Verdu E, Navarro X
Department of Cell Biology and Physiology, Universitat Autonoma de Barcelona, Bellaterra, Spain.
Exp Neurol. 1997 Jul;146(1):187-98. doi: 10.1006/exnr.1997.6517.
In order to investigate the usefulness of immunohistochemical detection of regenerating axons as a correlate of functional recovery, reinnervation of mouse foot pads, hairy skin, and muscle were studied at several intervals along 3 months after sciatic nerve crush using immunohistochemical markers PGP 9.5 and CGRP. These histological results were compared with functional recovery of sweat glands (SGs), plantar muscles, and pain sensibility. One week after nerve injury all neural functions were abolished in the operated hindpaw of all mice, no CGRP-immunoreactive (-ir) fibers were seen in the samples studied, while PGP 9.5 immunofluorescence remained at dim levels within nerve trunks, but disappeared from terminal innervation. The first PGP 9.5- and CGRP-ir regenerating fibers were seen at 15-16 days postoperation (dpo) in dermal nerve trunks of dorsal hairy skin and some days later in dermal trunks of foot pads. Regenerating nerve fibers progressed along the periphery of the dermis reinnervating the different dermal appendages. At 25 dpo all target organs were reinnervated. The first SGs activated by pilocarpine reappeared by 16 dpo and increased in number to 88% of control counts. Nociceptive responses reappeared at 17 dpo and reached 100% of control values. The first PGP immunofluorescence in neuromuscular junctions was seen at 16 dpo, while the first muscle action potentials were recorded at 19 dpo, and the potentials amplitude increased to 66% of controls. Good correlations were found between morphological and functional results of reinnervation. However, the density and distribution of nerve profiles in the tissues studied did not reach normal levels, while neural functions conveyed by small fibers reached levels similar to controls.
为了研究免疫组织化学检测再生轴突作为功能恢复指标的实用性，在坐骨神经挤压伤后的3个月内，使用免疫组织化学标志物PGP 9.5和降钙素基因相关肽（CGRP），在几个时间点对小鼠脚垫、有毛皮肤和肌肉的神经再支配情况进行了研究。将这些组织学结果与汗腺（SGs）、足底肌肉的功能恢复以及痛觉敏感性进行了比较。神经损伤1周后，所有小鼠手术侧后爪的所有神经功能均消失，在所研究的样本中未见到CGRP免疫反应性（-ir）纤维，而PGP 9.5免疫荧光在神经干内仍处于暗淡水平，但在终末神经支配处消失。术后15 - 16天（dpo），在背部有毛皮肤的真皮神经干中首次见到PGP 9.5和CGRP免疫反应性再生纤维，几天后在脚垫的真皮神经干中也见到。再生神经纤维沿着真皮周边延伸，重新支配不同的真皮附属器。术后25天，所有靶器官均实现了神经再支配。毛果芸香碱激活的第一批汗腺在术后16天重新出现，数量增加至对照计数的88%。伤害性反应在术后17天重新出现，达到对照值的100%。神经肌肉接头处的第一批PGP免疫荧光在术后16天可见，而第一批肌肉动作电位在术后19天记录到，电位幅度增加至对照的66%。神经再支配的形态学和功能结果之间存在良好的相关性。然而，所研究组织中神经轮廓的密度和分布未达到正常水平，而小纤维传递的神经功能达到了与对照相似的水平。
