VESTIBULOSPINAL CONTROL OF POSTURE AND LOCOMOTION

姿势和运动的前庭脊髓控制

• 批准号: 6104453
• 负责人: JANE MACPHERSON
• 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/6104453
• 关键词: balance; biological models; biomechanics; brain electrical activity; cats; chordate locomotion; computer simulation; electromyography; electrostimulus; experimental brain lesion; head movements; model design /development; posture; proprioception /kinesthesia; sensory feedback; vertigo; vestibular apparatus; vestibuloocular reflex

The long-term goal of this research is to understand how the nervous system controls stance and balance and, in particular, what role the vestibular system plays in this control. The ability to maintain stability during stance is fundamental for the successful performance of many functional motor tasks, and yet little is known about the mechanisms that the CNS uses to solve the complex control problems of stance. Dizziness is one of the most common complaints faced by clinicians, and symptoms of dizziness are often accompanied by problems with balance. A significant proportion of these problems of instability could be related to pathology, injury, or degeneration in the vestibular system. Therefore, it is vital to understand how vestibular inputs are used by the motor system to maintain stance and stability. The goal of this proposal is to examine the role of the vestibular canals and otoliths in the dynamic control of stance and locomotion through experimentation and computational modelling. Experiments will quantify the dynamics of unrestrained stance and treadmill locomotion in cats, before and after lesions of the vestibular apparatus. Two hypotheses underlie the proposed work: i) that dynamic stabilization of the head is required for maintaining a stable postural orientation to earth vertical and, ii) altered vestibular input results in hypermetria that arises from increased system gain. The specific aims are 1) to quantify the frequency response characteristics of the balance control system of the unrestrained standing animal, by applying sinusoidal perturbations to the support surface. A systems analysis approach will be applied in analyzing the ground reaction forces under each limb of the cat, positions of the body segments (especially the head), joint torques, trajectory of the center of mass, and electromyographic activity from selected muscles of the neck, trunk, and limbs. 2) to determine patterns of coordination between head movement and limb movement during locomotion, 3) to quantify the excitability of local spinal circuits using low-threshold stimulation of cutaneous nerves. All these procedures will be carried out before and after lesion of the vestibular apparatus (either total bilateral labyrinthectomy, or bilateral plugging of the semicircular canals). The advantage of the animal model is the ability to precisely control the lesion, and to follow each animal during the acute phase and as it undergoes sensory-motor adaptation. Each animal will be tested in all behaviors and will serve as its own control. Finally, 4) to create a computational model of the cat balance control system, incorporating not only proprioceptors, but also the head-based sensors (vestibular, visual, and neck proprioceptors). The data and models generated by these studies will provide valuable insights into neuromotor control processes and will lead to new hypotheses and predictions about vestibular dysfunction as well as vestibular function under altered force field environments.

这项研究的长期目标是了解紧张的人 系统控制的立场和平衡，特别是什么作用， 前庭系统在这种控制中起作用。 能力保持 站立期间的稳定性是成功执行 许多功能性运动任务，但对机制知之甚少 CNS用来解决复杂的姿态控制问题。 头晕是临床医生最常见的主诉之一， 头晕的症状往往伴随着平衡问题。 这些不稳定问题的很大一部分可能是 与前庭系统的病理学、损伤或退化有关。 因此，了解前庭输入如何被使用是至关重要的。 运动系统来保持姿势和稳定性。 这个目标 建议是检查前庭管和耳石在 通过实验对站立和移动进行动态控制， 计算机建模 实验将量化 猫无约束的站立和跑步机运动，前后 前庭器官的病变。 有两个假设 建议的工作：i）需要头部的动态稳定， 保持相对于地球垂直的稳定姿势取向，以及，ii） 前庭输入的改变会导致 增加系统增益。 具体目标是1）量化频率响应 无约束平衡控制系统的特性 站立动物，通过对支架施加正弦扰动 面 本研究将采用系统分析的方法， 地面反作用力下的每肢的猫，身体的位置 节段（尤其是头部）、关节扭矩、中心轨迹 的质量，和肌电图活动从选定的肌肉的 颈部躯干和四肢 2)以确定协调模式， 运动过程中的头部运动和肢体运动，3）量化 局部脊髓回路的兴奋性，使用低阈值刺激 皮神经 所有这些程序都将在 前庭器官损伤后（无论是完全双侧 半规管切除术或双侧半规管堵塞）。 的 动物模型的优点是能够精确地控制 病变，并在急性期和 经历了感觉运动适应。 每只动物将在所有 行为，并将其作为自己的控制。 （4）创建一个 猫平衡控制系统的计算模型，不包括 不仅是本体感受器，而且还有基于头部的传感器（前庭，视觉， 和颈部本体感受器）。 这些研究产生的数据和模型 将为神经运动控制过程提供有价值的见解， 导致了关于前庭功能障碍的新假设和预测， 以及在改变的力场环境下的前庭功能。