The Morphological Tracing Analysis Of Intraspinal Sprouting Of Spared Dorsal Root Central Axon Terminals Following Electroacupuncture

[Objective]: To explore the relationship between electroacupuncture (EA) and the spared L5 neuritis sprouting of SD rats with partial dorsal rhizotomy.[Methods]: 5 SD rats were injected CB-HRP after 3 months left hindlimb acupoints (Zusanli-Xuanzhong and Futu-Sanyinjiao) EA treatment following bilateral dorsal rhizotomy. After 5 days survival time, the T12-S1 spinal segments and spared dorsal root ganglions (DRG) were underwent the CB-HRP-TMB-SNP transneuronal labeling histochemistry methods, employed widely in morphological neurobiology.[Results]: In the shame-operated (SO) group, the normal CB-HRP labeling nerve fiber in the spinal dorsal horn were observed mainly in theⅢ,Ⅳ,Ⅴlaminae of L2-L5, as well as L1 laminaeⅢ,Ⅳand the laminaⅠof L4 and L5．After 3 months partial deafferentation (PD), besides the aforesaid labeling range, the nerve terminals of L5 ascendent projection were also be detected in L1 laminaⅠand laminaⅢ,Ⅳof T13, while the descendent projection could be labeled at laminaeⅢ,Ⅳ,Ⅴof L6．For the EA-PD side, the enzymohistochemistry staining could be found in T12 laminaⅢascendingly and S1 laminaeⅢandⅣdescendingly, the other positive labeling distributions were same as the PD side. The quantity of labeling nerve fiber at respective spinal segments of EA-PD side was more abundant compared with that of PD side, while the later was richer than that of SO group.[Conclusion]: EA stimulation might promote the intraspinal neuritis sprouting of spared L5 DRG collaterally and longitudely, which was benefit to the spinal neuroplasticity.