中文摘要：

目的：观察坐骨神经结扎后神经生长因子（NGF）在背根神经节的表达变化。方法：健康SD大鼠随机分为正常对照组、假手术对照组和坐骨神经结扎组，实验组结扎后分别存活1、3、5、7、14、21、28d，取腰4～6背根神经节（DRG），行NGF免疫组织化学显色结合图像分析技术分析其表达变化。结果：结扎后1d DRG NGF表达无明显变化；3d开始下降，7d达最低值，持续到21d；28d恢复正常。结论：神经结扎后DRG神经元NGF表达变化可能参与了神经损伤后的可塑性。

英文摘要：

Objective： To study the expression changes of nerve growth factor （NGF） in dorsal root ganglion （DRG） after sciatic nerve ligation in rats. Methods： Totally 45 healthy adult Sprague-Dawley rats were randomly divided into a normal group, a sham-operation group and an experimental group, and respectively survived for 1, 3, 5, 7, 14, 21 and 28 d after sciatic nerve ligation （at each time point）. The distribution and changes of NGF in L46 DRG were detected by irnmuno-staining. Then the gray scale values of NGF-immunopositive products were analyzed. Results： No change in NGF expression was found in DRG neurons after sciatic nerve ligation at 1 d. However, it began to drop at 3 d, then peaked at 7 d and lasted to 21 d after ligation. At 28 d after ligation, the expression of NGF returned to normal in DRG neurons. Conclusion： Present results suggest that expression changes of NGF in DRG neurons may be involved in the neuronal plasticity after nerve injury.