Kumagai K, Ushiki T, Tohyama K, Arakawa M, Ide C
Department of Anatomy, School of Medicine, Iwate Medical University, Morioka, Japan.
J Electron Microsc (Tokyo). 1990;39(2):108-14.
A predenervated sciatic nerve segment, which had been treated by repeated freezing and thawing to kill Schwann cells, was grafted to the original sciatic nerve in the rat. Three to five days later, the graft was chemically fixed and treated by KOH-collagenase digestion, a treatment which selectively removes almost all non-cellular elements including the collagen fibrils and basal laminae from the tissue, thus making it possible to observe regenerating axons by scanning electron microscopy. Debris of degraded Schwann cells and myelin sheaths remained in the form of "columns", and several thick (2-3 microns in diameter) and thin (less than 1 micron in diameter) axons ran singly or in bundles on such "cell debris columns." Thick axons have an almost straight contour, while there were various swellings at intervals along the thin axons. In most cases, the growing tips of regenerating axons were swollen as growth cones ranging from 2 microns to 5 microns in diameter. Growth cones exhibited fusiform to polygonal variations in structure and had only a few filopodial processes on the surface.
将一段预先去神经支配的坐骨神经节段（该节段已通过反复冻融处理以杀死雪旺细胞）移植到大鼠的原坐骨神经上。三到五天后，将移植物进行化学固定，并用氢氧化钾 - 胶原酶消化处理，这种处理可选择性地从组织中去除几乎所有非细胞成分，包括胶原纤维和基膜，从而能够通过扫描电子显微镜观察再生轴突。降解的雪旺细胞和髓鞘碎片以“柱状”形式留存，几条粗（直径2 - 3微米）细（直径小于1微米）的轴突单独或成束地在这些“细胞碎片柱”上延伸。粗轴突轮廓几乎笔直，而细轴突沿线有间隔的各种肿胀。在大多数情况下，再生轴突的生长尖端肿胀成直径为2微米至5微米的生长锥。生长锥结构呈现梭形到多边形的变化，表面只有少数丝状伪足突起。
