REPRODUCTIVE AGING AND THE HYPOTHALAMUS

更年期标志着一个动态的生理系统的停止， 垂体和卵巢激素的周期性释放。 由于 不可逆转的卵泡损失， 类固醇的生产。 血清促性腺激素水平升高， 推测是由于缺乏类固醇的负反馈对更高的中心。 这种类固醇负反馈在人类的网站是未知的。 我们 初步研究表明含有雌激素的神经元肥大 绝经后妇女漏斗核受体基因转录本的研究 妇女 我们假设绝经后神经元肥大是 继发于卵巢抑制性反馈效应的撤销 类固醇，而不是由于老化本身。 拟议的研究旨在 为了验证这一假设，并确定神经元的特异性， 绝经后女性漏斗核肥大。 形态测量方法和计算机显微镜将用于测量 神经元横截面积在各种，下丘脑区域的前和 绝经后妇女。 我们还将测量神经元的横截面积 在年轻的卵巢切除妇女的漏斗核中， 雌激素替代疗法和男性。 将使用原位杂交 以确定肥大神经元的神经递质含量。 最后，我们将建立一个绝经后神经元损伤的实验模型， 通过切除卵巢在实验室大鼠中进行。 这些研究将 提供有关绝经后妇女生理学的新信息， 女性，人类生殖功能的控制，以及 性腺衰老与神经内分泌衰老的关系 而且由于 绝经后神经元肥大代表了一种早期的， 与年龄相关的人类变化。这些研究将提供新的 对人类正常衰老和年龄相关疾病的深入了解。

Menopause marks the cessation of a dynamic physiological system regulating the cyclic release of pituitary and ovarian hormones. Due to an irreversible loss of ovarian follicles there is a marked decline in the production of steroids. Serum levels of gonadotropins become elevated, presumably due to the lack of steroid negative feedback on higher centers. The site of this steroid negative feedback in the human is unknown. Our preliminary studies demonstrate hypertrophy of neurons containing estrogen receptor gene transcripts in the infundibular nucleus of postmenopausal women. We hypothesize that postmenopausal neuronal hypertrophy is secondary to the withdrawal of the inhibitory feedback effects of ovarian steroids and not due to aging per se. The proposed studies are designed to test this hypothesis and determine the specificity of neuronal hypertrophy in the infundibular nucleus of postmenopausal females. Morphometric methods and computer microscopy will be used to measure neuronal cross-sectional areas in various, hypothalamic regions of pre- and postmenopausal women. We will also measure neuronal cross-sectional areas in the infundibular nucleus of young ovariectomized women, women with estrogen replacement therapy, and men. In situ hybridization will be used to determine the neurotransmitter content of the hypertrophied neurons. Finally, we will establish an experimental model of postmenopausal neuronal hypertrophy in laboratory rats by removing the ovaries. These studies will provide new information concerning the physiology of postmenopausal females, the control of reproductive function in humans, and the relationship between gonadal and neuroendocrine aging. Moreover, because postmenopausal neuronal hypertrophy represents an early, dramatic age-associated change in the human. brain, these studies will provide new insights into normal human aging and age-associated disease.