This article reviews the main results in resent years of studies on the roleof central Ach in pain modulation and analgesia

including.(1) cholinergicallyinduced analgesia (CIA).Cholinomimetic drugs raised the pain threshold orinhibited the unit discharges of hypothalamus parafascicularis nuclens in rats

and these actions were revesed by atropine not by nicotine.(2) Ach and acu-puncture analgesia (AA).The effect of electroacupuncture was changed byadministration of HC-3

atropine

etc.(3) Ach and stress analgesia (SA).Scopolamine reduced the hind foot shock induced analgesia

and this kind of SAwas probably mediated by m-receptors existed at supraspinal

rather than spinallevel.Swimming and immobilization analgesia were also related to Ach.Thesedata suggested that the central cholinergic system is very important in painmodulation and analgesia and the cenatral Ach is essential transmitter or modu-lator in this analgesic pathway.But the problem is whether the mechanism ofCIA is involvtd in opiate analgesic system or not.