Hormonal determinants in the development of masculine and feminine behavior in the female hamster

Abstract

Female hamsters treated neonatally with aromatizable androgens (testosterone, testosterone propionate or androstenedione) or with estrogens (estradiol, estradiol benzoate or diethylstilbestrol) displayed mounting behavior in adulthood in response to daily injections of testosterone propionate. Treatment neonatally with nonaromatizable androgens (androsterone or dihydrotestosterone) or with control substances failed to induce the potential for masculine behavior. These results support the hypothesis that development of masculine sexual behavior is dependent upon the presence of estrogen or androgen which can be metabolized to estrogen during sexual differentiation. Additional tests for sexual receptivity were conducted 6 weeks after the masculine behavior tests. In these tests the females were tested following estrogen-progesterone priming. Neonatal treatment with testosterone propionate, estradiol benzoate, estradiol and diethylstilbestrol reduced levels of sexual receptivity as measured by frequency and duration of lordosis responding. Treatment of the female with any of the androgens early in life resulted in significantly greater clitoral bone and cartilage development than neonatal treatment with estrogenic or control substances. Dissociation of the effects of neonatal treatment upon behavior from those upon peripheral morphology suggests that the induction of masculine behavior results from a central neural hormone action.