【摘要】 目的:研究大鼠脊髓损伤后不同时间点坐骨神经兴奋阈值、动作电位(AP)幅度和传导速度,以及损伤脊髓GAP-43蛋白表达的改变。方法:采用改良的Allen′s重物坠落致大鼠脊髓损伤实验模型、电生理学和免疫组织化学染色。结果:大鼠SCI后1、3、7 d时,坐骨神经兴奋阈值升高,AP幅度和传导速度降低,呈时间依赖性改变;SCI后14 d,AP产生阈值、幅度和传导速度较SCI第7 d有所恢复。正常大鼠脊髓灰质神经元的胞浆和轴突中有少量GAP-43蛋白表达;SCI后第1、3、5、7 d时损伤脊髓周围区灰质GAP-43蛋白表达逐渐增强;在SCI后第14 d其阳性表达开始减弱。结论:大鼠SCI后能够导致坐骨神经电生理学兴奋性和传导性的降低,以及神经结构重构蛋白GAP-43表达增加。更多还原

【Abstract】 Objective: To investigate the changes of threshold,amplitude and conduction velocity of the action potential(AP) in the sciatic nerve and the expression of GAP-43 protein in rats with spinal cord injury(SCI).Methods: Electrophysiological and immunohistochemistry techniques were used in experimental rats that were induced by the Allen’s spinal cord weight-drop-injury method.Results: The increase of threshold, the decrease of amplitude and conduction velocity of AP in the sciatic nerve showed a time-dependent manner at 1 d,3 d and 7 d following SCI.However,the above changes attenuated at 14 d following SCI.Expression of GAP-43 proteins progressively increased at 1 d,3 d,and 7 d following SCI,and reached a peak at the 7th d.Conclusion: The excitability and conductibility of the sciatic nerve degrade and the expression of GAP-43 protein increases following SCI in rats.更多还原