Scott C, Perry M J, Raven P E, Massey E J, Lisney S J
Johnson and Johnson Research, The Australian Technology Park, Eveleigh, NSW, Australia.
Neuroscience. 2000;95(2):535-41. doi: 10.1016/s0306-4522(99)00444-3.
The aim of the present study was to investigate changes in contralateral nerves associated with peripheral nerve injuries. Transection and subsequent regeneration of the saphenous nerve on one side caused a suppression of the ability of the contralateral saphenous nerve to produce a neurogenic plasma extravasation response. This effect was transient, and was first evident two weeks after injury, reaching its maximum at four weeks, but was no longer detectable at eight weeks. This change was paralleled by a decrease in the content of substance P, a neuropeptide involved in neurogenic plasma extravasation, in the contralateral nerve. The neurotoxin capsaicin was used to deplete the nerve of a subclass of C-fibres, namely the polymodal nociceptor afferents. Pretreatment of the nerve to be lesioned with capsaicin was sufficient to significantly attenuate the changes in the plasma extravasation response and substance P content observed on the contralateral side. The effectiveness of the capsaicin treatment was confirmed by histological examination. These results strongly suggest that changes observed at a site distant from the location of the nerve injury are dependent on the integrity of capsaicin-sensitive C-fibre afferents within the injured nerve. Furthermore, given that the contralateral nerve has commonly been used as the control for an injury conducted on the homologous nerve or muscle on the opposite side of the body, the underlying assumption being that the contralateral nerve remained unchanged, the present findings emphasize the need for separate groups of control animals which have undergone no surgical procedures.
本研究的目的是调查与周围神经损伤相关的对侧神经的变化。一侧隐神经的横断及随后的再生导致对侧隐神经产生神经源性血浆外渗反应的能力受到抑制。这种效应是短暂的，在损伤后两周首次显现，四周时达到最大，但在八周时不再可检测到。这种变化与对侧神经中P物质（一种参与神经源性血浆外渗的神经肽）含量的减少平行。神经毒素辣椒素被用于耗尽神经中的一类C纤维，即多模式伤害感受器传入纤维。用辣椒素预处理待损伤的神经足以显著减弱对侧观察到的血浆外渗反应和P物质含量的变化。辣椒素治疗的有效性通过组织学检查得到证实。这些结果强烈表明，在远离神经损伤部位观察到的变化取决于损伤神经内辣椒素敏感的C纤维传入纤维的完整性。此外，鉴于对侧神经通常被用作身体另一侧同源神经或肌肉损伤的对照，潜在的假设是对侧神经保持不变，目前的研究结果强调需要有未接受任何手术操作的单独对照组动物。
