针刺及某些神经介质对延脑巨细胞核神经元痛反应的影响

<正> 应用各种不同的实验方法证明:针刺镇痛过程中常伴随着中枢神经系统介质的变化,而改变中枢的介质水平可影响针刺镇痛的效果,说明神经介质在针刺镇痛过程中起着重要的作用。已知延脑网状结构巨细胞核是痛觉传递的一个驿站,并参与针刺镇痛作用。我们应用多管微电极电泳的方法,试图观察某些神经介质对这一核团神经元痛反应的影响,并与针刺的作用进行比较.

THE EFFECTS OF ACUPUNCTURE AND NEUROTRANSMITTERS ON THE PAIN RESPONSE OF GIGANTOCELLULAR NEURONS IN MEDULLA OBLONGATA

It has been known that neurotransmitters may play a marked role in acupuncture analgesia,and that changes in tha level of neurotransmitters in CNS may occur during acunupcture analgesia.It is the-refore desirable to investigate the relationship between acupuncture analgesia and the neurotransmittersin CNS.Microelectrophoretic technique was used to study the effect of some transmitters on thenociceptive response of neurones in the nucleus gigantocellularis,and the effect was compared with that of electric needling.The experiments were performed on 28 Chloralosed cats immobilized with Flaxedil.The left ma-jor splanchic nerve was placed on a bipolar silver electrode for noxious stimulation.Five of sevenbar rel electrodes were employed to record the discharge potential evoked by the stimulation,and themicroelectrophoresis of the neurotransmitters was given one after another.The spikes were displayedon an oscilloscope,and integrated on a pen-recorder.In twenty eight cats,fifty four neurones were found to sensitive to high voltage stimulationof the splanchnic nerve.Such neurones had long latency and lacked adaptation to the noxious stimula-tion.Their firing were depressed by the administration of morphine hydrochloride(5mg/kg i.v.),andthus,they were referred to as nociceptive neurones.The results showed that the nociceptive firings of a majority of the neurones were depressed byneedling “Zusanli” and Weishu “or by nor-adrenaline(NA),acetylcholine(ACh)and 5-hydroxytryp-tamine(5-HT)administered by microelectrophoresis.Other neurones were unaffected,and a few exci-ted.The marked decrease of the neuronal firings occurred in thirty out of forty six units(65%)byneedling,twenty nine oat of fifty(58%),seventeen out of forty two(40%)and five out of twentyfour(20%)by NA,ACh and 5-HT respectively.Marked inhibitory effect was produced by electricneedling or NA.The mode of action and the time course of inhibition by needling and NA weresimilar.Among thirty six units examined before,during and after the electrophoretic ministrationof NA and needling,thirty one(86%)showed similar responses to needling and NA.The results suggested that electroneedling might enhance the release of noradrenaline at the levelof medulla and it might be an important factor in the mechanism of acupuncture analgesia.