GLIAL REACTION TO ISCHEMIC BRAIN INJURY

神经胶质对缺血性脑损伤的反应

• 批准号: 6126094
• 负责人: Richard P Kraig
• 金额: $ 27.62万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 1983
• 资助国家: 美国
• 起止时间: 1983-04-01 至 2003-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6126094
• 关键词: acid base balance; astrocytes; biological signal transduction; calcium channel; calcium flux; cerebral ischemia /hypoxia; digital imaging; disease /disorder model; electrical measurement; electrophysiology; enzyme linked immunosorbent assay; fluorescent dye /probe; gap junctions; glial fibrillary acidic protein; gliosis; hippocampus; laboratory rat; membrane channels; membrane potentials; neurons; organ culture; pyramidal cells; spreading cortical depression; voltage /patch clamp; western blottings

Ischemic brain injury is a major cause of death and disability with few effective treatments. Spreading depression (SD) can enhance brain injury if it occurs less than a day before ischemia. However, SD also can reduce injury if it occurs 1-3 days before ischemia, so-called ischemic tolerance. Thus, neural cells and tissues have an endogenous ability to modulate the extent of their own injury. SD itself is noninjurious. Furthermore it induces astrogliosis over the same time period as SD- induced ischemic tolerance. Since glia vitalize neurons, SD-induced gliosis may be a key transformation needed for the development of SD- induced tolerance to ischemic injury. Accordingly, the general goal of this proposal is to define the fundamental signaling mechanisms responsible for SD and so begin to define the basic triggers needed for SD-induced gliosis and SD-induced tolerance to excitotoxic injury. Experiments will systematically combine an innovative in vitro preparation with modern investigative tools to explore fundamental physiologic and anatomic changes of SID. Hippocampal organ cultures (HOTCs) will be used throughout this project because: (A) the HOTC is an intact area of brain tissue that maintains many cell-to-cell relationships found in vivo yet HOTCs survive in vitro for months; (B) microenvironmental conditions of HOTCs can be easily controlled; (C) individual cells within the HOTC can be followed in space and time; (D) we have shown that HOTCs support SD and develop astrogliosis like that seen in vivo. Thus, SD, SD-induced gliosis and SD-induced tolerance which require days to evolve, can now be examined for the first time in vitro. This means that the experimental advantages of easy access and microenvironmental control of in vitro preparations can be applied to answer 'mechanistic' questions at the cellular and molecular level of events that require intact tissues. Patch clamp technology, computer- based imaging strategies, and molecular biologic techniques will be used to accomplish the following specific aims. (1) Examine the spatiotemporal dynamics of gap junction functional changes between neurons and between astrocytes associated with SD. (2) Examine the spatiotemporal changes and identity of SD-induced currents in hippocampal pyramidal cells. (3) Examine the mechanisms of cellular and interstitial Ca2+ changes of SD. (4) Examine how modulation of Ca2+ or acid-base changes of SD influence SD-induced gliosis and tolerance to excitotoxic injury.

缺血性脑损伤是死亡和残疾的主要原因，很少 有效的治疗方法。扩散抑郁（SD）可以增强脑损伤 如果发生不到缺血的一天。 但是，SD也可以 减少缺血前1-3天发生的伤害，所谓的缺血 宽容。 因此，神经细胞和组织具有内源能力 调节自己受伤的程度。 SD本身是毫无趣味的。 此外，它在与SD-的同一时期内诱导了星形胶质病 诱导的缺血性耐受性。 由于神经胶质使神经元具有生命，因此SD诱导 神经胶质病可能是SD-发展所需的关键转变 诱发缺血性损伤的耐受性。因此， 该建议是定义基本信号机制 负责SD，因此开始定义 SD诱导的神经胶质病和SD诱导的兴奋性毒性损伤的耐受性。 实验将系统地结合体外的创新性 使用现代调查工具进行准备，以探索基本 SID的生理和解剖学变化。 海马器官培养物 （HOTC）将在整个项目中使用：（a）HOTC是 保持许多细胞对细胞的完整区域 在体内发现的关系在体外生存了几个月。 （b） HOTC的微环境条件很容易控制； （C） 可以在空间和时间上遵循HOTC中的单个单元。 （D） 我们已经表明，HOTC支持SD并发展类似的星形胶质病 在体内看到。因此，SD，SD诱导的神经胶质病和SD诱导的耐受性 现在需要几天才能进化，现在可以首次检查 体外。 这意味着易于访问的实验优势和 可以将体外制剂的微环境控制应用于 在细胞和分子水平上回答“机械性”问题 需要完整组织的事件。 补丁夹技术，计算机 - 将使用基于基于的成像策略和分子生物学技术 实现以下特定目标。 （1）检查 间隙连接功能变化的时空动力学之间的变化 神经元以及与SD相关的星形胶质细胞之间。 （2）检查 SD诱导电流的时空变化和身份 海马锥体细胞。 （3）检查细胞和 SD的间隙Ca2+变化。 （4）检查CA2+或 SD的酸碱变化影响SD诱导的神经胶质病和对 兴奋性损伤。