针刺对神经营养素3在脊髓可塑性中表达的影响

Effect of Acupuncture on the Expression of NT_3 in the Process of Spinal Plasticity

目的 探讨针刺对神经营养素 3(NT3)在脊髓可塑性中表达的影响。方法 用 NT3 抗血清和NT3c RNA探针 ,以免疫组化和原位杂交技术观察针刺前后备用背根节及脊髓 板层中 NT3表达的变化。结果 针刺侧备用背根节 (DRG) NT3及其 m RNA阳性大神经元 (>5 7μm)和小神经元 (<42μm )百分数均较非针刺侧者明显增多 (P<0 .0 5 )。此外 ,脊髓针刺侧 板层 NT3阳性神经元及胶质细胞百分数针刺侧亦较非针刺侧明显增多(P<0 .0 5 ) ,但两侧均未见 NT3m RNA的杂交信号。结论 针刺促进脊髓可塑性可能与 DRG大、小神经元表达NT3和脊髓 板层

Objective To explore the change in the expression of NT 3 in the process of promoting the plasticity of spinal cord by acupuncture. Methods Five adult cats were subjected to unilateral spared root rhizotomy; their L 1 L 5, L 7 S 2 dorsal root ganglia (DRG) were sectioned, but L 6 was spared. And two groups of acupoints 〔Zusani (St.36) and Xuanzhong (G.B.39); Futu (St.32) and Sanyingjiao (Sp.6)〕 located in hind limb were electro stimulated for thirty minutes q.d.×7. At seven days, after acupuncture, the L 5 segment of spinal cord and spared dorsal root ganglion (L 6) were taken and made into frozen section 20 μm in thickness. Immunohistochemistry (NT 3 antibody 1∶1500) and in situ hybridization (NT 3 cRNA probe 1∶100) techniques were used. The numbers of positive neuron for NT 3 and it's mRNA in large, medium, small neuron of L 6 DRG and the numbers of positive neurons and glia cells for NT 3 in lamina Ⅱ were counted respectively. Results The numbers of positive large,small neurons for NT 3 and its mRNA in DRG and the number of positive neurons and glia cells for NT 3 in lamina Ⅱ on the acupuncture side increased apparently than those on the non acupuncture side ( P <0.05). However, the positive signal of NT 3 mRNA in lamina Ⅱ was not seen in our study. Conclusion The results indicate that acupuncture promoting the plasticity of spinal cord involves both the increase in expression of NT 3 in large and small neurons of spared DRG and the increase in number of NT 3 positive neurons and glia cells in spinal lamina Ⅱ. Moreover, NT 3 may play a role in the process of promoting the plasticity of spinal cord by acupuncture.