Cerebellar malfunction and damage during ischemia

缺血期间的小脑功能障碍和损伤

• 批准号: 7164417
• 负责人: DAVID J ROSSI
• 金额: $ 33.41万
• 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/7164417
• 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

DESCRIPTION (provided by applicant): ' 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.

描述（由申请人提供）：“本提案的主要目标是研究脑缺血期间可能涉及小脑损伤和功能障碍的机制。在心脏骤停、中风和围产期窒息期间发生的脑缺血是死亡和长期残疾的主要原因。小脑是中风的常见靶点，小脑浦肯野细胞是最易受缺血性损伤的脑细胞之一。然而，关于浦肯野细胞如何对缺血作出反应以及如何被缺血损伤的知识相对较少。这种信息的缺乏是有问题的，因为在其他脑区运作的许多缺血机制涉及在浦肯野细胞中不表达或具有不寻常构型的分子过程。本研究将利用脑切片模型模拟体外脑缺血，并采用膜片钳记录、共聚焦荧光成像和药物干预等方法研究小脑缺血性损伤的机制。模拟缺血诱导浦肯野细胞的严重去极化，其由非NMDA离子型谷氨酸受体（和可能的其他谷氨酸受体/转运体）的激活介导，但其发作被GABAA受体的激活延迟。这些电生理反应与广泛的组织肿胀和随后的坏死和凋亡性细胞死亡的发展相关，与体内模型观察到的非常相似。模拟缺血也严重破坏通过小脑的电信号传导，并且在缺血发作终止后，这种破坏持续很长时间。确定细胞损伤和信号处理中断的机制应该为治疗的发展提供有用的信息。本研究的具体目的是：1）确定导致浦肯野细胞周围谷氨酸蓄积的机制，阐明哪些受体介导浦肯野细胞反应，并确定它们对细胞损伤的贡献; 2）确定GABAA受体激活延迟浦肯野细胞去极化开始的机制，并确定延迟是有益的还是有害的;以及3）确定在小脑电路中的何处以及通过何种机制电信号转导被中断。