The effects of protein malnutrition and cortisol treatment on motor activity of rats

Virgin female Wistar rats were randomly assigned to one of three isocaloric diets (20, 11 and 6.7% protein content). From a week prior to mating and during gestation and suckling periods they were fed ad lib. At the beginning of gestation period each dietary group was subdivided into two groups according to the treatment with a daily injection of either hydrocortisone acetate solution or saline solution they were to receive until delivery. After weaning, only the male pups were selected and fed ad lib with the same diet as their mothers. They were weighed and evaluated in an open field test every 10 days for 70 days. The body weight of the animals diminished as protein content in diet decreased. The 6.7% group was hyperactive and less emotional than the other dietary groups. The 11% group showed more vertical activity than the 20 and 6.7% groups. Cortisol administration during gestation decreased motor activity in the 20% group, but had no effect on the two malnourished groups.