The effects of a fimbria-fornix lesion on distance discrimination in rats

Abstract

In order to study the role of hippocampus in spatial learning, fimbria-fornix (FF) lesioned and control rats, eignt each, were trained for a distance discrimination task in a rectangular test box (120×60×35cm). A rat was placed in a start box at one of the corners of the test box, and then released to choose the bottle that contained food reward. Two bottles, at the distance of 50cm, were placed along the walls, one short and the other long, on either side of the start box, and to find the reward the rat had to discriminate the distance, i.e., short vs. long wall of the test box. Results showed that control rats were able to make the discrimination, while FF rats were not. The finding suggests that hippocampus plays an important role in processing distance information in general, and distance discrimination in particular.