ESTROGENIC EFFECTS IN ANDROGEN SENSITIVE MOTONEURONS

描述：雌激素被认为是主要代谢产物 负责性别双态大脑区域的分化。 在 相反，脊髓中的性二型核的发育 一直被认为是由雄激素严格调节的。 测试 这种明显的二分法的有效性和局限性， 参与神经系统性别分化的类固醇激素 和潜在的差异，在其网站的行动是重点， 提议 在大鼠中使用简单的神经肌肉敏感系统 脊髓，将检查该系统的三个不同特征： 运动神经元形态学方面（组织化学），关键神经元的分布 酶（免疫细胞化学）和神经肌肉功能 （电生理学）。 雌激素和雄激素的协同作用， 雌激素可用性的必要性，脊髓上和局部 间神经元，雌激素敏感的传入，和自然的影响， 将评估形态发育中出现的雌激素水平。 由于芳香化酶的瞬时表达已在多种植物中报道， 发育中的神经结构，出生后的脊髓将被分析， 芳香化酶的存在。 雌激素在调节 缝隙连接的发展，这是常见的这些运动神经元，将 也要检查。 在发育过程中运动神经元兴奋性的变化， 可能负责脊髓介导的反射的发作，以及 雌激素和雄激素在几个功能特性的发展 将评估这些对运动神经元敏感的运动神经元。 因为最近 有证据表明雌激素实际上与脊髓有关 男性化，这些研究可能有助于统一我们对 性分化的过程在整个发展中的哺乳动物中央 神经系统

DESCRIPTION: Estrogen is considered to be the primary metabolite responsible for the differentiation of sexually dimorphic brain regions. In contrast, the development of sexually dimorphic nuclei in the spinal cord has been considered to be regulated strictly by androgens. Testing the validity and limitations of this apparent dichotomy in the critical forms of steroid hormones involved in sexual differentiation of the nervous system and potential differences in their site of action is the focus of this proposal. Using a simple hormone-sensitive neuromuscular system in the rat spinal cord, three different features of this system will be examined: aspects of motoneuron morphology (histochemistry), distribution of critical enzymes (immunocytochemistry), and neuromuscular function (electrophysiology). Synergistic effects of estrogen and androgen, the necessity of estrogen availability, the role of supraspinal and local interneuronal, estrogen-sensitive afferents, and the effects of naturally occurring estrogen levels in morphological development will be assessed. Because the transient expression of aromatase has been reported in a variety of developing neural structures, postnatal spinal cords will be assayed for the presence of aromatase. The role of estrogen in regulating the development of gap junctions, which are common in these motoneurons, will also be examined. Changes in motoneuron excitability during development are likely responsible for the onset of spinally mediated reflexes, and the role of estrogen and androgen in the development of several functional properties of these hormone-sensitive motoneurons will be assessed. Because recent evidence suggests that estrogen is in fact involved in spinal cord masculinization, these studies may help in unifying our understanding of the process of sexual differentiation across the developing mammalian central nervous system.