Objective To observe the effects of electroacupuncture(EA)stimulation of different tissues(nerve stem

muscular layer)at"Huantiao"(GB 30)acupoint on expression of phosphorylated c-jun N-terminal kinase(p-JNK)and c-jun(pc-jun)proteins in the lumbar spinal cord in rats with sciatic nerve injury

so as to explore its mechanism underlying improvement of peripheral neuropathic damage.Methods Forty-eight SD rats were randomly divided into normal

model(the left sciatic nerve severed)

GB 30 deep needling(the acupuncture needle tip was inserted to the sciatic nerve trunk to elicit an instantaneous jerk of the hind limb)and GB 30 shallow needling(the needle tip was inserted to the muscle layer to evoke a local muscular contraction)groups(n=12rats in each group).EA stimuli were delivered at 2Hz/100 Hz

1mA

20 min in duration per treatment for 10 consecutive days.Histo-pathological changes were observed by Hematoxylin-eosin(HE)staining and immunohistochemical assay was carried out to examine the pathological change of spinal segments(L4-L5)and the expression of p-JNK and p-c-jun proteins

respectively.Results For rats with the sciatic nerve severed

the spinal neurons became swelling

degeneration or even apoptosis.Acupuncture intervention reduced the number of apoptosic neurons and improved the pathological change

which was relatively better in the deep needling group than in the shallow needling group.Likewise

the elevated spinal p-JNK and p-c-jun expression levels of the model group were significantly reduced by EA intervention(deep needling vs shallow needling

P<0.01).Conclusion Acupuncture can improve the spinal pathological changes in rats with sciatic nerve injury

which is probably achieved by decreasing the p-JNK and p-c-jun expression and inhibiting the JNK signaling pathway

and thereby

reducing the apoptosis of the spinal neurons.Deep needling results in greater benefits than shallow needling.