부산대학교 도서관

ERα and ERβ, are expressed in many brain regions of rodents, but the expression pattern is different between the two receptors. In previous studies, the expression of ERβ but not ERα was detected in the adult cerebellum, by in situ hybridization and immunohistochemistry. In the present study, quantitative real-time RT-PCR demonstrated that levels of cerebellar ERα mRNA in neonatal pups were significantly higher than in adults. In contrast, cerebellar ERβ mRNA remained at similar levels during postnatal development. Using in situ hybridization and immunohistochemistry, ERα mRNA and protein were detected in Purkinje cells of the developing rat cerebellum. However, ERα immunoreactivity was detected only in a few Purkinje cells in the adult cerebellum. Thus, ERα expression was transiently increased during the time when Purkinje cell dendritic growth and synapse formation proceed, suggesting that a role for ERα in Purkinje cell differentiation. ERβ expression occurred in Golgi type neurons in the granular layer at P7, Purkinje cells at P14, and basket cells in the molecular layer at P21, and was detected in all the cell types in the adult cerebellum, suggesting a role for ERβ associated with neuronal differentiation and maintenance. Furthermore, double-label immunofluorescence for ERα and ERβ demonstrated their co-localization in Purkinje cells at P14, suggesting a possible interaction. between the two receptors. The discrete expression profiles for ERα and ERβ in the developing cerebellum suggest the two ERs play distinct roles in cerebellar development. [J Physiol Sci. 2007;57 Suppl:S44]