Stretch Reflex Contributions to Multijoint Coordination

牵张反射对多关节协调的贡献

• 批准号: 8535216
• 负责人: ERIC JON PERREAULT
• 金额: $ 29.47万
• 依托单位: REHABILITATION INSTITUTE OF CHICAGO D/B/A SHIRLEY RYAN ABILITYLAB
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8535216
• 关键词: Adaptive Behaviors; Address; Affect; Age; Behavior; Behavioral; Brain Injuries; Brain Stem; Cerebral Palsy; Consensus; Corticospinal Tracts; Data; Diffusion Magnetic Resonance Imaging; Disease; Eating; Freedom; Functional disorder; Funding; Goals; Hand; Human; Impairment; Individual; Lead; Lesion; Link; Literature; Mediating; Modification; Motor; Movement; Muscle; Neural Pathways; Parkinson Disease; Pathway interactions; Pattern; Performance; Population; Posture; Protocols documentation; Public Health; Reaction; Reflex action; Reflex control; Regulation; Rehabilitation therapy; Relative (related person); Research; Robot; Robotics; Role; Speed; Spinal cord injury; Stroke; Structure; Survivors; System; Testing; Therapeutic Intervention; Time; Training; Uncertainty; Work; arm; base; disability; haptics; hemiparesis; motor impairment; nervous system disorder; neuromechanism; novel strategies; post stroke; relating to nervous system; research study; response; spinal reflex; stretch reflex

DESCRIPTION (provided by applicant): There is a fundamental gap in our understanding of how long-latency stretch reflexes (LLSRs) contribute to the control of multijoint posture and movement in the human arm. This is an important problem because many neurological disorders impair stretch reflexes, resulting in well-documented motor dysfunction. Attempts to enhance motor function through a modification of reflex behavior have been largely equivocal, however, due at least in part to the unknown relationships between specific reflex subtypes and motor abilities. Our central theme is that much of the gap can be filled by considering the pathways that contribute to LLSRs and their specific, context-dependent contributions to motor function. LLSRs contain at least two key behavioral compo- nents: "stabilizing reflexes", contributing to posture regulation, and "triggered reactions" for the rapid release of planned actions. We have shown that these behaviors are mediated by separate pathways and that their relative importance depends on the task performed. Our recent work focused on the stabilizing component of the LLSR. Here we propose to investigate triggered reactions. Our central hypothesis is that triggered reactions can act independently from stabilizing reflexes, based on our preliminary data demonstrating that stabilizing LLSRs are lost following stroke but that triggered reactions are spared. Importantly, our data also suggest that appropriately triggered reactions increase speed and coordination in stroke subjects, potentially forming the basis for effective rehabilitation. First, however, we must clarify the LLSR role in controlling unimpaired posture and movement, and its integrity and function following stroke. Our Specific Aims are: 1) to determine if stabilizing reflexes and triggered reactions are controlled independently; 2) to determine how uncertainty affects the planning, execution and efficacy of triggered reactions; and 3) to determine how brain injury due to stroke im- pairs stabilizing stretch reflexes and triggered reactions. The first two aims focus on the behavioral relevance of triggered reactions, and will be completed in unimpaired subjects using a 3D robotic manipulator to charac- terize LLSRs during the key transition from maintaining arm posture to initiating a reach. Our third aim will be completed in stroke subjects and age-matched controls. It parallels the first two aims, but also will use diffusion tensor imaging (DTI) to quantify lesions in the descending pathways thought to regulate the stabilizing and triggered components of the LLSR. The contributions of this research will be a clear description of the role of triggered reactions in the control of movement, how that role is integrated with posture-stabilizing components of the LLSR, and how the LLSR is impaired following stroke in relation to the neural pathways contributing to it. With this refined understanding, we hope to lay the groundwork for using triggered reactions in rehabilitation training paradigms aimed at enhancing the ability to voluntarily initiate appropriate motor patterns at appropri- ate latencies in stroke survivors.

描述(申请人提供)：对于长潜伏期伸展反射(LLSR)如何有助于控制人类手臂的多关节姿势和运动，我们的理解存在一个根本的空白。这是一个重要的问题，因为许多神经疾病会损害拉伸反射，导致有据可查的运动功能障碍。然而，通过改变反射行为来增强运动功能的尝试在很大程度上是模棱两可的，至少部分原因是特定的反射亚型与运动能力之间的关系尚不清楚。我们的中心主题是，通过考虑促成LLSR的途径及其对运动功能的特定、上下文相关的贡献，可以填补大部分缺口。LLSR至少包含两个关键的行为成分：“稳定反射”，有助于姿势调节，以及“触发反应”，用于快速释放有计划的动作。我们已经证明，这些行为是由不同的途径调节的，它们的相对重要性取决于所执行的任务。我们最近的工作集中在LLSR的稳定部分。在这里，我们建议研究触发反应。我们的中心假设是，触发的反应可以独立于稳定的反射发挥作用，这是基于我们的初步数据，该数据表明，中风后稳定的LLSR会丢失，但触发的反应可以幸免。重要的是，我们的数据还表明，适当的触发反应可以提高中风受试者的速度和协调性，可能形成有效康复的基础。然而，首先，我们必须澄清LLSR在控制未受损的姿势和运动中的作用，以及它在中风后的完整性和功能。我们的具体目标是：1)确定稳定反射和触发反应是否独立控制；2)确定不确定性如何影响触发反应的计划、执行和有效性；3)确定中风导致的脑损伤是如何影响稳定拉伸反射和触发反应的。前两个目标集中在触发反应的行为相关性上，并将在从维持手臂姿势到启动伸展的关键转变过程中，使用3D机器人机械手在未受损的受试者身上完成LLSR的特征。我们的第三个目标将在中风受试者和年龄匹配的对照组中完成。它与前两个目标平行，但也将使用扩散张量成像(DTI)来量化下行通路中的病变，以调节LLSR的稳定和触发成分。这项研究的贡献将是清楚地描述触发反应在运动控制中的作用，该作用如何与LLSR的姿势稳定成分相结合，以及LLSR在中风后如何受损与参与它的神经通路有关。有了这些精细化的理解，我们希望为在康复训练模式中使用触发反应奠定基础，旨在提高中风幸存者在适当的潜伏期自愿启动适当运动模式的能力。