Steffensen I, Dulin M F, Walters E T, Morris C E
Neurosciences, Loeb Institute, University of Ottawa, Ontario, Canada.
J Exp Biol. 1995 Oct;198(Pt 10):2067-78. doi: 10.1242/jeb.198.10.2067.
Morphological methods were used to examine injury-induced growth of peripheral and central axons of nociceptive mechanosensory neurones in the ventrocaudal (VC) clusters of the pleural ganglia of Aplysia californica. Pedal nerve crush transected all axons in the nerve while leaving the overlying sheath largely intact. Immunohistochemical staining was performed with an antibody to a sensory-neurone-specific peptide, sensorin-A. Following bilateral crush of pedal nerve p9, which innervates the tail, sensorin-A immunofluorescence was lost distal to the crush site within 2 days. Fine immunopositive fibres began to invade the crush region within 5 days. These fibres arborized in the crush region and gradually extended down the crushed nerve. Immunopositive fibres were found near the tail within 3 weeks. Similar results were obtained after injecting individual sensory neurone somata in the tail/p9 region of the VC cluster with biocytin. Biocytin injections and horseradish peroxidase injections 3 weeks after ipsilateral pedal nerve crush revealed new fibres projecting rostrally from the tail/p9 region of the VC cluster and entering the pleural-cerebral and pleural-abdominal connectives. Such projections were never observed in control, uncrushed preparations. These results demonstrate that nerve injury triggers extensive growth of both peripheral and central processes of the VC sensory neurones.
运用形态学方法，研究了加利福尼亚海兔胸膜神经节腹尾（VC）簇中伤害性机械感觉神经元外周和中枢轴突损伤诱导的生长情况。足神经挤压切断了神经中的所有轴突，同时使覆盖的神经鞘基本保持完整。使用针对感觉神经元特异性肽sensorin - A的抗体进行免疫组织化学染色。在双侧挤压支配尾部的足神经p9后，2天内挤压部位远端的sensorin - A免疫荧光消失。5天内，细小的免疫阳性纤维开始侵入挤压区域。这些纤维在挤压区域形成分支，并逐渐沿着挤压的神经向下延伸。3周内在尾部附近发现了免疫阳性纤维。在用生物胞素注射VC簇尾/p9区域的单个感觉神经元胞体后，也得到了类似的结果。同侧足神经挤压3周后进行生物胞素注射和辣根过氧化物酶注射，结果显示有新的纤维从VC簇的尾/p9区域向头端投射，并进入胸膜 - 脑和胸膜 - 腹连接部。在对照的未挤压标本中从未观察到这种投射。这些结果表明，神经损伤会触发VC感觉神经元外周和中枢突起的广泛生长。
