RESTORATION OF PLASTICITY AFTER PEDIATRIC TRAUMATIC BRAIN INJURY

这个子项目是许多利用资源的研究子项目之一 由NIH/NCRR资助的中心拨款提供。子项目的主要支持 而子项目的主要调查员可能是由其他来源提供的， 包括其它NIH来源。 列出的子项目总成本可能 代表子项目使用的中心基础设施的估计数量， 而不是由NCRR赠款提供给子项目或子项目工作人员的直接资金。 创伤性脑损伤（TBI）是儿童和青少年死亡和残疾的唯一最重要的原因，但对区分儿童脑损伤与成人脑损伤的潜在机制知之甚少。据了解，对未成熟大脑的创伤性生物力学损伤可以表现为慢性认知和行为问题，并丧失发育潜力。可塑性被定义为大脑改变细胞和网络结构和功能以应对环境变化的机制。越来越多的证据表明，小儿创伤性脑损伤可导致可塑性受损和神经传递改变。谷氨酸代表中枢神经系统中的主要兴奋性神经递质，并且与TBI的急性病理生理学密切相关，但对于正常发育和神经可塑性也是至关重要的。本申请提出研究未成熟脑中对TBI的神经递质能反应，特别是涉及N-甲基-D-天冬氨酸（NMDA）受体的反应。该建议的中心假设是NMDA受体功能障碍是发育性TBI后可塑性丧失的基础，并且可以使用表征良好的儿科TBI实验模型在分子（特定目的1和2），电生理（特定目的3）和认知（特定目的4）方面测量这种扰动。通过确定损伤后这一重要神经递质系统变化的时间进程，将有可能确定NMDA受体神经反应性受损的窗口。然后，对该时间段的适当鉴定将指导本申请的最终目的（具体目的5），其是利用增强NMDA受体神经传递的药理学试剂来使发育中的大脑的分子谱正常化并减轻行为和认知缺陷。该提案提供了一个独特的机会，可以严格测试针对特定年龄的治疗策略，该策略旨在为最易受TBI影响的患者人群（儿童）带来益处。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Traumatic brain injury (TBI) is the single most important cause of death and disability in children and adolescents, yet relatively little is known about the underlying mechanisms that distinguish pediatric brain injury from that in adults. It is understood the traumatic biomechanical injury to the immature brain can manifest as chronic cognitive and behavioral problems with a loss of developmental potential. Plasticity is defined as a mechanism by which the brain modifies cellular and network structure and function to respond to changes in the environment. There is increasing evidence that pediatric TBI can result in impaired plasticity and alterations in neurotransmission. Glutamate represents the major excitatory neurotransmitter in the central nervous system and is intimately involved in the acute pathophysiology of TBI, but also is critical for normal development and for neural plasticity. This application proposes to investigate the glutamatergic response to TBI in the immature brain, in particular, that which involves the N-methyl-D-aspartate (NMDA) receptor. The central hypothesis of this proposal is that dysfunction at the NMDA receptor underlies the loss of plasticity seen following developmental TBI, and that this perturbation can be measured molecularly (Specific Aims 1 and 2), electrophysiologically (Specific Aim 3) and cognitively (Specific Aim 4), using a well-characterized experimental model of pediatric TBI. By determining the post-injury time course of changes in this important neurotransmitter system, it will be possible to identify the window of impaired neural responsiveness at the NMDA receptor. Proper identification of this time period will then direct the final aim (Specific Aim 5) of this application, which is to utilize pharmacological agents that augment NMDA receptor neurotransmission to normalize the molecular profile of the developing brain and to alleviate behavioral and cognitive deficits. This proposal provides a unique opportunity to rigorously test an age-specific therapeutic strategy that is designed to be beneficial for the patient population most vulnerable to TBI, children.