THE EFFECTS OF PERIRHINAL CORTICAL-LESIONS ON SPATIAL REFERENCE MEMORY IN THE RAT

Rats with bilateral, electrolytic lesions of the perirhinal cortex and sham operated control rats were tested in the Morris water maze, a pr ocedure which has repeatedly been shown to be sensitive to hippocampal and limbic system dysfunction. The results of the present study demon strate that perirhinal lesioned rats were mildly impaired on this task . The lesioned animals took significantly longer than controls to loca te the hidden platform during place navigation acquisition, and had si gnificantly larger heading errors across the entire experimental proce dure. In addition, these lesioned animals made fewer platform crossing s than control rats during the probe trials. These results suggest tha t the perirhinal cortex, like the anatomically related entorhinal cort ex and hippocampus, may be involved in mnemonic processing.