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.

项目总结 本体感觉是对身体在空间中的位置和运动不可或缺的感觉。精细电机控制 依靠本体感受器来监测运动动作的机械后果。尤其是肌肉 纺锤体是一类主要的本体感受器，它探测肌肉的长度并在梭内纤维处拉伸。这个 肌梭产生的信号是复杂的，通过γ动态调节梭内纤维长度 运动神经元(梭形马达)活动。肌梭前馈机械信号之间的相互作用 以及在亲本肌肉中的下行运动指令，特别是在自然运动的背景下， 人们对此仍然知之甚少。关于肌梭是否被动地感觉肌肉，对立的观点意见不一 长度/伸展或基于对肌肉的运动命令主动处理生物力学信号。使用 啮齿动物下颌本体感受器在后脑中脑三叉神经(MeV)核的独特优势，我将 测试这一假设，即运动指令以上下文相关的方式灵活地调整下颌肌梭编码。 通过对颌骨感觉运动电路的多个层次的实验访问，我将确定如何前馈 机械信号和下行运动指令在初级本体感受器上相互作用。目标1将找到 被动状态下颌肌运动单位活动与相应肌梭活动的关系 和活跃的动作。目标2将记录肌梭活动，包括(A)颌骨上的外部负荷和(B) 光遗传将马达驱动与肌肉驱动的运动分离。AIM 3将提供一个总体框架 将爪子系统建模为反馈控制回路。拟议的项目调查本体感觉反馈。 在颅面结构中，控制颌骨功能的电生理机制和定量模型 神经控制器和下巴肌肉。本项目巨大的培训潜力在于应用 新的活体电生理学工具，良好设计的光遗传学的使用，以及植根于 控制理论。这项拟议的工作对阐明口腔面部本体感觉具有重要意义。 与适应不良相关的颞颌关节紊乱和口面部疼痛的初级受体和理解 控制下巴。