Expression of estrogen receptor-beta protein and mRNA in the cerebellum of the rat

Estrogen has been shown to play a modulatory role in cerebellar neuronal signaling. Recent reports have also shown that estrogen receptor beta (ER-β) mRNA is expressed in cerebellum. The purpose of the present study was to identify and map ER-β protein expression, and to determine the identity of the major splice variants of ER-β mRNA in the cerebellum. Polyclonal antibodies raised against the NH₃- and COOH-termini of rat ER-β were used for immunohistochemistry. Mapping of ER-β immunoreactivity was compared with the distribution of ER-β mRNA using in situ hybridization. We also determined, using RT-PCR, whether the ER-β mRNA was variably spliced in cerebellum. Our results show that in all cases the distribution of ER-β protein was identical to the distribution of ER-β mRNA. Both Purkinje cells and scattered cells in the granule cell layer, perhaps golgi cells, robustly expressed ER-β. Reverse transcription-polymerase chain reaction analysis showed that three splice variants in addition to wild type ER-β are expressed in rat cerebellum. However, wild type ER-β was the predominant form. These observations provide anatomical evidence that neurons in the cerebellum express ER-β and thus may be targets of estrogen action. Copyright (C) 2000 Elsevier Science Ireland Ltd.