ESTROGEN AND CHOLINERGIC SYSTEM INTERACTIONS IN AGING

描述：（申请人摘要中的逐字记录）在这些研究中，我们 建议检查雌激素刺激代偿性 胆碱能系统的萌芽反应在一个地区，是第一个和最 在阿尔茨海默病（AD）中，内嗅皮层（EC）受到深刻影响。 一些报道描述了增加的突触发芽， 雌激素，并暗示这种激素在上调胆碱能 在基底前脑中起作用。根据这些研究和我们自己的结果， 我们假设雌激素可能诱导胆碱能发芽和反应性生长， 突触的发生，可能会导致某种程度的 功能恢复拟议实验的基本前提是， 雌激素具有神经保护作用， 受损的基底前脑胆碱能神经元男性和女性Fisher 344 大鼠，年轻（3月龄）和老年（24月龄），均切除性腺， 将接受模拟皮质胆碱能去神经支配的损伤 在AD中。单侧病变（允许对侧充当 内部控制）将产生在核的水平肢体的 Broca对角线带（HDB），使用192 IgG-皂草素免疫毒素复合物作为 损伤工具。这种免疫毒素特异性靶向胆碱能神经元。 雌激素或安慰剂治疗将在病变后四周开始， 出现最大EC去神经。对于具体目标1，我们将使用标准 免疫组织化学技术来测量病变诱导的 雌激素治疗导致EC中的胆碱能发芽。在 具体目的2我们将采用改良的Fonnum方法来测定 胆碱乙酰转移酶（ChAT）活性。具体目标 我们将研究雌激素对存活的基底细胞的再生作用。 半定量RT/PCR分析前脑胆碱能神经元的变化 在两种胆碱能标记物的mRNA表达中，合成酶ChAT 和囊泡乙酰胆碱转运体（VAChT）。最后，具体目标4 我们将检验雌激素可以改善病变的假设， 年龄依赖性行为障碍实验动物将被测试 在雌激素治疗前后使用气味辨别任务，即 对EC损伤敏感。由此产生的行为测量将与 皮质纤维发芽和胆碱能活性水平 皮质和基底前脑。

DESCRIPTION: (Verbatim from the Applicant's Abstract) In these studies we propose to examine the ability of estrogen to stimulate the compensatory sprouting response of the cholinergic system in an area that is first and most profoundly affected in Alzheimer's disease (AD), the entorhinal cortex (EC). Several reports have described increased synaptic sprouting in response to estrogen, and have implicated this hormone in the upregulation of cholinergic function in the basal forebrain. Based on these studies and on our own results, we hypothesize that estrogen may induce cholinergic sprouting and reactive synaptogenesis in response to cell loss, and perhaps bring about some degree of functional recovery. The basic premise of the proposed experimentation is that estrogen has a neuroprotective effect that restores and prolongs the function of damaged basal forebrain cholinergic neurons. Male and female Fisher 344 rats, young (3 months old) and aged (24 months old), both gonadectomized and intact, will receive a lesion that mimics the cortical cholinergic denervation in AD. Unilateral lesions (allowing for the contralateral side to act as an internal control) will be produced in the nucleus of the horizontal limb of the diagonal band of Broca (HDB) using 192 IgG-saporin immunotoxin complex as the lesioning tool. This immunotoxin specifically targets cholinergic neurons. Treatment with estrogen or placebo will begin four weeks after lesioning, when maximal EC denervation has occurred. For specific aim 1 we will use standard immunohistochemical techniques to measure the change in lesion-induced cholinergic sprouting in the EC that results from estrogen treatment. In specific aim 2 we will employ a modification of the Fonnum method to assay choline acetyltransferase (ChAT) activity in the same EC area. In specific aim 3 we will examine the regenerative effects of estrogen on surviving basal forebrain cholinergic neurons by semi-quantitative RT/PCR analysis of changes in the mRNA expression of two cholinergic markers, the synthetic enzyme ChAT and the vesicular acetylcholine transporter (VAChT). Finally, in specific aim 4 we will test the hypothesis that estrogen can ameliorate lesion- and age-dependent behavioral impairments. Experimental animals will be tested before and after estrogen treatment using an odor discrimination task that is sensitive to EC damage. The resulting measures of behavior will be correlated with cortical fiber sprouting and with levels of cholinergic activity in the cortex and basal forebrain.