CENTER FOR CNS INJURY STUDIES

中枢神经系统损伤研究中心

• 批准号: 2519973
• 负责人: WISE YOUNG
• 金额: $ 94.98万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-09-01 至 2001-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2519973
• 关键词: brain injury; cerebral ischemia /hypoxia; spinal cord injury

This application proposes four projects and core facilities to investigate mechanisms of CNS injury. Project 1 Experimental Therapy of Spinal Cord Injury. We recently discovered that cyclosporin A (CsA) reduces responses, releases vasodilatory and inflammatory substances, and modulates neurotransmitter receptors and release. We propose to study the role of calcineurin in spinal cord injury. The experiments will compare the effects of CsA, FK506 (another calcineurin inhibitor), alone and in combination with rapamycin (an antagonist of K506 (another calcineurin inhibitor), alone and in combination with rapamycin (an antagonist of FK506 inhibition of calcineurin), on spinal cord ionic shifts, lesion volumes, motor recovery, blood flow, and serotonin-,GABA- and glutamate-induced spinal excitability and injury. Project 2. Acid-base homeostasis in brain injury. The mechanisms and consequences of pH changes in injured tissues are not well-understood. We will measure pH, PCO2, HCO3, and CO32 in ischemic brains and injured spinal cords, to determine the role of buffer capacity, lactoacidosis, and carbonic anhydrase in the pH changes. We propose that pH shifts modulate NMDA receptors and that interstitial buffering influences the rate and magnitude of spreading depression and ischemic injury in brain slices. Using on-selective microelectrodes, voltage clamp, and spectrophotometric methods, we will test the hypothesis that voltage-dependent Na:HCO3 co-transport governs H+, Na+, and HCO3- distribution across astrocytic membranes in normo- and hyperglycemic ischemia. Project 3. Ascorbate and glutathione in CNS Injury. We hypothesize that ascorbate (Asc) and glutathione (GSH) loss contributes to brain cell vulnerability to oxidative damage. Extracellular Asc will be measured in hypoxic brain slices and in ischemic cerebral cortex after middle cerebral artery occlusion. Intracellular Asc will be estimated from extracellular volumes and total tissue levels. Preliminary studies suggest that Asc and GSH are localized in neurons and astrocytes respectively, that both Asc and GSH decline with age and are lower in females. We will confirm these results, determine whether hypoxia and age compromises Asc homeostasis, assess protective effects of Asc and GSH in hypoxic brain slices, identify mechanisms of Asc and GSH loss in ischemia, and correlate tissue damage with Asc loss in male and females. Project 4. Water compartmentalization in Ischemia. The objective of this project is to understand how water shifts between extra- and intracellular compartments in ischemic brain tissues. Water shifts will be assessed with extracellular tracers, ion-elective microelectrodes, and weighing-drying method. We will manipulate extracellular ionic levels and block ionic transport and glutamate receptors. Water movements will be investigated in slices from aged animals. The role of the Na:HCO3 cotransport will be assessed. Light scattering and Na-K changes will be compared with wet-dry weight and tracer measurements.

本申请提出了四个项目和核心设施来调查 中枢神经系统损伤的机制。 项目1脊髓实验疗法 受伤。 我们最近发现，环孢菌素A（CSA）减少了反应， 释放血管舒张和炎症物质，并调节 神经递质受体和释放。 我们建议研究 脊髓损伤中的钙调神经蛋白酶。 实验将比较 CSA，FK506（另一种钙调神经酶抑制剂）的影响，单独和IN 与雷帕霉素（K506的拮抗剂 抑制剂），单独并与雷帕霉素（FK506的拮抗剂 抑制钙调神经素），在脊髓离子移位，病变体积， 运动恢复，血流以及5-羟色胺，GABA-和谷氨酸诱导的 脊柱兴奋性和损伤。 项目2。大脑中的酸碱稳态 受伤。 受伤组织pH变化的机制和后果 不被理解。 我们将测量pH，PCO2，HCO3和CO32 缺血性大脑和受伤的脊髓，以确定缓冲液的作用 pH变化的容量，乳酸性病和碳酸酐酶。 我们 提出pH值转移调节NMDA受体和间隙 缓冲会影响扩散抑郁症的速度和幅度 脑切片中缺血性损伤。 使用选择性微电极， 电压夹和分光光度法方法，我们将检验假设 依赖电压的Na：HCO3共同传输控制H+，Na+和HCO3- 正常和高血糖的星形胶质膜之间的分布 缺血。 项目3。中枢神经系统损伤中的抗坏血酸和谷胱甘肽。 我们假设这一点 抗坏血酸（ASC）和谷胱甘肽（GSH）损失有助于脑细胞 氧化损伤的脆弱性。 细胞外ASC将在 中大脑中缺血性脑切片和脑缺血性脑皮质。 动脉阻塞。 细胞内ASC将从细胞外估计 体积和总组织水平。 初步研究表明ASC和 GSH分别位于神经元和星形胶质细胞中，ASC和ASC都 GSH随着年龄的增长而下降，女性较低。 我们将确认这些 结果，确定缺氧和年龄是否损害ASC稳态， 评估ASC和GSH在低氧脑切片中的保护作用，识别 缺血中ASC和GSH损失的机制，并将组织损伤相关 男性和女性的ASC损失。 项目4。缺血中的水腔。 这个目的 项目是要了解水在细胞内和细胞内之间的变化 缺血性脑组织中的隔室。 水移将通过 细胞外示踪剂，离子与微电极和称重干燥 方法。 我们将操纵细胞外离子水平并阻塞离子 运输和谷氨酸受体。 水运动将在 来自老年动物的切片。 Na：HCO3共汇款的作用将是 评估。 光散射和NA-K变化将与湿干 重量和示踪剂测量。