BEHAVIORAL-RESPONSE OF RATS WITH CORTICAL-LESIONS TO CHOLINOMIMETICS

This study examined the performance of cortically lesioned rats and their response to cholinomimetic agents in passive avoidance and water maze tasks. Lesions encompassing mainly the frontal and parietal cortices produce a deficit in a 5-day passive avoidance retention test. This deficit was attenuated by the intraperitoneal (IP) administration of muscarinic agonists or an anticholinesterase. In the Morris water maze task, lesioned vehicle-treated animals showed greater escape latency times when compared to their sham counterparts. Cholinomimetics, injected daily during acquisition, improved mean escape latency time on days 3 and 4 of testing. The perfomance of the various groups in a cued version of the water task did not differ. This work demonstrates that performance deficits arising from neocortical loss can be attenuated by cholinergic drugs.