Objective To observe the effect of electroacupuncture(EA) of "Futu"(LI 18)

etc.on the expression of genes of glial cell line-derived neurotrophic factor(GDNF)

brain-derived neurotrophic factor(BDNF) and their receptors in the cervico-spinal cord in neck-incision pain rats

so as to study its mechanism underlying incision-pain relief.Methods A total of 50 Sprague Dawley male rats were randomly divided into normal

model(incision pain)

EA-Futu(LI 18)

EA-Hegu(LI 4)-Neiguan(PC 6

LI 4-PC 6) and EA-Zusanli(ST 36)-Yanglingquan(GB 34

ST 36-GB 34) groups(n=10/group).A 1.5 cm long longitudinal incision was made along the midline of the neck under anesthesia to duplicate neck-incision pain model.Thermal pain threshold(PT) was measured before and after modeling and after the treatment

respectively.EA(1-2 mA

2 Hz/100 Hz) was applied to bilateral LI 18

PC 6-LI 4 and ST 36-GB 34 for 30 min.The expression of genes of GDNF and its receptor GFRα-1

and BDNF and its receptors TrkA

TrkB in the spinal cord(C1-C4) tissue was detected by quantitative real-time-PCR.Results In comparison with pre-modeling in the same one group

the thermal PT levels were decreased obviously in the model

LI 18

LI 4-PC 6 and ST 36-GB 34 groups after neck incision(P<0.05).Compared with the model group

the PT levels were increased markedly in LI 18

LI 4-PC 6 and ST 36-GB 34 groups after the EA treatment(P<0.05).Correspondingly

the expression levels of spinal GDNF mRNA and GFRα-1 mRNA were obviously lower

as well as BDNF mRNA was markedly higher in the model group than in the control group(P<0.05)

and those of TrkA mRNA and TrkB mRNA were increased slightly in the model group than in the control group(P>0.05).In comparison with the model group

the expression levels of spinal GDNF mRNA and GFRα-1 mRNA were up-regulated considerably(P<0.001)

whereas those of BDNF mRNA

TrkA mRNA and TrkB mRNA were decreased slightly(P>0.05) in the LI 18

LI 4-PC 6 and ST 36-GB 34 groups after EA treatment.Conclusion EA stimulation can significantly suppress pain reaction of neck incision

which is closely associated with its effects in up-regulating the expression of GDNF and its receptor GFRa-1 genes in the cervical spinal cord(C1-C4).