Neonatal estrogen stimulation and aggressive behavior in female mice

Abstract

This experiment sought to compare the effects of neonatal androgenization and neonatal estrogenization upon the development of mechanisms for aggressive behavior in mice. Female mice were given either estradiol benzoate (EB) or testosterone propionate (TP) on the day of birth. Other females were given a control injection of oil on the day of birth; male mice received an injection of oil on the day of birth. As adults all mice were gonadectomized, given replacement therapy with TP, and tested in pairs for fighting. Ninety-two per cent of the pairs of females given EB at birth fought following androgen replacement therapy in adulthood. Only 25 per cent of the females given oil at birth fought in adulthood. One hundred per cent of the males and 100 per cent of the females given TP on the day of birth fought in adulthood. It was concluded that administration of estrogen to neonatal female mice facilitates the differentiation of androgen sensitive mechanisms for adult aggressive behavior. In this regard, neonatal estrogenization appears to mimic the effects of neonatal androgenization.