Abstract
Introduction : The aim of the study is to investigate the suppressive action of electroacupuncture on cold alloynia development in the rat model of neuopathic pain. Methods : To produce neuropathic pain, the right superior caudal trunk was resected $1{\sim}2\;mm$ between S1 and S2 spinal nerves. The rats were divided into control and four electroacupuncture groups: Two electroacupuncture groups were given 2 Hz or 100 Hz electroacupuncture for 20 minutes everyday after the sacral nerve injury. Other two electroacupuncture groups were given 2 Hz or 100 Hz electroacupuncture for 20 minutes just one session at one hour after the sacral nerve injury. The right point of Joksamni (ST36) was applied for electroacupuncture. The control group was induced neuropathic pain without electroacupuncture. The cold allodynia was assessed by immersing the tail in $4^{\circ}C$ water. The latency to an abrupt tail movement after rat tail immersion was measured with a cut-off time of 15 sec at 4th, 7th and 14th day after the sacral nerve injury. Results : The results were as follows; 1. At 4th experimental day, there were no significant differences between 2 Hz or 100 Hz electroacupuncture groups and the control group. 2. At 7th experimental day, everyday 2 Hz or 100 Hz electroacupuncture groups showed significant differences compared with the control group. But There were no significant differences between 2 Hz and 100 Hz electroacupuncture groups. 3. At 14th experimental day, everyday 2 Hz electroacupuncture group showed significant differences compared with the control group. But everyday 100 Hz electroacupuncture group showed no significant difference compared with the control group and everyday 2 Hz electroacupuncture group. 4. There were no significant differences between the control and 2 Hz or 100 Hz electroacupuncture groups which were done just one session at one hour after the surgery. 5. Everyday 2 Hz electroacupuncture group showed significant differences in the one session of the 100 Hz electroacupuncture group. Conclusion : Everyday 2 Hz electroacupuncture exerts a suppressive action on cold allodynia development in the rat model of neuropathic pain.