Objective To observe the effect of electroacupuncture(EA) on the expression of ionotropic glutamate receptor(iGluR) subunits and their mRNAs in the lumbar segments of spinal cord in rats with neuropathic pain

so as to explore its underlying mechanism in relieving spinal hyperalgesia.Methods Thirty SD rats were randomly divided into control

model

and EA groups

with 10 rats in each.The spared nerve injury(SNI) model was established by ligature of the sural nerve after cutting off the common peroneal nerve and anterior tibial nerve.EA(2Hz

1mA) was applied to "Huantiao"(GB30) and "Weizhong"(BL40) for 30min

once daily for 7 days.Mechanical pain threshold was detected before and after modeling and before and after EA treatment.The expression levels of N-methyl-d-aspartic acid(NMDA) receptor subunits NR1 and NR2B

and AMPA receptor subunit GluR1 of iGluR and their genes were assayed by Western blot and reverse transcription polymerase chain reaction(RT-PCR) separately.Results In comparison with control group

the mechanical pain thresholds were decreased significantly on day 2

7 and day 14 following modeling in the model group(P<0.05

P<0.01).While compared with the model group

the pain threshold was increased considerably on day 14 in the EA group(P<0.01).Compared with the control group

the expression levels of lumbar spinal cord NR2B and NR2B mRNA in the model group were increased significantly(P<0.05)

and those of lumbar spinal cord NR1 and NR1 mRNA

GluR1 and GluR1 mRNA in the model group increased slightly(P>0.05).In comparison with the model group

the expression levels of lumbar spinal cord NR2B and NR2B mRNA in the EA group were down-regulated remarkably(P<0.05)

and those of lumbar spinal cord NR1 and NR1 mRNA

GluR1 and GluR1 mRNA in the EA group down-regulated slightly(P>0.05).Conclusion EA can significantly suppress pain reaction in rats with neuropathic pain proba-bly through down-regulating the expression of lumbar spinal cord NR2B protein and NR2B mRNA.