Allgood JuliAnne E, Roballo Kelly C Santos, Sparks Bridger B, Bushman Jared S
Division of Pharmaceutical Sciences, University of Wyoming, Laramie, WY, United States.
Front Cell Neurosci. 2022 Nov 14;16:1055490. doi: 10.3389/fncel.2022.1055490. eCollection 2022.
Segmental peripheral nerve injuries (PNI) are the most common cause of enduring nervous system dysfunction. The peripheral nervous system (PNS) has an extensive and highly branching organization. While much is known about the factors that affect regeneration through sharp bisections and linear ablations of peripheral nerves, very little has been investigated or documented about PNIs that ablate branch points. Such injuries present additional complexity compared to linear segmental defects. This study compared outcomes following ablation of a branch point with branched grafts, specifically examining how graft source and orientation of the branched graft contributed to regeneration. The model system was Lewis rats that underwent a 2.5 cm ablation that started in the sciatic nerve trunk and included the peroneal/tibial branch point. Rats received grafts that were rat sciatic autograft, inbred sciatic allograft, and inbred femoral allograft, each of which was a branched graft of 2.5 cm. Allografts were obtained from Lewis rats, which is an inbred strain. Both branches of the sciatic grafts were mixed motor and sensory while the femoral grafts were smaller in diameter than sciatic grafts and one branch of the femoral graft is sensory and the other motor. All branched grafts were sutured into the defect in two orientations dictated by which branch in the graft was sutured to the tibial vs peroneal stumps in recipients. Outcome measures include compound muscle action potentials (CMAPs) and CatWalk gait analysis throughout the recovery period, with toluidine blue for intrinsic nerve morphometry and retrograde labeling conducted at the 36-week experimental end point. Results indicate that graft source and orientation does play a significant role earlier in the regenerative process but by 36 weeks all groups showed very similar indications of regeneration across multiple outcomes.
节段性周围神经损伤（PNI）是导致持久神经系统功能障碍的最常见原因。周围神经系统（PNS）具有广泛且高度分支的结构。虽然对于影响周围神经锐性横断和线性切除后再生的因素已有很多了解，但对于切除分支点的PNI的研究和记录却很少。与线性节段性缺损相比，此类损伤呈现出额外的复杂性。本研究比较了用分支移植物切除分支点后的结果，特别研究了移植物来源和分支移植物的方向如何促进再生。模型系统是Lewis大鼠，其坐骨神经干进行了2.5厘米的切除，包括腓总神经/胫神经分支点。大鼠接受的移植物有大鼠坐骨自体移植物、近交系坐骨同种异体移植物和近交系股同种异体移植物，每种都是2.5厘米的分支移植物。同种异体移植物取自Lewis大鼠，这是一个近交系。坐骨移植物的两个分支均为混合运动和感觉神经，而股移植物的直径小于坐骨移植物，股移植物的一个分支是感觉神经，另一个是运动神经。所有分支移植物均以两种方向缝合到缺损处，这取决于移植物中的哪个分支缝合到受体的胫神经与腓总神经残端。结果测量包括在整个恢复期的复合肌肉动作电位（CMAP）和CatWalk步态分析，在实验终点36周时用甲苯胺蓝进行固有神经形态测量和逆行标记。结果表明，移植物来源和方向在再生过程的早期确实起着重要作用，但到36周时，所有组在多个结果上都显示出非常相似的再生迹象。
