Investigation on mechanism underlying the formation of the propagated sensa- tion along meridians (PSM) is one of the important problems in meridian resea- rch.In order to interpret the problem more satisfactorily

we had advanced a hypothesis in 1987

that is

‘integration of periphery’ and CNS under the domination of substantial process proceeding along the meridians”.According to this hypothesis

“periphery” and “central mechanism” are operated as a whole.However

it also emphasized that the peripheral substantial process is the determinant factor in the formation of PSM.And then

is there really a peripheral substantial process

or

in other word

a peripheral activator during the advance of PSM.The afferent discharges were directly led from the superficial branch of radial nerve.Nineteen volunteers with marked PSM were under observation.The preliminary results demonstrated that as PSM

evoked by stimulating Jianyu (LI15) or Ying Xiang Acupoint (LI20)

travelled along the course of Large Intestine Meridian to the hand or index finger

the corresponding afferent impulses could be recorded from that nerve branch in a part of experiments.Through a series of control obse- rvations

it has been proved that the impulses recorded was not resulted from other responses

but really the afferent impulse discharged by the neuroreceptor apparatus distributing along the meridian

which was activated by certain stimu- lation.The facts demonstrated that “the peripheral activator” really appeared during the advance of PSM.It is of significance for the investigation on the mechanism underlying the formation of PSM.