Plasticity of human motoneurone properties

人类运动神经元特性的可塑性

• 批准号: 105424-2006
• 负责人: Garland, Jayne
• 金额: $ 1.86万
• 依托单位: University of Western Ontario
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2007
• 资助国家: 加拿大
• 起止时间: 2007-01-01 至 2008-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=363304
• 关键词: Plasticity; human; motoneurone; properties

Motor control research using animal models has helped establish relations between properties of the motoneurone and the muscle fibers that it innervates.  In humans, Matthews (1996) developed a model for estimating one of the motoneurone properties (afterhyperpolarization (AHP) time-course).  This model represents one of the only windows to view the properties of motoneurones in humans.  The time-course of the AHP influences the capacity of the motoneurone to discharge action potentials and, thereby, the force produced by the muscle.  The adaptability of the AHP has not been thoroughly investigated in animal models and is virtually unexplored in humans.  The proposed research will determine the capacity of synaptic input to modify the time-course of the motoneurone AHP in humans.  We will study three synaptic inputs in separate experiments: cutaneous (skin) input, muscle spindle input, and input from group III-IV afferents activated by muscle fatigue.  Low-force contractions with the ankle dorsiflexor muscles (tibialis anterior) will be held for 30 min: 10 min before, during, and after the addition of synaptic input, with the motoneurone AHP being calculated in each phase from a train of motor unit potentials collected with a fine wire electrode.  Either a non- painful cutaneous stimulus will be applied to the skin overlying tibialis anterior, or vibration will be applied to the tibialis anterior tendon, or the muscle will be fatigued by performing a low-force contraction under ischemic conditions.  Healthy adult volunteers and volunteers with unilateral motor paresis after stroke will participate in the study.  This research program will advance our understanding of human motoneurone properties when they are activated voluntarily with both descending commands and sensory inputs.  This research will have far-reaching implications for motor control mechanisms that have not been investigated to date, primarily because the corresponding animal experiments do not involve voluntary contractions.  The acquired knowledge will contribute to our understanding of motor control disorders and whether sensory inputs may be useful in modifying motoneurone properties after a neurological insult, such as a stroke.

使用动物模型进行的运动控制研究有助于建立运动神经元特性与其所支配的肌肉纤维之间的关系，Matthews (1996) 在人类中开发了一种模型，用于估计运动神经元特性之一（超极化后 (AHP) 时程）。 ）。该模型是观察人类运动神经元特性的唯一窗口之一。​​AHP 的时间进程影响运动神经元的放电能力。动作电位以及肌肉产生的力 AHP 的适应性尚未在动物模型中得到彻底研究，并且实际上尚未在人类中进行探索。人类运动神经元 AHP 的时间进程。我们将在单独的实验中研究三种突触输入：皮肤输入、肌梭输入和由肌肉激活的 III-IV 组传入神经的输入踝背屈肌（胫骨前肌）的低力收缩将保持 30 分钟：在添加突触输入之前、期间和之后各 10 分钟，并根据运动单位电位序列计算每个阶段的运动神经元 AHP用细线电极收集。要么对胫骨前肌施加无痛的皮肤刺激，要么对胫骨施加振动​健康成年志愿者和中风后患有单侧运动麻痹的志愿者将参与这项研究，该研究项目将增进我们对人类运动神经元特性的理解。当它们通过下降命令和感觉输入自愿激活时。这项研究将对迄今为止尚未研究的运动控制机制产生深远的影响，主要是因为相应的动物实验不涉及自愿所获得的知识将有助于我们了解运动控制障碍和感觉输入是否有助于改变神经损伤（例如中风）后的运动神经元特性。