Prenatal testosterone causes shift of asymmetry in neonatal tail posture of the rat

Neonatal tail posture is a sexually dimorphic behavior with females more biased leftwards than males. Prenatal exposure of female pups to testosterone propionate (TP) but not dihydrotestosterone propionate (DHTP) shifts the population pattern of tail posture to the right. No effects were found with male pups. Since TP is aromatizable and DHTP is not, it is concluded that TP exerts its effects on tail posture via the CNS.