Evaluation of effect of scopolamine on stages of active avoidance learning in rats

Abstract

Objective: To investigate the effect of scopolamine administered at different stages of learning and memory process in active avoidance task in rats. Methods: Adult male Sprague-Dawley rats were trained on active avoidance task. Each animal received a daily session of 15 trials for 5 days i.e., a maximum of 75 trials. Scopolamine (3 mg/kg, i.p) was administered at different time points according to acquisition, consolidation and recall of active avoidance learning in the three groups (n=8). Increase in avoidance response on 5th session as compared to 1st session was taken as criteria of learning and failure of learning was considered as dementia. Results: There was a significant increase in the avoidance response on 5th session as compared to 1st session in the control group. Among scopolamine treated groups, most marked dementia was observed in the group that received scopolamine after the last trial of 1st session. Conclusion: Results of this study show that scopolamine preferentially affects acquisition and consolidation as compared to recall of memory in the learning process.