Pubertal BPA exposure changes central ERα levels in female mice

• Pubertal exposure to BPA increased level of ERα in some brain regions.
• E2 and BPA exposures during puberty increased ERα in different brain sites.
• Pubertal exposure to BPA increased sexual dimorphism in levels of central ERα.
• Effects of pubertal BPA on ERα-IR neurons are sex-dependent.

Despite many studies on the effects of perinatal Bisphenol A (BPA) exposure on the brain, its effects on brain estrogen receptor (ERα) expression during puberty remain unclear. Here, mice were injected subcutaneously with BPA (50 μg/kg), estradiol (10 μg 17β-E2/kg) or oil (0.05 ml sesame oil) daily during puberty (postnatal days 23–30). Immunohistochemistry was used to examine changes in ERα immunoreactive neurons in different brain regions. Compared to control animals, pubertal exposure to BPA significantly increased ERα immunoreactive neurons in the bed nucleus of the stria terminalis (BST), arcuate hypothalamic nucleus (Arc), ventromedial hypothalamic nucleus (VMH) and medial amygdaloid nucleus (MeA) in females. E2 exposure during puberty also increased ERα immunoreactive neurons in the lateral septum (LS) of females. No effect was detected in males. These results indicate that the effects of estrogenic chemicals on ERα immunoreactive neurons are sex-dependent.