胃经穴位电针调节胃运动的神经作用机制

目的胃经穴位电针对胃运动具有良好的调节作用，但其作用机制目前还不是很清楚。以往人们推测胃经穴位电针调节胃运动可能是通过对中枢某些核团的激活作用实现的。对此我们进行了相关的研究，并探讨其神经作用机制：方法采用同步实验，电生理学的方法，在电针足三里穴、上巨虚穴及非经非穴等穴位的情况下以及在离断迷走神经和坐骨神经条件下电针刺激足三里穴，观察延髓中与胃运动密切相关的孤束核(NTS)及迷走神经背运动核(DMV)中神经元细胞放电的变化情况，同时采用浆膜法检测胃电的变化。结果电针刺激足三里穴，在中枢延髓的孤束核(NTS)及迷走神经背运动核(DMV)中神经元细胞放电频率的变化以及胃电的变化情况均较明显，与电针刺激胃经其它穴位存在着显著差异。而在离断迷走神经或坐骨神经条件下，胃电未产生明显的变化。结论胃经穴位电针对胃运动具有调节作用。这种调节作用的实现，与孤束核(NTS）及迷走神经背运动核(DMV)的激活密切相关。而且，这种调节作用的完成依据于完整的神经途径。     

辣椒素对电针调控胃运动的影响作用及意义

目的探讨辣椒素毁损感觉神经生长的情况下,对电针调控胃运动的影响作用及意义。方法电针刺激经辣椒素干预大鼠足三里穴,采用免疫组织化学方法及电生理的方法,检测原癌基因c fos在中枢延髓的孤束核(NTS)及迷走神经背运动核(DMV)中的表达以及中枢延髓的孤束核及迷走神经背运动核中神经元细胞放电频率的变化情况,同时采用浆膜法观察胃电的变化情况。结果辣椒素针刺组胃电的波幅和频率与生理盐水针刺组存在显著性差异(P <0 .0 1) ,生理盐水针刺组胃电的波幅和频率与单纯生理盐水组胃电的波幅和频率存在显著性差异(P <0 .0 1)。原癌基因c fos在孤束核及迷走神经背运动核中的表达,辣椒素针刺组阳性率与生理盐水针刺组存在显著性差异(P <0 .0 1) ,生理盐水针刺组阳性率与单纯生理盐水组存在显著性差异(P <0 .0 1)。辣椒素针刺组NTS与DMV内神经元细胞放电频率的变化与生理盐水针刺组存在显著性差异(P <0 .0 1)。而与辣椒素非针刺组及单纯生理盐水组未见有明显差异(P >0 .0 5 ) ;同时,生理盐水针刺组NTS与DMV内神经元细胞放电频率与单纯生理盐水组存在显著性差异(P <0 .0 1)。结论电针对胃运动具有调控作用,且电针对穴位的作用性质可能是一种伤害性刺激。     

电针对LPS干预大鼠延髓NOS神经元的影响

目的探讨细菌脂多糖（LPs）对大鼠延髓一氧化氮合酶（NOS）神经元的影响，进一步观察电针足三里穴对这种影响的作用，并探讨其与胃排空功能的关系。方法。先行电针刺激大鼠足三里穴或非经非穴5天，之后予LPS2．5ms／kg腹腔注射，与不行电针单纯LPs处理组作对照；以免疫组化（ABC法）检测大鼠延髓神经元型NOS（nNOS）、诱导型NOS（iNOS）阳性神经元分布及数日，结果正常大鼠延髓各核团未观察到nNOS阳性神经元，延髓迷走神经背运动核（DMV）及孤束核（NTS）可见极少数iNOS阳性神经元分布。LPs腹腔注射7．5h后，延髓DMV中nNOS、iNOS阳性神经元的数目均明显增多；若先予以电针足三里穴5天，则可明届抑制LPS引起的此种反应（P＜0．01），而非经非穴点电针效果不明显。大鼠腹腔注射LPs后，延髓DMV中nNOS及iNOS阳性细胞数日明显增加，电针足三里穴可使之明显减少。结论电针对胃运动的作用可能与其对DMV中NO合成神经元的作用有关。     

胃电刺激诱导大鼠延髓孤束核和迷走神经运动背核c-fos蛋白表达

背景：胃电刺激（GES）可以调控胃慢波，但其作用机制尚不完全清楚。原癌基因蛋白c—fos的表达可作为神经元功能活动的标志物。目的：以c-fos蛋白的表达为观察指标，探讨GES调控胃肌电慢波的神经机制。方法：将雌性Wistar大鼠随机分为对照组和GES组。GES以控制胃慢波为准，持续1h。分别于刺激后0．5、1、2和5h处死大鼠，以免疫组化方法观察c—fos蛋白在延髓孤束核和迷走神经运动背核中的表达。结果：对照组延髓孤束核和迷走神经运动背核仅见微量c—fos蛋白表达，GES后0．5h其表达开始增强，1h时达高峰，以后逐渐减弱。结论：GES可以调控胃肌电慢波，GES后延髓孤束核和迷走神经运动背核神经元c-fos蛋白表达阳性提示迷走神经可能参与了该调控作用。     

辣椒素阻断迷走神经后胃电起搏诱导大鼠脑c-fos表达研究

目的以 c-fos 表达为观察指标,探讨迷走神经是否参与外源性胃电起搏调控胃肌电慢波活动。方法将雌性 Wistar 大鼠,分为手术对照组、胃电起搏组、辣椒素对照组和辣椒素胃电起搏组。电起搏组均给予电刺激,以控制慢波为准,持续刺激1 h。用 SP 免疫组化法观察 c-fos 在中枢延髓孤束核(NTS)及迷走神经运动背核(DMV)中的表达。结果胃电起博组 NTS 中 c-fos 阳性细胞数(75.00±9.03)明显高于辣椒素胃电起搏组(19.40±5.50),P<0.01;辣椒素胃电起搏组 NTS 中 c-fos 阳性细胞数与辣椒素对照组(14.00±3.39)和手术对照组(11.80±2.38)相比差异无统计学意义(P>0.05)。胃电起搏组 DMV 中 c-fos 阳性细胞数(35.00±6 28)明显高于辣椒素胃电起博组(13.80±4.21),P<0.01;辣椒素胃电起搏组 DMV 中 c-fos 阳性细胞数与辣椒素对照组(9.20±2.38)和于术对照组(8.20±2.17)相比差异无统计学意义(P>0.05)。结论外源性胃电起搏可调控胃肌电慢波活动,迷走神经可能参与这种调控作用。     

大鼠结肠扩张性刺激引起内脏活动变化的实验研究

目的研究结肠扩张性牵张刺激导致的内脏活动变化的作用机制，为减少因结肠牵张性引起的并发症提供理论依据。方法采用气囊充气模拟结肠镜引起大鼠结肠扩张性牵张刺激的方法，利用电生理学方法观察大鼠支配内脏活动的神经中枢延髓内脏带（Medullary visceral zone，MVZ）中迷走复合体（vagus-solotary complex）放电频率的变化，并以胃的运动功能变化为指标，同步观察了大鼠胃电变化情况。应用免疫荧光技术，以原癌基因c—fos为标志，观察MVZ中迷走复合体的神经元被激活情况。结果给予气囊充气达0．8ml时，迷走复合体中神经元放电频率、Fos的表达以及胃电没有明显改变。给予气囊充气达1．0ml时，迷走复合体中神经元放电、Fos的表达以及胃电开始增加。当气囊充气达1．2ml时，迷走复合体中神经元放电、Fos的表达以及胃电开始有明显增加的改变。气囊充气达1．4ml时，迷走复合体中神经元放电、Fos的表达以及胃电的改变最为明显，而当气囊注入空气1．5ml时，迷走复合体中神经元放电、Fos的表达以及胃电的变化与气囊充气1．4ml时相比，差异不是很明显。结论结肠扩张性刺激可以对支配内脏活动的延髓内脏带中的神经元有明显的激活作用，进而导致内脏活动的相应变化。     

白萝卜提取物对胃动力的影响

目的探讨萝卜提取物（Crude radish extract,Ecr）对胃动力的作用,为开发中药提供新的途径。方法在前期工作的基础上,采用灌胃给药方法,给大鼠以最有效剂量的萝卜提取物按60mg/kg灌胃后,经胃电记录,观察其对胃运动的影响,并对其对中枢支配胃运动的迷走复合体（dorsal vagal complex,DVC）中神经元放电频率的变化以及c-Fos表达的情况为标志,观察上述两个核团中神经元被激活状况,来探讨萝卜提取物促胃动力的作用机制。结果给药30min大鼠的胃电变化最为明显,给药45min后药物的作用逐渐降低,给药60min后胃电的变化基本接近于正常对照组。神经元的放电和Fos的表达情况与胃电变化情况相近。结论萝卜提取物对胃有较为明显的动力作用,而且按60mg/kg给药后的30min其促动力作用最为明显。     

大鼠迷走神经背核在电针保护胃粘膜损伤中的作用

研究了大鼠迷走神经背核（DMV）在调节胃功能和影响电针保护胃粘膜损伤中的作用。电损毁DMV组与假手术组和掼毁其他脑组织组（网状巨细胞核）比较，可降低胃粘膜血流量和跨膜电位差，在应激后更加剧（P＜0．01）。损毁DMV后能基本消除电针对胃粘膜损伤的保护作用。结果提示，中枢迷走通路，特别是DMV在调整胃功能和影响电针的保护效应中起重要作用。     

针刺调控胃酸分泌作用及机制

1 胃酸分泌的调节机制 胃酸分泌受头相、胃相和肠相的各种因素调节。中枢神经系统、外周神经系统(包括肠神经系统)及细胞内信号系统在各期中都发挥重要调节作用,胃粘膜中壁细胞、D细胞、主细胞、G细胞和嗜铬样细胞(ECL)是实现胃酸分泌功能的五大主要细胞,最终泌酸效应依赖于上述细胞间的相互作用。 1.1 中枢神经系统的调节 中枢神经系统内与酸分泌调节相关的主要部位是迷走神经运动背核,下丘脑和孤束核。迷走神经运动背核是中枢刺激的最终整合中枢,破坏此核后,中枢刺激的酸分泌消失;而电刺激该核则产生强的分泌效应,损毁     

急性心肌损伤后大鼠孤束核的FOS核神经胶质原纤维酸性蛋白表达的变化

目的：观察急性心肌损伤后大鼠延髓孤束核(Nucleus Tractus Solitarii, NTS)神经元和星形胶质细胞的反应。方法：向心肌内注射福尔马林造成急性心肌损伤，免疫荧光染色观察NTS中Fos阳性和GFAP阳性细胞的反应情况。结果：急性心肌损伤后2 h，大鼠NTS中Fos阳性神经元显著升高，4 h达到峰值，然后开始下降。急性心肌损伤后4 h GFAP阳性星形胶质细胞荧光强度明显增强，24 h达到高峰然后下降。结论：急性心肌损伤后，大鼠延髓NTS中神经元和星形胶质细胞被心肌伤害性刺激激活，参与心肌损伤后疼痛的中枢调控。     

Electro-acupuncture of Tsusanli and Shangchuhsu regulates gastric activity possibly through mediation of the vagus-solotary complex

BACKGROUND/AIMS: Acupuncture has been reportedly used to treat gastrointestinal diseases, however, its precise mechanism remains unknown. METHODOLOGY: In our study, the effects and mechanism of electro-acupuncture (EA) at Tsusanli (ST 36), Shangchuhsu (ST 37) on regulation of gastric activity were observed. RESULTS: EA at Tsusanli showed that gastric electric change was the most obvious, with significantly higher frequency and wave amplitude compared with that of the Shangchuhsu group and other groups. EA at Shangchuhsu demonstrated that the change of gastric electric level was much higher than that of the non-acupoint group and control group. After bilateral vagotomy, Tsusanlis was electro-acupunctured, the changes of electro-gastric graph (EGG) weren't significant with the control group. The frequency of electro-physiological activity in nucleus of solitary tract (NTS) and dorsal motor nucleus of the vagus nerve (DMV) in the Tsusanli group was markedly increased compared with that in the other group. Fos and GFAP expression in NTS and DMV in the Tsusanli group was significantly higher than that in other groups and control group. The results have indicated that EA at Tsusanli and Shangchuhsu cannot only regulate gastric activity, but also activate neurons and astrocytes in NTS and DMV. The effects on regulation and activation of EA at Tsusanli were very obvious. CONCLUSIONS: Our study suggests that this electroacupuncture regulation of gastric activity may partially depend upon integrated nerve pathway and related central neurons and astrocytes in the vagus-solitary complex.     

Rapid inhibition of neurons in the dorsal motor nucleus of the vagus by leptin

The peptide leptin conveys the availability of adipose energy stores to the brain. Increasing evidence implicates a significant role for extrahypothalamic sites of leptin action, including the dorsal vagal complex, a region critical for regulating visceral parasympathetic function. The hypothesis that leptin suppresses cellular activity in the dorsal motor nucleus of the vagus nerve (DMV) was tested using whole-cell patch-clamp recordings in brainstem slices. Leptin caused a rapid membrane hyperpolarization in 50% of rat DMV neurons. Leptin also hyperpolarized a subset of gastric-related neurons (62%), identified after gastric inoculation with a transneuronal retrograde viral tracer. The hyperpolarization was associated with a decrease in input resistance and cellular responsiveness and displayed characteristics consistent with an increased K+ conductance. Perfusion of tolbutamide (200 microM) reversed the leptin-induced hyperpolarization, and tolbutamide or wortmannin (10-100 nM) prevented the hyperpolarization, indicating that leptin activated an ATP-sensitive K+ channel via a phosphoinositide-3-kinase-dependent mechanism. Leptin reduced the frequency of spontaneous and miniature excitatory postsynaptic currents (EPSCs), whereas inhibitory postsynaptic currents (IPSCs) were largely unaffected. Electrical stimulation of the nucleus tractus solitarii (NTS) resulted in constant-latency EPSCs, which were decreased in amplitude by leptin. The paired-pulse ratio was increased, suggesting leptin effects involved activation of receptors presynaptic to the recorded neuron. A leptin-induced suppression of EPSCs, but not IPSCs, evoked by focal photolytic uncaging of glutamate within the NTS was also observed, supportive of leptin effects on the glutamatergic NTS projection to the DMV. Therefore, leptin directly hyperpolarized and indirectly suppressed excitatory synaptic activity to DMV neurons involved in visceral regulation, including gastric-related neurons.     

Inhibitory effects of cholecystokinin on postprandial gastric myoelectrical activity

While a number of studies have investigated the effects of cholecystokinin (CCK) on gastrointestinal motility, little is known on the effects of CCK on gastric myoelectrical activity, which regulates gastric motility. The aim of this study was to investigate the effects of intravenous infusion of CCK-8 on gastric myoelectrical activity in normal humans. Gastric myoelectrical activity was measured in 10 healthy subjects with a noninvasive electrogastrographic technique by placing abdominal electrodes on the epigastric area. Two study sessions were performed in each subject on two separate days with double-blinded infusion of either saline or CCK (24 pmol/kg/hr). The procedure for each session was as follows: (A) 30-min baseline fasting electrogastrogram (EGG); (B) start infusion, another 30-min EGG; (C) give meal, 60-min EGG; and (D) stop infusion, another 60-min EGG. The dominant frequency and peak power (amplitude) of the EGG, and the percentage of normal 2–4 cycles/min slow waves during each recording session were computed and compared between placebo and CCK. It was found that normal 3 cpm slow waves were recorded in all EGGs. Infusion of CCK had no effect on the frequency of the gastric slow wave and did not induce gastric dysrhythmias. It was also found that intravenous infusion of CCK significantly decreased the EGG peak power (amplitude) during the first hour after the meal (the infusion was given during this period) in comparison with placebo (P<0.05). This inhibitory effect on EGG peak power was sustained but not significant during the second postprandial hour (the infusion was not given during this period). It was concluded that intravenous infusion of CCK at a physiological concentration significantly decreased the postprandial EGG amplitude in normal humans, suggesting an inhibitory effect on postprandial gastric motility, but did not change the frequency and regularity of the gastric slow wave.     

Role of Medullary Cholinoceptors in Baroreflex Bradycardia

Cholinergic receptors present in three medullary nuclei namely, the nucleus tractus solitarii (NTS), nucleus ambiguus (AMB) and the dorsal motor nucleus of the vagus nerve (DMV) have been studied with regard to their role in regulation of heart rate (HR), blood pressure (BP) and baroreceptor reflex activation induced bradycardia in cats.

Microinjection of carbachol into NTS was without effect while administration of carbachol or pilocarpine into AMB and DMV elicited dose related decrease in HR without affecting BP. These effects were completely antagonized by ethylbenztropine. Bilateral muscarinic cholinoceptor blockade of either AMB or DMV, with ethylbenztropine, produced a partial inhibition of the baroreflex bradycardia while intra-cisternal ethylbenztropine completely abolished this reflex response. Involvement of muscarinic cholinoceptors of AMB or DMV in baroreflex mediated adjustments of HR is therefore suggested.     

Clinical Applications of Electrogastrography

Recently, electrogastrography (EGG) has received more and more attention. While gastroenterologists are interested in its clinical applications, concerns remain regarding the reliability and analysis of the EGG and the correlation between the EGG and gastric motility. The aims of this paper are to address these concerns and to review the potential clinical applications of the EGG. The following areas are discussed, based on the literature and our own experience with EGG: the refined method for the measurement of the EGG, the advanced techniques for quantitative analyses of the EGG, the reliability of the EGG in measuring gastric myoelectrical activity, the correlation between the EGG and gastric motility, and applications of the EGG in clinical gastroenterology.     

Expression and localization of c-Fos and NOS in the central nerve system following esophageal acid stimulation in rats

AIM: To determine the distribution of neurons expressing c-Fos and nitric oxide synthase (NOS) in the central nerve system (CNS) following esophageal acid exposure, and to investigate the relationship between c-Fos and NOS. METHODS: Twelve Wistar rats were randomly divided into two equal groups. Hydrochloric acid with pepsin was perfused in the lower part of the esophagus for 60 min. As a control, normal saline was used. Thirty minutes after the perfusion, the rats were killed and brains were removed and processed for c-Fos immunohistochemistry and NADPH-d histochemistry. Blood pressure (BP), heart rate (HR), and respiratory rate (RR) during the experimental procedures were recorded every 10 min. RESULTS: There were no significant differences in BP, HR and RR between the two groups. c-Fos immunoreactivity was significantly increased in rats receiving acid plus pepsin perfusion in amygdala (AM), paraventricular nucleus (PVN), parabrachial nucleus (PBN), nucleus tractus solitarius and dorsal motor nucleus of vagus (NTS/DMV), nucleus ambiguous (NA), reticular nucleus of medulla (RNM) and area postrema (AP). NOS reactivity in this group was significantly increased in PVN, PBN, NTS/DMV, RNM and AP. c-Fos and NOS had significant correlation between PVN, PBN, NTS/DMV, RNM and AP. CONCLUSION: Acid plus pepsin perfusion of the esophagus results in neural activation in areas of CNS, and NO is likely one of the neurotransmitters in some of these areas.