FATIGUE OF SEGMENTAL MOTOR MECHANISMS

描述（改编自申请人的摘要）：它是公认的 在各种正常和病理生理条件下， 肌肉疲劳的表现可归因于 从中枢神经系统（CNS）的前脑到收缩性 活动肌肉中的单纤维机械。 关于神经的知识 然而，疲劳的神经肌肉方面远不如 纯粹的肌肉机制。 这种不平衡是由 主要原因是需要获得更多关于 整个CNS中的IN和CNS内的MN的重复放电 大脑和脊髓 在这个建议中，重点是首先对重复点火性能的 脊髓运动神经元（MN）和腹角中间神经元（程度较轻） （INs）。 研究表明，通过获得更多的两个关键发射率信息， 特性，刺激电流（I）-尖峰频率（f）的关系 MN和尖峰频率适配（即，随时间的f下降 和INs，应该可以提供对基本脊柱 与肌肉疲劳有关的机制。 接下来，将展示如何 关于导弹发射模式的信息对于开发这种力量具有重要意义 由新鲜和疲劳的肌肉中的运动单位产生。 这涉及到考虑 I-f关系、尖峰频率 MN的适应，激活频率（f）-力（F）关系， 由MN提供的运动单元，以及由运动单元提供的F开发 随着时间 总体办法有两个具体目标。 首先，探索脊柱 神经调节的内在I-f关系的MN和 脊髓MN和IN的尖峰频率适应，然后使用MN 成分的结果，以探讨I-F关系和F下降 新鲜和疲劳肌肉运动单位的时间。 其目的是，这些研究将有助于基本信息， 肌肉疲劳的细胞神经生物学，因此，有助于 必须作为研究未来临床方法基础的科学依据 肌肉疲劳。 临床领域，如运动控制骨科， 运动控制康复、功能性电刺激和运动 修复术需要一个基础， 基础神经科学，特别是更深层次的 了解脊柱IN和MN的重复放电特性 被转化为运动在新鲜，疲劳和病理生理 states.

DESCRIPTION (Adapted from the Applicant's Abstract): It is well established that in a variety of normal and pathophysiological conditions, the manifestation of muscle fatigue is attributable to mechanisms that extend from the forebrain of the central nervous system (CNS) to the contractile machinery of single fibers in active muscles. Knowledge about the neural and neuromuscular aspects of fatigue is, however, far less complete than that about purely muscular mechanisms. This imbalance is attributable largely to the need to gain more information on the mechanisms underlying the repetitive firing of INs throughout the entire CNS, and of MNs within the brain and spinal cord. In this proposal, the focus is first on the repetitive firing properties of spinal motoneurons (MNs) and, to lesser extent, ventral-horn interneurons (INs). It is shown that by gaining more information on two key firing-rate properties, the stimulus current (I) -spike-frequency (f) relationship of MNs and the spike frequency adaptation (i.e., the f drop over time) of MNs and INs, it should be possible to provide insight into fundamental spinal mechanisms associated with muscle fatigue. Next, it is shown how information on MN firing patterns has significance for the force developed by motor units in fresh and fatigued muscle. This involves consideration of the associations between the I-f relationship, the spike-frequency adaptation of MNs, the activation frequency (f) -force (F) relationship of the motor units supplied by the MNs, and the F development by motor units over time. The overall approach, has two specific aims. First, to explore the spinal neuromodulation of the intrinsic I-f relationship of MNs and the spike-frequency adaptation of spinal MNs and INs, and, next, to use the MN component of the results to explore the I-F relationship and F drop over time of motor units in fresh and fatigued muscle. The intent is that these studies will contribute fundamental information on the cellular neurobiology of muscle fatigue and as such, contribute to the scientific basis that must underlie future clinical approaches to the study of muscle fatigue. Clinical fields like motor-control orthopedics, motor-control rehabilitation, functional electrical stimulation and motor prosthetics require a foundation that includes a substantial component of fundamental neuroscience including, in particular, a far deeper understanding of how the repetitive firing properties of spinal INs and MNs are translated into movement in fresh, fatigued and pathophysiological states.