目的观察大鼠马尾神经受压后脊髓圆锥神经元的形态变化,检测脊髓神经元凋亡数量及脑源性神经营养因子(BDNF)mRNA的表达,以及探讨上述变化的可能机制。方法将90只成年SD大鼠分为马尾受压模型组、假手术组与正常对照组,分别于造模术后30min、2h、4h、8h、1d、3d、1周、2周、3周取样。采用光镜与透射电镜观察马尾受压后脊髓圆锥神经细胞的形态变化;采用原位缺口末端标记(TUNEL)技术检测细胞凋亡;原位杂交法测定BDNF mRNA阳性细胞的数量。计算单位面积内的阳性细胞数,单因素方差分析比较马尾受压后不同时间组与对照组之间的差异。结果马尾神经受压可导致脊髓圆锥神经元形态结构出现明显伤害性改变。TUNEL染色与BDNF mRNA原位杂交显示,阳性细胞分别于制模术后8h、4h起较对照组有明显增多,并于术后3d达高峰,术后3周上述阳性细胞的数量仍明显高于对照组。结论马尾神经受压后,可导致相应脊髓圆锥神经细胞结构的明显变化,其凋亡数量明显增加,说明马尾受损可导致中枢神经元的不可逆损伤,这可能是马尾综合征逾期手术效果不理想的重要原因之一。在马尾严重受压后,神经元及胶质细胞的BDNFmRNA的表达明显增加,可能对神经细胞的保护及修复起一定作用。 Objective To observe the morphological changes of spinal conical neurons after cauda equina compression in rats and to detect the number of neurons in spinal cord and the expression of brain derived neurotrophic factor (BDNF) mRNA, and to explore the possible mechanism. Methods Ninety adult Sprague-Dawley rats were divided into three groups: the cauda equina compression model group, the sham operation group and the normal control group at 30 min, 2 h, 4 h, 8 h, 1 d, 3 d, sampling. Morphological changes of spinal coned nerve cells were observed under light and transmission electron microscopy. Apoptosis was detected by TUNEL. The number of BDNF mRNA positive cells was determined by in situ hybridization. Calculate the number of positive cells per unit area, single-factor analysis of variance after cauda equina pressure compared to different time groups and control group differences. Results Horsetail nerve compression can cause significant damage to the morphological structure of the spinal cord conical neurons. TUNEL staining and BDNF mRNA in situ hybridization showed that the number of positive cells increased significantly from 8h and 4h after operation in model group and peaked at 3d postoperatively respectively. The number of positive cells was still significantly higher than that at 3 weeks after operation Control group. Conclusions The cauda equina nerve compression can lead to significant changes in the structure of the corresponding spinal cord conic nerve cells, the number of apoptotic significantly increased, indicating that cauda equina injury can lead to irreversible damage to the central neurons, which may be due to overdue phentosis surgery results are not satisfactory One of the important reasons. After severe cauda equina compression, BDNF mRNA expression in neurons and glial cells significantly increased, which may play a role in the protection and repair of nerve cells.