ABSTRACT
ER-α36, a novel variant of ER-α, is expressed in breast, uterus, digestive tract, respiratory tract etc. The aim of the present study was to investigate the distribution and expression of ER-α36 in the central nervous system (CNS). Here, we comparatively analyzed the expression pattern of ER-α36 in the hippocampus and cortex of neonatal (1-day-old) and adult (12-week-old) Sprague-Dawley (SD) rats by using immunohistochemistry/immunocytochemistry analysis and Western blot. The results showed that ER-α36 was expressed both in hippocampus and cortex of adult rats, but mainly distributed in pyramidal neurons. ER-α36 was mainly located on the cytomembrane of hippocampal and cortical neurons from neonatal rats. Compared with the cortical neurons, the hippocampal neurons showed lower ER-α36 protein expression in the neonatal rats, but exhibited higher level of ER-α36 in the adult rats. Furthermore, the adult rats showed higher levels of ER-α36 expression in both hippocampus and cortex compared with the neonatal rats. These results suggest that ER-α36 might be involved in the regulation of membrane-initiated estrogen signaling throughout the postnatal development of diverse brain regions, and thus will be a potential target for the treatment of degenerative diseases in nervous system.