5-HT and muscarine (M) recepters total binding capacities (Rt) in different brain areas and spleen were determined using recepter radioligand binding assay (RLBA) after needling zusanli of rats. And the rats without needling and needling Taichong point were used as contral. These results showed that 5-HT and M recepters Rt were decreased obviously than control group in rat's cerebral cortex

hippocampus

striatum

spinal cord and spleen when needling zusanli can produce obivous acupuncture analgesia. 5-HT Rt in briain stem and medulln oblongata was obviously decreased and not changed in thalamus. M receptor Rt value was not changed clearly in brain stem and medulla oblongata as well

but it was obviously decreased in thelamus. These results showed that effects of acupoints on Various meridians are different

thus the results of acupuncture at Zusanli are distinct from taichong