Selective effects of perinatal estrogen on proliferation and new neurons in hippocampus and piriform cortex of rats at weaning

A recent report links heightened prenatal amniotic estrogen levels to an increased risk of autism spectrum disorder (ASD). In this study, we examined the developmental effects of perinatal estrogen treatment on stem cell activity in weaned rats. Sprague-Dawley rats received ethinyl estradiol (EE2, 10 µg/kg/day) or vehicle orally from gestational day 6 until parturition. Offspring were then treated with the same daily dose from postnatal days (PNDs) 1–21. The effects of perinatal estrogen treatment on stem cell activities in the subgranular zone (SGZ) of the hippocampus and the piriform cortex were evaluated in male and female rat pups. EE2 treatment increased the total Ki67-immunoreactive (Ki67-ir) cell counts in the SGZ of males and females (p