Corticospinal and vestibulospinal control of motor actions

运动动作的皮质脊髓和前庭脊髓控制

• 批准号: RGPIN-2018-06498
• 负责人: Levin, Mindy
• 金额: $ 2.4万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=657374
• 关键词: Corticospinal; vestibulospinal; control; motor; actions

The controversy between 2 major theories of motor control creates uncertainty in the understanding of basic principles and interferes with progress in behavioral neuroscience. One theory suggests that the brain pre-programs movement trajectories and motor commands pre-computed by internal models of the system. The other theory suggests that motor control is accomplished parametrically, without computations, by changing threshold positions of body segments at which motoneuronal recruitment begins. According to the latter, the brain shifts the balance (attractor point) of the system and converts posture-stabilizing reflexes and intrinsic muscle properties into movement-producing mechanisms such that motor commands emerge without computations. Objective 1 of the program is to help resolve the controversy through experiments directly designed to test hypotheses of each approach. Objective 2 is to determine the role of different descending systems in the control of whole-body postures and movements (i.e., corticospinal (CS) and vestibulospinal (VS) systems). Hypothesis 1 is that the CS system mainly controls the body configuration in a task-specific way in the limits pre-determined by the VS system. The latter is responsible for motor equivalency – reaching the motor goal regardless of the number of body segments involved (Hypothesis 2) and for the appropriate orientation of body posture and movement in the gravitational field (Hypothesis 3). VS and CS influences will be evaluated using transcranial magnetic stimulation of the motor cortex and galvanic vestibular stimulation during arm motion with or without trunk in sitting subjects and during forward body leaning in standing subjects (4 tasks). Objective 3 is to elaborate a new diagnostic tool − a portable ultrasound-based device for evaluation of VS deficits in patients with neurological movement problems. The device will be evaluated in arm reaching movements with and without trunk involvement (Task 5). The resolution of the controversy between two major theories of motor control (Objective 1) and progress in the understanding of functional differences between the VS and CS systems (Objective 2) will advance basic science of motor control, affect the way we teach students in behavioral neuroscience, help clinicians assess and treat neurological motor deficits (Objective 3), and provide an example of applying results of basic science to engineering and health research in Canada.

运动控制的两种主要理论之间的争论造成了对基本原理理解的不确定性，并干扰了行为神经科学的进展。一种理论认为，大脑预先编程了由系统内部模型预先计算的运动轨迹和运动命令。另一种理论认为，运动控制是通过改变运动神经元募集开始的身体部位的阈值位置来参数化地完成的，而不需要计算。根据后者，大脑改变了系统的平衡（吸引点），并将姿势稳定反射和内在肌肉特性转化为运动产生机制，从而无需计算即可产生运动命令。该计划的目标1是通过直接设计来测试每种方法的假设的实验来帮助解决争议。目的2是确定不同下行系统在控制全身姿势和运动中的作用（即，皮质脊髓（CS）和前庭脊髓（VS）系统）。假设1是CS系统主要在VS系统预先确定的范围内以特定于任务的方式控制身体构型。后者负责运动等效性-达到运动目标，而不管涉及的身体部分的数量（假设2）和身体姿势和运动在重力场中的适当方向（假设3）。在坐位受试者有或无躯干的手臂运动期间和站立受试者身体前倾期间（4项任务），将使用运动皮层的经颅磁刺激和前庭电刺激评价VS和CS影响。目标3是阐述一种新的诊断工具-一种便携式超声设备，用于评估神经运动问题患者的VS缺陷。将在累及和不累及躯干的手臂伸展运动中评价器械（任务5）。运动控制两大理论之争的解决（目标1）以及对VS和CS系统之间功能差异的理解进展（目标2）将推进运动控制的基础科学，影响我们教授学生行为神经科学的方式，帮助临床医生评估和治疗神经运动缺陷（目标3），并提供了一个例子，应用基础科学的成果，在加拿大的工程和卫生研究。