[Effect of acupuncture on the expression of NT3 in the process of spinal plasticity].

Abstract

Objective: To explore the change in the expression of NT3 in the process of promoting the plasticity of spinal cord by acupuncture.

Methods: Five adult cats were subjected to unilateral spared root rhizotomy; their L1-L5, L7-S2 dorsal root ganglia (DRG) were sectioned, but L4 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. x 7. At seven days, after acupuncture, the L5 segment of spinal cord and spared dorsal root ganglion (L6) were taken and made into frozen section 20 microns in thickness. Immunohistochemistry (NT3 antibody 1:1500) and in situ hybridization (NT3 cRNA probe 1:100) techniques were used. The numbers of positive neuron for NT3 and it's mRNA in large, medium, small neuron of L6 DRG and the numbers of positive neurons and glia cells for NT3 in lamina II were counted respectively.

Results: The numbers of positive large, small neurons for NT3 and its mRNA in DRG and the number of positive neurons and glia cells for NT3 in lamina II on the acupuncture side increased apparently than those on the non-acupuncture side (P < 0.05). However, the positive signal of NT3 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 NT3 in large and small neurons of spared DRG and the increase in number of NT3 positive neurons and glia cells in spinal lamina II. Moreover, NT3 may play a role in the process of promoting the plasticity of spinal cord by acupuncture.