针刺对脑源性神经营养因子在脊髓Ⅱ板层可塑性中表达的影响

采用免疫组化和原位杂交技术 ,探讨了针刺促进脊髓 板层可塑性过程中脑源性神经营养因子及其 m RNA表达的变化。结果显示 :针刺侧备用背根节的脑源性神经营养因子及其 m RNA阳性中 (4 2～ 5 7μm)、小 (<42 μm)型神经元的百分数有所增加 (P<0 .0 5 ) ;脊髓 板层的脑源性神经营养因子的阳性神经膨体密度明显增多 (P<0 .0 1)而阳性神经元百分数无变化 (P>0 .0 5 ) ;针刺后脊髓 板层未见脑源性神经营养因子 m RNA的杂交信号。提示针刺促进脊髓 板层可塑性可能与背根节中、小神经元表达脑源性神经营养因子的增多有关

THE EFFECT OF ACUPUNCTURE ON THE EXPRESSION OF BDNF IN THE PROCESS OF SPINAL PLASTICITY

In order to explore the change of expression of BDNF in the process of spinal plasticity promoted by acupuncture, five adult cats were performed unilateral spared root rhizotomy (L 1～L 5, L 7～S 2 DRG were sectioned, but L 6 was spared). And two groups of xuewei (Zu San Li and Xuan Zhong, Futu and San Yin Jiao) located in hind limb were electro stimulated for thirty minutes everyday. 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 (BDNF antibody 1∶1500) and in situ hybridization (BDNF cRNA probe 1∶100) techniques were used. The numbers of positive neurons for BDNF and its mRNA in large, medium, small neurons of L 6 DRG and the numbers of positive varicosities for BDNF in lamina Ⅱ were counted respectively. The results showed that the numbers of positive medium, small neurons for BDNF and its mRNA in DRG and the number of positive varicosities for BDNF in lamina Ⅱ in acupuncture side increased apparently than those of unacupuncture side (P<0.05). However, the positive signal for BDNF mRNA in lamina Ⅱ was not seen in our study. The results indicated that acupuncture promoting the plasticity of spinal cord may be related to both the increase in expression of BDNF in medium and small neurons of spared DRG and the increase in number or density of positive varicosities for BDNF in spinal lamina Ⅱ. Moreover, BDNF may play a role in the process of the plasticity of spinal lamina Ⅱ promoted by acupuncture.