Spatial Distribution of Motor Endplates and its Adaptive Change in Skeletal Muscle
Spatial Distribution of Motor Endplates and its Adaptive Change in Skeletal Muscle
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骨骼肌运动终板的空间分布及其适应性变化
DOI：
10.7150/thno.28729
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发表时间：
2019-01-01
期刊：
影响因子：
12.4
通讯作者：
Jiang, Baoguo
中科院分区：
文献类型：
--
作者：
Yin, Xiaofeng;Yu, Tingting;Jiang, Baoguo
运动终板（MEPs）是周围神经与肌纤维之间的重要接口。对运动终板空间分布的研究有助于我们更好地理解神经肌肉功能活动，并改进相关疾病的诊断和治疗。
方法：注射荧光α - 银环蛇毒素以标记整装骨骼肌中的运动终板，采用组织光学透明技术结合光片显微镜研究野生型和转基因荧光小鼠不同骨骼肌中运动终板和肌内神经分支的空间分布。使用电生理学确定运动终板空间分布与肌肉功能之间的关系。
结果：首次获得了运动终板在整个骨骼肌中的精确三维分布。我们发现肌肉中的运动终板呈片状簇的有序模式分布，在片状区域之外没有运动终板。每个运动终板片层由一个独立的肌内神经分支支配，并介导一个独立的肌肉亚群收缩。此外，去神经后运动终板沿片状簇发生改变，再神经支配后恢复初始模式。运动终板的完整性和空间分布能够反映肌肉的功能状态。某个运动终板片层信号缺失可能提示肌肉某部分存在问题。
结论：运动终板片层簇可能是神经肌肉功能的基础，运动终板的空间分布可作为评估肌肉功能状态以及与运动终板相关的治疗靶点图的试验平台。
Motor endplates (MEPs) are the important interfaces between peripheral nerves and muscle fibers. Investigation of the spatial distribution of MEPs could help us better understand neuromuscular functional activities and improve the diagnosis and therapy of related diseases. Methods: Fluorescent α-bungarotoxin was injected to label the motor endplates in whole-mount skeletal muscles, and tissue optical clearing combined with light-sheet microscopy was used to investigate the spatial distribution of MEPs and in-muscle nerve branches in different skeletal muscles in wild-type and transgenic fluorescent mice. Electrophysiology was used to determine the relationship between the spatial distribution of MEPs and muscle function. Results: The exact three-dimensional distribution of MEPs in whole skeletal muscles was first obtained. We found that the MEPs in the muscle were distributed in an organized pattern of lamella clusters, with no MEPs outside the lamella zone. Each MEP lamella was innervated by one independent in-muscle nerve branch and mediated an independent muscle subgroup contraction. Additionally, the MEPs changed along the lamella clusters after denervation and regained the initial pattern after reinnervation. The integrity and spatial distribution of MEPs could reflect the functional state of muscles. The signal absence of a certain MEP lamella could suggest a problem in certain part of the muscle. Conclusions: The MEP lamella clusters might be the basis of neuromuscular function, and the spatial distribution of MEPs could serve as a testbed for evaluating the functional status of muscle and the therapeutic targeting map related to MEPs.