Effect of Neonatal Food Restriction in Mice on Brain Growth, DNA and Cholesterol, and on Adult Delayed Response Learning

Abstract

This study was designed to examine the long-term effects of a limited period of nutritional restriction on ultimate brain size and functional capacity. Experimental mice were intermittently removed from their mothers during the period of rapid brain growth between 2 and 16 days of age, producing a 57% reduction in body weight compared with littermate controls. Thereafter they were fed ad libitum. At 9 months, body, cerebral and cerebellar weights were reduced in the males by 17, 7 and 14%, respectively, below control values. Total DNA was reduced 8% in the cerebrum and 22% in the cerebellum. Cerebral cholesterol was reduced slightly. Despite these brain changes, the restricted groups showed no lasting impairment in voluntary running, in learning a Lashley type III maze, or a visual discrimination with escape from water as a reward. The restricted males showed an unexpected improvement in learning a delayed response task. The restriction experience may have altered reaction patterns so that the restricted males were able to more than compensate for any possible handicap due to the nutritional deprivation. The restricted females did not manifest this improved performance, and their final body size reduction exceeded that of the males.