Objective To observe the effect of electroacupuncture(EA) on cortical spreading depression(CSD) and contents of plasma calcitonin gene-related peptide(CGRP) and substance P(SP) in migraine rats.Methods Thirty male SD rats were equally randomized into control

model and EA groups.Migraine model was established by topical application of KCl(3mol/L) immersed in a piece of filter paper to the cerebral cortex(parietal lobe

6mm posterior to the Bregma and 5mm to the sagital fissure) after exposure of the skull(in reference to Michael' method).KCl stimulation evoked CSD potentials(3mm rostral to the Bregma

and 2mm to the sagital fissure) were recorded by using a glass microelectrode.For rats of control group

filter paper containing 0.9% NaCl was applied to the same parietal cortex area.EA(1mA

2Hz/100Hz) was applied to bilateral "Yanglingquan"(GB 34) and "Taichong"(LR 3) for 30min.The contents of plasma CGRP and SP were assayed by radioimmunoassay.Results CSD was induced 3-5 min after application of KCl to the parietal lobe.The average amplitude of model group was(-25.13±1.23)mV

and that of EA group was(-19.19±1.53)mV

displaying a significant reduction of CSD amplitude after EA(P<0.01).Comparison among 3 groups showed that both plasma CGRP and SP contents in model group were significantly higher than those of control group(P<0.001

P<0.01)

while compared with model group

plasma CGRP and SP levels in EA group decreased considerably(P<0.05

P<0.001)

suggesting an inhibitory effect of EA on pain-producing substance.Conclusion EA of GB 34 and LR 3 can effectively suppress KCl provoked cortical spreading depression and plasma CGRP and SP levels in the rat

which may contribute to its effect in relieving migraine in clinic.