Integrated Mechanism In The Nervous Center Of Neiguan And Zusanli Acupoints In Together Regulating Both The Cardiac And Gastric Functions

Objective:To explore the mechanism of "one meridian or acupoint controlling many diseases and many acupoints controlling one viscus" and clarify that nucleus of the solitary tract(NTS) may be an important primary nervous center in the medulla oblongata of "Neiguan" and "Zusanli" acupoints regulating cardiac and gastric functions,differences between acupuncture at "Neiguan" and "Zusanli" acupoints on neuronal discharges and c-fos expression in the NTS,and gastric pressure,as well as STⅡof electrocardiogram were observed in the normal and model rats.Method:Effects of acupuncture at "Neiguan" and "Zusanli" acupoints on discharges of neurons in the NTS sensitive or not sensitive to gastric distension or arrhythmia and on c-fos expression in the NTS in gastric distension and myocardial ischemia rats were respectively observed by extracellular recording and immunohistochemistry techniques.Results:1.neurons in the NTS was mainly excitatory response after acupuncture at Zusanli,Neiguan,Pianli and Heyang acupoints,however, there was significant difference between Zusanii and Neiguan groups and Pianli and Heyang groups in the ratio of appearance of those excitatory neurons(P＜0.01).Furthermore,discharge frequency of those excitatory neurons in four groups after acupuncture was higher than that before acupuncture(P＜0.01),showing that acupuncture has an obvious activation on neurons in the NTS.The percentage changes of the frequency of excitatory neurons in Zusanli and Neiguan groups were also obvious higher than those in Pianli and Heyang groups(P＜0.01).2.①In 149 neurons in the NTS,65 neurons were responsive to gastric distension,in which 44 neurons were excited and 21 neurons were inhibited to the stimulation,showing neurons in the NTS were mainly excited to gastric distension.After acupuncture at Zusanli,Neiguan, Pianli and Heyang acupoints,those excitatory neurons mentioned above were inhibited,moreover,the ratio of inhibitory neurons in the Zusanli and Neiguan groups was obvious higher than that in the Pianli and Heyang groups(P＜0.01,P＜0.05).Acupuncture at Zusanli,Neiguan, Pianli and Heyang acupoints all produced remarkable decreases in discharge ratio of excitatory neurons in rats induced by gastric distension (P＜0.01),furthermore,the percentage changes of the frequency in the Zusanli and Neiguan groups were noticeably higher than those in the Pianli and Heyang groups(P＜0.01).②In 116 neurons in the NTS,54 neurons were responsive to arrhythmia, in which 46 neurons were inhibited and 8 neurons were excited to the stimulation,showing that neurons in the NTS were mainly inhibited to arrhythmia.After acupuncture at Zusanli,Neiguan,Pianli and Heyang acupoints,those inhibitory neurons mentioned above were excited, moreover,the ratio of excitatory neurons in the Neiguan groups was obvious higher than that in the Pianli and Heyang groups(P＜0.05). Acupuncture at Zusanli,Neiguan,Pianli and Heyang acupoints all produced remarkable increases in discharge ratio of inhibitory neurons in rats induced by arrhythmia(P＜0.01),furthermore,the percentage changes of the frequency in the Zusanli and Neiguan groups were noticeably higher than those in the Pianli and Heyang groups(P＜0.01).3.①The number of fos-immunoreactive(fos-IR) neurons in the NTS in Zusanli and Neiguan groups was significantly lower than that in the gastric distension group(P＜0.01) and obviously higher than that in Pianli and Heyang groups(P＜0.01).②A similar phenomenon was observed in the arrhythmia rats.The number of fos-immunoreactive(fos-IR) neurons in the NTS in Zusanli and Neiguan groups was significantly lower than that in the arrhythmia group(P＜0.01) and obviously higher than that in Pianli and Heyang groups(P＜0.01).4.②Acupuncture at Zusanli and Neiguan acupoints increased significantly gastric pressure(P＜0.01),which was obviously higher than that after acupuncture at Pianli and Heyang acupoints(P＜0.01).②In the myocardial ischemia rats,acupuncture at Zusanli and Neiguan acupoints decreased significantly the value of STⅡof myocardiogram(P＜0.01), which was more obvious than that after acupuncture at Pianli and Heyang acupoints(P＜0.01).Conclusion:1.Somatic afferent information induced by acupuncture at Neiguan and Zusanli acuponts and noxious visceral stimuli from the heart and stomach may converge in the NTS.2.NTS may be one of integrated nervous center of Neiguan and Zusanli acuponts in together regulating both the cardiac and gastric functions.3."One meridian or acupoint controlling many diseases and many acupoints controlling one viscus" is relative specificity.