Role of peripheral afferent nerve fiber in acupuncture analgesia elicited by needling point zusanli.

Needling acupuncture point zusanli shows a significant suppressive effect characterized by the response of jaw movement. The afferent analgesic impulses arising from the point zusanli for producing this effect are transmitted largely by A beta gamma fibers in the peroneal nerve. Sufficient amount of A beta gamma fibers brought in to action is an important factor in achieving this prominent analgesic effect. The inhibitory action of the large fibers, such as A beta gamma, mediating analgesic impulses upon the small fibers such as A delta and C, carrying painful impulses, seems to be one of the component parts of the mechanism of acupuncture analgesia.