Prenatal exposure to prednisone permanently alters fighting behavior of female mice

Female mice born of mothers administered 100 μg prednisone on Days 13–18 of gestation attacked a stimulus male significantly sooner following the commencement of testosterone treatment in adult life than did mice born of control mothers. In a second experiment, significantly fewer prenatally prednisone-exposed females displayed postpartum aggression as compared to controls. In both experiments females of the 100 μg prednisone group showed a reduction in birth weight relative to controls. The effect on body weight did not persist since no differences were observed on Day 21 of life. The data show that prenatal exposure to prednisone permanently modifies the later intraspecific fighting behavior of female mice.