Effect of feed restriction on learning, memory and stress of rodents

Abstract

Feed restriction (FR) has been recognized as the major experimental assay able to retard aging and degeneration diseases, although the effects of dietary manipulation at Central Nervous System (CNS) superior functions as learning and memory remain controversial. The aim of the present study was to evaluate the FR effects in CNS superior functions focusing in learning and memory in rodent models. Male Wistar rats were divided into three groups (n = 9/group) according to dietary conditions: ad libitum (AL) with unlimited access to standard rat diet (22% of protein, 8% fiber, 4% fat, 10% minerals, 1.4% Calcium, 0.8% Phosphorus); FR30 and FR60 groups were fed with 70% and 40%, respectively, of total rat diet offered to the AL group for 15 weeks. The animals FR30 and FR60 showed significant increase of learning performance in Y maze compared to animals fed ad libitum. The FR30 group, in memory task, also showed strong preference to the correct arm in Y maze at the first trials and greater rightness probability, in relation to the AL and FR60 groups. The AL group had significantly higher exploratory activity at the open field test than both FR groups. These findings implicate the FR on modulation of CNS functions as learning, suggesting, also, a possible anxiogenic-like effect of stress caused by FR.