Mantilla Carlos B, Sieck Gary C
Department of Anesthesiology, Mayo Clinic, 4-184 W. Joseph SMH, 200 First St SW, Rochester, MN 55905, USA.
Respir Physiol Neurobiol. 2008 Dec 10;164(1-2):252-62. doi: 10.1016/j.resp.2008.07.018.
The function of a motor neuron and the muscle fibers it innervates (i.e., a motor unit) determines neuromotor output. Unlike other skeletal muscles, respiratory muscles (e.g., the diaphragm, DIAm) must function from birth onwards in sustaining ventilation. DIAm motor units are capable of both ventilatory and non-ventilatory behaviors, including expulsive behaviors important for airway clearance. There is significant diversity in motor unit properties across different types of motor units in the DIAm. The mechanisms underlying the development and maintenance of motor unit diversity in respiratory muscles (including the DIAm) are not well understood. Recent studies suggest that trophic factor influences contribute to this diversity. Remarkably little is known about the expression of trophic factors and their receptors in phrenic motor neurons. This review will focus on the contribution of trophic factors to the establishment and maintenance of motor unit diversity in the DIAm, during development and in response to injury or disease.
运动神经元及其所支配的肌纤维（即一个运动单位）的功能决定了神经运动输出。与其他骨骼肌不同，呼吸肌（如膈肌）从出生起就必须发挥作用以维持通气。膈肌运动单位能够进行通气和非通气行为，包括对气道清理很重要的排出行为。膈肌中不同类型的运动单位在运动单位特性方面存在显著差异。呼吸肌（包括膈肌）中运动单位多样性的发育和维持所涉及的机制尚未得到充分理解。最近的研究表明，营养因子的影响促成了这种多样性。关于神经营养因子及其受体在膈运动神经元中的表达，人们所知甚少。本综述将聚焦于营养因子在膈肌运动单位多样性的建立和维持过程中，在发育期间以及对损伤或疾病的反应中所起的作用。
