The effect of short-term dietary restriction on reference and working memory in adult rats

Abstract

Thirty-two rats were divided into dietary restricted or ad libitum feeding groups at 70 days of age in order to examine the effects of short-term dietary restriction on performance of the Morris water maze task (a reference memory task) and delayed-matching-to-place (DMTP) task (a working memory task). The dietary restricted rats were kept at a body weight of 280g throughout training. When they reached 93 days old, behavioral training was initiated. Half rats from each group were trained with the water maze task first, followed by the DMTP task, and the other rats in the reversed order. Regardless of the order of the tasks, dietary restriction had no effect on performance on the water maze task. In the DMTP task, restricted rats performed significantly poorer than ad lib rats at 30 minutes delay, but not at 30 seconds delay. These results suggest that dietary restriction has no effect on reference and working memory tasks when the memory load is light, but it causes impairment on the working memory task when the memory load is heavier.