Objective:To anatomically and phenotypically characterize the insular cortex(IC)-nucleus tractus soli-tari(NTS)neural pathway.Methods:Adult male Sprague-Dawley rats were divided into three experimental cohorts for neu...Objective:To anatomically and phenotypically characterize the insular cortex(IC)-nucleus tractus soli-tari(NTS)neural pathway.Methods:Adult male Sprague-Dawley rats were divided into three experimental cohorts for neural circuit tracing.Anterograde labeling was achieved by injecting anterograde self-complementary adeno-associated viruses(scAAVs)into the IC.Retrograde tracing involved NTS injections of either retrograde scAAVs or FluoroGold(FG),combined with immunofluorescence histochemical staining to identify IC-originating projection neurons.For postsynaptic neurochemical phenotype characterization,IC was injected with AAV2/1-CaMKII-Cre,while a mixture of AAV2/9-Syn-DIO-mCherry and AAV2/9-VGAT1-EGFP was injected into the NTS.The rats were allowed to survive for one week following scAAVs or FG injection or four weeks after recombinase-dependent systems injection.Then the rats were sacrificed,and serial brain sections were prepared for immunofluorescence histochemical staining(brain section containing FG)and subsequent fluorescence/confocal microscopic analysis.Results:(1)Anterograde viral tracing re-vealed dense axonal terminals from the IC projecting to the medial subnucleus of the NTS,while retrograde tracing re-vealed that IC neurons projecting to the NTS were predominantly localized within the dysgranular layer;(2)IC-NTS projection neurons were exclusive glutamatergic(100%,n=3);(3)NTS neurons receiving IC inputs were mainly lo-calized in the medial subnucleus,and were predominantly GABAergic(79.8±3.2%,n=3).Conclusion:The pres-ent results indicate that a descending pathway from excitatory neurons of the IC terminates onto inhibitory neurons of the NTS,which might represent a potential neuromodulatory target for visceral pain disorders.展开更多
Objective Endogenous nitric oxide （NO） has been implicated in the regulation of neuronal activity which mediates cardiovascular reflexes. However, there is controversy concerning the role of NO in the nucleus tractu...Objective Endogenous nitric oxide （NO） has been implicated in the regulation of neuronal activity which mediates cardiovascular reflexes. However, there is controversy concerning the role of NO in the nucleus tractus solitarius （NTS）. The present study aims to elucidate the possible physiological role of endogenous NO in modulating the excitatory vagal afferent input to NTS neurons. Methods All the experiments in the rat were conducted under anaesthetic conditions. Ionophoresis method was used for the application of NO donor or nitric oxide synthase （NOS） inhibitor, and single unit recording method was employed to detect the effects of these applications on vagal afferentor cardio-pulmonary C-fibre reflex-evoked neuronal excitation in NTS. Results Ionophoresis applications of L-arginine （L-Arg）, a substrate of NOS, and sodium nitroprusside （SNP）, a NO donor, both attenuated the vagal afferent-evoked discharge by （51.5±7.6）% （n = 17） and （68.3±7.1）% （n = 9）, respectively. In contrast, application of D-Arg at the same current exerted no overall effect on this input. Also, both L-Arg and SNP inhibited spontaneous firing of most of the recorded neurons. In contrast, ionophoresis application of NG-nitro-Larginine methyl ester （L-NAME） enhanced vagal afferent-evoked excitation by （66.3±11.4）% （n = 7）. In addition, ionophoresis application of L-Arg and SNP significantly attenuated cardio-pulmonary C-fibre reflex-induced excitation in the tested NTS neurons. Conclusion Activation of local NO pathway in the NTS could suppress vagal afferent-evoked excitation, suggesting that NO is an important neuromodulator of visceral sensory input in the NTS.展开更多
The hippocampus is involved in the regulation of the autonomic nervous system,together with the hypothalamus and brainstem nuclei,such as the paraventricular nucleus and nucleus tractus solitarius.The vagus nerve-nucl...The hippocampus is involved in the regulation of the autonomic nervous system,together with the hypothalamus and brainstem nuclei,such as the paraventricular nucleus and nucleus tractus solitarius.The vagus nerve-nucleus tractus solitarius pathway has an important role in cardiovascular reflex regulation.Myocardial ischemia has been shown to cause changes in the autonomic nervous system,affecting the dynamic equilibrium of the sympathetic and vagal nerves.However,it remains poorly understood how the hippocampus communicates with brainstem nuclei to regulate the autonomic nervous system and alleviate myocardial ischemic tissue damage.A rat model of acute myocardial ischemia（AMI） was made by ligating the left anterior descending branch of the coronary artery.Three days before ischemia,the hippocampal CA1 region was damaged.Then,3 days after ischemia,electroacupuncture（EA） at Shenmen（HT7）-Tongli（HT5） was performed（continuous wave,1 m A,2 Hz,duration of 30 minutes）.Cluster analysis of firing patterns showed that one type of neuron was found in rats in the sham and AMI groups.Three types of neurons were observed in the AMI ＋ EA group.Six types of neurons were found in the AMI ＋ EA ＋ Lesion group.Correlation analysis showed that the frequency of vagus nerve discharge in each group was negatively correlated with heart rate（HR）（P 〈 0.05,r =-0.424）,and positively correlated with mean arterial pressure（MAP）（P 〈 0.05,r = 0.40987） and the rate-pressure product（RPP）（P 〈 0.05,r = 0.4252）.The total frequency of the nucleus tractus solitarius discharge in each group was positively correlated with vagus nerve discharge（P 〈 0.01,r = 0.7021）,but not with hemodynamic index（HR： P 〉 0.05,r =-0.03263; MAP： P 〉 0.05,r =-0.08993; RPP： P 〉 0.05,r =-0.03263）.Some neurons（Neuron C） were negatively correlated with vagus nerve discharge,HR,MAP and RPP in the AMI ＋ EA group（vagus nerve discharge： P 〈 0.05,r =-0.87749; HR： P 〈 0.01,r =-0.91902; MAP： P 〈 0.05,r =-0.85691; RPP： P 〈 0.01,r =-0.91902）.Some neurons（Neurons C,D and E） were positively correlated with vagus nerve discharge,HR,MAP and RPP in the AMI ＋ EA ＋ Lesion group（vagus nerve discharge： P 〈 0.01,r = 0.8905,P 〈 0.01,r = 0.9725,P 〈 0.01,r = 0.9054; HR： P 〈 0.01,r = 0.9347,P 〈 0.01,r = 0.9089,P 〈 0.05,r = 0.8247; MAP： P 〈 0.05,r = 0.8474,P 〈 0.01,r = 0.9691,P 〈 0.01,r = 0.9027; RPP： P 〈 0.05,r = 0.8637,P 〈 0.01,r = 0.9407,P 〈 0.01,r = 0.9027）.These findings show that the hippocampus-nucleus tractus solitarius-vagus nerve pathway is involved in the cardioprotective effect of EA at the heart meridian.Some interneurons in the nucleus tractus solitarius may play a particularly important role in the cardiomodulatory process.展开更多
Previous studies have shown that somatic sensation by acupuncture and visceral nociceptive stimulation can converge in the nucleus tractus solitarii where neurons integrate signals impact- ing on the function of organ...Previous studies have shown that somatic sensation by acupuncture and visceral nociceptive stimulation can converge in the nucleus tractus solitarii where neurons integrate signals impact- ing on the function of organs. To explore the role of the nucleus tractus solitarii in the protective mechanism of pre-moxibustion on gastric mucosa, nucleus tractus solitarii were damaged in rats and pre-moxibustion treatment at the Zusanli （ST36） point followed. The gastric mucosa was then damaged by the anhydrous ethanol lavage method. Morphological observations, enzyme linked immunosorbent assays, and western immunoblot analyses showed that gastric mucosa surface lesion and the infiltration of inflammatory cells were significantly ameliorated after pre-moxibustion treatment. Furthermore, the gastric mucosal damage index and somatostatin level were reduced, and epidermal growth factor content in the gastric mucosa and heat-shock protein-70 expression were increased. These results were reversed by damage to the nucleus tractus solitarii. These findings suggest that moxibustion pretreatment at the Zusanli point is protective against acute gastric mucosa injury, and nucleus tractus solitarii damage inhibits these responses. Therefore, the nucleus tractus solitarii may be an important area for regulating the signal transduction of the protective effect of pre-moxibustion on gastric mucosa.展开更多
BACKGROUND Central sensitization plays a pivotal role in the maintenance of chronic pain induced by chronic pancreatitis(CP).We hypothesized that the nucleus tractus solitarius(NTS),a primary central site that integra...BACKGROUND Central sensitization plays a pivotal role in the maintenance of chronic pain induced by chronic pancreatitis(CP).We hypothesized that the nucleus tractus solitarius(NTS),a primary central site that integrates pancreatic afferents apart from the thoracic spinal dorsal horn,plays a key role in the pathogenesis of visceral hypersensitivity in a rat model of CP.AIM To investigate the role of the NTS in the visceral hypersensitivity induced by chronic pancreatitis.METHODS CP was induced by the intraductal injection of trinitrobenzene sulfonic acid(TNBS)in rats.Pancreatic hyperalgesia was assessed by referred somatic pain via von Frey filament assay.Neural activation of the NTS was indicated by immunohistochemical staining for Fos.Basic synaptic transmission within the NTS was assessed by electrophysiological recordings.Expression of vesicular glutamate transporters(VGluTs),N-methyl-D-aspartate receptor subtype 2B(NR2B),andα-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor subtype 1(GluR1)was analyzed by immunoblotting.Membrane insertion of NR2B and GluR1 was evaluated by electron microscopy.The regulatory role of the NTS in visceral hypersensitivity was detected via pharmacological approach and chemogenetics in CP rats.RESULTS TNBS treatment significantly increased the number of Fos-expressing neurons within the caudal NTS.The excitatory synaptic transmission was substantially potentiated within the caudal NTS in CP rats(frequency:5.87±1.12 Hz in CP rats vs 2.55±0.44 Hz in sham rats,P<0.01;amplitude:19.60±1.39 pA in CP rats vs 14.71±1.07 pA in sham rats;P<0.01).CP rats showed upregulated expression of VGluT2,and increased phosphorylation and postsynaptic trafficking of NR2B and GluR1 within the caudal NTS.Blocking excitatory synaptic transmission via the AMPAR antagonist CNQX and the NMDAR antagonist AP-5 microinjection reversed visceral hypersensitivity in CP rats(abdominal withdraw threshold:7.00±1.02 g in CNQX group,8.00±0.81 g in AP-5 group and 1.10±0.27 g in saline group,P<0.001).Inhibiting the excitability of NTS neurons via chemogenetics also significantly attenuated pancreatic hyperalgesia(abdominal withdraw threshold:13.67±2.55 g in Gi group,2.00±1.37 g in Gq group,and 2.36±0.67 g in mCherry group,P<0.01).CONCLUSION Our findings suggest that enhanced excitatory transmission within the caudal NTS contributes to pancreatic pain and emphasize the NTS as a pivotal hub for the processing of pancreatic afferents,which provide novel insights into the central sensitization of painful CP.展开更多
Leptin,an adipocyte-derived peptide hormone,has been shown to facilitate breathing.However,the central sites and circuit mechanisms underlying the respiratory effects of leptin remain incompletely understood.The prese...Leptin,an adipocyte-derived peptide hormone,has been shown to facilitate breathing.However,the central sites and circuit mechanisms underlying the respiratory effects of leptin remain incompletely understood.The present study aimed to address whether neurons expressing leptin receptor b(LepRb)in the nucleus tractus solitarii(NTS)contribute to respiratory control.Both chemogenetic and optogenetic stimulation of LepRb-ex-pressing NTS(NTS^(LepRb))neurons notably activated breathing.Moreover,stimulation of NTS^(LepRb) neurons projecting to the lateral parabrachial nucleus(LPBN)not only remarkably increased basal ventilation to a level similar to that of the stimulation of all NTS^(LepRb) neurons,but also activated LPBN neurons projecting to the preBotzinger complex(preBotC).By contrast,ablation of NTS^pRb neurons projecting to the LPBN notably eliminated the enhanced respiratory effect induced by NTSLepRb neuron stimulation.In brainstem slices,bath application of leptin rapidly depolarized the membrane potential,increased the spontaneous firing rate,and accelerated the Ca2+transients in most NTSLepRb neurons.Therefore,leptin potentiates breathing in the NTS most likely via an NTS-LPBN-preBdtC circuit.展开更多
BACKGROUND： Electrophysiology can prove the integration of afferent information from the stomach meridian of Foot-Yangming in the nucleus tractus solitarius （NTS） and objectively describe the specific association b...BACKGROUND： Electrophysiology can prove the integration of afferent information from the stomach meridian of Foot-Yangming in the nucleus tractus solitarius （NTS） and objectively describe the specific association between meridian vessels and Zang Fu organs. OBJECTIVE： To investigate the effects of afferent information from acupuncture at Sibai （ST 2） acupoint on neuronal discharge in rat NTS. DESIGN, TIME AND SETFING： A randomized, controlled, animal experiment was performed at the Key Laboratory of Meridian-Vessels and Zang Fu Organs, Traditional Chinese Medicine University of Hunan, State Administration of Traditional Chinese Medicine, and Key Laboratory of Acupuncture, Moxibustion, and the Biological Information of Hunan Higher Education Institutes, between December 2005 and October 2008. MATERIALS： A total of 52 Sprague Dawley rats, of either gender, aged 4 months, were included in this study. Acupuncture needles of 0.32 mm （diameter） x 40 mm （length） were used. METHODS： An extracellular recording protocol was applied. The Sibai （ST 2） acupoint in the stomach meridian of Foot-Yangming was used as an acupuncture point （acupoint）. Simultaneously, Dicang （ST 4） and Neiting （ST 44） acupoints in the stomach meridian of Foot-Yangming, Quanliao （S118） acupoint in the small intestine meridian of Hand-Taiyang, and a non-acupoint lateral to Sibai （ST 2） acupoint, were selected as controls. The Sibai （ST 2） acupoint was stimulated for 30 seconds by hand acupuncture through twirling and rotating, to determine the neurons responding to body surface stimulation in the NTS. MAIN OUTCOME MEASURES： Frequency of responding NTS neurons after acupuncture at four acupoints including Sibai （ST 2）, Dicang （ST 4）, Neiting （ST 44） and Quanliao （SI 18） and one non-acupoint. RESULTS： The frequency of responding NTS neurons was significantly higher after acupuncture at Sibaithan at control sites including the Dicang （ST 4）, Neiting （ST 44） and Quanliao （S118） acupoints and at the non-acupoint （P 〈 0.01）. The frequency of responding NTS neurons at Dicang （ST 4） and Quanliao （SI 18） was significantly higher than at Quanliao （SI 18） and the non-acupoint （P 〈 0.05）. The rate of frequency change of responding NTS neurons for the Sibai （ST 2）, Dicang （ST 4）, Neiting （ST 44）, and Quanliao （S118） acupoints as well as the non-acupoint was （35.08±4.80） %, （28.25± 5.46） %, （27.57± 4.87） %, （20.02 ±4.23） %, and （18.55 ±2.49） % respectively. Simultaneously, significant differences existed between Sibai （ST 2） and the other acupoints （P 〈 0.05 or P〈 0.01）. CONCLUSION： Compared with the Dicang （ST 4） and Neiting （ST 44） acupoints in the stomach meridian of Foot-Yangming, Quanliao （SI 18） acupoint in the small intestine meridian of Hand-Taiyang, and the non-acupoint lateral to Sibai （ST 2） acupoint, the Sibai （ST 2） acupoint in the stomach meridian of Foot- Yangming is more closely related to the NTS. In the stomach meridian of Foot- Yangming, afferent information is different in distant and near Shu acupoints, indicating that each Shu acupoint has its own specificity.展开更多
The relationship between 5-HT receptor and α-adrenoceptor was investigated inrat medullary slice preparations.In 57 nucleus tractus solitarii(NTS)neurons,47(82.5%)responded to both serotonin(5-HT)and norepinephrine(N...The relationship between 5-HT receptor and α-adrenoceptor was investigated inrat medullary slice preparations.In 57 nucleus tractus solitarii(NTS)neurons,47(82.5%)responded to both serotonin(5-HT)and norepinephrine(NE).After synapse transmissionwas blocked by perfusion of artificial cerebrospinal fluid(ACSF)with low calcium andhigh magnesium,5 in 8 neurons were still sensitive to both 5-HT and NE.On the otherhand,3 in 5 neurons responding only to 5-HT or NA were sensitive to both 5-HT andNE after the synapse transmission blockage.In some neurons which exhibited excitatoryor inhibitory responses to 5-HT or NE alone,the responses were inversed when perfusedwith 5-HT and NE in combination.These results suggest that there may exist aninhibitory interaction between 5-HT receptors and α-adrenoceptors in NTS and that most5-HT and α-adrenoceptors coexist in the same NTS neurons.展开更多
The nucleus tractus solitarii(NTS)is one of the morphologically and functionally defined centers that engage in the autonomic regulation of cardiovascular activity.Phenotypically-characterized NTS neurons have been im...The nucleus tractus solitarii(NTS)is one of the morphologically and functionally defined centers that engage in the autonomic regulation of cardiovascular activity.Phenotypically-characterized NTS neurons have been implicated in the differential regulation of blood pressure(BP).Here,we investigated whether phenylethanolamine N-methyltransferase(PNMT)-expressing NTS(NTS^(PNMT))neurons contribute to the control of BP.We demonstrate that photostimulation of NTS^(PNMT)neurons has variable effects on BP.A depressor response was produced during optogenetic stimulation of NTS^(PNMT)neurons projecting to the paraventricular nucleus of the hypothalamus,lateral parabrachial nucleus,and caudal ventrolateral medulla.Conversely,photostimulation of NTS^(PNMT)neurons projecting to the rostral ventrolateral medulla produced a robust pressor response and bradycardia.In addition,genetic ablation of both NTS^(PNMT)neurons and those projecting to the rostral ventrolateral medulla impaired the arterial baroreflex.Overall,we revealed the neuronal phenotype-and circuit-specific mechanisms underlying the contribution of NTS^(PNMT)neurons to the regulation of BP.展开更多
BACKGROUND Hydrogen sulfide(H2S)is a recently discovered gaseous neurotransmitter in the nervous and gastrointestinal systems.It exerts its effects through multiple signaling pathways,impacting various physiological a...BACKGROUND Hydrogen sulfide(H2S)is a recently discovered gaseous neurotransmitter in the nervous and gastrointestinal systems.It exerts its effects through multiple signaling pathways,impacting various physiological activities.The nucleus tractus solitarius(NTS),a vital nucleus involved in visceral sensation,was investigated in this study to understand the role of H2S in regulating gastric function in rats.AIM To examine whether H2S affects the nuclear factor kappa-B(NF-κB)and transient receptor potential vanilloid 1 pathways and the neurokinin 1(NK1)receptor in the NTS.METHODS Immunohistochemical and fluorescent double-labeling techniques were employed to identify cystathionine beta-synthase(CBS)and c-Fos co-expressed positive neurons in the NTS during rat stress.Gastric motility curves were recorded by inserting a pressure-sensing balloon into the pylorus through the stomach fundus.Changes in gastric motility were observed before and after injecting different doses of NaHS(4 nmol and 8 nmol),physiological saline,Capsazepine(4 nmol)+NaHS(4 nmol),pyrrolidine dithiocarbamate(PDTC,4 nmol)+NaHS(4 nmol),and L703606(4 nmol)+NaHS(4 nmol).RESULTS We identified a significant increase in the co-expression of c-Fos and CBS positive neurons in the NTS after 1 h and 3 h of restraint water-immersion stress compared to the expressions observed in the control group.Intra-NTS injection of NaHS at different doses significantly inhibited gastric motility in rats(P<0.01).However,injection of saline,first injection NF-κB inhibitor PDTC or transient receptor potential vanilloid 1(TRPV1)antagonist Capsazepine or NK1 receptor blockers L703606 and then injection NaHS did not produce significant changes(P>0.05).CONCLUSION NTS contains neurons co-expressing CBS and c-Fos,and the injection of NaHS into the NTS can suppress gastric motility in rats.This effect may be mediated by activating TRPV1 and NK1 receptors via the NF-κB channel.展开更多
This experiment aimed to investigate the effect of adrenergic system in the subnucleus commissuriu of nucleus solitrius tractus (CNTS) on renal nerve discharges. Norepinephrine (NE) was microinjected into the CNTS of ...This experiment aimed to investigate the effect of adrenergic system in the subnucleus commissuriu of nucleus solitrius tractus (CNTS) on renal nerve discharges. Norepinephrine (NE) was microinjected into the CNTS of rabbits and mean arterial blood pressure (MAP) and renal nerve discharges (FRND) were synchronously recorded. The results indicated that (1) microinjection of norepinephine into the CNTS of rabbit could significantly attenuate the frequency of renal nerve discharge, and at the same time decrease markedly the mean arterial pressure. (2) Microinjection of 0.3 nmol yohimbin into CNTS had no significant influence on FRND and MAP, but could attenuate and even reverse the effects of NE on FRND and MAP. These results suggest that microinjection of NE into CNTS may activate the alpha-adrenorecptor located in CNTS and secondarily produce a depressor effect by attenuating the activity of peripheral sympathetic nervous system.展开更多
The central amygdala(CeA)is a crucial modulator of emotional,behavioral,and autonomic functions,including cardiovascular responses.Despite its importance,the specific circuit by which the CeA modulates blood pressure ...The central amygdala(CeA)is a crucial modulator of emotional,behavioral,and autonomic functions,including cardiovascular responses.Despite its importance,the specific circuit by which the CeA modulates blood pressure remains insufficiently explored.Our investigations demonstrate that photostimulation of GABAergic neurons in the centromedial amygdala(CeMGABA),as opposed to those in the centrolateral amygdala(CeL),produces a depressor response in both anesthetized and freely-moving mice.In addition,activation of CeMGABA axonal terminals projecting to the nucleus tractus solitarius(NTS)significantly reduces blood pressure.These CeMGABA neurons form synaptic connections with NTS neurons,allowing for the modulation of cardiovascular responses by influencing the caudal or rostral ventrolateral medulla.Furthermore,CeMGABA neurons targeting the NTS receive dense inputs from the CeL.Consequently,stimulation of CeMGABA neurons elicits hypotension through the CeM-NTS circuit,offering deeper insights into the cardiovascular responses associated with emotions and behaviors.展开更多
AIM: To investigate the effect and mechanism of stimulation of the hypothalamic paraventricular nucleus with glutamate acid in rats with ulcerative colitis(UC).METHODS: The rats were anesthetized with 10% chloral hydr...AIM: To investigate the effect and mechanism of stimulation of the hypothalamic paraventricular nucleus with glutamate acid in rats with ulcerative colitis(UC).METHODS: The rats were anesthetized with 10% chloral hydrate via abdominal injection and treated with an equal volume of TNBS + 50% ethanol enema, injected into the upper section of the anus with the tail facing up. Colonic damage scores were calculated after injecting a certain dose of glutamic acid into the paraventricular nucleus(p VN), and the effect of the nucleus tractus solitarius(NTS) and vagus nerve in alleviating UC injury through chemical stimulation of the p VN was observed in rats. Expression changes of C-myc, Apaf-1, caspase-3, interleukin(IL)-6, and IL-17 during the protection against UC injury through chemical stimulation of the p VN in rats were detected by Western blot. Malondialdehyde(MDA) content and superoxide dismutase(SOD) activity in colon tissues of rats were measured by colorimetric methods. RESULTS: Chemical stimulation of the PVN significantly reduced UC in rats in a dose-dependent manner. The protective effects of the chemical stimulationof the p VN on rats with UC were eliminated after chemical damage to the p VN. After glutamate receptor antagonist kynurenic acid was injected into the p VN, the protective effects of the chemical stimulation of the p VN were eliminated in rats with UC. After AVpVl receptor antagonist([Deamino-penl, val4, D-Arg8]-vasopressin) was injected into NTS or bilateral chemical damage to NTS, the protective effect of the chemical stimulation of p VN on UC was also eliminated. After chemical stimulation of the p VN, SOD activity increased, MDA content decreased, C-myc protein expression significantly increased, caspase-3 and Apaf-1 protein expression significantly decreased, and IL-6 and IL-17 expression decreased in colon tissues in rats with UC. CONCLUSION: Chemical stimulation of the hypothalamic p VN provides a protective effect against UC injury in rats. Hypothalamic p VN, NTS and vagus nerve play key roles in this process.展开更多
Central sensitization is essential in maintaining chronic pain induced by chronic pancreatitis(CP),but cortical modulation of painful CP remains elusive.Here,we examined the role of the anterior cingulate cortex(ACC)i...Central sensitization is essential in maintaining chronic pain induced by chronic pancreatitis(CP),but cortical modulation of painful CP remains elusive.Here,we examined the role of the anterior cingulate cortex(ACC)in the pathogenesis of abdominal hyperalgesia in a rat model of CP induced by intraductal administration of trinitrobenzene sulfonic acid(TNBS).TNBS treatment resulted in long-term abdominal hyperalgesia and anxiety in rats.Morphological data indicated that painful CP induced a significant increase in FOS-expressing neurons in the nucleus tractus solitarii(NTS)and ACC,and some FOS-expressing neurons in the NTS projected to the ACC.In addition,a larger portion of ascending fibers from the NTS innervated pyramidal neurons,the neural subpopulation primarily expressing FOS under the condition of painful CP,rather than GABAergic neurons within the ACC.CP rats showed increased expression of vesicular glutamate transporter 1,and increased membrane trafficking and phosphorylation of the N-methyl-D-aspartate receptor(NMDAR)subunit NR2B and theα-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor(AMPAR)subunit GluR1 within the ACC.Microinjection of NMDAR and AMPAR antagonists into the ACC to block excitatory synaptic transmission significantly attenuated abdominal hyperalgesia in CP rats,which was similar to the analgesic effect of endomorphins injected into the ACC.Specifically inhibiting the excitability of ACC pyramidal cells via chemogenetics reduced both hyperalgesia and comorbid anxiety,whereas activating these neurons via optogenetics failed to aggravate hyperalgesia and anxiety in CP rats.Taken together,these findings provide neurocircuit,biochemical,and behavioral evidence for involvement of the ACC in hyperalgesia and anxiety in CP rats,as well as novel insights into the cortical modulation of painful CP,and highlights the ACC as a potential target for neuromodulatory interventions in the treatment of painful CP.展开更多
Objective To examine the neuroanatomical substrates underlying the effects of minocycline in alleviating lipopolysaccharide(LPS)-induced neuroinflammation.Methods Forty C57BL/6 male mice were randomly and equally divi...Objective To examine the neuroanatomical substrates underlying the effects of minocycline in alleviating lipopolysaccharide(LPS)-induced neuroinflammation.Methods Forty C57BL/6 male mice were randomly and equally divided into eight groups.Over three conse-cutive days,saline was administered to four groups of mice and minocycline to the other four groups.Immediately after the administration of saline or minocycline on the third day,two groups of mice were additionally injected with saline and the other two groups were injected with LPS.Six or 24 hours after the last injection,mice were sacrificed and the brains were removed.Immunohistochemical staining across the whole brain was performed to detect microglia activation via Iba1 and neuronal activation via c-Fos.Morphology of microglia and the number of c-Fo-positive neurons were analyzed by Image-Pro Premier 3D.One-way ANOVA and Fisher’s least-significant differences were employed for statistical analyses.Results Minocycline alleviated LPS-induced neuroinflammation as evidenced by reduced activation of microglia in multiple brain regions,including the shell part of the nucleus accumbens(Acbs),paraventricular nucleus(PVN)of the hypothalamus,central nucleus of the amygdala(CeA),locus coeruleus(LC),and nucleus tractus solitarius(NTS).Minocycline significantly increased the number of c-Fo-positive neurons in NTS and area postrema(AP)after LPS treatment.Furthermore,in NTS-associated brain areas,including LC,lateral parabrachial nucleus(LPB),periaqueductal gray(PAG),dorsal raphe nucleus(DR),amygdala,PVN,and bed nucleus of the stria terminali(BNST),minocycline also significantly increased the number of c-Fo-positive neurons after LPS administration.Conclusion Minocycline alleviates LPS-induced neuroinflammation in multiple brain regions,possibly due to increased activation of neurons in the NTS-associated network.展开更多
Estrogen receptor a is widely distributed in the rat brain, but the tissue- or target-specificity of the estrogen receptor a gene promoters remains unknown. In the present study, we used transgenic rats expressing enh...Estrogen receptor a is widely distributed in the rat brain, but the tissue- or target-specificity of the estrogen receptor a gene promoters remains unknown. In the present study, we used transgenic rats expressing enhanced green fluorescent protein under the control of the estrogen receptor a 0/B promoter to examine expression driven by this promoter in two significant nuclei that regulate cardiovascular activity, the area postrema and the nucleus tractus solitarius. Immunohistochemistry showed that enhanced green fluorescent protein-labeled cells were distributed in the area postrema and the nucleus tractus solitarius of both female and male transgenic rats, and a neural network of enhanced green fluorescent protein-positive fibers was seen between the area postrema and the nucleus tractus solitarius. The number of enhanced green fluorescent protein-labeled cells in the area postrema of female rats was significantly higher than in the males, but no significant difference was found in the number of enhanced green fluorescent protein-labeled cells in the nucleus tractus solitarius. The sex differences in the number of enhanced green fluorescent protein-labeled cells in the area postrema was not affected after ovariectomy or 1713-estradiol benzoate treatment in adult rats. Our results suggest that the effects of estrogen in the area postrema are related to the expression of estrogen receptor a under the control of the 0/B promoter, and changes in the sex hormone environment in the adult period do not affect estrogen receptor a expression in the area postrema or the nucleus tractus solitarius.展开更多
The brainstem is a major site in the central nervous system involved in the processing of the cardiovascular reflexes such as the baroreflex and the peripheral chemoreflex. The nucleus tractus solitarius and the rostr...The brainstem is a major site in the central nervous system involved in the processing of the cardiovascular reflexes such as the baroreflex and the peripheral chemoreflex. The nucleus tractus solitarius and the rostral ventrolateral medulla are 2 important brainstem nuclei, and they play pivotal roles in autonomic cardiovascular regulation. Angiotensin II is one of the neurotransmitters involved in the processing of the known that one of the mechanisms by which angiotensin II exerts cardiovascular reflexes within the brainstem. It is well- its effect is via the activation of pathways that generate reactive oxygen species （ROS）. In the central nervous system, ROS are reported to be involved in several pathological dis- eases such as hypertension, heart failure and sleep apnea. However, little is known about the role of ROS in the processing of the cardiovascular reflexes within the brainstem. The present review mainly discussed some recent findings documenting a role for ROS in the processing of the baroreflex and the peripheral chemoreflex in the brainstem.展开更多
One likely mechanism of essential hypertension(EH) is increased sympathoexcitation due to abnormal functions in the cardiovascular center of the brain. Recent findings obtained using experimental animal models of EH h...One likely mechanism of essential hypertension(EH) is increased sympathoexcitation due to abnormal functions in the cardiovascular center of the brain. Recent findings obtained using experimental animal models of EH have shown that abnormal inflammation in the cardiovascular center may contribute to the onset of hypertension. Inflammatory molecules such as cytokines and reactive oxygen species released from the inflamed vasculature and glial cells in the medulla oblongata and hypothalamus might directly or indirectly affect neuronal functions. This in turn could increase sympathetic nerve activity and consequently arterial pressure. Abnormal inflammatory responses in the brain could also be central mechanisms underlying angiotensin Ⅱ-related EH. In this review, we present the current understanding of EH mechanisms with regard to inflammatory responses in the cardiovascular center.展开更多
Objective:Oncocardiology is increasingly hot research field/topic in the clinical management of cancer with anti-angiogenic therapy of vascular endothelial growth factor(VEGF)that may cause cardiovascular toxicity,suc...Objective:Oncocardiology is increasingly hot research field/topic in the clinical management of cancer with anti-angiogenic therapy of vascular endothelial growth factor(VEGF)that may cause cardiovascular toxicity,such as hypertension via vascular dysfunction and attenuation of eNOS/NO signaling in the baroreflex afferent pathway.The aim of the current study was to evaluate the potential roles of VEGF/VEGF receptors(VEGFRs)expressed in the baroreflex afferent pathway in autonomic control of blood pressure(BP)regulation.Methods:The distribution and expression of VEGF/VEGFRs were detected in the nodose ganglia(NG)and nucleus of tractus solitary(NTS)using immunostaining and molecular approaches.The direct role of VEGF was tested by NG microinjection under physiological and hypertensive conditions.Results:Immunostaining data showed that either VEGF or VEGFR2/VEGFR3 was clearly detected in the NG and NTS of adult male rats.Microinjection of VEGF directly into the NG reduced the mean blood pressure(MBP)dose-dependently,which was less dramatic in renovascular hypertension(RVH)rats,suggesting the VEGF-mediated depressor response by direct activation of the 1st-order baroreceptor neurons in the NG under both normal and disease conditions.Notably,this reduced depressor response in RVH rats was directly caused by the downregulation of VEGFR2,which compensated the up regulation of VEGF/VEGFR3 in the NG during the development of hypertension.Conclusion:It demonstrated for the first time that the BP-lowering property of VEGF/VEGFRs signaling via the activation of baroreflex afferent function may be a common target/pathway leading to BP dysregulation in anti-angiogenic therapy.展开更多
Foreign bodies ingestion is regularly observed in gastroenterology context. The evolution is favorable with early extraction. Our main objective was to evaluate foreign bodies managed in digestive endoscopic center of...Foreign bodies ingestion is regularly observed in gastroenterology context. The evolution is favorable with early extraction. Our main objective was to evaluate foreign bodies managed in digestive endoscopic center of University hospital center Gabriel Touré. The study was retrospective from January 2007 to October 2017 in the endoscopic center of the service of gastroenterology of University hospital center Gabriel Touré and concerned the patients who have been addressed at this center for foreign bodies. We collated 44 patients who ingested foreign bodies among 2750 digestive endoscopies</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> that is to say</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> a frequency of 0.16%. In patient’s history, we found caustic obstruction in 2.3% of patients. The foreign body ingestion was accidental in 97.7% of cases. Pieces of money were more frequent (54.4%). In 86.4%, the foreign bodies were into the esophagus. Upper digestive endoscopy performed foreign bodies extraction in 88.6 of cases. In 9.1%</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">the elimination was spontaneous on 72 hours. Surgeon was indicated in 2.3% of patients. The evolution was favorable in 97.7% of patients. One patient died by digestive bleeding. Conclusion: Foreign bodies ingestion is frequent in children. The upper digestive endoscopy can do the diagnosis and the management.展开更多
文摘Objective:To anatomically and phenotypically characterize the insular cortex(IC)-nucleus tractus soli-tari(NTS)neural pathway.Methods:Adult male Sprague-Dawley rats were divided into three experimental cohorts for neural circuit tracing.Anterograde labeling was achieved by injecting anterograde self-complementary adeno-associated viruses(scAAVs)into the IC.Retrograde tracing involved NTS injections of either retrograde scAAVs or FluoroGold(FG),combined with immunofluorescence histochemical staining to identify IC-originating projection neurons.For postsynaptic neurochemical phenotype characterization,IC was injected with AAV2/1-CaMKII-Cre,while a mixture of AAV2/9-Syn-DIO-mCherry and AAV2/9-VGAT1-EGFP was injected into the NTS.The rats were allowed to survive for one week following scAAVs or FG injection or four weeks after recombinase-dependent systems injection.Then the rats were sacrificed,and serial brain sections were prepared for immunofluorescence histochemical staining(brain section containing FG)and subsequent fluorescence/confocal microscopic analysis.Results:(1)Anterograde viral tracing re-vealed dense axonal terminals from the IC projecting to the medial subnucleus of the NTS,while retrograde tracing re-vealed that IC neurons projecting to the NTS were predominantly localized within the dysgranular layer;(2)IC-NTS projection neurons were exclusive glutamatergic(100%,n=3);(3)NTS neurons receiving IC inputs were mainly lo-calized in the medial subnucleus,and were predominantly GABAergic(79.8±3.2%,n=3).Conclusion:The pres-ent results indicate that a descending pathway from excitatory neurons of the IC terminates onto inhibitory neurons of the NTS,which might represent a potential neuromodulatory target for visceral pain disorders.
基金supported by Chongqing Science and Technology Commission (No.CHTC2007BA5025)Shanghai Pujiang Program (No.07PJ14015)Chongqing Educational Department (No. KJ0707021)
文摘Objective Endogenous nitric oxide （NO） has been implicated in the regulation of neuronal activity which mediates cardiovascular reflexes. However, there is controversy concerning the role of NO in the nucleus tractus solitarius （NTS）. The present study aims to elucidate the possible physiological role of endogenous NO in modulating the excitatory vagal afferent input to NTS neurons. Methods All the experiments in the rat were conducted under anaesthetic conditions. Ionophoresis method was used for the application of NO donor or nitric oxide synthase （NOS） inhibitor, and single unit recording method was employed to detect the effects of these applications on vagal afferentor cardio-pulmonary C-fibre reflex-evoked neuronal excitation in NTS. Results Ionophoresis applications of L-arginine （L-Arg）, a substrate of NOS, and sodium nitroprusside （SNP）, a NO donor, both attenuated the vagal afferent-evoked discharge by （51.5±7.6）% （n = 17） and （68.3±7.1）% （n = 9）, respectively. In contrast, application of D-Arg at the same current exerted no overall effect on this input. Also, both L-Arg and SNP inhibited spontaneous firing of most of the recorded neurons. In contrast, ionophoresis application of NG-nitro-Larginine methyl ester （L-NAME） enhanced vagal afferent-evoked excitation by （66.3±11.4）% （n = 7）. In addition, ionophoresis application of L-Arg and SNP significantly attenuated cardio-pulmonary C-fibre reflex-induced excitation in the tested NTS neurons. Conclusion Activation of local NO pathway in the NTS could suppress vagal afferent-evoked excitation, suggesting that NO is an important neuromodulator of visceral sensory input in the NTS.
基金supported by the National Natural Science Foundation of China,No.81273858a grant from the Anhui University Research and Innovation Platform Team Construction Project in China,No.2015TD033
文摘The hippocampus is involved in the regulation of the autonomic nervous system,together with the hypothalamus and brainstem nuclei,such as the paraventricular nucleus and nucleus tractus solitarius.The vagus nerve-nucleus tractus solitarius pathway has an important role in cardiovascular reflex regulation.Myocardial ischemia has been shown to cause changes in the autonomic nervous system,affecting the dynamic equilibrium of the sympathetic and vagal nerves.However,it remains poorly understood how the hippocampus communicates with brainstem nuclei to regulate the autonomic nervous system and alleviate myocardial ischemic tissue damage.A rat model of acute myocardial ischemia（AMI） was made by ligating the left anterior descending branch of the coronary artery.Three days before ischemia,the hippocampal CA1 region was damaged.Then,3 days after ischemia,electroacupuncture（EA） at Shenmen（HT7）-Tongli（HT5） was performed（continuous wave,1 m A,2 Hz,duration of 30 minutes）.Cluster analysis of firing patterns showed that one type of neuron was found in rats in the sham and AMI groups.Three types of neurons were observed in the AMI ＋ EA group.Six types of neurons were found in the AMI ＋ EA ＋ Lesion group.Correlation analysis showed that the frequency of vagus nerve discharge in each group was negatively correlated with heart rate（HR）（P 〈 0.05,r =-0.424）,and positively correlated with mean arterial pressure（MAP）（P 〈 0.05,r = 0.40987） and the rate-pressure product（RPP）（P 〈 0.05,r = 0.4252）.The total frequency of the nucleus tractus solitarius discharge in each group was positively correlated with vagus nerve discharge（P 〈 0.01,r = 0.7021）,but not with hemodynamic index（HR： P 〉 0.05,r =-0.03263; MAP： P 〉 0.05,r =-0.08993; RPP： P 〉 0.05,r =-0.03263）.Some neurons（Neuron C） were negatively correlated with vagus nerve discharge,HR,MAP and RPP in the AMI ＋ EA group（vagus nerve discharge： P 〈 0.05,r =-0.87749; HR： P 〈 0.01,r =-0.91902; MAP： P 〈 0.05,r =-0.85691; RPP： P 〈 0.01,r =-0.91902）.Some neurons（Neurons C,D and E） were positively correlated with vagus nerve discharge,HR,MAP and RPP in the AMI ＋ EA ＋ Lesion group（vagus nerve discharge： P 〈 0.01,r = 0.8905,P 〈 0.01,r = 0.9725,P 〈 0.01,r = 0.9054; HR： P 〈 0.01,r = 0.9347,P 〈 0.01,r = 0.9089,P 〈 0.05,r = 0.8247; MAP： P 〈 0.05,r = 0.8474,P 〈 0.01,r = 0.9691,P 〈 0.01,r = 0.9027; RPP： P 〈 0.05,r = 0.8637,P 〈 0.01,r = 0.9407,P 〈 0.01,r = 0.9027）.These findings show that the hippocampus-nucleus tractus solitarius-vagus nerve pathway is involved in the cardioprotective effect of EA at the heart meridian.Some interneurons in the nucleus tractus solitarius may play a particularly important role in the cardiomodulatory process.
基金funded by the National Basic Research Program of China(973 Pro-gram),No.2009CB522904the National Natural Science Foundation of China,No.81303050,81173326 and 81202770the Ph.D.Programs Foundation of Ministry of Education of China,No.20124323110001 and 20124323120002
文摘Previous studies have shown that somatic sensation by acupuncture and visceral nociceptive stimulation can converge in the nucleus tractus solitarii where neurons integrate signals impact- ing on the function of organs. To explore the role of the nucleus tractus solitarii in the protective mechanism of pre-moxibustion on gastric mucosa, nucleus tractus solitarii were damaged in rats and pre-moxibustion treatment at the Zusanli （ST36） point followed. The gastric mucosa was then damaged by the anhydrous ethanol lavage method. Morphological observations, enzyme linked immunosorbent assays, and western immunoblot analyses showed that gastric mucosa surface lesion and the infiltration of inflammatory cells were significantly ameliorated after pre-moxibustion treatment. Furthermore, the gastric mucosal damage index and somatostatin level were reduced, and epidermal growth factor content in the gastric mucosa and heat-shock protein-70 expression were increased. These results were reversed by damage to the nucleus tractus solitarii. These findings suggest that moxibustion pretreatment at the Zusanli point is protective against acute gastric mucosa injury, and nucleus tractus solitarii damage inhibits these responses. Therefore, the nucleus tractus solitarii may be an important area for regulating the signal transduction of the protective effect of pre-moxibustion on gastric mucosa.
基金Supported by National Natural Science Foundation of China,No.81620108008Major Research and Development Project of Hainan Province,No.2018153 to Yun-Qing LiTraining Program for Scientific Research Scholars of Fujian Provincial Health and Family Planning Commission,No.2018-ZQN-74 to Ying-Biao Chen
文摘BACKGROUND Central sensitization plays a pivotal role in the maintenance of chronic pain induced by chronic pancreatitis(CP).We hypothesized that the nucleus tractus solitarius(NTS),a primary central site that integrates pancreatic afferents apart from the thoracic spinal dorsal horn,plays a key role in the pathogenesis of visceral hypersensitivity in a rat model of CP.AIM To investigate the role of the NTS in the visceral hypersensitivity induced by chronic pancreatitis.METHODS CP was induced by the intraductal injection of trinitrobenzene sulfonic acid(TNBS)in rats.Pancreatic hyperalgesia was assessed by referred somatic pain via von Frey filament assay.Neural activation of the NTS was indicated by immunohistochemical staining for Fos.Basic synaptic transmission within the NTS was assessed by electrophysiological recordings.Expression of vesicular glutamate transporters(VGluTs),N-methyl-D-aspartate receptor subtype 2B(NR2B),andα-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor subtype 1(GluR1)was analyzed by immunoblotting.Membrane insertion of NR2B and GluR1 was evaluated by electron microscopy.The regulatory role of the NTS in visceral hypersensitivity was detected via pharmacological approach and chemogenetics in CP rats.RESULTS TNBS treatment significantly increased the number of Fos-expressing neurons within the caudal NTS.The excitatory synaptic transmission was substantially potentiated within the caudal NTS in CP rats(frequency:5.87±1.12 Hz in CP rats vs 2.55±0.44 Hz in sham rats,P<0.01;amplitude:19.60±1.39 pA in CP rats vs 14.71±1.07 pA in sham rats;P<0.01).CP rats showed upregulated expression of VGluT2,and increased phosphorylation and postsynaptic trafficking of NR2B and GluR1 within the caudal NTS.Blocking excitatory synaptic transmission via the AMPAR antagonist CNQX and the NMDAR antagonist AP-5 microinjection reversed visceral hypersensitivity in CP rats(abdominal withdraw threshold:7.00±1.02 g in CNQX group,8.00±0.81 g in AP-5 group and 1.10±0.27 g in saline group,P<0.001).Inhibiting the excitability of NTS neurons via chemogenetics also significantly attenuated pancreatic hyperalgesia(abdominal withdraw threshold:13.67±2.55 g in Gi group,2.00±1.37 g in Gq group,and 2.36±0.67 g in mCherry group,P<0.01).CONCLUSION Our findings suggest that enhanced excitatory transmission within the caudal NTS contributes to pancreatic pain and emphasize the NTS as a pivotal hub for the processing of pancreatic afferents,which provide novel insights into the central sensitization of painful CP.
基金supported by the National Natural Science Foundation of China(31800981 and 31971058)the Natural Science Foundation of Hebei Province for Distinguished Young Scholars(H2020206509)a Hebei Province Government Grant(CXZZBS2020119).
文摘Leptin,an adipocyte-derived peptide hormone,has been shown to facilitate breathing.However,the central sites and circuit mechanisms underlying the respiratory effects of leptin remain incompletely understood.The present study aimed to address whether neurons expressing leptin receptor b(LepRb)in the nucleus tractus solitarii(NTS)contribute to respiratory control.Both chemogenetic and optogenetic stimulation of LepRb-ex-pressing NTS(NTS^(LepRb))neurons notably activated breathing.Moreover,stimulation of NTS^(LepRb) neurons projecting to the lateral parabrachial nucleus(LPBN)not only remarkably increased basal ventilation to a level similar to that of the stimulation of all NTS^(LepRb) neurons,but also activated LPBN neurons projecting to the preBotzinger complex(preBotC).By contrast,ablation of NTS^pRb neurons projecting to the LPBN notably eliminated the enhanced respiratory effect induced by NTSLepRb neuron stimulation.In brainstem slices,bath application of leptin rapidly depolarized the membrane potential,increased the spontaneous firing rate,and accelerated the Ca2+transients in most NTSLepRb neurons.Therefore,leptin potentiates breathing in the NTS most likely via an NTS-LPBN-preBdtC circuit.
基金Supported by:Major State Basic Research Development Program of China(973 Program),No. 2009CB522904
文摘BACKGROUND： Electrophysiology can prove the integration of afferent information from the stomach meridian of Foot-Yangming in the nucleus tractus solitarius （NTS） and objectively describe the specific association between meridian vessels and Zang Fu organs. OBJECTIVE： To investigate the effects of afferent information from acupuncture at Sibai （ST 2） acupoint on neuronal discharge in rat NTS. DESIGN, TIME AND SETFING： A randomized, controlled, animal experiment was performed at the Key Laboratory of Meridian-Vessels and Zang Fu Organs, Traditional Chinese Medicine University of Hunan, State Administration of Traditional Chinese Medicine, and Key Laboratory of Acupuncture, Moxibustion, and the Biological Information of Hunan Higher Education Institutes, between December 2005 and October 2008. MATERIALS： A total of 52 Sprague Dawley rats, of either gender, aged 4 months, were included in this study. Acupuncture needles of 0.32 mm （diameter） x 40 mm （length） were used. METHODS： An extracellular recording protocol was applied. The Sibai （ST 2） acupoint in the stomach meridian of Foot-Yangming was used as an acupuncture point （acupoint）. Simultaneously, Dicang （ST 4） and Neiting （ST 44） acupoints in the stomach meridian of Foot-Yangming, Quanliao （S118） acupoint in the small intestine meridian of Hand-Taiyang, and a non-acupoint lateral to Sibai （ST 2） acupoint, were selected as controls. The Sibai （ST 2） acupoint was stimulated for 30 seconds by hand acupuncture through twirling and rotating, to determine the neurons responding to body surface stimulation in the NTS. MAIN OUTCOME MEASURES： Frequency of responding NTS neurons after acupuncture at four acupoints including Sibai （ST 2）, Dicang （ST 4）, Neiting （ST 44） and Quanliao （SI 18） and one non-acupoint. RESULTS： The frequency of responding NTS neurons was significantly higher after acupuncture at Sibaithan at control sites including the Dicang （ST 4）, Neiting （ST 44） and Quanliao （S118） acupoints and at the non-acupoint （P 〈 0.01）. The frequency of responding NTS neurons at Dicang （ST 4） and Quanliao （SI 18） was significantly higher than at Quanliao （SI 18） and the non-acupoint （P 〈 0.05）. The rate of frequency change of responding NTS neurons for the Sibai （ST 2）, Dicang （ST 4）, Neiting （ST 44）, and Quanliao （S118） acupoints as well as the non-acupoint was （35.08±4.80） %, （28.25± 5.46） %, （27.57± 4.87） %, （20.02 ±4.23） %, and （18.55 ±2.49） % respectively. Simultaneously, significant differences existed between Sibai （ST 2） and the other acupoints （P 〈 0.05 or P〈 0.01）. CONCLUSION： Compared with the Dicang （ST 4） and Neiting （ST 44） acupoints in the stomach meridian of Foot-Yangming, Quanliao （SI 18） acupoint in the small intestine meridian of Hand-Taiyang, and the non-acupoint lateral to Sibai （ST 2） acupoint, the Sibai （ST 2） acupoint in the stomach meridian of Foot- Yangming is more closely related to the NTS. In the stomach meridian of Foot- Yangming, afferent information is different in distant and near Shu acupoints, indicating that each Shu acupoint has its own specificity.
文摘The relationship between 5-HT receptor and α-adrenoceptor was investigated inrat medullary slice preparations.In 57 nucleus tractus solitarii(NTS)neurons,47(82.5%)responded to both serotonin(5-HT)and norepinephrine(NE).After synapse transmissionwas blocked by perfusion of artificial cerebrospinal fluid(ACSF)with low calcium andhigh magnesium,5 in 8 neurons were still sensitive to both 5-HT and NE.On the otherhand,3 in 5 neurons responding only to 5-HT or NA were sensitive to both 5-HT andNE after the synapse transmission blockage.In some neurons which exhibited excitatoryor inhibitory responses to 5-HT or NE alone,the responses were inversed when perfusedwith 5-HT and NE in combination.These results suggest that there may exist aninhibitory interaction between 5-HT receptors and α-adrenoceptors in NTS and that most5-HT and α-adrenoceptors coexist in the same NTS neurons.
基金supported by the Natural Science Foundation of China(31971050)the Natural Science Foundation of Hebei Province for Distinguished Young Scholars(H2020206509)+1 种基金Hebei Province Innovative Research Project for Postgraduate(2021074)the Natural Science Foundation of Hebei Province for Innovative Research Group Project(H2021206203).
文摘The nucleus tractus solitarii(NTS)is one of the morphologically and functionally defined centers that engage in the autonomic regulation of cardiovascular activity.Phenotypically-characterized NTS neurons have been implicated in the differential regulation of blood pressure(BP).Here,we investigated whether phenylethanolamine N-methyltransferase(PNMT)-expressing NTS(NTS^(PNMT))neurons contribute to the control of BP.We demonstrate that photostimulation of NTS^(PNMT)neurons has variable effects on BP.A depressor response was produced during optogenetic stimulation of NTS^(PNMT)neurons projecting to the paraventricular nucleus of the hypothalamus,lateral parabrachial nucleus,and caudal ventrolateral medulla.Conversely,photostimulation of NTS^(PNMT)neurons projecting to the rostral ventrolateral medulla produced a robust pressor response and bradycardia.In addition,genetic ablation of both NTS^(PNMT)neurons and those projecting to the rostral ventrolateral medulla impaired the arterial baroreflex.Overall,we revealed the neuronal phenotype-and circuit-specific mechanisms underlying the contribution of NTS^(PNMT)neurons to the regulation of BP.
基金the Natural Science Foundation of Shandong Province,No.ZR2019MC020。
文摘BACKGROUND Hydrogen sulfide(H2S)is a recently discovered gaseous neurotransmitter in the nervous and gastrointestinal systems.It exerts its effects through multiple signaling pathways,impacting various physiological activities.The nucleus tractus solitarius(NTS),a vital nucleus involved in visceral sensation,was investigated in this study to understand the role of H2S in regulating gastric function in rats.AIM To examine whether H2S affects the nuclear factor kappa-B(NF-κB)and transient receptor potential vanilloid 1 pathways and the neurokinin 1(NK1)receptor in the NTS.METHODS Immunohistochemical and fluorescent double-labeling techniques were employed to identify cystathionine beta-synthase(CBS)and c-Fos co-expressed positive neurons in the NTS during rat stress.Gastric motility curves were recorded by inserting a pressure-sensing balloon into the pylorus through the stomach fundus.Changes in gastric motility were observed before and after injecting different doses of NaHS(4 nmol and 8 nmol),physiological saline,Capsazepine(4 nmol)+NaHS(4 nmol),pyrrolidine dithiocarbamate(PDTC,4 nmol)+NaHS(4 nmol),and L703606(4 nmol)+NaHS(4 nmol).RESULTS We identified a significant increase in the co-expression of c-Fos and CBS positive neurons in the NTS after 1 h and 3 h of restraint water-immersion stress compared to the expressions observed in the control group.Intra-NTS injection of NaHS at different doses significantly inhibited gastric motility in rats(P<0.01).However,injection of saline,first injection NF-κB inhibitor PDTC or transient receptor potential vanilloid 1(TRPV1)antagonist Capsazepine or NK1 receptor blockers L703606 and then injection NaHS did not produce significant changes(P>0.05).CONCLUSION NTS contains neurons co-expressing CBS and c-Fos,and the injection of NaHS into the NTS can suppress gastric motility in rats.This effect may be mediated by activating TRPV1 and NK1 receptors via the NF-κB channel.
文摘This experiment aimed to investigate the effect of adrenergic system in the subnucleus commissuriu of nucleus solitrius tractus (CNTS) on renal nerve discharges. Norepinephrine (NE) was microinjected into the CNTS of rabbits and mean arterial blood pressure (MAP) and renal nerve discharges (FRND) were synchronously recorded. The results indicated that (1) microinjection of norepinephine into the CNTS of rabbit could significantly attenuate the frequency of renal nerve discharge, and at the same time decrease markedly the mean arterial pressure. (2) Microinjection of 0.3 nmol yohimbin into CNTS had no significant influence on FRND and MAP, but could attenuate and even reverse the effects of NE on FRND and MAP. These results suggest that microinjection of NE into CNTS may activate the alpha-adrenorecptor located in CNTS and secondarily produce a depressor effect by attenuating the activity of peripheral sympathetic nervous system.
基金supported by grants from the National Natural Science Foundation of China(32171126,U23A20431)a Natural Science Foundation of Hebei Province for Innovative Research Grant Group Project(H2021206203).
文摘The central amygdala(CeA)is a crucial modulator of emotional,behavioral,and autonomic functions,including cardiovascular responses.Despite its importance,the specific circuit by which the CeA modulates blood pressure remains insufficiently explored.Our investigations demonstrate that photostimulation of GABAergic neurons in the centromedial amygdala(CeMGABA),as opposed to those in the centrolateral amygdala(CeL),produces a depressor response in both anesthetized and freely-moving mice.In addition,activation of CeMGABA axonal terminals projecting to the nucleus tractus solitarius(NTS)significantly reduces blood pressure.These CeMGABA neurons form synaptic connections with NTS neurons,allowing for the modulation of cardiovascular responses by influencing the caudal or rostral ventrolateral medulla.Furthermore,CeMGABA neurons targeting the NTS receive dense inputs from the CeL.Consequently,stimulation of CeMGABA neurons elicits hypotension through the CeM-NTS circuit,offering deeper insights into the cardiovascular responses associated with emotions and behaviors.
文摘AIM: To investigate the effect and mechanism of stimulation of the hypothalamic paraventricular nucleus with glutamate acid in rats with ulcerative colitis(UC).METHODS: The rats were anesthetized with 10% chloral hydrate via abdominal injection and treated with an equal volume of TNBS + 50% ethanol enema, injected into the upper section of the anus with the tail facing up. Colonic damage scores were calculated after injecting a certain dose of glutamic acid into the paraventricular nucleus(p VN), and the effect of the nucleus tractus solitarius(NTS) and vagus nerve in alleviating UC injury through chemical stimulation of the p VN was observed in rats. Expression changes of C-myc, Apaf-1, caspase-3, interleukin(IL)-6, and IL-17 during the protection against UC injury through chemical stimulation of the p VN in rats were detected by Western blot. Malondialdehyde(MDA) content and superoxide dismutase(SOD) activity in colon tissues of rats were measured by colorimetric methods. RESULTS: Chemical stimulation of the PVN significantly reduced UC in rats in a dose-dependent manner. The protective effects of the chemical stimulationof the p VN on rats with UC were eliminated after chemical damage to the p VN. After glutamate receptor antagonist kynurenic acid was injected into the p VN, the protective effects of the chemical stimulation of the p VN were eliminated in rats with UC. After AVpVl receptor antagonist([Deamino-penl, val4, D-Arg8]-vasopressin) was injected into NTS or bilateral chemical damage to NTS, the protective effect of the chemical stimulation of p VN on UC was also eliminated. After chemical stimulation of the p VN, SOD activity increased, MDA content decreased, C-myc protein expression significantly increased, caspase-3 and Apaf-1 protein expression significantly decreased, and IL-6 and IL-17 expression decreased in colon tissues in rats with UC. CONCLUSION: Chemical stimulation of the hypothalamic p VN provides a protective effect against UC injury in rats. Hypothalamic p VN, NTS and vagus nerve play key roles in this process.
基金supported by the National Natural Science Foundations of China(81620108008 and 31971112)the Innovation Capability Support Program of Shaanxi Province,China(2021TD-57).
文摘Central sensitization is essential in maintaining chronic pain induced by chronic pancreatitis(CP),but cortical modulation of painful CP remains elusive.Here,we examined the role of the anterior cingulate cortex(ACC)in the pathogenesis of abdominal hyperalgesia in a rat model of CP induced by intraductal administration of trinitrobenzene sulfonic acid(TNBS).TNBS treatment resulted in long-term abdominal hyperalgesia and anxiety in rats.Morphological data indicated that painful CP induced a significant increase in FOS-expressing neurons in the nucleus tractus solitarii(NTS)and ACC,and some FOS-expressing neurons in the NTS projected to the ACC.In addition,a larger portion of ascending fibers from the NTS innervated pyramidal neurons,the neural subpopulation primarily expressing FOS under the condition of painful CP,rather than GABAergic neurons within the ACC.CP rats showed increased expression of vesicular glutamate transporter 1,and increased membrane trafficking and phosphorylation of the N-methyl-D-aspartate receptor(NMDAR)subunit NR2B and theα-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor(AMPAR)subunit GluR1 within the ACC.Microinjection of NMDAR and AMPAR antagonists into the ACC to block excitatory synaptic transmission significantly attenuated abdominal hyperalgesia in CP rats,which was similar to the analgesic effect of endomorphins injected into the ACC.Specifically inhibiting the excitability of ACC pyramidal cells via chemogenetics reduced both hyperalgesia and comorbid anxiety,whereas activating these neurons via optogenetics failed to aggravate hyperalgesia and anxiety in CP rats.Taken together,these findings provide neurocircuit,biochemical,and behavioral evidence for involvement of the ACC in hyperalgesia and anxiety in CP rats,as well as novel insights into the cortical modulation of painful CP,and highlights the ACC as a potential target for neuromodulatory interventions in the treatment of painful CP.
基金supported by the research grants from the National Natural Science Foundation of China(81625008 and 31970952)the National Key Research and Development Program of China(2020YFA0804500,2020YFA0804502)。
文摘Objective To examine the neuroanatomical substrates underlying the effects of minocycline in alleviating lipopolysaccharide(LPS)-induced neuroinflammation.Methods Forty C57BL/6 male mice were randomly and equally divided into eight groups.Over three conse-cutive days,saline was administered to four groups of mice and minocycline to the other four groups.Immediately after the administration of saline or minocycline on the third day,two groups of mice were additionally injected with saline and the other two groups were injected with LPS.Six or 24 hours after the last injection,mice were sacrificed and the brains were removed.Immunohistochemical staining across the whole brain was performed to detect microglia activation via Iba1 and neuronal activation via c-Fos.Morphology of microglia and the number of c-Fo-positive neurons were analyzed by Image-Pro Premier 3D.One-way ANOVA and Fisher’s least-significant differences were employed for statistical analyses.Results Minocycline alleviated LPS-induced neuroinflammation as evidenced by reduced activation of microglia in multiple brain regions,including the shell part of the nucleus accumbens(Acbs),paraventricular nucleus(PVN)of the hypothalamus,central nucleus of the amygdala(CeA),locus coeruleus(LC),and nucleus tractus solitarius(NTS).Minocycline significantly increased the number of c-Fo-positive neurons in NTS and area postrema(AP)after LPS treatment.Furthermore,in NTS-associated brain areas,including LC,lateral parabrachial nucleus(LPB),periaqueductal gray(PAG),dorsal raphe nucleus(DR),amygdala,PVN,and bed nucleus of the stria terminali(BNST),minocycline also significantly increased the number of c-Fo-positive neurons after LPS administration.Conclusion Minocycline alleviates LPS-induced neuroinflammation in multiple brain regions,possibly due to increased activation of neurons in the NTS-associated network.
基金supported by a Japan-China Sasakawa Medical Fellowship from the Japan China Medical Association
文摘Estrogen receptor a is widely distributed in the rat brain, but the tissue- or target-specificity of the estrogen receptor a gene promoters remains unknown. In the present study, we used transgenic rats expressing enhanced green fluorescent protein under the control of the estrogen receptor a 0/B promoter to examine expression driven by this promoter in two significant nuclei that regulate cardiovascular activity, the area postrema and the nucleus tractus solitarius. Immunohistochemistry showed that enhanced green fluorescent protein-labeled cells were distributed in the area postrema and the nucleus tractus solitarius of both female and male transgenic rats, and a neural network of enhanced green fluorescent protein-positive fibers was seen between the area postrema and the nucleus tractus solitarius. The number of enhanced green fluorescent protein-labeled cells in the area postrema of female rats was significantly higher than in the males, but no significant difference was found in the number of enhanced green fluorescent protein-labeled cells in the nucleus tractus solitarius. The sex differences in the number of enhanced green fluorescent protein-labeled cells in the area postrema was not affected after ovariectomy or 1713-estradiol benzoate treatment in adult rats. Our results suggest that the effects of estrogen in the area postrema are related to the expression of estrogen receptor a under the control of the 0/B promoter, and changes in the sex hormone environment in the adult period do not affect estrogen receptor a expression in the area postrema or the nucleus tractus solitarius.
文摘The brainstem is a major site in the central nervous system involved in the processing of the cardiovascular reflexes such as the baroreflex and the peripheral chemoreflex. The nucleus tractus solitarius and the rostral ventrolateral medulla are 2 important brainstem nuclei, and they play pivotal roles in autonomic cardiovascular regulation. Angiotensin II is one of the neurotransmitters involved in the processing of the known that one of the mechanisms by which angiotensin II exerts cardiovascular reflexes within the brainstem. It is well- its effect is via the activation of pathways that generate reactive oxygen species （ROS）. In the central nervous system, ROS are reported to be involved in several pathological dis- eases such as hypertension, heart failure and sleep apnea. However, little is known about the role of ROS in the processing of the cardiovascular reflexes within the brainstem. The present review mainly discussed some recent findings documenting a role for ROS in the processing of the baroreflex and the peripheral chemoreflex in the brainstem.
基金Supported by The British Heart FoundationJSPS KAKENHI,Nos.19599022 and 25870639
文摘One likely mechanism of essential hypertension(EH) is increased sympathoexcitation due to abnormal functions in the cardiovascular center of the brain. Recent findings obtained using experimental animal models of EH have shown that abnormal inflammation in the cardiovascular center may contribute to the onset of hypertension. Inflammatory molecules such as cytokines and reactive oxygen species released from the inflamed vasculature and glial cells in the medulla oblongata and hypothalamus might directly or indirectly affect neuronal functions. This in turn could increase sympathetic nerve activity and consequently arterial pressure. Abnormal inflammatory responses in the brain could also be central mechanisms underlying angiotensin Ⅱ-related EH. In this review, we present the current understanding of EH mechanisms with regard to inflammatory responses in the cardiovascular center.
基金supported by the National Natural Science Foundation of China(31171122,81573431,81971326 for B.-y.,Li).
文摘Objective:Oncocardiology is increasingly hot research field/topic in the clinical management of cancer with anti-angiogenic therapy of vascular endothelial growth factor(VEGF)that may cause cardiovascular toxicity,such as hypertension via vascular dysfunction and attenuation of eNOS/NO signaling in the baroreflex afferent pathway.The aim of the current study was to evaluate the potential roles of VEGF/VEGF receptors(VEGFRs)expressed in the baroreflex afferent pathway in autonomic control of blood pressure(BP)regulation.Methods:The distribution and expression of VEGF/VEGFRs were detected in the nodose ganglia(NG)and nucleus of tractus solitary(NTS)using immunostaining and molecular approaches.The direct role of VEGF was tested by NG microinjection under physiological and hypertensive conditions.Results:Immunostaining data showed that either VEGF or VEGFR2/VEGFR3 was clearly detected in the NG and NTS of adult male rats.Microinjection of VEGF directly into the NG reduced the mean blood pressure(MBP)dose-dependently,which was less dramatic in renovascular hypertension(RVH)rats,suggesting the VEGF-mediated depressor response by direct activation of the 1st-order baroreceptor neurons in the NG under both normal and disease conditions.Notably,this reduced depressor response in RVH rats was directly caused by the downregulation of VEGFR2,which compensated the up regulation of VEGF/VEGFR3 in the NG during the development of hypertension.Conclusion:It demonstrated for the first time that the BP-lowering property of VEGF/VEGFRs signaling via the activation of baroreflex afferent function may be a common target/pathway leading to BP dysregulation in anti-angiogenic therapy.
文摘Foreign bodies ingestion is regularly observed in gastroenterology context. The evolution is favorable with early extraction. Our main objective was to evaluate foreign bodies managed in digestive endoscopic center of University hospital center Gabriel Touré. The study was retrospective from January 2007 to October 2017 in the endoscopic center of the service of gastroenterology of University hospital center Gabriel Touré and concerned the patients who have been addressed at this center for foreign bodies. We collated 44 patients who ingested foreign bodies among 2750 digestive endoscopies</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> that is to say</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> a frequency of 0.16%. In patient’s history, we found caustic obstruction in 2.3% of patients. The foreign body ingestion was accidental in 97.7% of cases. Pieces of money were more frequent (54.4%). In 86.4%, the foreign bodies were into the esophagus. Upper digestive endoscopy performed foreign bodies extraction in 88.6 of cases. In 9.1%</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">the elimination was spontaneous on 72 hours. Surgeon was indicated in 2.3% of patients. The evolution was favorable in 97.7% of patients. One patient died by digestive bleeding. Conclusion: Foreign bodies ingestion is frequent in children. The upper digestive endoscopy can do the diagnosis and the management.
