Abstract: 【Objective】The effects of estrogen on the expression of ER, NGF and ChAT in cerebellum of rats were studied.【Method】 The model of aging female rat were established to study the expression and distribution of estrogen receptor (ER), nerve growth factor (NGF) and choline acetyltransferase (ChAT) in the cerebellum after 17β - estradiol treatment by using technique of immunohistochemical ultrasensitive SP in Sprague-Dawley rat. 【Result】 The immunoreactive productions were distributed in stratum Purkinje cell, nucleus dentatus, nucleus interpositus and nucleus fastigii of cerebellum, and the ER positive production mainly located in plasma, cytoplasmic membrane and neurite, also existed in nucleus. The general tendency of the expression of ER, NGF and ChAT positive production in cerebellum cortex and nuclei of aging rat significantly decreased, while the intensity and quantity of the immunoreactive production ascended predominantly after 17β - estradiol treatment, simultaneously, the positive neurite of Purkinje cell showed the same tendency. 【Conclusion】 The above results suggested that the estrogen upregulated the expression of NGF and ChAT, and played a vital role in sustaining and protecting the structure and function of cerebellum neurons. Furthermore, the similarity of their changing tendency implied that they were correlated and cooperated during the course in effect of estrogen in cerebellum. It also showed that the action of estrogen in cerebellum could via genomic and nongenomic mechanism.

Key words: ER, ChAT, NGF, Immunohistochemical ultrasensitive SP, Cerebellum, Rat