Sympathetic-somatomotor coupling in human SCI

描述（由申请人提供）：在不完全性脊髓损伤（SCI）患者中，对肌肉活动期间心血管系统的调节知之甚少。过去，在SCI中，躯体运动和交感神经控制的中断被分别研究。我们建议研究交感神经和躯体运动控制的耦合，因为它与旨在改善躯体运动功能或增强体能的运动训练范式有关。我们的方法将是测量肌腱敲击反射，随意肌肉激活，以及膝盖（受伤以下）和肘部（受伤以上）的血流量之前和之后的交感神经刺激，包括冷加压试验，心理数学和急性运动。这些数据将提供有关肌肉活动期间交感神经控制血流的信息。交感神经-躯体运动神经耦合的可塑性也将通过在跑步机训练锻炼计划之前和之后进行测量来研究。这些实验将使我们能够实现三个目标。目的1将是表征交感神经和躯体运动系统的耦合低于脊髓损伤的水平。这一目标将研究脊髓交感神经和运动反射及其相互作用。它还将研究如何下行躯体运动耦合被破坏的脊髓损伤。在目标2中，我们将确定脊髓损伤上方交感神经和躯体运动系统相互作用的变化。由于损伤和损伤下方发生的变化，交感神经-躯体运动耦合也可能在手臂中被破坏。目标3将展示运动训练后交感神经-躯体运动耦合的可塑性。将测试三种不同的八周运动训练计划，包括1）上身测力计，2）运动水平与上身测力计匹配的跑步机训练，以及3）心率与上身测力计初始测试匹配的跑步机训练。演习训练将受到考验 在一项随机交叉研究设计中，运动训练模式之间间隔三个月。我们预计，将有可塑性的交感-躯体运动耦合和运动训练的影响将正常化控制这些系统。然而，由于受伤，我们预计，适应将不同于非受伤的控制。这项研究对人类SCI的运动训练有一定的意义。交感神经系统和躯体运动系统的耦合预计取决于运动目标是上身还是下身。功能的恢复需要改善对运动的控制以及对流向活动肌肉群的血流的调节。此外，这项研究对于了解跑步机运动训练对心血管健康的潜在影响很重要，这是一个对身体活动受限的人越来越感兴趣的话题。

DESCRIPTION (provided by applicant): The regulation of cardiovascular systems during muscle activity is poorly understood in people with incomplete spinal cord injury (SCI). In the past, disruptions in somatomotor and sympathetic control have been investigated separately in SCI. We propose to investigate the coupling of sympathetic and somatomotor control because it is relevant to exercise training paradigms that are designed to improve somatomotor function or enhance physical fitness. Our approach will be to measure tendon tap reflexes, voluntary muscle activation, and blood flow of the knee (below injury) and elbow (above injury) before and after sympathetic stimuli consisting of cold pressor tests, mental math and an acute bout of exercise. These data will provide information about sympathetic control of blood flow during muscle activity. Plasticity of the sympathetic- somatomotor coupling will also be investigated by making measurements before and after a treadmill training exercise program. These experiments will enable us to address three aims. Aim 1 will be to characterize coupling of sympathetic and somatomotor systems below the level of spinal injury. This aim will examine spinal sympathetic and motor reflexes and their interactions. It will also examine how descending somatomotor coupling is disrupted by the spinal injury. In Aim 2, we will identify changes in the interactions of sympathetic and somatomotor systems above a spinal injury. Because of the injury and the changes that occur below the injury, the sympathetic-somatomotor coupling is also likely to be disrupted in the arm. Aim 3 will then demonstrate plasticity of sympathetic-somatomotor coupling after exercise training. Three different eight week exercise training programs will be tested including 1) upper body ergometry, 2) treadmill training with exertion level matched to the upper body ergometry and 3) treadmill training with heart rate matched to an initial test of upper body ergometry. The exercise training will be tested in a randomized crossover study design with three months between exercise training paradigms. We anticipate that there will be plasticity of sympathetic-somatomotor coupling and that the exercise training effects will normalize control of these systems. However, because of the injury, we anticipate that adaptations will differ from non-injured controls. This study has implications for exercise training in human SCI. The coupling of sympathetic and somatomotor systems is expected to depend on whether exercise targets the upper or lower body. The recovery of function requires both the improvement in the control of movement as well as in the regulation of blood flow to active muscle groups. In addition, this study is important for understanding the potential impact of treadmill exercise training on cardiovascular fitness, a topic of increasing interest in people with limitations to physical activity.