The Human Motor Output Map

人体运动输出图

• 批准号: 9188215
• 负责人: Charles Heckman
• 金额: $ 47.76万
• 依托单位: NORTHWESTERN UNIVERSITY AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-07-01 至 2021-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9188215
• 关键词: Anatomy; Behavior; Brain Stem; Cells; Computer software; Data; Development; Disease; Distal; Electrodes; Goals; Hand; Human; Human body; Intramuscular; Investigation; Isometric Exercise; Joints; Leg; Light; Link; Maps; Measures; Methods; Motor; Motor Neurons; Motor output; Movement; Muscle; Muscle Fibers; Musculoskeletal; Musculoskeletal System; Neuraxis; Norepinephrine; Pattern; Physiological; Play; Population; Positioning Attribute; Process; Protocols documentation; Role; Sensory; Serotonin; Skin; Spinal cord injury; Structure; Surface; Synapses; Torque; Variant; arm; base; design; improved; insight; motor control; muscular structure; neuroregulation; novel; research study; sensory feedback

PROJECT SUMMARY/ABSTRACT All motor output is generated by motoneurons and consequently their firing patterns contain detailed information about the structure of motor commands. Remarkably, this information is accessible in humans, because motoneuron spikes are 1 to 1 with those of their muscle fibers. Our overall concept is that motoneuronal firing patterns vary systematically across the muscles of the human body and that this variation reflects fundamental connections between the synaptic organization of motor commands, the structure of the musculoskeletal system and the diversity of motor tasks. To understand these connections, our overall goal is to create a detailed “motor output map” of the human body, using newly developed array electrodes. The array electrodes are placed on the skin and are capable of measuring the firing patterns of up to 30 motor units simultaneously in the underlying muscle. We plan further technical development of these arrays to expand the range of motor tasks they can be used for. The human motor output map will be created from the analysis of firing patterns of populations of motor units in muscles throughout the body for matched motor tasks. We will interpret the resulting map in light of our recent advances in understanding of how firing patterns of motoneurons are determined by the organization of their synaptic inputs. The effects of excitatory and inhibitory inputs on firing patterns are fundamental for generating firing patterns, but neuromodulatory inputs from the brainstem are equally if not more important. These neuromodulatory inputs release serotonin and norepinephrine, which have a profound influence on the intrinsic excitability of motoneurons and thus control how motoneurons process their excitatory and inhibitory inputs. In Aim 1, we create a basic version of the human motor output map by asking subjects to generate slow linear increases and decreases in torque for more than 20 muscles across the body. The protocol is kept exactly the same across muscles to allow comparisons of the resulting firing patterns. Our primary hypothesis is that muscles involved in stabilization of the body, such as proximal muscles, will generate motor unit firing patterns consistent with high levels of neuromodulatory drive, while muscles involved more in precision tasks will generate patterns consistent with low levels of neuromodulation. These experiments are essentially function anatomy, the proximal-distal variations in firing patterns probably arise from differences in the anatomical projections of synaptic inputs to motor pools. In Aim 2, we assess whether there are task dependent changes in firing patterns, such as increases in neuromodulation drive with increased effort and increases in sensory inhibition with movement. Taken together, these experiments will define the fundamental structure of motor output for the human musculoskeletal structure and provide a quantitative basis for understanding the distortions that occur in disease states like spinal cord injury.

项目概要/摘要 所有运动输出均由运动神经元产生，因此它们的放电模式包含详细的 有关运动命令结构的信息。值得注意的是，人类可以获取这些信息， 因为运动神经元的尖峰与其肌纤维的尖峰是1比1的。我们的总体理念是 人体肌肉的运动神经元放电模式有系统地变化，并且这种变化 反映了运动命令的突触组织、神经突触结构之间的基本联系 肌肉骨骼系统和运动任务的多样性。为了理解这些联系，我们的总体目标是 使用新开发的阵列电极创建详细的人体“运动输出图”。数组 电极放置在皮肤上，能够测量多达 30 个运动单位的放电模式 同时在下面的肌肉中。我们计划对这些阵列进行进一步的技术开发，以扩大 它们可用于执行一系列运动任务。人体运动输出图将通过分析创建 全身肌肉中运动单位群的放电模式，以执行匹配的运动任务。我们将 根据我们最近在理解发射模式如何进行方面取得的进展来解释所得的地图 运动神经元由其突触输入的组织决定。兴奋性和兴奋性的影响 对放电模式的抑制输入是产生放电模式的基础，但神经调节输入 来自脑干的作用即使不是更重要，也同样重要。这些神经调节输入释放血清素并 去甲肾上腺素，对运动神经元的内在兴奋性有深远的影响，从而控制 运动神经元如何处理其兴奋性和抑制性输入。在目标 1 中，我们创建了一个基本版本 人体运动输出图，要求受试者产生缓慢的线性增加和减少扭矩 全身有20多块肌肉。该协议在肌肉之间保持完全相同，以允许 所产生的射击模式的比较。我们的主要假设是肌肉参与稳定 身体，例如近端肌肉，将产生与高水平一致的运动单位发射模式 神经调节驱动，而更多参与精确任务的肌肉将产生与 神经调节水平低。这些实验本质上是功能解剖学，近端-远端 放电模式的变化可能是由于突触输入的解剖学投影的差异引起的 电机池。在目标 2 中，我们评估激发模式是否存在任务相关的变化，例如 神经调节驱动随着努力的增加而增加，感觉抑制随着运动的增加而增加。 总而言之，这些实验将定义人类运动输出的基本结构 肌肉骨骼结构，并为理解发生的扭曲提供定量基础 脊髓损伤等疾病状态。