Division of Plastic Surgery, Department of Surgery, Washington University School of Medicine, St Louis, Missouri.
Department of Neurosurgery, Washington University School of Medicine, St Louis, Missouri.
Muscle Nerve. 2019 Nov;60(5):604-612. doi: 10.1002/mus.26654. Epub 2019 Aug 23.
In this study we present a reproducible technique to assess motor recovery after nerve injury via neuromuscular junction (NMJ) immunostaining and electrodiagnostic testing.
Wild-type mice underwent sciatic nerve transection with repair. Hindlimb muscles were collected for microscopy up to 30 weeks after injury. Immunostaining was used to assess axons (NF200), Schwann cells (S100), and motor endplates (α-bungarotoxin). Compound motor action potential (CMAP) amplitude was used to assess tibialis anterior (TA) function.
One week after injury, nearly all (98.0%) endplates were denervated. At 8 weeks, endplates were either partially (28.3%) or fully (71.7%) reinnervated. At 16 weeks, NMJ reinnervation reached 87.3%. CMAP amplitude was 83% of naive mice at 16 weeks and correlated with percentage of fully reinnervated NMJs. Morphological differences were noted between injured and noninjured NMJs.
We present a reproducible method for evaluating NMJ reinnervation. Electrodiagnostic data summarize NMJ recovery. Characterization of wild-type reinnervation provides important data for consideration in experimental design and interpretation.
本研究通过神经肌肉接头（NMJ）免疫染色和电诊断测试，提供了一种可重现的评估神经损伤后运动功能恢复的技术。
野生型小鼠进行坐骨神经切断修复。损伤后 30 周内采集后肢肌肉进行显微镜检查。免疫染色用于评估轴突（NF200）、施万细胞（S100）和运动终板（α-银环蛇毒素）。使用复合运动动作电位（CMAP）幅度评估胫前肌（TA）功能。
损伤后 1 周，几乎所有（98.0%）终板均失神经支配。8 周时，终板部分（28.3%）或完全（71.7%）再支配。16 周时，NMJ 再支配率达到 87.3%。16 周时，CMAP 幅度为正常小鼠的 83%，与完全再支配 NMJ 的百分比相关。损伤和未损伤 NMJ 之间存在形态差异。
我们提出了一种可重现的评估 NMJ 再支配的方法。电诊断数据总结了 NMJ 的恢复情况。野生型再支配的特征为实验设计和解释提供了重要数据。
