in these conditions with that shown when a fixed but visible platform was used, we have examined the role of the hippocampus in simple navigation.”

— Richard Morris et al.