The other of every pair was as the control. All experiemental procedures were the same as the electroacupuncture group except that the sciatic nerve wasn't stimulated. The contents of SP of NST(at the area postrema segment) of both the electroacupuncture and the control were measured with the micro-spectroscopic image analyser. The results obtained were as follows: 1. The distribution positions of SP-like immunoreactive nerve fibers in the electroacupuncture group were the same as in the control group

That is

SP-like immunoreactive nerve fibers distributed from the candal part to the rostral part in NST. 2. The contents and the area of SP-like immunoreactive nerve fibers. of the electroacupuncture were more than the control. There was a significant difference between the two groups. The results mentioned above suggested that the role of NST is involed in the acupuncture analgesia.