Sex Hormone - Mediated Differentiation of Neuroendocrine System

性类固醇激素（如雌激素和雄激素）参与神经内分泌功能的发育和决定已得到充分证实。在本项目中，我们通过免疫组织化学（IHC）和原位杂交组织化学（ISHH）检测了这些类固醇激素受体信号在发育中的大鼠脑中枢和周围神经系统中的分布。结果表明：(1)雌激素受体a （Era）在视前区、下丘脑弓状核、下丘脑腹内侧核腹外侧部分、杏仁核内侧等与生殖功能有关的区域均有免疫反应；(2) Era的表达在特定区域存在明显的性别差异，雌性强于雄性。这一观察结果支持了睾丸起源的雄激素转化为雌激素，然后抑制Era表达（下调）的概念；(3)在大脑皮层、海马、中脑中央灰区等区域也检测到Era信号，虽然较为分散，但清晰。海马和中脑中枢灰质的Era信号位于中间神经元；(4)我们还在背根神经节中检测到Era - ir信号，它们与降钙素生成肽（CGRP）共定位。这一发现提示雌激素参与调节CGRP的表达。

Involvement of sex steroid hormones such as estrogen and androgen in development and determination of neuroendocrine functions has been well established . In this project , we examined distribution of receptor signals for these steroid hormones in the central and peripheral nervous systems in the developing rat brain by immunohistochemistry ( IHC ) and by in situ hybridization histochemistry ( ISHH ) . The following points were revealed by a series of experiments : (1) The immunoreactivities ( ir ) for estrogen receptor a (Era ) were detected in those regions that are related to reproductive functions , such as the preoptic area , the hypothalamic arcuate nucleus , ventrolateral part of the hypothalamic ventromedial nucleus , and the medial amygdala nucleus ; (2) There was clear sex difference in the expression of Era , stronger in the female than the male , in the specific regions wherearomatase - ir was detected . This observation supports the concept that androgen of the testicular origin is converted into estrogen , and then suppresses Era expression ( down - regulation ) ; (3) Era signals were also detected in the regions such as in the cerebral cortex , the hippocampus , the midbrain central gray , although they were rather scattered but clearly . The Era signals in the hippocampus and the midbrain central gray were in the interneurons ; (4) We also detected Era - ir signals in the dorsal root ganglia where they were colocalized with the calcitonin generelated peptide ( CGRP ) . The finding suggests estrogen is involved in regulation of CGRP expression .