Differential mechanisms and consequences of Purkinje cell loss in an adult and pediatric model of global cerebral ischemia

 描述(由申请人提供)：心脏病发作引起的全球缺血导致许多幸存患者的运动、认知和记忆障碍。小脑中的浦肯野细胞对缺血性损伤特别敏感，但很少有研究集中在这类神经元上，尽管它们在协调运动功能方面发挥着关键作用。浦肯野细胞在出生后4-6周经历NMDA受体表达的晚期发育。这表明，青少年和成年人的谷氨酸信号、可塑性和兴奋毒性机制可能是根本不同的。利用我们实验室的儿童和成年小鼠心脏骤停和心肺复苏(CA/CPR)模型，这项建议将检验成年和儿童小鼠的损伤机制集中在CaMKII激活以介导损伤的假设。为了解决CA/CPR后的兴奋毒性机制，将给予谷氨酸受体拮抗剂和CaMKII抑制剂，并检查浦肯野细胞损失。这项建议还将研究全球脑缺血对浦肯野细胞兴奋性和运动协调缺陷的功能后果。它还将检查可塑性和小脑依赖学习是否受到损害。该提案中概述的实验将使用电生理学、活细胞成像和神经行为测试来研究CA/CPR后成人和青少年的变化。这些结果将进一步加深我们对浦肯野细胞损伤机制的理解，并有助于确定改善心脏病发作后运动协调障碍的治疗靶点。

 DESCRIPTION (provided by applicant): Global ischemia caused by a heart attack results in motor, cognitive, memory deficits in the many patients who survive. Purkinje cells in the cerebellum are particularly sensitive to ischemic injury but few studies have focused on this population of neurons despite their key role in coordinating motor function. Purkinje cells undergo a late developmental onset of NMDA receptor expression at 4-6 weeks after birth. This suggests that glutamate signaling, plasticity and excitotoxicity mechanisms may be fundamentally different in juveniles versus adults. Using our laboratories pediatric and adult mouse models of cardiac arrest and cardiopulmonary resuscitation (CA/CPR) this proposal will test the hypothesis that injury mechanism in adult and pediatric mice converge on CAMKII activation to mediate injury. To address excitotoxicity mechanisms following CA/CPR, glutamate receptor antagonists and CAMKII inhibitors will be administered and Purkinje cell loss will be examined. This proposal will also examine the functional consequences of global cerebral ischemia on Purkinje cell excitability and motor coordination deficits. It will also examine whether plasticity and cerebellar dependent learning are impaired. Experiments outlined in this proposal will use electrophysiology, live cell imaging and neurobehavioral testing to investigate changes in the adult and juvenile after CA/CPR. Results obtained will further our understanding of injury mechanisms in Purkinje cells and help to identify therapeutic targets to improve motor coordination deficits after heart attack.