Cerebellar malfunction and damage during ischemia

缺血期间的小脑功能障碍和损伤

基本信息

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
项目类别：
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

项目摘要

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.

该提案的主要目的是研究可能涉及小脑损害的机制和脑缺血期间的故障。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。小脑是一个常见的目标中风和小脑浦肯野细胞是最易感性脑细胞的缺血性损伤之一。然而，关于浦肯野细胞如何应对和缺血会损害的情况相对较少。这缺乏信息是有问题的，因为许多在其他大脑中运行的缺血机制区域涉及未表达的分子过程或在 Purkinje细胞。对于此提案，将使用脑切片模型在体外模拟脑缺血，并且贴片钳记录，共聚焦荧光成像和药理学操纵将用于研究小脑缺血损伤的机制。模拟的缺血会引起严重的去极化浦肯野细胞的激活是通过非NMDA离子型谷氨酸受体介导的（甚至可能是其他谷氨酸受体/转运蛋白），但它的发作被GABAA受体的激活延迟。这些电生理反应与大量组织肿胀有关，随后坏死和凋亡细胞死亡的发展与体内模型观察到的结构非常相似。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性发作终止后，长期存在。确定基础的机制蜂窝损伤和信号处理中断都应为开发提供有用的信息疗法。该提案的具体目的是：1）确定导致谷氨酸的机制在浦肯野细胞周围积聚，阐明受体介导呼普犬细胞反应的受体和确定它们对细胞损伤的贡献； 2）确定GABAA受体的机制激活延迟了浦肯野细胞去极化的发作，并确定延迟是有益的还是有害； 3）确定小脑电路中的位置以及通过哪种机制电信号转导中断。