Early Androgen Activity After Birth Determines the Hypothalamic Expression of Androgen and Estrogen Receptors in Adulthood in Female but Not in Male Rats

This study on 40 Wistar rats examined the effects of early postnatal androgen activity on the expression of androgen and estrogen receptors in the hypothalamus, revealing significant sex differences. In female rats, early androgen activity was found to influence the expression of androgen (AR) and estrogen receptors (ERα and ERβ) in adulthood, with specific inhibitors altering receptor mRNA levels. Aromatase inhibition increased AR and ERβ, while 5α-reductase inhibition decreased ERα. These effects were not observed in males. The findings underscore the critical role of early androgen exposure in programming hypothalamic receptor expression in females, highlighting the necessity of considering sex-specific pathways in brain development.