丘脑及大脑皮层在穴位电针抑制内脏神经-皮层诱发电位中的作用

<正> 我们曾报导了电针单侧“胃俞”、“足三里”穴可以不同程度地抑制电刺激内脏神经引起的皮层诱发电位,证明了这些诱发电位与内脏痛觉有关以及穴位存在相对特异性,并分析了电针“足三里”穴抑制内脏神经-皮层诱发电位的外周传入途径。为了进

THE ROLE OF THE THALAMUS AND CEREBRAL CORTEX IN THE INHIBITORY EFFECTS OF ELECTRICAL ACUPUNCTURE ON SPLANCHNIC-EVOKED CORTICAL POTENTIALS

1. Evoked potentials could be recorded in some main nuclei of the thalamus [N. ventralis posterolateralis (VPL), N. geniculatus medialis (GM) and N. centralis lateralis(CL)] in addition to the somatic sensory area Ⅰ and Ⅱ of the cerebral cortex in cats. The evoked potentials of thalamic nuclei as well as those of SⅠ and SⅡ in the left side of the brain could be inhibited by electrical acupuncture of either right "Weishu" or "Zusanli" point. It was always completely inhibited by electrical acupuncture of "Weishu"2. The cortical potentials evoked by splanchnic nerve stimulation were obviously diminished after destroying the VPL or GM by electric cauterization or cutting their connections with somatic sensory areas. There was no obvious effect on the evoked potentials after destroying CLexcept some temporary changes.3. Two pairs of insulated bipolar electrodes with bare tips were inserted into the same nucleus of the thalamus both for recording and stimulation. The potentials recorded from the thalamie nucleus by one pair of electrodes and the SⅠ cortical potentials both evoked by splanchnic nerve stimulation could be inhibited to various degrees by stimulation of the same thalamic nucleus through another pair of electrodes with currents of appropriate intensity and frequency. This inhibitory effect was very obvious in VPL and GM, but less so in CL.4. When two pairs of electrodes were inserted into area SⅠ of the cerebral cortex and a rather strong electric stimulus was delivered through one pair of the electrodes, the splanchnic-nerve-evoked cortical potentials recorded by another pair of electrodes were also inhibited but only slightly. A stronger strength and longer time stimulus was needed inducing such inhibition.It is suggested that the thalamus plays an important role in the integration of the afferent impulses of electrical acupuncture and the impulses from the splanchnic nerves which mediate visceral pain and other sensations. The cerebral cortex plays but a minor role. It has also been observed that the potentials of SⅡ evoked by splanchnic nerve stimulation could be inhibited by electric stimulation of SⅠ.