Neural Regeneration Laboratory, Department of Neurosurgery, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan.
Restor Neurol Neurosci. 2011;29(4):265-74. doi: 10.3233/RNN-2011-0597.
Nerve root traction injuries induce spinal cord inflammation and lead to neuronal death within days. In the present study, we examined the inflammatory response one week after multiple cervical root transections.
In the transection group, the left cervical roots (C6-8) of rats were cut at the spinal cord junction. In the repair group, transected roots were repaired with nerve grafts and the subsequent application of aFGF and fibrin glue. A sham group had nerve roots exposed without transection. Mechanical allodynia and spinal glial responses were evaluated.
Allodynia did not differ between the treatment groups on day 2. Rats with transected spinal nerve roots had significantly more allodynia by 7 days, which was associated with IL-1β expression in dorsal and ventral horn astrocytes, and microglia activation. Repair of nerve roots with autologous intercostal nerve grafts and FGF in fibrin glue attenuated the allodynia, reduced IL-1β expression in astroctyes and reduced microglia activation, along with a significant increase in arginase I expression.
This study demonstrated a correlation between an increased number of IL-1β-positive astrocytes and the development of allodynia. Our treatment significantly decreased IL-1β-positive astrocytes, thus preventing the occurrence of neuropathic pain following multiple cervical root injuries.
神经根牵引损伤会引发脊髓炎症，并在数天内导致神经元死亡。在本研究中，我们研究了多发颈椎神经根切断术后一周的炎症反应。
在切断组中，大鼠左侧颈椎神经根（C6-8）在脊髓连接处被切断。在修复组中，切断的神经根用神经移植物修复，并随后应用 aFGF 和纤维蛋白胶。假手术组暴露神经根而不切断。评估机械性痛觉过敏和脊髓神经胶质反应。
在第 2 天，治疗组之间的痛觉过敏没有差异。切断脊髓神经的大鼠在 7 天时痛觉过敏明显增加，这与背角和腹角星形胶质细胞中的 IL-1β表达以及小胶质细胞激活有关。用自体肋间神经移植物和纤维蛋白胶中的 FGF 修复神经根减轻了痛觉过敏，减少了星形胶质细胞中的 IL-1β表达，并减少了小胶质细胞激活，同时 Arg1 表达显著增加。
本研究表明，IL-1β阳性星形胶质细胞数量的增加与痛觉过敏的发生有关。我们的治疗显著减少了 IL-1β阳性星形胶质细胞，从而防止多发颈椎神经根损伤后发生神经病理性疼痛。
