ANGULAR AND LINEAR VESTIBULOCOLLIC REFLEXES IN HUMANS

人类前庭结肠角反射和线性前庭反射

• 批准号: 6104449
• 负责人: BARRY W PETERSON
• 金额: $ 12.5万
• 依托单位: NORTHWESTERN UNIVERSITY AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-08-01 至 1999-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6104449
• 关键词: balance; biological models; computer simulation; head movements; human subject; model design /development; neural information processing; otocyst /otolith; semicircular duct; vestibuloocular reflex; visual tracking

Proper stabilization of the head is essential for humans to carry out many of the essential activities of daily living. Throughout most of the activities in which we engage the head is held in a stereotyped position with respect to gravity. This helps to maintain the orientation of the head's special sensory receptors in space and regulates the attitude of the head on the trunk as part of overall postural control. Vestibulocollic reflexes, which utilize information from head position and velocity sensors in the otolith and semicircular canal receptors of the vestibular labyrinth to generate neck muscle activity to stabilize the head are a critical part of the head stabilization system. Our long-term goal is to determine how vestibulocollic reflexes (VCRs) contribute to head stabilization during linear, angular and combined linear-angular perturbations of the trunk in the sagittal and frontal planes. This project concentrates on the role of VCRs generated by otolith afferents and on the ways in which they interact with better known semicircular canal VCRs. We propose two series of experiments on normal human volunteers. The first will examine how the linear and angular VCRs interact with one another and with head movements generated by voluntary and visuomotor systems. This will help us understand the contexts in which VCRs contribute to maintaining head stability and the ways in which they are regulated or "gated" by other parts of the motor control system. The second series of experiments will measure the dynamic properties of otolith and canal VCRs across a wide range of frequencies and types of stimuli under conditions that minimize the contribution of visual and voluntary head movement systems. The two reflexes will be studied together during rotations or translations of the trunk with the head free to move while the VCRs will be studied in isolation during rotations or translations with the head fixed to the trunk. These experiments will help us understand the internal processing that occurs in these reflexes and the way in which their output is modified by the biomechanical properties of the head-neck system. Experimental results will be interpreted using two models. The first is a dynamic model which starts with well tested vestibuloocular reflex models and adds non-linear behavior and multiple rotation axes that characterize the head movement system. It will incorporate elements corresponding to known physiology of labyrinthine receptors and reflex pathways and will attempt to show how position, velocity and acceleration information, embedded in firing patterns of regular and irregular peripheral afferents, drives neck muscles to maintain stability of the head in space. The second is a detailed biomechanical model of the human head-neck system that quantifies the actions of all joints, muscles and passive mechanics and allows prediction of appropriate patterns of muscle activity to stabilize the head in the face of angular and linear perturbations.

头部的适当稳定对于人类执行任务至关重要 许多日常生活的基本活动。 纵观大部分时间 我们参与的活动头部处于固定位置 相对于重力。 这有助于保持方向 头部在空间中的特殊感觉感受器并调节姿态 作为整体姿势控制的一部分，头部位于躯干上。 前庭结肠反射，利用头部位置的信息 耳石和半规管感受器中的速度传感器 前庭迷路产生颈部肌肉活动以稳定 头部是头部稳定系统的关键部分。 我们的长期目标是确定前庭结肠反射 (VCR) 如何 有助于线性、角度和组合过程中的头部稳定性 躯干矢状面和额状面的线性角度扰动 飞机。 该项目的重点是 VCR 的作用 耳石传入以及它们如何更好地相互作用 已知的半规管VCR。 我们提出了两个系列的实验 正常人类志愿者。 第一个将检查线性和 有角度的 VCR 彼此相互作用并产生头部运动 通过自愿和视觉运动系统。 这将帮助我们理解 VCR 有助于维持头部稳定性和 它们被电机其他部分调节或“门控”的方式 控制系统。 第二系列实验将测量动态特性 各种频率和类型的耳石和耳道 VCR 在尽量减少视觉和视觉影响的条件下进行刺激 自愿头部运动系统。 将研究这两种反射 在头部自由的情况下躯干旋转或平移时一起 在旋转期间单独研究 VCR 时移动，或者 头部固定在躯干上的平移。 这些实验将 帮助我们理解这些反射中发生的内部处理 以及它们的输出被生物力学修改的方式 头颈系统的特性。 实验结果将使用两个模型来解释。 第一个是 以经过充分测试的前庭眼反射开始的动态模型 建模并添加非线性行为和多个旋转轴 描述头部运动系统的特征。 它将融入元素 对应于已知的迷路受体和反射的生理学 路径并尝试展示位置、速度和加速度如何 信息，嵌入规则和不规则的发射模式中 周围传入，驱动颈部肌肉以维持稳定性 头在太空中。 第二个是详细的人体生物力学模型 头颈系统，量化所有关节、肌肉和 被动力学并允许预测适当的肌肉模式 面对有角度和线性的物体时稳定头部的活动 扰动。