Steroid Hormone Receptor-Containing Neurons and Differentiation of Neuroendocrine Functions

分析了含有类固醇激素受体(如雌激素或雄激素受体)的神经元在大脑发育和分化中的作用。通过免疫组织化学(IHC)、原位杂交组织化学(ISHH)和逆转录聚合酶链式反应(RT-PCR)，我们已经发现雌激素受体α(ERα)在大鼠脑的视前区、下丘脑和杏仁核中有表达。此外，我们还发现，IHC和ISHH也在海马海拉区检测到ERα，它们零星地分布在海马菌丝的多态神经元和角质颗粒细胞中。未发现明显的性别差异。此外，雄激素受体免疫反应选择性地在位于下丘脑后部的腹侧乳头体前核被检测到。给予雄激素后，该核团的雄激素受体免疫反应性增强。由于在该核团中未检测到将睾酮转化为雌二醇的芳香酶，因此推测雄激素对该核团的神经元有直接作用。另一方面，最近在大鼠前列腺中发现的一种新的雌激素受体被命名为ERbeta，在大脑中也被检测到。IHC和ISHH也证实了ERbeta在大鼠脑内的表达。

Role of neurons that contain steroid hormone receptors, such as estrogen or androgen receptors in the development and differentiation of the brain was analyzed. By using immunohistochemistry (IHC), in situ hybridization histochemistry (ISHH) and reverse transcriptase-polymerase chain reaction (RT-PCR), we have already disclosed that estrogen receptor alpha (ERalpha) is expressed in the preoptic region, the hypothalamus and the amygdala in the rat brain. Moreover, we have disclosed ERalpha is also detected in the hylar region of the hippocampus both by IHC and ISHH.They were located sporadically in the polymorphic neurons of the hylus and granular cells of the cornus. No distinct sex difference was detected. In addition, androgen receptor immunoreactivity was detected selectively in the ventral premammillary nucleus that is located in the posterior region of the hypothalamus. The androgen receptor immunoreactivity in this nucleus increased by administration of androgen. Since no aromatase that converts testosterone into estradiol was detected in this nucleus, direct action of androgen on the neurons of this nucleus was suggested. On the other hand, a new kind of estrogen receptor that was found recently in the rat prostate and named as ERbeta is also detected in the brain. We also confirmed the expression of ERbeta in the rat brain by IHC and ISHH.