Corticospinal transmission in human subjects

皮质脊髓通路是从大脑到脊髓控制人的自主运动的主要途径。很少有人知道如何通过这一途径的传输可能会改变活动。众所周知，在大脑的其他地方，神经细胞之间的连接可以通过特定的活动模式变得更强或更弱，并且这种变化被认为是学习和记忆的基础。我们认为，类似的变化可能发生在脊髓中，在神经细胞之间的连接处，这些神经细胞从大脑传递信号，而神经细胞将信号传递到肌肉。该项目将证明，从大脑到肌肉的通路中的连接可以通过强加的活动模式以受控的方式加强或减弱。此外，我们知道，在自主收缩后，这条通路中的信号传递到肌肉的方式发生了巨大的变化。在短暂的强烈自主收缩后，肌肉反应立即减少。经过较长时间的收缩，肌肉变得疲劳，减少之后是反应的增加，可以持续数分钟。因此，该项目还将研究自然活动后从大脑到肌肉的通路的变化。还将研究人工或自然活动引起的变化对随意运动控制的影响。了解活动如何驱动控制随意运动的通路的变化对于涉及学习运动任务的所有情况都很重要。这些包括运动技能的正常发育和学习，以及各种神经或肌肉损伤后的康复。这对于理解运动变化也很重要，当运动因脊髓损伤或中风等疾病而改变时，运动变化就会发生。对发生过程的更好理解应该可以改善康复治疗。

The corticospinal pathway is the major route from the brain to the spinal cord for the control of voluntary movement in people. Little is known about how transmission through this pathway might alter with activity. It is known that, elsewhere in the brain, connections between nerve cells can be made stronger or weaker by specific patterns of activity and it is thought that such changes underlie learning and memory. We propose that similar changes might happen in the spinal cord at the connection between the nerve cells which carry signals from the brain and the nerve cells which carry the signals out to the muscle. This project will demonstrate that the connections in the pathway from the brain to the muscle can be strengthened or weakened in a controlled way by imposed patterns of activity. In addition, we know that after voluntary contractions, there are dramatic changes in the way signals in this pathway are transmitted to muscles. After brief strong voluntary contractions, muscle responses are immediately reduced. After longer contractions in which the muscles become fatigued, the reduction is followed by an increase in responses which can last many minutes. Thus, this project will also study changes in the pathway from the brain to the muscle after natural activity. The effects of changes induced by artificial or natural activity on the control of voluntary movement will also be investigated. Understanding how activity drives changes in the pathway that controls voluntary movement is important for all situations that involve learning motor tasks. These include normal development and learning of motor skills, as well as rehabilitation after all kinds of nerve or muscle injury. It is also important in understanding motor changes that occur when activity is altered by disorders like spinal cord injury or stroke. Improved understanding of the processes occuring should allow improvement in rehabilitation therapies.