Objective To observe the effect of electroacupuncture(EA)stimulation of"Zusanli"(ST 36)-"Yanglingquan"(GB 34)on expression of pain sensory and affection processing-related corticotropin-releasing factor(CRF)receptor

glutamatergic NMDA receptor and GABA receptor subtype genes in the amygdala in chronic constrictive injury(CCI)of the sciatic nerve rats

so as to reveal its mechanism underlying pain relief.Methods Experiments were separately performed in 36 male Wistar rats which were randomized into normal control

CCI model and EA+CCI;normal control

CCI+negative affection(NA)model and CCI+NA+EA groups(n=6in each group).Neuropathic pain model was established by ligature of the left sciatic nerve

and NA model established by ligation of the left sciatic nerve and repeated skin stimulation(acupuncture needle pricking+direct current stimulation)of the paw-bottom

once daily for 3days.EA(2Hz/15 Hz

1mA)was applied to bilateral ST 36-GB 34 for 30min

once daily for 7days.Thermal pain threshold(paw withdrawal latency

PWL)of the bilateral paws was measured by using a Tail-Flick Unit 37360.Expression levels of CRF-1R

CRF-2R

NR 2A

NR 2B

GABAaR and GABAcR genes in the amygdala were determined using quantitative RT-PCR.Results In comparison with the normal control groups

PWL difference(PWLD)values of the bilateral paws of CCI model and CCI+NA model groups were significantly increased(P<0.05).In comparison with the model group

following 7days' EA stimulation

PWLD were considerably decreased(P<0.05)

showing a pain relief.RT-PCR results indicated that compared to the normal control group

the expression levels of CRF-1R

CRF-2R

NR2 Aand NR 2Bgenes were apparently increased in the CCI model group(P<0.01

P<0.001)

and those of CRF-1R

CRF-2R

NR 2A

NR 2B

GABAaR and GABAcR genes were remarkably down-regulated in the CCI+NA model group(P<0.05

P<0.01

P<0.001).After EA intervention for 7days

CRF-2R

NR 2Aand NR 2Bwere significantly down-regulated in the CCI+EA group

and CRF-1R

CRF-2R

NR 2B

GABAaR and GABAcR genes were obviously up-regulated in the CCI+NA+EA group(P<0.01

P<0.001).Conclusion Repeated EA stimulation of ST 36-GB 34 has a definite analgesic effect in neuropathic pain and negative affection rats

which may be respectively related to its effects in down-regulating expression of CRF-2R

NR 2Aand NR 2Bgenes

and up-regulating expression of CRF-1R

CRF-2R

NR 2B

GABAaR and GABAcR genes in the amygdala.