Social behaviour of rats following pre- and early postnatal undernutrition

Abstract

The social behaviour of adult male rats which had been undernourished at some stage before weaning was investigated. Litters were cross-fostered at birth between well fed and underfed dams. Thus, some were undernourished only during gestation, others only during the suckling period and others throughout both periods. After weaning all animals had free access to food and were grouped with two or three littermates. Each adult previously undernourished rat was allocated its own control partner which had been well fed throughout life. Four measures of social interaction were recorded during five 10 min tests. Postnatal undernutrition increased the frequency of allogroom and walk over and pre with postnatal undernutrition had a similar effect. Rearing and mount were unaffected by either treatment. Prenatally growth restricted rats did not differ from controls on any measure. Thus, adult social behaviour was more affected by the postnatal than by the prenatal experience. In another experiment smaller control rats were found not to differ in their social behaviour from larger control rats, indicating that size is not an important factor in these studies.