Abstract
A study has been undertaken to find out a possible role of brain-specific S-100 protein in the impairment of learned behaviour with lactational undernourishment of rats. The results showed a decrease in the body weight, brain weight as well as brain DNA and S-100 protein of the weanling undernourished rats while the concentration of soluble brain proteins was similar in the weanling undernourished and weanling control rats. When both the groups were subjected to shock-avoidance criterion, the learning and memory were found to be deficient in the undernourished group. It was further observed that nutritional rehabilitation at weaning could not restore the learning and memory of the undernourished animals. The decrease in the concentration of brain-specific S-100 and the deficient learning and memory could be due to a possible structural underdevelopment of brain in these animals.