To study the neuropeptides involved in the peripheral information transmission across dermatomes and the relevant mechanisms. Methods: Wistar rats are used in this study. Stimulate one nerve innervating a acupoint of "Pangguang Meridian of Foot Taiyang" antidromically and record the discharge of the other nerve innervating the neighboring acupoint next to or several segments away from the stimulated nerve. Using the model of the information transmission across dermatomes

the discharges from the acupoint are observed by treatment respectively with capcaisin (destroying the peptidergic nerves)

substance P (SP)

calcitonin gene related peptide (CGRP)

neuropeptide A (NKA) and NK 1 receptor antagonist and H 1 receptor antagonist. Results: This study proves for the first time that imitating acupoint stimulation may induce information transmission across dermatomes along the route of meridian. The characteristics of the information transmission across dermatomes is accord with regularities of propagation of sensation along meridians (PSM)

that may contribute to the phenomenon of PSM in clinic. The information transmitted across dermatomes decreased significantly after treatment with capcaisin to destroy the peptidergic nerves. SP

CGRP and NKA facilitated the information transmission across dermatomes and the intensity and duration of the effect are SP>CGRP>NKA. NK 1 receptor antagonist (WIN 51

708) and H 1 receptor antagonist (benzhydramine) decrease the information transmitted across dermatomes. These results suggest that SP

CGRP

NKA

histamine

etc. may contribute to the information transmission across dermatomes via combining with their receptors. The activation of sympathetic nerve may enhance the information transmission. Conclusion: Multiple types of neuropeptides and their receptors are involved in PSM.