Cerebellar malfunction and damage during ischemia

缺血期间的小脑功能障碍和损伤

• 批准号: 7342456
• 负责人: DAVID J ROSSI
• 金额: $ 33.47万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-01-01 至 2010-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7342456
• 关键词: Affect; Anions; Apoptosis; Apoptotic; Area; Asphyxia Neonatorum; Biological Assay; Brain; Brain Injuries; Brain Ischemia; Brain region; Cause of Death; Cell Death; Cell membrane; Cells; Cerebellar cortex structure; Cerebellum; Chloride Channels; Chromosome Pairing; Clinical; Development; Disruption; Event; Exocytosis; Exposure to; Fiber; Future; Glutamate Receptor; Glutamate Transporter; Glutamates; Goals; Heart Arrest; Hippocampus (Brain); In Vitro; Ischemia; Ischemic Brain Injury; Lead; Measures; Mediating; Metabotropic Glutamate Receptors; Modeling; Modification; Molecular; Necrosis; Neurons; Osmotic Pressure; Output; Process; Purkinje Cells; Receptor Activation; Research Personnel; Role; Signal Transduction; Simulate; Slice; Stroke; Swelling; Synapses; System; Testing; Therapeutic; Therapeutic Intervention; Time; Tissues; Traumatic Brain Injury; United States; Vertebral column; Vesicle; brain cell; cell injury; computerized data processing; design; disability; fluorescence imaging; gamma-Aminobutyric Acid; granule cell; improved; in vivo; in vivo Model; mossy fiber; patch clamp; postsynaptic; prevent; programs; receptor; research study; response; therapeutic target; therapy development; tool; transmission process; uptake; voltage; voltage clamp

The primary goal of this proposal is to investigate mechanisms that may be involved in cerebellar damage and malfunction during brain ischemia. Brain ischemia, which occurs during cardiac arrest, stroke and perinatal asphyxia, is a leading cause of death and long term disability. The cerebellum is a frequent target of stroke, and cerebellar Purkinje cells are one of the most susceptible brain cells to ischemic damage. However, relatively little is known about how Purkinje cells respond to and are damaged by ischemia. This lack of information is problematic because many of the ischemic mechanisms operating in other brain regions involve molecular processes that are either not expressed or have an unusual configuration in Purkinje cells. For this proposal, a brain slice model will be used to simulate brain ischemia in vitro and patch-clamp recording, confocal fluorescence imaging and pharmacological manipulations will be used to investigate mechanisms of cerebellar ischemic damage. Simulated ischemia induces a severe depolarization of Purkinje cells which is mediated by activation of non-NMDA ionotropic glutamate receptors (and possibly other glutamate receptors/transporters) but its onset is delayed by activation of GABAA receptors. These electrophysiological responses are associated with extensive tissue swelling and the subsequent development of necrotic and apoptotic cell death very similar to that observed with in vivo models. Simulated ischemia also severely disrupts electrical signal transduction through the cerebellum and the disruption persists for long periods after the ischemic episode is terminated. Determining the mechanisms that underlie both cellular damage and disrupted signal processing should provide useful information for the development of therapies. The specific aims of this proposal are: 1) To determine the mechanisms that lead to glutamate accumulation around Purkinje cells, elucidate which receptors mediate the Purkinje cell response and determine their contribution to cell damage; 2) To determine the mechanisms by which GABAA receptor activation delays the onset of Purkinje cell depolarization and to determine if the delay is beneficial or damaging; and 3) To determine where in the cerebellar circuitry and by what mechanism electrical signal transduction is disrupted.

该提案的主要目标是研究可能涉及小脑损伤的机制 以及脑缺血时的功能障碍。脑缺血，发生在心脏骤停、中风和 围产期窒息是死亡和长期残疾的主要原因。小脑是常见的目标 中风和小脑浦肯野细胞是最容易受到缺血性损伤的脑细胞之一。 然而，人们对浦肯野细胞如何响应缺血以及如何受到缺血的损害知之甚少。这 缺乏信息是有问题的，因为许多缺血机制在其他大脑中运作 区域涉及分子过程，这些过程要么不表达，要么具有不寻常的配置 浦肯野细胞。对于该提案，将使用脑切片模型来模拟体外脑缺血并 膜片钳记录、共焦荧光成像和药理学操作将用于 研究小脑缺血损伤的机制。模拟缺血引起严重的去极化 浦肯野细胞的激活是由非 NMDA 离子型谷氨酸受体（也可能是 其他谷氨酸受体/转运蛋白），但其发作因 GABAA 受体的激活而延迟。这些 电生理反应与广泛的组织肿胀和随后的反应有关 坏死和凋亡细胞死亡的发展与体内模型观察到的非常相似。模拟 缺血还严重破坏了通过小脑的电信号转导和破坏 缺血发作结束后仍持续很长一段时间。确定其背后的机制 细胞损伤和信号处理中断都应该为发育提供有用的信息 的疗法。该提案的具体目标是：1）确定导致谷氨酸的机制 浦肯野细胞周围的积累，阐明哪些受体介导浦肯野细胞反应和 确定它们对细胞损伤的贡献； 2) 确定GABAA受体的作用机制 激活延迟浦肯野细胞去极化的发生，并确定延迟是否有益或 损坏； 3) 确定小脑电路中的位置以及通过什么机制产生电信号 转导被破坏。