孫維仁2006-07-262018-07-132006-07-262018-07-132003http://ntur.lib.ntu.edu.tw//handle/246246/28870Although induction of deep aching sensation, De-Qi, is generally accepted as a standard acupunctural practice, whether an intense nociceptive stimulation is required for optimal analgesic effect remains controversial. In freely moving rats we first demonstrated that intramuscular injection of 100 μl 5% formalin, a noxious irritant, in the Zusanli acupoint (ST-36) induced intense nociceptive behavior. Tail-flick latency and c-fos expression were then compared among halothane-anesthetized rats receiving either low-intensity electroacupuncture (10× threshold of local muscle contraction), high-intensity (20× threshold) electroacupuncture (30 min, 4Hz), intramuscular formalin, or normal saline injection at the right Zusanli acupoint. We found that formalin injection at the acupoint markedly increased tail-flick latency and induced greater c-fos expression at the superficial and deep laminae of spinal cord dorsal horn compared to saline injection. Electroacupuncture prolonged the cumulative tail-flick latency in an intensity-dependent manner but, in contrast to formalin, did not provide intensity sufficient to induce c-fos expression throughout the 2nd to 5th lumbar segments. Our data indicated that although noxious chemical stimulation at the acupoint can elicit comparable analgesic effect, non-noxious electrical stimulations produce even greater analgesic responses in an intensity-dependent manner. These findings suggest that generation of intense aching sensation, De-Qi, is not required for the analgesic effect provided by electroacupuncture.application/pdf132157 bytesapplication/pdfzh-TW國立臺灣大學醫學院麻醉科electroacupuncture, tail flick, formalin, c-fos expression, stimulation intensity, anesthesiajournal articlehttp://ntur.lib.ntu.edu.tw/bitstream/246246/28870/1/912314B002241.pdf