Long-term memory of a DRL task in mature and aged rats.

Mature (6 mo.) and aged (26 mo.) rats were trained on a DRL 6-sec schedule. In order to produce equivalent levels of task performance, the mature rats were trained for 16 sessions while the aged rats were trained for 20 sessions. After a 21-day interval, rats were tested for retention of the DRL task. No age-related differences in LTM of the DRL task were found. If the DRL schedule is considered an analog of a recall task, the present results do not agree with Campbell et al. (1980) who found age differences in retention of a FI schedule after 8 days of training. In the present experiment animals were more extensively trained on the task to be remembered. Thus, the present experiment suggests that an age-related difference in LTM, even on recall tasks, will not be significant if aged animals are overtrained on the task to be remembered.