Quantitative model of jaw proprioception during active movements

主动运动过程中下颌本体感觉的定量模型

• 批准号: 10750622
• 负责人: Jeong Jun Kim
• 金额: $ 5.35万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-11 至 2025-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10750622
• 关键词: Affect; Anesthesia procedures; Behavior; Biomechanics; Cell Nucleus; Code; Complex; Coupling; Dedications; Electrophysiology (science); Elements; Feedback; Fiber; Gamma Motor Neurons; Goals; Jaw; Length; Masticatory muscles; Mechanics; Modality; Modeling; Monitor; Motion; Motor; Motor Cortex; Motor output; Movement; Mus; Muscle; Muscle Spindles; Musculoskeletal; Nature; Neurons; Noise; Orofacial Pain; Parents; Pattern; Process; Property; Proprioception; Proprioceptor; Regulation; Rodent; Sensory; Signal Transduction; Source; Stretching; System; Temporomandibular Joint Disorders; Testing; Training; Trigeminal Nuclei; Trigeminal System; Work; awake; body position; body sense; computer framework; control theory; craniofacial structure; density; design; flexibility; hindbrain; in vivo; jaw movement; kinematics; mechanical force; mechanical signal; motor control; nerve supply; neural; neural model; neuromechanism; novel; optogenetics; orofacial; receptor; sensor; sensorimotor system; tool

PROJECT SUMMARY Proprioception is an indispensable sense of the body’s position and movement in space. Fine motor control depends on proprioceptors to monitor the mechanical consequences of motor actions. In particular, muscle spindles are a class of primary proprioceptors that detect muscle length and stretch at the intrafusal fibers. The signals generated by muscle spindles are complex with dynamical regulation of intrafusal fiber lengths via γ motor neuron (fusimotor) activity. The interaction between feedforward mechanical signals at the muscle spindle and descending motor commands at the parent muscle, especially in the context of naturalistic movements, remains poorly understood. Opposing views disagree on whether muscle spindles passively sense muscle length/stretch or actively process biomechanical signals based on motor commands to the muscle. Using the unique advantages of rodent jaw proprioceptors in the hindbrain mesencephalic trigeminal (MeV) nucleus, I will test the hypothesis that motor commands flexibly tune jaw muscle spindle coding in a context-dependent manner. With experimental access to many levels of the jaw sensorimotor circuit, I will determine how feedforward mechanical signals and descending motor commands interact at the primary proprioceptors. Aim 1 will find the relationship between motor unit activity in jaw muscles and corresponding muscle spindle activity during passive and active movements. Aim 2 will record muscle spindle activity with (a) external loads on the jaw and (b) optogenetic decoupling of motor drives from muscle-driven motion. Aim 3 will provide an overarching framework to model the jaw system as a feedback control loop. The proposed project investigates proprioceptive feedback in craniofacial structures, electrophysiological mechanisms for controlling jaw function, and quantitative models of the neural controller and muscles of the jaw. The immense training potential in this project lies in the application of novel in vivo electrophysiology tools, well-designed use of optogenetics, and quantitative modeling rooted in control theory. The proposed work has important implications in elucidating orofacial proprioception at the primary receptors and understanding temporomandibular disorders and orofacial pain involving maladaptive control of the jaw.

项目摘要 本体感受是对人体在太空中的位置和运动的必要意义。精细的电机控制 取决于本体受体来监测运动动作的机械后果。特别是肌肉 纺锤体是一类主要的本体感受器，可检测肌肉长度并在偶内纤维处伸展。这 由肌肉纺锤体产生的信号是复杂的，并通过γ的动态调节次体内纤维长度。 运动神经元（融合）活性。肌螺旋处的前馈机械信号之间的相互作用 并在父母的肌肉上下降运动命令，尤其是在自然主义运动的背景下， 仍然很了解。反对观点对肌肉是否被动地感知肌肉不同意 长度/伸展或主动根据电动机命令对肌肉进行生物力学信号。使用 啮齿动物颌骨本体受体在后脑脑脑脑中三叉神经（MEV）核中具有独特的优势，我将 测试马达命令以上下文依赖性方式灵活调节肌肉纺锤体编码的假设。 通过实验访问许多级别的下颌感觉运动电路，我将确定馈送方式 机械信号和下降电动机命令在主要的本体受体相互作用。 AIM 1会发现 被动过程中的运动单位活动与相应的肌肉主轴活动之间的关系 和主动运动。 AIM 2将记录肌肉主轴活动，（a）下颌上的外部载荷和（b） 从肌肉驱动的运动中，电动驱动器的光遗传学脱钩。 AIM 3将提供一个总体框架 将JAW系统建模为反馈控制循环。拟议的项目调查了本体感受反馈 在颅面结构中，用于控制下颌功能的电生理机制和定量模型 颌骨的神经控制器和肌肉。该项目的巨大培训潜力在于申请 新型体内电生理学工具，精心设计的光遗传学使用以及植根于定量建模 控制理论。拟议的工作对阐明口面本体感受具有重要意义 主要受体和理解颞下颌疾病和涉及适应不良的口面疼痛 控制下颌。