外周神经损伤后对大鼠脊髓运动神经元及背根节感觉神经元的影响

大鼠左腓总神经离断后与胫神经端侧吻合，于术后第1至8周取L4～5脊髓和背根节（DRG）做冰冻切片，分别显示前角运动神经元（SMN）AChE活性和DRG神经元NOS活性。结果发现；①正常鼠SMN－AChE活性中－强度阳性反应。实验组外侧核SMN－AChE活性和阳性细胞数，于术后2～3周比正常者明显减低，有的SMN－核周体出现空泡样变性；术后4～8周，SMN酶活性和阳性细胞数渐增，并明显高于正常者。同体对照组与实验组同期比较，SMN酶活性相对较弱。②正常鼠部分中－小型DRG神经元NOS活性为中－强度阳性反应。实验组于术后第1～4周，NOS活性和阳性细胞数较正常者明显增高；术后第5～8周其渐趋正常。对照组DRG神经元NOS活性表达较强及与实验组有相应的变化梯度。二组DRG内均见到空泡样变性的神经元核周体。结果提示，坐骨神经慢性损伤所产生SMN－AChE活性增强，可能是轴突再生的反应，并对由NO介导的一级感觉信息传导有一定影响。

The Histochemical Observation on the Influence of the Motoneurons inthe Spinal Anterior Horn and the Sensory Neurons in the Dorsal Root Ganglionafter the Injury of Peripheral Nerve of the Rat

The unilateral common peroneal nerve was cut and end-to-lateral reanastomosed with the tibial nerve of the rats. In the postoperative time of 1 to 8 weeks, the L4 to L5 spinal cords and the dorsal root ganglion (DRG) were removed, and the sections in cryostat were stained for AChE activity in the spinal motoneurons (SMN) by karnovsky-Root's method and NOS activity in DRG neurons by the NADPH-d method of Dawson's, respectively. The results were as follows: (1 ) In the normal rats, AChE activity in the SMN perikarya was revealed to be moderate-strong positive. In the Two to 3 weeks after operation in the experimental group, the activity of SMN-AChE and the positive cells in the lateral nucleus were obviously reduced as compared with in the control group. Four to 8 weeks after operation, AChE activity and SMN-AChE positive cells were gradually increased, significantly higher than in the control group. As compared to that of the experimental group at the corresponding period, AChE activity of SMN perikarya in the control group was weaker; (2)In the control group, the NOS medial-strong positive reactions were demonstrated in some little-medium type DRG neurons. In the experimental group, NOS activity and the NOS-positive neurons in DRG were much higher than in the control group in the first 4 weeks after operation, but in the following 5th to 8th weeks these were gradually returned to the normal. NOS-activities of DRG neurons in the contralateral of the same animal were observed to have similar changes, but stronger than in the expermental group. There were vacoule-like degeneration in the SMN and DRG neurons of both groups. It was suggested that the increase of AChE activity in the SMN-perikarya might probably represent the response of the axon-regeneratoin, and the chronic nociceptive-stimulation caused by sciatic nerve injury were thought to have difinite effect on the primary sensory information mediated by the nitric oxide.