【摘要】 应用电镜定量方法观测猫单侧腰骶背根切除术后15天和30天脊髓L₅II板层内两类突触性终末数量,大小变化.因两组动物手术侧Ⅱ板层面积,Ⅱ板层神经毯面积分数,胞体和血管的面积分数末发生改变,两组动物非手术侧Ⅱ板层两类突触性终末数量无明显差民.直接比较了两组动物手术侧Ⅱ板层两类突触性终未数量及大小,术后15天组和30天组,手术侧复合终末（主要来源于背根的初级传入纤维）数量分别为非手术侧的36%和51%,30天组明显高于15天组,复合终末数的面积大小及突触数目与手术侧相比无差异.表明手术后30天.从L_?备用根来的初级传入纤维在L_?平面有侧支出芽并重建突触联系.30天组,手术侧简单终末（主要来源于下行投射纤维和中间神经元）数量比非手术侧增加18%.表明除背根来源的神经纤维有侧支出芽外,还有非背根来源的神经纤维出芽并形成突触.更多还原

【Abstract】 We observed the changes of the size and number of two types of synaptic terminals in L5 lamina II 15 and 30 days after unilateral dorsal rhizotomy by using quantitative electron microscopic methods. Since there were no significant changes of the area of lamina II, the area fraction of the neuropil, perikaryon and blood vessel of two groups in operated sides, and since there was no obvious difference of the number of two types of synpatic terminals in unoperated sides of two groups, a direct comparison was made between the two group in the size and number of synaptic terminals of the operated sides. In the 15 day group, the number of complex terminals (CT), originating mainly from dorsal roots, reduced to 36% compared with that in the unoperated side. In the 30 day group, the CT number increased to 51%, which was significantly greater than that of the 15 day group. However, There were no significant difference between the operated and the unoperated sides in the CT mean size and number of synapse per CT. These results indicated that partial dorsal rhizotomy could induce the L6 spared root to sprout collaterally and reestablish synaptic contacts in deafferented area. In the 30 day group, the number of simple terminals (ST), originating mainly from decending and intraspinal axons, increased significantly (18%) in compari-sion with that of the unoperated sides. The result suggested that partial dorsal rhizotomy could induce both the nerve fibers from the L6 spared roots and non-dorsal roots to spout collaterally and reestablish synaptic contacts.更多还原