The Neural Control of Internal Joint State

内部关节状态的神经控制

基本信息

批准号：
9273197
负责人：
Matthew Tresch
金额：
$ 0.42万
依托单位：
NORTHWESTERN UNIVERSITY AT CHICAGO
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-07-01 至 2017-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9273197
关键词：
Affect Anatomy Animal Model Animals Arthralgia Arthritis Behavior Behavioral Chronic Controlled Study Deafferentation procedure Disease Equilibrium Esthesia Experimental Models Failure Feedback Femur Goals Health Hindlimb Human Injury Isometric Exercise Joint Dislocation Joints Knee Knee bone Knee joint Lead Ligaments Limb structure Locomotion Measures Mechanics Modeling Motion Movement Muscle Nervous System control Nervous system structure Neuraxis Pain Paralysed Rattus Regulation Research Role Rupture Sensory Stress Structure Task Performances Techniques Time Torque articular cartilage biomechanical model bone clinical application clinical practice functional restoration improved in vivo internal control joint injury joint stress kinematics motor control neuroregulation novel quadriceps muscle relating to nervous system research study response

项目摘要

DESCRIPTION (provided by applicant): Most motor control studies consider how the CNS controls task level variables, examining, for example, how the CNS produces the joint torques necessary to achieve behaviors such as locomotion. In this context, it is the set of torques produced by a muscle that determines its activation by the CNS. However, this focus on task performance ignores the control of another critical set of variables, those characterizing the state of internal joint structures such as ligaments and articular cartilage (i.e. ligament strainsor bone contact forces). Failure to regulate these internal joint variables can have significant consequences to health both in the short term (e.g. ligament rupture, joint dislocation) and in the long term (e.g. chronic joint pain, arthritis). The CNS should therefore consider both task performance and internal joint variables when determining muscle activations. How internal joint variables might be incorporated into motor control strategies, however, is poorly understood. The overall goal of the experiments described in this proposal is to evaluate these issues, examining the control of internal joint variables by the CNS. We will examine these issues using an animal model, focusing on the control of the knee joint by quadriceps muscles in the rat. The specific anatomy of the rat knee allows for a clear separation between the effects of quadriceps muscles on task performance variables (joint torques) and internal joint variables (mediolateral patellar forces). Using this model we can therefore make strong predictions about how the control of internal joint variables should be reflected in muscle activations across a range of behavioral conditions. We will perform three sets of related experiments. In Aim 1 we will characterize the mechanical actions of quadriceps muscles on task performance and internal joint variables. We hypothesize that quadriceps muscles will produce similar knee joint torques but distinct mediolateral patellar forces. In Aim 2, we will examine whether the neural control of quadriceps reflects the regulation of internal joint variables. We first hypothesize that in intact animals, the correlation in the variability of EMGs reflects the balancing of mediolateral patellar forces. Further, we hypothesize that following selective muscle paralysis or perturbations of patellar forces, long term adaptations in muscle activations will improve the control of internal joint variables. In Aim 3 we will examine the role of joint afferents in the control of internal jont variables. We hypothesize that joint afferents are not used for rapid feedback control of muscle activations but are used to guide long term adaptations of muscle activations following perturbations to internal joint variables. These experiments provide a systematic analysis of the role of internal joint variables in the neural control of behavior, using a range of techniques in conceptually simple and tractable experimental model. The results of these experiments have the potential to significantly impact motor control, both in our basic understanding of motor control and in clinical applications that seek to restore function after injury.

描述（由申请人提供）：大多数运动控制研究都考虑中枢神经系统如何控制任务水平变量，例如检查中枢神经系统如何产生实现诸如运动等行为所需的关节扭矩。在这种情况下，正是由肌肉产生的一组扭矩决定了中枢神经系统的激活。但是，这种关注任务性能忽略了另一组临界变量的控制，这些变量表征了内部关节结构（例如韧带和关节软骨）的状态（即韧带支链骨骨接触力）。在短期内（例如，韧带破裂，关节位错）和在长期（例如慢性关节疼痛，关节炎）。因此，在确定肌肉激活时，中枢神经系统应考虑任务性能和内部关节变量。然而，如何将内部关节变量纳入运动控制策略。本提案中描述的实验的总体目标是评估这些问题，研究中枢神经系统对内部关节变量的控制。我们将使用动物模型检查这些问题，重点是大鼠股四头肌对膝关节的控制。大鼠膝盖的特异性解剖结构使股四头肌肌肉对任务性能变量（联合扭矩）和内部关节变量（中外侧pa骨力）的影响之间存在明显的分离。因此，使用此模型，我们可以在一系列行为条件下如何反映在肌肉激活中如何反映对内部关节变量的控制。我们将执行三组相关的实验。在AIM 1中，我们将表征股四头肌肌肉对任务性能和内部关节变量的机械作用。我们假设股四头肌肌肉会产生相似的膝关节扭矩，但会产生不同的中外侧pat骨力。在AIM 2中，我们将检查股四头肌的神经控制是否反映了内部关节变量的调节。我们首先假设这是完整的动物，EMG的变异性的相关性反映了中外侧pat的平衡力量。此外，我们假设在选择性肌肉瘫痪或pat骨力的扰动之后，肌肉激活中的长期适应将改善内部关节变量的控制。在AIM 3中，我们将研究关节传入在控制内部JONT变量中的作用。我们假设关节传入不用于对肌肉激活的快速反馈控制，而是用于指导内部关节变量扰动后肌肉激活的长期适应。这些实验使用概念上简单且可拖延的实验模型中的一系列技术提供了内部关节变量在行为神经控制中的作用的系统分析。这些实验的结果有可能在我们对运动控制的基本理解和试图在受伤后恢复功能的临床应用中显着影响运动控制。