Experiments were performed on rat model given unilateral lumbosacral dorsal rhizotomical opera tion from L2 to S2 with sparing L5. The effect of acupuncture on expression of GAP3 in dorsal area of spinal cord was observed with histocytochemistrical and in situ hybridizational methods. The results showed that after unilateral dorsal rhizotomied

the expression of GAP43 in lamina Ⅱ of spinal cord (L5) was significantly more than contralateral or control group. When acupuncture trement was giv en

the expression of GAP43 was elevated to higher level. These results implied that ① in some condi tion nerve system injury can induce the increasing GAP43 expression of neurons which mediate the plastisity of central nerve system

② the acupuncture treatment can regulate the plasticity of the nerve system through GAP43 mechanism