Diversity Supplement to 2R01NS064004

反射亢进是皮质脊髓束（CST）损伤的破坏性后果，单独或 在皮质的起源处，或在脊髓损伤（SCI）之后。反射亢进有多种可能的机制。一 机制反映了CST丢失后损伤尾部本体感受传入（PA）纤维的异常发芽; 与运动神经元形成突触的PA纤维越多，PA反射的强度越强。PA端子通常 在GABA能突触前抑制调节下。我们假设PA在损伤后发芽， 相关的GABA能突触前调节，这可以增强反射作用，导致临床 反射亢进的后果，也就是痉挛状态和痉挛。 父R 01的总体重点是确定挫伤SCI后的哪些运动障碍可能是 然后启动CST修复以针对特定损伤。拟议 本多样性增刊中的研究将检验单侧锥体束中GABA能失调假说 损伤（PTX），一种模型损伤，从一个半球切断所有CST轴突而不对脊髓产生损伤， 或颈脊髓挫伤，一种损害CST以及其他通路的临床前损伤模型， 脊髓的组成部分。我们将使用高分辨率的形态学分析的PA突触的变化，在脊髓 灰质（Aim 1）以及一种新的多通道脊髓电生理记录方法（Aim 2）， 解决反射亢进。 该项目第1年大部分时间的重点是选择性CST损伤（PTX）后的反射亢进。使用此 用于Thelma补充项目的CST损伤模型通过提供额外的新颖性来补充父R 01 SCI焦点， 反射亢进问题的机制基础以及神经调节如何改善它。 在项目第一年完成后，候选人计划提交NRSA F31申请。成功完成 拟议的第一年的研究将定位候选人准备一个有竞争力的NRSA F31应用程序的基础上强大的 有影响力的调查结果的前提。预计SCI损伤模型将在申请提交后进行审查， 在第二年。该项目的成功完成将告知反射亢进的机制。 除了进行研究，候选人将学习新的尖端技术，提供一个新颖的 对反射亢进问题的独特观点，这将加强她与生理过程相关的训练 创伤后神经元兴奋性的潜在变化。 1

Hyperreflexia is a devastating consequence of a lesion that damages the corticospinal tract (CST), in isolation, or at its origins in the cortex, or after a spinal cord injury (SCI). Multiple possible mechanisms underlie hyperreflexia. One mechanism reflects aberrant sprouting of proprioceptive afferent (PA) fibers caudal to the injury after CST loss; with more PA fibers synapsing on motoneurons, the strength of PA reflexes may be augmented. PA terminals are normally under GABAergic presynaptic inhibitory regulation. We hypothesize that PA sprouting after an injury occurs without associated GABAergic presynaptic regulation and that this can enhance reflex actions, leading to the clinical consequences of hyperreflexia, which is spasticity and spasms. An overall focus of the parent R01 is to determine which motor impairments after a contusion SCI may be attributable to the loss of the CST, and then to initiate CST repair to target the particular impairment. The proposed studies in this Diversity Supplement will examine the GABAergic dysregulation hypothesis in a unilateral pyramidal tract lesion (PTX), a model injury that severs all CST axons from one hemisphere without producing injury to the spinal cord, or a cervical spinal cord contusion, a preclinical injury model that lesions the CST as well as other pathways and components of the spinal cord. We will use high-resolution morphologic analyses of PA synapse changes in the spinal gray matter (Aim 1) together with a novel multi-channel spinal cord electrophysiological recording approach (Aim 2) to address hyperreflexia. The focus for most of year 1 of the project will be on hyperreflexia after selective CST lesion (PTX). Using this CST lesion model for Thelma's supplement project complements the parent R01 SCI focus by providing additional novel mechanistic underpinnings of the problem of hyperreflexia and how neuromodulation can ameliorate it. Near the completion of year 1 of the project, the candidate plans to submit an NRSA F31 application. Successful completion of proposed year 1 studies will position the candidate to prepare a competitive NRSA F31 application based on a strong premise of impactful findings. It is expected that the SCI injury model will be examined after application submission, during year 2. Successful completion of the project will inform the mechanisms of hyperreflexia. In addition to conducting the research, the candidate will learn new cutting-edge techniques that provide a novel and unique perspective on the problem of hyperreflexia and this will bolster her training related to physiological processes underlying changes in neuronal excitability after trauma. 1