Abstract: Reversible middle cerebral artery(MCA)occlusion in rats was made by intraluminal filament technique. After 1 h of ischemia, the filaments were withdrawn to allow reperfusion for 1 h and 2 h, respectively. In situ hybridyzation studies showed that after 1 h and 2 h of reperfusion, c-fos mRNA was induced remarkably in ipsilateral ischemic neocortex(frontal, parietal), hippocampus CA1, CA2, CA3 and CA4 areas, and dentate gyrus. c-Fos protein expression as demonstrated by immunohistochemical stain was also induced in all the brain areas mentioned above. With electroacupuncture at the points of "Baihui" and "Fengfu" for 30 min before reperfusion, both induction of c-fos mRNA and c-Fos protein were significantly enhanced in the cortex of frontal and parietal lobe(P<0.001)and dentate gyrus(P< 0.01)in ischemic hemisphere. In hippocampus, electro acupuncture increased the c-Fos protein expression both after 1 h and 2 h of reperfusion significantly(CA1 and CA4: P<0.05; CA2 and CA3: P< 0.01), while marked increase of c-fos mRNA occurred only after 1 h of reperfusion in CA1 and CA4 areas(P<0.05). HE stain showed less neurol degeneration in ischemic area in rats that received electro acupuncture before reperfusion. The results showed that the treatment with electro acupuncture at the point of "Baihui" and "Fengfu" increased the expression of both c-fos mRNA and c-Fos protein after focal cerebral ischemia and reperfusion, which may play an important role in the brain protection of the animal model the authors used.

Key words: ischemia reperfusion, electro acupuncture, c-fos mRNA, c-Fos