While there is some evidence for a possible antidepressant effect of ERα, for example, injections of an ERα agonist have been shown to mitigate postpartum depression-like responses in rats with resulting changes in BDNF and pERK signaling29, our study identifies transcriptional regulation of numerous downstream targets (Fig. 5) as the basis of ERα action. Here, BDNF is linked to postpartum depression.