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Shao P, Li H, Jiang J, Guan Y, Chen X, Wang Y. Role of Vagus Nerve Stimulation in the Treatment of Chronic Pain. Neuroimmunomodulation 2023; 30:167-183. [PMID: 37369181 PMCID: PMC10614462 DOI: 10.1159/000531626] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Accepted: 06/15/2023] [Indexed: 06/29/2023] Open
Abstract
Vagus nerve stimulation (VNS) can modulate vagal activity and neuro-immune communication. Human and animal studies have provided growing evidence that VNS can produce analgesic effects in addition to alleviating refractory epilepsy and depression. The vagus nerve (VN) projects to many brain regions related to pain processing, which can be affected by VNS. In addition to neural regulation, the anti-inflammatory property of VNS may also contribute to its pain-inhibitory effects. To date, both invasive and noninvasive VNS devices have been developed, with noninvasive devices including transcutaneous stimulation of auricular VN or carotid VN that are undergoing many clinical trials for chronic pain treatment. This review aimed to provide an update on both preclinical and clinical studies of VNS in the management for chronic pain, including fibromyalgia, abdominal pain, and headaches. We further discuss potential underlying mechanisms for VNS to inhibit chronic pain.
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Affiliation(s)
- Peiqi Shao
- Department of Anesthesiology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- Department of Anesthesiology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
| | - Huili Li
- Department of Anesthesiology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Jia Jiang
- Department of Anesthesiology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
| | - Yun Guan
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - Xueming Chen
- Department of Orthopedics, Beijing Luhe Hospital, Capital Medical University, Beijing, China
| | - Yun Wang
- Department of Anesthesiology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- Department of Anesthesiology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
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2
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Patel ABU, Bibawy PPWM, Althonayan JIM, Majeed Z, Gan WL, Abbott TEF, Ackland GL. Effect of transauricular nerve stimulation on perioperative pain: a single-blind, analyser-masked, randomised controlled trial. Br J Anaesth 2023; 130:468-476. [PMID: 36822987 PMCID: PMC10080471 DOI: 10.1016/j.bja.2022.12.025] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 12/05/2022] [Accepted: 12/22/2022] [Indexed: 02/23/2023] Open
Abstract
BACKGROUND Activation of central autonomic pathways, including those regulating the arterial baroreflex, might reduce acute pain. We tested the hypothesis that transcutaneous auricular nerve stimulation (TAN) reduces pain after orthopaedic trauma surgery through autonomic modulation. METHODS A total of 86 participants aged >18 yr were randomly assigned to 50 min of either sham or active bilateral TAN, undertaken before, and again 24 h after, surgery for orthopaedic trauma. The primary outcome was absolute change in pain 24 h postoperatively, comparing the 100 mm visual analogue scale (VAS) before and after TAN. Secondary outcomes included the minimal clinically important difference in pain (>10 mm increase or reduction in VAS) before/after surgery, using intention-to-treat analysis. Holter monitoring, the analysis of which was masked to allocation, quantified autonomic modulation of heart rate. RESULTS From June 22, 2021 to July 7, 2022, 79/86 participants (49 yr; 45% female) completed TAN before and after surgery. For the primary outcome, the mean reduction in VAS was 19 mm (95% confidence interval [CI]: 12-26) after active TAN (n=40), vs 10 mm (95% CI: 3-17) after sham TAN (n=39; P=0.023). A minimally clinically important reduction in postoperative pain occurred in 31/40 (78%) participants after active TAN, compared with 15/39 (38%) allocated to sham TAN (odds ratio 5.51 [95% CI: 2.06-14.73]; P=0.001). Only active TAN increased heart rate variability (log low-frequency power increased by 0.19 ms2 [0.01-0.37 ms2]). Prespecified adverse events (auricular skin irritation) occurred in six participants receiving active TAN, compared with two receiving sham TAN. CONCLUSION Bilateral TAN reduces perioperative pain through autonomic modulation. These proof-of-concept data support a non-pharmacological, generalisable approach to improve perioperative analgesia.
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Affiliation(s)
- Amour B U Patel
- Translational Medicine and Therapeutics, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary, University of London, London, UK
| | - Phillip P W M Bibawy
- Barts and the London School of Medicine and Dentistry, Queen Mary, University of London, UK
| | | | - Zehra Majeed
- Translational Medicine and Therapeutics, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary, University of London, London, UK
| | - Weng L Gan
- Barts and the London School of Medicine and Dentistry, Queen Mary, University of London, UK
| | - Tom E F Abbott
- Translational Medicine and Therapeutics, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary, University of London, London, UK
| | - Gareth L Ackland
- Translational Medicine and Therapeutics, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary, University of London, London, UK.
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Bascour-Sandoval C, Gajardo-Burgos R, Muñoz-Poblete C, Riedemann-González P, Erices-Salas S, Martínez-Molina A, Gálvez-García G. Transcutaneous Vagal Stimulation in Knee Osteoarthritis (TRAVKO): Protocol of a Superiority, Outcome Assessor- and Participant-Blind, Randomised Controlled Trial. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 20:311. [PMID: 36612632 PMCID: PMC9819338 DOI: 10.3390/ijerph20010311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 11/22/2022] [Accepted: 11/24/2022] [Indexed: 06/17/2023]
Abstract
Current treatments for knee osteoarthritis (KOA) are partially effective. It is, therefore, necessary to find new strategies that can complement the existing ones. In this scenario, transcutaneous vagal stimulation (TVS) neurophysiological effects could be a helpful solution. However, there is no evidence of the efficacy of TVS in KOA. This trial aims to assess the efficacy of TVS in decreasing pain in participants aged 55 years or older with KOA. A randomised controlled, two-arm, double-blind (participants and outcome assessors) and clinical superiority trial will be conducted for 70 patients with KOA. All the participants will carry out an exercise program. It consists of 12 sessions over four weeks. In addition, they will be randomly assigned to (1) active TVS plus physical exercise or (2) sham TVS plus physical exercise. The application of active TVS consists of electronic stimulation of the auricular concha using a portable device. Sham TVS condition consists of the stimulation of the earlobe that does not cause neurophysiological effects. The primary outcome is the reduction in pain intensity. Additionally, functional capacity, physical performance, pain-related interference, pain-related distress, quality of life in older adults and global change will be measured. Assessments will be conducted at the beginning of the study (baseline), at the end of the intervention and after 1 and 3 months of follow-up. This trial will generate evidence regarding the efficacy of TVS in pain perception in individuals with KOA. This information will serve as an input in the clinical decision-making on the use or non-use of TVS in individuals with KOA. Thus, if the efficacy of TVS is confirmed, a new therapeutic tool may be included in the rehabilitation of individuals with KOA.
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Affiliation(s)
- Claudio Bascour-Sandoval
- Departamento de Ciencias de la Rehabilitación, Universidad de La Frontera, Temuco 4780000, Chile
- Programa de Magister en Terapía Física Mención Musculoesquelética, Departamento de Ciencias de la Rehabilitación, Universidad de La Frontera, Temuco 4780000, Chile
| | - Rubén Gajardo-Burgos
- Programa de Magister en Terapía Física Mención Musculoesquelética, Departamento de Ciencias de la Rehabilitación, Universidad de La Frontera, Temuco 4780000, Chile
- Instituto de Aparato Locomotor y Rehabilitación, Facultad de Medicina, Universidad Austral de Chile, Valdivia 5090000, Chile
| | - Claudio Muñoz-Poblete
- Departamento de Ciencias de la Rehabilitación, Universidad de La Frontera, Temuco 4780000, Chile
- Programa de Magister en Terapía Física Mención Musculoesquelética, Departamento de Ciencias de la Rehabilitación, Universidad de La Frontera, Temuco 4780000, Chile
| | | | | | - Agustín Martínez-Molina
- Departamento de Psicología Social y Metodología, Facultad de Psicología, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Germán Gálvez-García
- Departamento de Psicología, Universidad de La Frontera, Temuco 4780000, Chile
- Departamento de Psicología Básica, Psicobiología y Metodología de las Ciencias del Comportamiento, Universidad de Salamanca, 37008 Salamanca, Spain
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Thieme K, Jung K, Mathys MG, Gracely RH, Turk DC. Cardiac-Gated Neuromodulation Increased Baroreflex Sensitivity and Reduced Pain Sensitivity in Female Fibromyalgia Patients. J Clin Med 2022; 11:jcm11206220. [PMID: 36294542 PMCID: PMC9605536 DOI: 10.3390/jcm11206220] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Revised: 10/03/2022] [Accepted: 10/17/2022] [Indexed: 01/24/2023] Open
Abstract
The study presents a novel approach of programing pain inhibition in chronic pain patients based on the hypothesis that pain perception is modulated by dysfunctional dorsal medial nucleus tractus solitarii (dmNTS) reflex arcs that produce diminished baroreflex sensitivity (BRS) resulting from a conditioned response. This study tested whether administration of noxious and non-noxious electrical stimuli synchronized with the cardiac cycle resets BRS, reestablishing pain inhibition. A total of 30 pain-free normotensives controls (NC) and 32 normotensives fibromyalgia (FM) patients received two, ≈8 min-epochs of cardiac-gated, peripheral electrical stimuli. Non-painful and painful electrical stimuli were synchronized to the cardiac cycle as the neuromodulation experimental protocol (EP) with two control conditions (CC1, CC2). BRS, heart-rate-variability (HRV), pain threshold and tolerance, and clinical pain intensity were assessed. Reduced BRS in FM at baseline increased by 41% during two, ≈8 min-epochs of stimulation. Thresholds in FM increased significantly during the experimental protocol (all Ps < 0.001) as did HRV. FM levels of clinical pain significantly decreased by 35.52% during the experimental protocol but not during control stimulations (p < 0.001). Baroreceptor training may reduce FM pain by BRS-mediated effects on intrinsic pain regulatory systems and autonomic responses.
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Affiliation(s)
- Kati Thieme
- Department of Medical Psychology, Philipps-University Marburg, 35037 Marburg, Germany
- Correspondence: ; Tel.: +49-15158532986
| | - Kathrin Jung
- Department of Medical Psychology, Philipps-University Marburg, 35037 Marburg, Germany
| | - Marc G. Mathys
- Department of Medical Psychology, Philipps-University Marburg, 35037 Marburg, Germany
| | - Richard H. Gracely
- Center for Pain Research and Innovation, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Dennis C. Turk
- Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, WA 98195, USA
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Patel AB, Bibawy PP, Majeed Z, Gan WL, Ackland GL. Trans-auricular vagus nerve stimulation to reduce perioperative pain and morbidity: protocol for a single-blind analyser-masked randomised controlled trial. BJA OPEN 2022; 2:None. [PMID: 35832337 PMCID: PMC9258962 DOI: 10.1016/j.bjao.2022.100017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 05/02/2022] [Accepted: 05/18/2022] [Indexed: 11/22/2022]
Abstract
Background Established or acquired loss of parasympathetic vagal tone is associated with complications, including pain, after noncardiac surgery. We describe a study protocol designed to test the hypothesis that transcutaneous auricular nerve stimulation may preserve efferent parasympathetic activity to reduce pain and morbidity after noncardiac surgery. Methods Participants aged >18 yr scheduled for urgent/elective orthopaedic surgery (n=86) will be randomly allocated to bilateral transcutaneous auricular nerve stimulation or sham protocol for 50 min at the same time of day, before and 24 h after surgery. Holter monitoring, the analysis of which is masked to allocation, will quantify autonomic modulation of HR. The primary outcome will be pain, quantified by absolute changes in VAS 24 h after surgery following sham or stimulation. Secondary outcomes include presence or absence of >10 mm change in the 100 mm VAS (which defines a minimum clinically important change) and postoperative morbidity (Postoperative Morbidity Survey) before and 24 h after surgery. The relationship between the explanatory variable (HR variability), VAS, and morbidity will be examined using a multilevel (mixed-error component) regression model. Safety and complications of the intervention will also be recorded. The study was approved by the NHS Research Ethics Committee (21/LO/0272). As of 25 December 2021, 34/86 participants (mean [standard deviation] age: 48 [19] yr; 14 females [41.2%]) have been recruited, with complete collection of Holter data. Conclusions This phase 2b study will explore whether noninvasive autonomic neuromodulation may reduce pain or morbidity using trans-auricular vagus nerve stimulation, providing proof-of-concept data for a non-pharmacological, generalisable approach to improve perioperative outcomes. Clinical trial registration Researchregistry7566.
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Affiliation(s)
- Amour B.U. Patel
- Translational Medicine and Therapeutics, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Phillip P.W.M. Bibawy
- Translational Medicine and Therapeutics, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Zehra Majeed
- Translational Medicine and Therapeutics, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Weng Liang Gan
- Translational Medicine and Therapeutics, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Gareth L. Ackland
- Translational Medicine and Therapeutics, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
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Li H, Page AJ. Altered Vagal Signaling and Its Pathophysiological Roles in Functional Dyspepsia. Front Neurosci 2022; 16:858612. [PMID: 35527812 PMCID: PMC9072791 DOI: 10.3389/fnins.2022.858612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 03/28/2022] [Indexed: 11/20/2022] Open
Abstract
The vagus nerve is crucial in the bidirectional communication between the gut and the brain. It is involved in the modulation of a variety of gut and brain functions. Human studies indicate that the descending vagal signaling from the brain is impaired in functional dyspepsia. Growing evidence indicate that the vagal signaling from gut to brain may also be altered, due to the alteration of a variety of gut signals identified in this disorder. The pathophysiological roles of vagal signaling in functional dyspepsia is still largely unknown, although some studies suggested it may contribute to reduced food intake and gastric motility, increased psychological disorders and pain sensation, nausea and vomiting. Understanding the alteration in vagal signaling and its pathophysiological roles in functional dyspepsia may provide information for new potential therapeutic treatments of this disorder. In this review, we summarize and speculate possible alterations in vagal gut-to-brain and brain-to-gut signaling and the potential pathophysiological roles in functional dyspepsia.
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Affiliation(s)
- Hui Li
- Vagal Afferent Research Group, Adelaide Medical School, The University of Adelaide, Adelaide, SA, Australia
- Nutrition, Diabetes and Gut Health, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, SA, Australia
- *Correspondence: Hui Li,
| | - Amanda J. Page
- Vagal Afferent Research Group, Adelaide Medical School, The University of Adelaide, Adelaide, SA, Australia
- Nutrition, Diabetes and Gut Health, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, SA, Australia
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Patel AB, Weber V, Gourine AV, Ackland GL. The potential for autonomic neuromodulation to reduce perioperative complications and pain: a systematic review and meta-analysis. Br J Anaesth 2022; 128:135-149. [PMID: 34801224 PMCID: PMC8787777 DOI: 10.1016/j.bja.2021.08.037] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 08/09/2021] [Accepted: 08/25/2021] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND Autonomic dysfunction promotes organ injury after major surgery through numerous pathological mechanisms. Vagal withdrawal is a key feature of autonomic dysfunction, and it may increase the severity of pain. We systematically evaluated studies that examined whether vagal neuromodulation can reduce perioperative complications and pain. METHODS Two independent reviewers searched PubMed, EMBASE, and the Cochrane Register of Controlled Clinical Trials for studies of vagal neuromodulation in humans. Risk of bias was assessed; I2 index quantified heterogeneity. Primary outcomes were organ dysfunction (assessed by measures of cognition, cardiovascular function, and inflammation) and pain. Secondary outcomes were autonomic measures. Standardised mean difference (SMD) using the inverse variance random-effects model with 95% confidence interval (CI) summarised effect sizes for continuous outcomes. RESULTS From 1258 records, 166 full-text articles were retrieved, of which 31 studies involving patients (n=721) or volunteers (n=679) met the inclusion criteria. Six studies involved interventional cardiology or surgical patients. Indirect stimulation modalities (auricular [n=23] or cervical transcutaneous [n=5]) were most common. Vagal neuromodulation reduced pain (n=10 studies; SMD=2.29 [95% CI, 1.08-3.50]; P=0.0002; I2=97%) and inflammation (n=6 studies; SMD=1.31 [0.45-2.18]; P=0.003; I2=91%), and improved cognition (n=11 studies; SMD=1.74 [0.96-2.52]; P<0.0001; I2=94%) and cardiovascular function (n=6 studies; SMD=3.28 [1.96-4.59]; P<0.00001; I2=96%). Five of six studies demonstrated autonomic changes after vagal neuromodulation by measuring heart rate variability, muscle sympathetic nerve activity, or both. CONCLUSIONS Indirect vagal neuromodulation improves physiological measures associated with limiting organ dysfunction, although studies are of low quality, are susceptible to bias and lack specific focus on perioperative patients.
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Affiliation(s)
- Amour B.U. Patel
- Translational Medicine and Therapeutics, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary, University of London, London, UK
| | - Valentin Weber
- Translational Medicine and Therapeutics, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary, University of London, London, UK
| | - Alexander V. Gourine
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Gareth L. Ackland
- Translational Medicine and Therapeutics, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary, University of London, London, UK,Corresponding author.
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Komisaruk BR, Frangos E. Vagus nerve afferent stimulation: Projection into the brain, reflexive physiological, perceptual, and behavioral responses, and clinical relevance. Auton Neurosci 2021; 237:102908. [PMID: 34823149 DOI: 10.1016/j.autneu.2021.102908] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 11/01/2021] [Accepted: 11/06/2021] [Indexed: 12/26/2022]
Abstract
The afferent vagus nerves project to diverse neural networks within the brainstem and forebrain, based on neuroanatomical, neurophysiological, and functional (fMRI) brain imaging evidence. In response to afferent vagal stimulation, multiple homeostatic visceral reflexes are elicited. Physiological stimuli and both invasive and non-invasive electrical stimulation that activate the afferent vagus elicit perceptual and behavioral responses that are of physiological and clinical significance. In the present review, we address these multiple roles of the afferent vagus under normal and pathological conditions, based on both animal and human evidence.
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Affiliation(s)
- Barry R Komisaruk
- Department of Psychology, Rutgers, The State University of New Jersey, Newark, NJ 07102, United States.
| | - Eleni Frangos
- National Center for Complementary and Integrative Health, National Institutes of Health, Bethesda, MD 20892, United States
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Kaniusas E, Kampusch S, Tittgemeyer M, Panetsos F, Gines RF, Papa M, Kiss A, Podesser B, Cassara AM, Tanghe E, Samoudi AM, Tarnaud T, Joseph W, Marozas V, Lukosevicius A, Ištuk N, Šarolić A, Lechner S, Klonowski W, Varoneckas G, Széles JC. Current Directions in the Auricular Vagus Nerve Stimulation I - A Physiological Perspective. Front Neurosci 2019; 13:854. [PMID: 31447643 PMCID: PMC6697069 DOI: 10.3389/fnins.2019.00854] [Citation(s) in RCA: 144] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 07/30/2019] [Indexed: 01/07/2023] Open
Abstract
Electrical stimulation of the auricular vagus nerve (aVNS) is an emerging technology in the field of bioelectronic medicine with applications in therapy. Modulation of the afferent vagus nerve affects a large number of physiological processes and bodily states associated with information transfer between the brain and body. These include disease mitigating effects and sustainable therapeutic applications ranging from chronic pain diseases, neurodegenerative and metabolic ailments to inflammatory and cardiovascular diseases. Given the current evidence from experimental research in animal and clinical studies we discuss basic aVNS mechanisms and their potential clinical effects. Collectively, we provide a focused review on the physiological role of the vagus nerve and formulate a biology-driven rationale for aVNS. For the first time, two international workshops on aVNS have been held in Warsaw and Vienna in 2017 within the framework of EU COST Action "European network for innovative uses of EMFs in biomedical applications (BM1309)." Both workshops focused critically on the driving physiological mechanisms of aVNS, its experimental and clinical studies in animals and humans, in silico aVNS studies, technological advancements, and regulatory barriers. The results of the workshops are covered in two reviews, covering physiological and engineering aspects. The present review summarizes on physiological aspects - a discussion of engineering aspects is provided by our accompanying article (Kaniusas et al., 2019). Both reviews build a reasonable bridge from the rationale of aVNS as a therapeutic tool to current research lines, all of them being highly relevant for the promising aVNS technology to reach the patient.
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Affiliation(s)
- Eugenijus Kaniusas
- Institute of Electrodynamics, Microwave and Circuit Engineering, Vienna University of Technology, Vienna, Austria
| | - Stefan Kampusch
- Institute of Electrodynamics, Microwave and Circuit Engineering, Vienna University of Technology, Vienna, Austria
- SzeleSTIM GmbH, Vienna, Austria
| | - Marc Tittgemeyer
- Max Planck Institute for Metabolism Research, Cologne, Germany
- Cologne Cluster of Excellence in Cellular Stress and Aging Associated Disease (CECAD), Cologne, Germany
| | - Fivos Panetsos
- Neurocomputing and Neurorobotics Research Group, Complutense University of Madrid, Madrid, Spain
| | - Raquel Fernandez Gines
- Neurocomputing and Neurorobotics Research Group, Complutense University of Madrid, Madrid, Spain
| | - Michele Papa
- Laboratory of Neuronal Networks, Department of Mental and Physical Health and Preventive Medicine, University of Campania “Luigi Vanvitelli”, Naples, Italy
| | - Attila Kiss
- Ludwig Boltzmann Cluster for Cardiovascular Research at the Center for Biomedical Research, Medical University of Vienna, Vienna, Austria
| | - Bruno Podesser
- Ludwig Boltzmann Cluster for Cardiovascular Research at the Center for Biomedical Research, Medical University of Vienna, Vienna, Austria
| | | | - Emmeric Tanghe
- Department of Information Technology, Ghent University/IMEC, Ghent, Belgium
| | | | - Thomas Tarnaud
- Department of Information Technology, Ghent University/IMEC, Ghent, Belgium
| | - Wout Joseph
- Department of Information Technology, Ghent University/IMEC, Ghent, Belgium
| | - Vaidotas Marozas
- Biomedical Engineering Institute, Kaunas University of Technology, Kaunas, Lithuania
| | - Arunas Lukosevicius
- Biomedical Engineering Institute, Kaunas University of Technology, Kaunas, Lithuania
| | - Niko Ištuk
- Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture, University of Split, Split, Croatia
| | - Antonio Šarolić
- Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture, University of Split, Split, Croatia
| | | | - Wlodzimierz Klonowski
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| | - Giedrius Varoneckas
- Sleep Medicine Centre, Klaipeda University Hospital, Klaipëda, Lithuania
- Institute of Neuroscience, Lithuanian University of Health Sciences, Palanga, Lithuania
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Lerman I, Davis B, Huang M, Huang C, Sorkin L, Proudfoot J, Zhong E, Kimball D, Rao R, Simon B, Spadoni A, Strigo I, Baker DG, Simmons AN. Noninvasive vagus nerve stimulation alters neural response and physiological autonomic tone to noxious thermal challenge. PLoS One 2019; 14:e0201212. [PMID: 30759089 PMCID: PMC6373934 DOI: 10.1371/journal.pone.0201212] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 11/12/2018] [Indexed: 11/23/2022] Open
Abstract
The mechanisms by which noninvasive vagal nerve stimulation (nVNS) affect central and peripheral neural circuits that subserve pain and autonomic physiology are not clear, and thus remain an area of intense investigation. Effects of nVNS vs sham stimulation on subject responses to five noxious thermal stimuli (applied to left lower extremity), were measured in 30 healthy subjects (n = 15 sham and n = 15 nVNS), with fMRI and physiological galvanic skin response (GSR). With repeated noxious thermal stimuli a group × time analysis showed a significantly (p < .001) decreased response with nVNS in bilateral primary and secondary somatosensory cortices (SI and SII), left dorsoposterior insular cortex, bilateral paracentral lobule, bilateral medial dorsal thalamus, right anterior cingulate cortex, and right orbitofrontal cortex. A group × time × GSR analysis showed a significantly decreased response in the nVNS group (p < .0005) bilaterally in SI, lower and mid medullary brainstem, and inferior occipital cortex. Finally, nVNS treatment showed decreased activity in pronociceptive brainstem nuclei (e.g. the reticular nucleus and rostral ventromedial medulla) and key autonomic integration nuclei (e.g. the rostroventrolateral medulla, nucleus ambiguous, and dorsal motor nucleus of the vagus nerve). In aggregate, noninvasive vagal nerve stimulation reduced the physiological response to noxious thermal stimuli and impacted neural circuits important for pain processing and autonomic output.
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Affiliation(s)
- Imanuel Lerman
- VA Center of Excellence for Stress and Mental Health, VA San Diego Healthcare System, La Jolla, CA, United States of America
- Department of Anesthesiology, Center for Pain Medicine, University of California San Diego School of Medicine, La Jolla, CA, United States of America
- Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, CA, United States of America
- * E-mail:
| | - Bryan Davis
- Department of Anesthesiology, Center for Pain Medicine, University of California San Diego School of Medicine, La Jolla, CA, United States of America
| | - Mingxiong Huang
- Department of Radiology, University of California San Diego School of Medicine, La Jolla, CA, United States of America
- Department of Radiology, VA San Diego Healthcare System, La Jolla, CA, United States of America
| | - Charles Huang
- Department of Radiology, University of California San Diego School of Medicine, La Jolla, CA, United States of America
- Department of Radiology, VA San Diego Healthcare System, La Jolla, CA, United States of America
| | - Linda Sorkin
- Department of Anesthesiology, Center for Pain Medicine, University of California San Diego School of Medicine, La Jolla, CA, United States of America
| | - James Proudfoot
- Department of Anesthesiology, Center for Pain Medicine, University of California San Diego School of Medicine, La Jolla, CA, United States of America
| | - Edward Zhong
- Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, CA, United States of America
| | - Donald Kimball
- Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, CA, United States of America
| | - Ramesh Rao
- Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, CA, United States of America
| | - Bruce Simon
- electroCore LLC, Basking Ridge NJ, United States of America
| | - Andrea Spadoni
- VA Center of Excellence for Stress and Mental Health, VA San Diego Healthcare System, La Jolla, CA, United States of America
- Department of Psychiatry University of California San Diego School of Medicine, La Jolla, CA, United States of America
| | - Irina Strigo
- Department of Psychiatry, VA San Francisco Healthcare System, San Francisco, CA, United States of America
| | - Dewleen G. Baker
- VA Center of Excellence for Stress and Mental Health, VA San Diego Healthcare System, La Jolla, CA, United States of America
- Department of Psychiatry University of California San Diego School of Medicine, La Jolla, CA, United States of America
| | - Alan N. Simmons
- VA Center of Excellence for Stress and Mental Health, VA San Diego Healthcare System, La Jolla, CA, United States of America
- Department of Psychiatry University of California San Diego School of Medicine, La Jolla, CA, United States of America
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11
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Wiberg M, Widenfalk B. Involvement of Connections Between the Brainstem and the Sympathetic Ganglia in the Pathogenesis of Rheumatoid Arthritis. ACTA ACUST UNITED AC 2018. [DOI: 10.1080/02844311.1993.12005640] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- Mikael Wiberg
- Department of Anatomy, Uppsala University, and the Department of Plastic Surgery, Uppsala University Hospital, Uppsala, Sweden
| | - Bertil Widenfalk
- Department of Anatomy, Uppsala University, and the Department of Plastic Surgery, Uppsala University Hospital, Uppsala, Sweden
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A pilot study on skin potential recordings as a measure of nociception in pain-free dogs and humans, and in dogs with persistent pain. ACTA VET-BEOGRAD 2018. [DOI: 10.2478/acve-2018-0004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
The Pain Trace™ device can detect changes in the skin's electrical potentials claimed to be associated with pain related alterations in the sympathetic and parasympathetic nervous system activity. Positive voltages represent the absence of major pain, whereas negative voltages represent moderate to severe pain. Unlike in humans and horses, no baseline skin potential recordings have been reported in dogs. In study Part 1 baseline skin potentials were recorded in healthy dogs and compared to readings obtained in human volunteers. In dogs, data were recorded with electrodes placed at three separate sites: neck, axilla, and thorax. In humans, data were collected from the palms. Readings over a 90-second period were averaged and comparisons between groups were performed using the Kruskal-Wallis test. All voltage recordings were positive. Readings in dogs had greater variability. Recordings from the thorax were more homogeneous, this being the reason why this site was chosen for study Part 2. No significant differences in recordings were noted between pain-free dogs and humans. The main hypothesis was that shifting from positive to negative skin potential voltages serves as an indicator of canine patients sensing moderate to severe pain. Therefore, we obtained preoperative readings from dogs with cranial cruciate ligament disease that were experiencing associated persistent pain, and compared these data with readings from pain-free dogs (thorax). In dogs undergoing surgery, all pre-surgery voltage readings were positive and thus no consistent relationship between skin potential recordings and pain perception could be established. Further investigation is needed to confirm any relationship between skin potential and pain severity in dogs.
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Cui S, Wang K, Wu SB, Zhu GQ, Cao J, Zhou YP, Zhou MQ. Electroacupuncture modulates the activity of the hippocampus-nucleus tractus solitarius-vagus nerve pathway to reduce myocardial ischemic injury. Neural Regen Res 2018; 13:1609-1618. [PMID: 30127122 PMCID: PMC6126117 DOI: 10.4103/1673-5374.237124] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
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 mA, 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.
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Affiliation(s)
- Shuai Cui
- Research Institute of Acupuncture and Meridian, Anhui University of Chinese Medicine, Hefei, Anhui Province; Clinical Medical College of Acupuncture, Moxibustion and Rehabilitation, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong Province, China
| | - Kun Wang
- Research Institute of Acupuncture and Meridian, Anhui University of Chinese Medicine, Hefei, Anhui Province, China
| | - Sheng-Bing Wu
- Key Laboratory of Xin' An Medicine, Ministry of Education, Anhui University of Chinese Medicine, Hefei, Anhui Province, China
| | - Guo-Qi Zhu
- Key Laboratory of Xin' An Medicine, Ministry of Education, Anhui University of Chinese Medicine, Hefei, Anhui Province, China
| | - Jian Cao
- Department of Science and Technology, Anhui University of Chinese Medicine, Hefei, Anhui Province, China
| | - Yi-Ping Zhou
- Research Institute of Acupuncture and Meridian, Anhui University of Chinese Medicine, Hefei, Anhui Province, China
| | - Mei-Qi Zhou
- Research Institute of Acupuncture and Meridian, Anhui University of Chinese Medicine; Key Laboratory of Xin' An Medicine, Ministry of Education, Anhui University of Chinese Medicine, Hefei, Anhui Province, China
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15
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Do the psychological effects of vagus nerve stimulation partially mediate vagal pain modulation? NEUROBIOLOGY OF PAIN 2017; 1:37-45. [PMID: 29057372 PMCID: PMC5648334 DOI: 10.1016/j.ynpai.2017.03.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
There is preclinical and clinical evidence that vagus nerve stimulation modulates both pain and mood state. Mechanistic studies show brainstem circuitry involved in pain modulation by vagus nerve stimulation, but little is known about possible indirect descending effects of altered mood state on pain perception. This possibility is important, since previous studies have shown that mood state affects pain, particularly the affective dimension (pain unpleasantness). To date, human studies investigating the effects of vagus nerve stimulation on pain perception have not reliably measured psychological factors to determine their role in altered pain perception elicited by vagus nerve stimulation. Thus, it remains unclear how much of a role psychological factors play in vagal pain modulation. Here, we present a rationale for including psychological measures in future vagus nerve stimulation studies on pain.
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Lucena F, Foletto V, Mascarin LZ, Tonussi CR. Analgesic and anti-edematogenic effects of oral trypsin were abolished after subdiaphragmatic vagotomy and spinal monoaminergic inhibition in rats. Life Sci 2016; 166:60-65. [PMID: 27729269 DOI: 10.1016/j.lfs.2016.10.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Revised: 09/29/2016] [Accepted: 10/07/2016] [Indexed: 01/07/2023]
Abstract
AIMS Rheumatoid arthritis brings great burdens to the patients. In addition to the highly expensive treatment, they are commonly associated with severe side effects. In such context, the research for safe and affordable treatments is needed. MAIN METHODS Arthritis was induced by CFA (0.5mg/mL) in female wistar rats. Trypsin was given p.o. (2.95mg/kg; 2mL) 24h after the intra-articular CFA injection. Articular incapacitation was measured daily by counting the paw elevation time (PET; s) during 1-min periods of stimulated walk, throughout the 7-days after intra-articular CFA injection. Articular diameter (AD) was accessed just after each PET measurement, taken the difference between naïve and diseased knee-joint diameter (cm). KEY FINDINGS The present study showed that orally administered trypsin was able to reduce nociception and edema, effects that could be observed throughout the evaluation period. These effect, however, were not observed in animals underwent subdiaphragmatic vagotomy, suggesting a vagal mediation for trypsin effects. Likewise, these effects were blocked in rats which received intrathecal injection of the neurotoxins 5,7-dihydroxytryptamine or 6-hydroxydopamine, suggesting the involvement of spinal amines from axon terminals. SIGNIFICANCE The present study proposes that oral trypsin may cause vagal activation, followed by the activation of descending inhibitory pathways and such mechanism may lead to a novel approach for the treatment of arthritis.
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Affiliation(s)
- Flora Lucena
- Department of Pharmacology, Federal University of Santa Catarina, Florianópolis, SC 88040-900, Brazil
| | - Vanessa Foletto
- Department of Pharmacology, Federal University of Santa Catarina, Florianópolis, SC 88040-900, Brazil
| | - Lucas Zanon Mascarin
- Department of Pharmacology, Federal University of Santa Catarina, Florianópolis, SC 88040-900, Brazil
| | - Carlos Rogério Tonussi
- Department of Pharmacology, Federal University of Santa Catarina, Florianópolis, SC 88040-900, Brazil.
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17
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Wernze H. [Reduced pain perception in bulimia]. MMW Fortschr Med 2016; 158:57-8. [PMID: 27119702 DOI: 10.1007/s15006-016-7822-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Heinrich Wernze
- Innere Medizin Forschung, Königsberger Straße 44, D-97072, Würzburg, Deutschland
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18
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Hermes SM, Andresen MC, Aicher SA. Localization of TRPV1 and P2X3 in unmyelinated and myelinated vagal afferents in the rat. J Chem Neuroanat 2015; 72:1-7. [PMID: 26706222 DOI: 10.1016/j.jchemneu.2015.12.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Revised: 11/18/2015] [Accepted: 12/09/2015] [Indexed: 01/15/2023]
Abstract
The vagus nerve is dominated by afferent fibers that convey sensory information from the viscera to the brain. Most vagal afferents are unmyelinated, slow-conducting C-fibers, while a smaller portion are myelinated, fast-conducting A-fibers. Vagal afferents terminate in the nucleus tractus solitarius (NTS) in the dorsal brainstem and regulate autonomic and respiratory reflexes, as well as ascending pathways throughout the brain. Vagal afferents form glutamatergic excitatory synapses with postsynaptic NTS neurons that are modulated by a variety of channels. The organization of vagal afferents with regard to fiber type and channels is not well understood. In the present study, we used tract tracing methods to identify distinct populations of vagal afferents to determine if key channels are selectively localized to specific groups of afferent fibers. Vagal afferents were labeled with isolectin B4 (IB4) or cholera toxin B (CTb) to detect unmyelinated and myelinated afferents, respectively. We find that TRPV1 channels are preferentially found in unmyelinated vagal afferents identified with IB4, with almost half of all IB4 fibers showing co-localization with TRPV1. These results agree with prior electrophysiological findings. In contrast, we found that the ATP-sensitive channel P2X3 is found in a subset of both myelinated and unmyelinated vagal afferent fibers. Specifically, 18% of IB4 and 23% of CTb afferents contained P2X3. The majority of CTb-ir vagal afferents contained neither channel. Since neither channel was found in all vagal afferents, there are likely further degrees of heterogeneity in the modulation of vagal afferent sensory input to the NTS beyond fiber type.
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Affiliation(s)
- Sam M Hermes
- Oregon Health & Science University, Department of Physiology and Pharmacology, 3181 Sam Jackson Park Road, Mailcode: L334, Portland, OR 97239-3098, United States
| | - Michael C Andresen
- Oregon Health & Science University, Department of Physiology and Pharmacology, 3181 Sam Jackson Park Road, Mailcode: L334, Portland, OR 97239-3098, United States
| | - Sue A Aicher
- Oregon Health & Science University, Department of Physiology and Pharmacology, 3181 Sam Jackson Park Road, Mailcode: L334, Portland, OR 97239-3098, United States.
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19
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Chakravarthy K, Chaudhry H, Williams K, Christo PJ. Review of the Uses of Vagal Nerve Stimulation in Chronic Pain Management. Curr Pain Headache Rep 2015; 19:54. [DOI: 10.1007/s11916-015-0528-6] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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20
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Botha C, Farmer AD, Nilsson M, Brock C, Gavrila AD, Drewes AM, Knowles CH, Aziz Q. Preliminary report: modulation of parasympathetic nervous system tone influences oesophageal pain hypersensitivity. Gut 2015; 64:611-7. [PMID: 24870622 DOI: 10.1136/gutjnl-2013-306698] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
OBJECTIVES Autonomic nervous system dysfunction has been implicated in visceral hypersensitivity. However, the specific contribution of the parasympathetic nervous system (PNS) is unclear. We aimed to determine whether physiological and pharmacological manipulation of parasympathetic tone influences the development of hypersensitivity in a validated model of acid-induced oesophageal pain. DESIGN Prior to, and following, a 30-min distal oesophageal infusion of 0.15 M hydrochloric acid, pain thresholds to electrical stimulation were determined in the proximal non-acid exposed oesophagus in healthy subjects. Validated sympathetic (skin conductance response) and parasympathetic (cardiac vagal tone) parameters were measured at baseline and continuously thereafter. In study 1, 55 subjects were randomised in a pragmatic blinded crossover design to receive deep breathing or un-paced breathing during acid infusion. In study 2, 32 subjects were randomised in a blinded, crossover design to receive intravenous atropine or placebo (saline) with deep breathing during acid infusion. RESULTS Study 1: Deep breathing increased cardiac vagal tone (2.1±2.3 vs -0.3±2.3, p=0.0006) with concomitant withdrawal of skin conductance response (-0.6±4.9 vs 3±4.8, p=0.03) in comparison with un-paced breathing. Deep breathing prevented the development of acid-induced oesophageal hypersensitivity in comparison with sham breathing (p=0.0001). Study 2: Atropine, in comparison with placebo, blocked the attenuating effect of deep breathing on the development of acid-induced oesophageal hypersensitivity (p=0.046). CONCLUSIONS The development of oesophageal hyperalgesia is prevented by physiologically increasing parasympathetic tone. This effect is pharmacologically blocked with atropine, providing evidence that the PNS influences the development of oesophageal pain hypersensitivity.
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Affiliation(s)
- Claude Botha
- Centre for Digestive Diseases, Blizard Institute of Cell & Molecular Science, Wingate Institute of Neurogastroenterology, Barts and the London School of Medicine & Dentistry, Queen Mary University of London, London, UK
| | - Adam D Farmer
- Centre for Digestive Diseases, Blizard Institute of Cell & Molecular Science, Wingate Institute of Neurogastroenterology, Barts and the London School of Medicine & Dentistry, Queen Mary University of London, London, UK
| | - Matias Nilsson
- Mech-Sense, Department of Gastroenterology, Aalborg University Hospital, Aalborg, Denmark
| | - Christina Brock
- Mech-Sense, Department of Gastroenterology, Aalborg University Hospital, Aalborg, Denmark
| | - Ana D Gavrila
- Centre for Digestive Diseases, Blizard Institute of Cell & Molecular Science, Wingate Institute of Neurogastroenterology, Barts and the London School of Medicine & Dentistry, Queen Mary University of London, London, UK
| | - Asbjørn Mohr Drewes
- Mech-Sense, Department of Gastroenterology, Aalborg University Hospital, Aalborg, Denmark
| | - Charles H Knowles
- Centre for Digestive Diseases, Blizard Institute of Cell & Molecular Science, Wingate Institute of Neurogastroenterology, Barts and the London School of Medicine & Dentistry, Queen Mary University of London, London, UK
| | - Qasim Aziz
- Centre for Digestive Diseases, Blizard Institute of Cell & Molecular Science, Wingate Institute of Neurogastroenterology, Barts and the London School of Medicine & Dentistry, Queen Mary University of London, London, UK
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21
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22
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Goldstein DS. Concepts of scientific integrative medicine applied to the physiology and pathophysiology of catecholamine systems. Compr Physiol 2014; 3:1569-610. [PMID: 24265239 DOI: 10.1002/cphy.c130006] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
This review presents concepts of scientific integrative medicine and relates them to the physiology of catecholamine systems and to the pathophysiology of catecholamine-related disorders. The applications to catecholamine systems exemplify how scientific integrative medicine links systems biology with integrative physiology. Concepts of scientific integrative medicine include (i) negative feedback regulation, maintaining stability of the body's monitored variables; (ii) homeostats, which compare information about monitored variables with algorithms for responding; (iii) multiple effectors, enabling compensatory activation of alternative effectors and primitive specificity of stress response patterns; (iv) effector sharing, accounting for interactions among homeostats and phenomena such as hyperglycemia attending gastrointestinal bleeding and hyponatremia attending congestive heart failure; (v) stress, applying a definition as a state rather than as an environmental stimulus or stereotyped response; (vi) distress, using a noncircular definition that does not presume pathology; (vii) allostasis, corresponding to adaptive plasticity of feedback-regulated systems; and (viii) allostatic load, explaining chronic degenerative diseases in terms of effects of cumulative wear and tear. From computer models one can predict mathematically the effects of stress and allostatic load on the transition from wellness to symptomatic disease. The review describes acute and chronic clinical disorders involving catecholamine systems-especially Parkinson disease-and how these concepts relate to pathophysiology, early detection, and treatment and prevention strategies in the post-genome era.
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Affiliation(s)
- David S Goldstein
- Clinical Neurocardiology Section, Clinical Neurosciences Program, Division of Intramural Research, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
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23
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Marques-Lopes J, Martins I, Pinho D, Morato M, Wilson SP, Albino-Teixeira A, Tavares I. Decrease in the expression of N-methyl-D-aspartate receptors in the nucleus tractus solitarii induces antinociception and increases blood pressure. J Neurosci Res 2011; 90:356-66. [PMID: 21948527 DOI: 10.1002/jnr.22760] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Revised: 07/05/2011] [Accepted: 07/08/2011] [Indexed: 12/18/2022]
Abstract
N-methyl-D-aspartate receptors (NMDAR) have a role in cardiovascular control at the nucleus tractus solitarii (NTS), eliciting increases or decreases in blood pressure (BP), depending on the area injected with the agonists. In spite of the association between cardiovascular control and pain modulation, the effects of manipulating NMDAR in pain responses have never been evaluated. In this study, we decreased the expression of NMDAR in the NTS using gene transfer to target receptor subunits and evaluate long-term effects. Seven days after the injection of lentiviral vectors containing the NR1a subunit cDNA of NMDAR, in antisense orientation, into the intermediate NTS of Wistar rats, BP was measured, and the formalin test of nociception was performed. The antisense vector induced a decrease of NR1 expression in the NTS and elicited BP rises and hypoalgesia. Antisense vectors inhibited formalin-evoked c-Fos expression in the spinal cord, indicating decreased nociceptive activity of spinal neurons. Using a time-course approach, we verified that the onset of both the increases in BP and the hypoalgesia was at 4 days after vector injection into the NTS. The injection of NMDA into the NTS reversed the effects of antisense vectors in pain behavioral responses and spinal neuronal activation and decreased BP and heart rate. The present study shows that the NR1 subunit of the NMDAR at the NTS is critical in the regulation of tonic cardiovascular and nociceptive control and shows an involvement of the nucleus in the modulation of sustained pain.
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Affiliation(s)
- J Marques-Lopes
- Instituto de Farmacologia & Terapêutica, Faculdade de Medicina, Universidade do Porto, Porto, Portugal
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Chen SL, Wu XY, Cao ZJ, Fan J, Wang M, Owyang C, Li Y. Subdiaphragmatic vagal afferent nerves modulate visceral pain. Am J Physiol Gastrointest Liver Physiol 2008; 294:G1441-9. [PMID: 18420825 PMCID: PMC3222235 DOI: 10.1152/ajpgi.00588.2007] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Activation of the vagal afferents by noxious gastrointestinal stimuli suggests that vagal afferents may play a complex role in visceral pain processes. The contribution of the vagus nerve to visceral pain remains unresolved. Previous studies reported that patients following chronic vagotomy have lower pain thresholds. The patient with irritable bowel syndrome has been shown alteration of vagal function. We hypothesize that vagal afferent nerves modulate visceral pain. Visceromotor responses (VMR) to graded colorectal distension (CRD) were recorded from the abdominal muscles in conscious rats. Chronic subdiaphragmatic vagus nerve sections induced 470, 106, 51, and 54% increases in VMR to CRD at 20, 40, 60 and 80 mmHg, respectively. Similarly, at light level of anesthesia, topical application of lidocaine to the subdiaphragmatic vagus nerve in rats increased VMR to CRD. Vagal afferent neuronal responses to low or high-intensity electrical vagal stimulation (EVS) of vagal afferent Adelta or C fibers were distinguished by calculating their conduction velocity. Low-intensity EVS of Adelta fibers (40 microA, 20 Hz, 0.5 ms for 30 s) reduced VMR to CRD at 40, 60, and 80 mmHg by 41, 52, and 58%, respectively. In contrast, high-intensity EVS of C fibers (400 microA, 1 Hz, 0.5 ms for 30 s) had no effect on VMR to CRD. In conclusion, we demonstrated that vagal afferent nerves modulate visceral pain. Low-intensity EVS that activates vagal afferent Adelta fibers reduced visceral pain. Thus EVS may potentially have a role in the treatment of chronic visceral pain.
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Shahabi P, Mirnajafi-Zadeh J, Fathollahi Y, Hoseinmardi N, Rezvani ME, Eslami-far A. Amygdala adenosine A1 receptors have no anticonvulsant effect on piriform cortex-kindled seizures in rat. Can J Physiol Pharmacol 2006; 84:913-21. [PMID: 17111036 DOI: 10.1139/y06-041] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Adenosine is an endogenous anticonvulsant that exerts its effects through A1 receptors. As the piriform/amygdala is a critical circuit for limbic seizure propagation, in this study, the role of basolateral amygdala A1 receptors on piriform cortex (PC)-kindled seizures was investigated. Rats were kindled by daily electrical stimulation of PC. In fully kindled animals, bilateral intra-amygdala N6-cyclohexyladenosine (CHA; 10–500 µmol/L, a selective A1 receptor agonist) had no effect on kindled-seizure parameters. However, bilateral intra-amygdala 2% lidocaine (reversal neuronal inhibitor) reduced the kindled seizure severity. There was significant increase in stage 4 latency and decrease in stage 5 duration. Bilateral lesion of basolateral amygdala of kindled animals (by electrical DC current) reduced the kindled seizure severity more dramatically. Our results showed afterdischarge duration, stage 5 duration, and seizure duration were decreased and stage 4 latency increased significantly. In addition, daily intra-amygdala CHA had no significant effect on PC kindling acquisition. Therefore, it may be concluded that although the basolateral amygdala neuronal activity has a critical role in the propagation of epileptic seizures from PC, the amygdala A1 receptors have no role in this regard. On the other hand, amygdala A1 receptors have no anticonvulsant or antiepileptogenic effect on PC-kindled seizures.
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Affiliation(s)
- Parviz Shahabi
- Department of Physiology, School of Medical Sciences, Tarbiat Modares University, Tehran, I.R. Iran
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26
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Sarihi A, Fathollahi Y, Motamedi F, Naghdi N, Rashidy-Pour A. Effects of lidocaine reversible inactivation of the median raphe nucleus on long-term potentiation and recurrent inhibition in the dentate gyrus of rat hippocampus. Brain Res 2003; 962:159-68. [PMID: 12543467 DOI: 10.1016/s0006-8993(02)03990-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Considering the fact that median raphe nucleus (MRN) constitutes one of the inputs of the hippocampus, the effects of reversible inactivation of MRN on long-term potentiation (LTP) and recurrent inhibition in the dentate gyrus (DG) of rat hippocampus, in vivo, were examined. Rats were anesthetized with urethane (1.5 g/kg, i.p.). MRN was temporarily suppressed by intra-MRN injection of lidocaine (0.5 microl, 2%). For LTP induction, eight episodes of high frequency stimuli (100 Hz) were delivered to the perforant path (PP), each consisting of 10 stimuli at 100 Hz. Population spikes (PS) and population excitatory post synaptic potentials ((P)EPSP) in DG were recorded 10 min before, and 5, 10, 20, 40, 60 and 120 min after tetanization. MRN inactivation itself had no effect on the amplitude of baseline responses. The PS amplitude and (P)EPSP slope in rats, injected with intra-MRN lidocaine, 5 min before tetanization, were not different from the control group. However, at 120 min PS amplitude was significantly higher than control. Lidocaine injection 5 min after tetanic stimuli caused a significant decrease in PS amplitude (10, 20 and 60 min) and (P)EPSP slope (20 and 40 min) after tetanization. The data showed that inactivation of MRN has no effect on LTP induction in the DG of hippocampus but it does affect its maintenance, and this effect depends on the pre- or post-tetanic inactivation. In the last part of this study, in order to investigate the effect of MRN on the efficacy of recurrent inhibition in the perforant-dentate synapses, paired pulse was applied to the PP at 10 and 20 ms interpulse intervals. Inactivation of MRN increased the amount of recurrent inhibition in the DG with 20 ms interpulse interval. This observation indicates that MRN inhibits the recurrent inhibition mechanism, which is in accordance with the suggested role of MRN neurons on inhibition of hippocampal GABAergic interneurons.
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Affiliation(s)
- Abdolrahman Sarihi
- Department of Physiology, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran.
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Bohotin C, Scholsem M, Multon S, Martin D, Bohotin V, Schoenen J. Vagus nerve stimulation in awake rats reduces formalin-induced nociceptive behaviour and fos-immunoreactivity in trigeminal nucleus caudalis. Pain 2003; 101:3-12. [PMID: 12507695 DOI: 10.1016/s0304-3959(02)00301-9] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Besides its well-established efficacy in epilepsy, vagus nerve stimulation (VNS) may be of potential interest in pain treatment. It has, however, not yet been assessed in animal pain models with the devices and stimulation protocols used in humans. We have therefore studied in awake rats the effects of left cervical VNS on trigeminal nociception using an implantable electrode and stimulator (NCP-Cyberonics). VNS was applied for 24h at 2 mA intensity, 20 Hz frequency, 0.5 ms pulse width and a duty cycle of 20s ON/18s OFF. As a nociceptive stimulus, we injected formalin into the left mystacial vibrissae, assessed behaviour for 45 min and sacrificed the animals 45 min later. Fos-immunoreactive (Fos-Ir) neurons were counted in laminae I-II of trigeminal nucleus caudalis (TNC) on both sides. We used three groups of control animals: VNS without formalin, formalin without VNS and sham VNS (implanted without stimulation or formalin). Whereas sham VNS had no significant effect, VNS alone increased Fos expression in ipsilateral TNC in addition to the expected increase in nucleus tractus solitarius. It also significantly attenuated the increase of Fos-Ir neurons observed in ipsilateral TNC laminae I-II after formalin injection. If the proper VNS effect on Fos-expression was subtracted, the reduction of formalin-induced nociceptor activation was 55%. VNS also reduced nociceptive behaviour on average by 96.1% during the early phase (0-6 min) and by 60.7% during the late phase (6-45 min) after the formalin injection. These results suggest that VNS applied with a device used in human therapy may have in awake rats a significant antinociceptive effect in a model of trigeminal pain.
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Affiliation(s)
- C Bohotin
- Department of Neuroanatomy, 20, rue de Pitteurs, B-4020, Liège, Belgium
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Mirnajafi-Zadeh J, Mortazavi M, Fathollahi Y, Alasvand Zarasvand M, Reza Palizvan M. Effect of transient hippocampal inhibition on amygdaloid kindled seizures and amygdaloid kindling rate. Brain Res 2002; 954:220-6. [PMID: 12414105 DOI: 10.1016/s0006-8993(02)03292-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In this study the effect of transient inhibition of the CA1 region of the dorsal hippocampus by lidocaine on amygdala kindling rate and amygdaloid kindled seizures was investigated. In experiment 1, rats were divided into four groups. In group 1, animals were implanted only with a tripolar electrode into the amygdala but in groups 2-4, two guide cannulae were also implanted into the CA1 regions of the dorsal hippocampi. Animals were stimulated daily to be kindled. In groups 3 and 4, saline or 2% lidocaine (1 microl/2 min) was also injected respectively into the hippocampus, 5 min before each stimulation. Results obtained showed that amygdala kindling rate and the number of stimulations to receive from stage 4 to stage 5 seizure were significantly increased in group 4. In experiment 2, lidocaine (1% and 2%) was infused (1 microl/2 min) into the hippocampus of amygdala kindled rats bilaterally and animals were stimulated at 5, 15 and 30 min after drug injection. Twenty four h before lidocaine injection, saline was also infused (1 microl/2 min) into the hippocampus as control. Obtained results showed that afterdischarge duration was reduced 5 min after lidocaine (1% and 2%) injection. Stage 5 seizure duration was also decreased 5 and 15 min after 2% lidocaine. Thus, it may be suggested that in amygdala kindling, activation of the hippocampal CA1 region has a role in seizure acquisition and seizure severity so that inhibition of this region results in decreasing of seizure severity and retards amygdala kindling rate.
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Affiliation(s)
- Javad Mirnajafi-Zadeh
- Department of Physiology, School of Medical Sciences, Tarbiat Modarres University, Tehran, Iran.
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29
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Sévoz-Couche C, Hamon M, Laguzzi R. Antinociceptive effect of cardiopulmonary chemoreceptor and baroreceptor reflex activation in the rat. Pain 2002; 99:71-81. [PMID: 12237185 DOI: 10.1016/s0304-3959(02)00055-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The effect on the nociceptive tail-flick (TF) reflex of cardiopulmonary chemoreceptor and arterial baroreceptor activation, producing Bezold-Jarisch like- and baro-reflex responses, respectively, was analysed in lightly halothane-anaesthetized rats. Intra-cardiac administration of phenylbiguanide (5-100 microg/kg, into the right atrium) or veratrine (30-150 microg/kg, into the left ventricle), which both elicited the characteristic Bezold-Jarisch-like cardiovascular reflex responses (hypotension and bradycardia), produced a dose-dependent increase in TF latency. A similar inhibitory influence on the TF reflex was noted upon baroreflex activation by acute administration of phenylephrine (15-50 microg/kg i.v.) or aortic depressor nerve stimulation (100-400 microA). As expected from the involvement of local excitatory amino acid receptors in both vagally mediated cardiovascular reflex responses and inhibition of the TF reflex, microinjections of kynurenic acid (3 nmol/0.1 microl), an N-methyl-D-aspartate (NMDA) and non-NMDA receptor antagonist, into the nucleus tractus solitarius, prevented the cardiovascular responses as well as the concomitant increase in TF latency produced by cardiopulmonary chemoreceptor and baroreceptor stimulations. The present data show that induction of the cardiopulmonary chemoreceptor and baroreceptor reflexes produces an antinociceptive effect which can be assessed using the TF test, and that glutamate ionotropic receptors within the nucleus tractus solitarius mediate this effect.
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Affiliation(s)
- Caroline Sévoz-Couche
- Neuropsychopharmacologie Moléculaire, Cellulaire et Fonctionnelle (INSERM U288), CHU Pitié-Salpêtrière, 91 Boulevard de l'Hôpital, 75634 Paris Cedex 13, France.
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Gschossmann JM, Mayer EA, Miller JC, Raybould HE. Subdiaphragmatic vagal afferent innervation in activation of an opioidergic antinociceptive system in response to colorectal distension in rats. Neurogastroenterol Motil 2002; 14:403-8. [PMID: 12213108 DOI: 10.1046/j.1365-2982.2002.00345.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Abstract In a number of different experimental paradigms of somatic pain, there is evidence for a vagally mediated antinociceptive system. This pathway probably involves opioid mechanisms. However, whether this pathway is activated in visceral pain or if it involves subdiaphragmatic vagal afferents is unclear. The aim of the present study was to determine whether subdiaphragmatic vagal afferents mediate antinociception in response to a visceral stimulus and whether this involves an opioid pathway. Colorectal distension was performed in fasted, conscious male Sprague-Dawley rats using a balloon catheter connected to an electronic distension device. The number of abdominal contractions (visceromotor response) in response to a tonic colorectal distension (60 mmHg for 10 min) was recorded. Experiments were performed in sham or subdiaphragmatically vagotomized, perineural vehicle- or capsaicin-treated rats (to functionally denervate vagal afferents) before and after administration of naloxone (25 mg kg(-1) bodyweight intraperitoneally). Vagotomy, capsaicin and naloxone pretreatments all significantly enhanced the visceromotor response to colorectal distension. The effect of naloxone in capsaicin-treated rats did not appear to be additive. These results suggest that activation of subdiaphragmatic afferents, which can be blocked by capsaicin, may play a role in opioid-dependent antinociceptive pathways activated by a noxious visceral stimulus.
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Affiliation(s)
- J M Gschossmann
- Neuroenteric Disease Program, CURE: Digestive Diseases Research Center, GLA VA HC, Departments of Medicine and Physiology, and Brain Research Institute, UCLA School of Medicine, Los Angeles, California 95616, USA
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31
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Takeda M, Tanimoto T, Nishikawa T, Ikeda M, Yoshida S, Ito M, Matsumoto S. Volume expansion suppresses the tooth-pulp evoked jaw-opening reflex related activity of trigeminal neurons in rats. Brain Res Bull 2002; 58:83-9. [PMID: 12121817 DOI: 10.1016/s0361-9230(02)00763-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The aim of the present study is to clarify whether physiological stimulation of vagal afferents modulates the activity of the trigeminal spinal nucleus oralis (TSNO) neurons related to the tooth-pulp (TP)-evoked jaw-opening reflex (JOR) in pentobarbital-anesthetized rats. The activity of TSNO neurons and the amplitude of digastric electromyogram (dEMG) increased proportionally during 1.0-3.5 times the threshold for JOR. The amplitude of the dEMG of 14 out of 17 rats was suppressed by physiological stimulation of vagal afferents after intravenous infusion of Ficoll. Out of 23, 18 TSNO unit activities in 14 rats were also suppressed by Ficoll infusion. This suppressive effect of unit and dEMG activities returned to the control level within 25 min. After administration of naloxone (0.5 and 1.0 mg/kg, i.v.) the suppressive effect of Ficoll infusion on the activity of TSNO neurons (5/7) was significantly attenuated compared to the control (p < 0.01). The inhibition TSNO neuronal and dEMG activities by Ficoll infusion was volume-dependent in a range of 5-10% of total blood volume. Furthermore, right vagus nerve ligation greatly inhibited the suppressive effect of Ficoll-induced TSNO activity. These results therefore suggest that low-pressure cardiopulmonary baroreceptors whose afferents travel in the vagus nerve inhibit the pulpal nociceptive transmission.
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Affiliation(s)
- Mamoru Takeda
- Department of Physiology, School of Dentistry at Tokyo, Nippon Dental University, Tokyo, Japan.
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Miyashita T, Williams CL. Glutamatergic transmission in the nucleus of the solitary tract modulates memory through influences on amygdala noradrenergic systems. Behav Neurosci 2002; 116:13-21. [PMID: 11895175 DOI: 10.1037/0735-7044.116.1.13] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The authors examined whether glutamate release from the vagus nerve onto the nucleus of the solitary tract (NTS) is one mechanism by which the vagus influences memory and neural activity in limbic structures. Rats trained to drink from a spout were given a footshock (0.35 mA) on Day 5 after approaching the spout. Phosphate-buffered saline or 5.0, 50.0, or 100.0 nmol/0.5 microl glutamate was then infused into the NTS. Glutamate (5.0 or 50.0 nmol) significantly enhanced memory on the retention test. In Experiment 2, this effect was attenuated by blocking noradrenergic receptors in the amygdala with propranolol (0.3 microg/0.5 microl). Experiment 3 used in vivo microdialysis to determine whether footshock plus glutamate (50.0 nmol) alters noradrenergic output in the amygdala. These treatments caused a significant and long-lasting increase in amygdala noradrenergic concentrations. The results indicate that glutamate may be one transmitter that conveys the effects of vagal activation on brain systems that process memory.
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Affiliation(s)
- Teiko Miyashita
- Department of Psychology, University of Virginia, Charlottesville 22904-4400, USA
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33
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Sunderam S, Osorio I, Watkins JF, Wilkinson SB, Frei MG, Davis RE. Vagal and sciatic nerve stimulation have complex, time-dependent effects on chemically-induced seizures: a controlled study. Brain Res 2001; 918:60-6. [PMID: 11684042 DOI: 10.1016/s0006-8993(01)02928-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Previous studies of the effects of electrical vagus stimulation on experimental seizures were without suitable controls or statistical validation, and ignored the potential role of vagally-induced hemodynamic depression on seizure expression. This study addresses these limitations. The effects of periodic left vagus nerve stimulation (LVNS) on chemically-induced seizures in rats were compared with control groups receiving no stimulation (NoS), left sciatic nerve stimulation (LSNS) and LVNS after pretreatment with methyl atropine (MA-LVNS). Stimulation followed a 30 s on-120 s off cycle over 130 min. Seizures were scored visually and the temporal variation of their probability P(s) across the stimulation cycle was measured statistically. P(s) was significantly different (P<0.01) for all groups: LSNS had the highest and MA-LVNS the lowest seizure probability; LVNS and NoS had intermediate values. While LVNS blocked seizures, it also precipitated them, explaining why its anti-seizure effect was only slightly greater than NoS. Neither LVNS nor MA-LVNS induced changes in cortical rhythms ('activation') associated with decreased P(s), unlike LSNS which increased cortical rhythm synchrony and with it, P(s). LVNS alone induced marked bradycardia and moderate hypoxemia. In conclusion, cranial and peripheral nerve stimulation have complex, time-varying effects on cerebral excitability: low frequency LSNS facilitated seizures, while LVNS both suppressed and facilitated them. The anti-seizure effect of LVNS was small and may have, in part, been due to a hemodynamically-induced deficit in energy substrates. The effects of MA-LVNS on seizure duration and P(s) raise the possibility that, in the absence of hemodynamic depression, stimulation of this nerve does not have a strong anti-seizure effect.
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Affiliation(s)
- S Sunderam
- Flint Hills Scientific L.L.C., 5020 W15th St. Suite A, Lawrence, KS 66049, USA
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34
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D'Aniello B, Fiorentin M, Pinelli C, Guarino FM, Angelini F, Rastogi RK. Localization of FMRFamide-like immunoreactivity in the brain of the viviparous skink (Chalcides chalcides). BRAIN, BEHAVIOR AND EVOLUTION 2001; 57:18-32. [PMID: 11359045 DOI: 10.1159/000047223] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Neuroanatomical distribution of FMRFamide-like immunoreactivity was investigated in the brain and olfactory system of the viviparous skink, Chalcides chalcides. In the adult brain FMRFamide immunoreactive (ir) perikarya were observed in the diagonal band of Broca, medial septal nucleus, accumbens nucleus, bed nucleus of the anterior commissure, periventricular hypothalamic nucleus, lateral forebrain bundle, and lateral preoptic, subcommissural, suprachiasmatic and lateral hypothalamic areas. This pattern was seen in both male and female brains. Though all major brain areas showed FMRFamide-ir innervation, the densest ir fiber network was observed in the hypothalamus. During development, ir elements were observed for the first time in embryos at mid-pregnancy. FMRFamide perikarya were located along the ventral surface of the vomeronasal nerve, in the olfactory peduncle mediobasally, as well as in the anterior olfactory nucleus and olfactory tubercle. Furthermore, some ir neurons were observed in the rhombencephalic reticular substance; however, the ir fiber network was poorly developed. Later in development FMRFamide-ir neurons appeared also in the bed nucleus of the anterior commissure as well as the rhombencephalic nucleus of solitary tract and the dorsal motor nucleus of vagus nerve. In juveniles, the distribution profile of FMRFamide immunoreactivity was substantially similar to that of the adults, with a less widespread neuronal distribution and a more developed fiber network. Ontogenetic presence of FMRFamide immunoreactivity in the nasal area has been linked to the presence of a nervus terminalis in this reptile.
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Affiliation(s)
- B D'Aniello
- Dipartimento di Zoologia, Università di Napoli Federico II, Napoli, Italy.
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35
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Guevara-Guzmán R, Buzo E, Larrazolo A, de la Riva C, Da Costa AP, Kendrick KM. Vaginocervical stimulation-induced release of classical neurotransmitters and nitric oxide in the nucleus of the solitary tract varies as a function of the oestrus cycle. Brain Res 2001; 898:303-13. [PMID: 11306017 DOI: 10.1016/s0006-8993(01)02207-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The effects of vaginocervical stimulation (VCS) on glutamate (GLU), aspartate (ASP), gamma-aminobutyric acid (GABA), noradrenaline (NA), arginine (ARG) and nitric oxide (NO) (citrulline) release in the nucleus of the solitary tract (nTS) were measured in anaesthetised female rats as a function of the oestrus cycle. During pro-oestrus/oestrus (P/E), but not during met-oestrus/di-oestrus (M/D), VCS significantly increased concentrations of NA, ASP, GLU, NO (citrulline) and GABA, but not ARG. Basal NA concentrations were also increased in P/E. These effects were prevented by bilateral section of either the vagus nerve or pelvic and hypogastric nerves. Vagotomy also significantly decreased basal NO concentrations in M/D and P/E while pelvic and hypogastric nerve section significantly increased GABA concentrations. Our results therefore confirm that the nTS is a relay structure for the visceral afferents sending information from the uterus into the central nervous system. The ability of VCS to trigger classical transmitter release and NO in the female is influenced by the stage of the oestrous cycle and is routed both via the vagus and pelvic/hypogastric nerves.
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Affiliation(s)
- R Guevara-Guzmán
- Departamento de Fisiología, Facultad de Medicina, UNAM, 04510 D.F., México, Mexico
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Clayton EC, Williams CL. Noradrenergic receptor blockade of the NTS attenuates the mnemonic effects of epinephrine in an appetitive light-dark discrimination learning task. Neurobiol Learn Mem 2000; 74:135-45. [PMID: 10933899 DOI: 10.1006/nlme.1999.3946] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
These experiments examined the contribution of noradrenergic neurons in the nucleus of the solitary tract (NTS) in mediating the memory-facilitating effects of epinephrine. In Experiment 1, saline or 0.05 or 0.1 mg/kg of epinephrine was given intraperitoneally (ip) to rats after the second day of training in a light-dark Y-maze discrimination task. On a 20-trial retention test given 2 and 7 days later, the 0.1 mg/kg epinephrine group made significantly more correct responses than controls and required fewer trials to reach criterion. In Experiment 2, phosphate-buffered saline or the noradrenergic antagonist dl-propranolol (0.3 or 1.0 microg/0.5 microl) was infused into the NTS prior to an ip injection of saline or 0.1 mg/kg of epinephrine. The memory-enhancing effects of epinephrine were attenuated by the infusion of 0.3 microg/0.5 microl of dl-propranolol into the NTS. These findings indicate an involvement of NTS noradrenergic neurons in mediating the effects of peripheral epinephrine on memory storage processes.
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Affiliation(s)
- E C Clayton
- Department of Psychology, University of Virginia, Charlottesville, Virginia 22903, USA
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Thurston-Stanfield CL, Ranieri JT, Vallabhapurapu R, Barnes-Noble D. Role of vagal afferents and the rostral ventral medulla in intravenous serotonin-induced changes in nociception and arterial blood pressure. Physiol Behav 1999; 67:753-67. [PMID: 10604848 DOI: 10.1016/s0031-9384(99)00128-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Intravenous administration of serotonin inhibits the nociceptive tail-flick (TF) reflex, partially through activation of vagal afferents. The present study examined the role of the rostral ventral medulla (RVM) in i.v. serotonin-produced inhibition of the TF reflex. In Experiment 1, the effects of anesthetic blockade of the RVM on serotonin-produced inhibition of the TF were determined. Lidocaine attenuated the serotonin-produced inhibition of the TF reflex, but had no effect on the cardiovascular effects of serotonin. In Experiment 2, the effects of i.v. serotonin on neural activity in the RVM in intact and cardiopulmonary deafferented rats were determined. Neurons in the RVM were classified as ON and OFF cells, where ON cells were excited by noxious heat, and OFF cells were inhibited. The effects of i.v. serotonin on TF latency, blood pressure, and ON or OFF cell activity were then determined. In intact rats, serotonin produced a dose-dependent increase in TF latency, triphasic changes in blood pressure, and bi- or triphasic changes in ON or OFF cell activity. The changes in blood pressure included an initial sharp decrease in blood pressure (Bezold-Jarisch reflex), followed by a brief pressor response, followed by a delay depressor response. ON cells were generally excited, although there was a period during which the excitation decreased. OFF cells were initially excited, followed by a period of inhibition, followed by a second period of excitation. Bilateral cervical vagotomy attenuated the increase in TF latency, the Bezold-Jarisch reflex, and the excitation of OFF cells, and potentiated the excitation of ON cells and the pressor response. Bilateral sinoaortic deafferentation attenuated the Bezold-Jarisch reflex and potentiated the pressor response. These findings indicate that i.v. serotonin inhibits the TF reflex through at least two distinct mechanisms, one of which requires the RVM. In addition, serotonin produces a vagally mediated excitation of OFF cells and inhibition of ON cells that may mediate some of the antinociception.
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Sarihi A, Motamedi F, Rashidy-Pour A, Naghdi N, Behzadi G. Reversible inactivation of the median raphe nucleus enhances consolidation and retrieval but not acquisition of passive avoidance learning in rats. Brain Res 1999; 817:59-66. [PMID: 9889321 DOI: 10.1016/s0006-8993(98)01196-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Involvement of median raphe nucleus (MRN) in acquisition, consolidation and retrieval of passive avoidance (PA) was investigated with functional suppression of this area by lidocaine. Rats carrying a chronically implanted cannula aimed at the MRN were trained on a step-through passive avoidance task and received intra-MRN injection of lidocaine or saline 5 min before training or 5, 90 and 360 min after acquisition trial or 5 min before the retrieval test. Lidocaine MRN inactivation had no effect on PA learning. Lidocaine injected 5 and 90 min after the acquisition trial significantly enhanced avoidance of the dark compartment in comparison with the control group injected with saline. But PA retention was not affected by lidocaine injected 360 min after acquisition or 5 min before training. Retention latency significantly increased, when lidocaine injected 5 min before retrieval test. Step-through latency of naive rats was not affected by MRN blockade. Furthermore, reversible inactivation of MRN did not have a significant effect on locomotor activity. Our results indicate that the MRN contributes to PA consolidation at least until 90 min after acquisition and involves in PA retrieval. It is concluded that functional ablation of the MRN may disrupt the inhibitory actions of MRN projections to sub-cortical circuits participating in PA memorization and retrieval.
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Affiliation(s)
- A Sarihi
- Department of Physiology, School of Medical Sciences, Tarbiat Modarres University, P.O. Box 14155-4838, Tehran, Iran.
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Davis G, Johns EJ. Renal nerve responses to somatic nerve activation in stroke-prone spontaneously hypertensive rats. JOURNAL OF THE AUTONOMIC NERVOUS SYSTEM 1996; 61:209-17. [PMID: 8988477 DOI: 10.1016/s0165-1838(96)00092-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
In chloralose/urethane anaesthetised stroke-prone spontaneously hypertensive rats, blood pressure and integrated renal nerve activity were higher whereas heart rate was lower than in Wistar rats by 37, 146 and 11%, respectively (all P < 0.001). The renal nerve signal was subjected to fast Fourier transformation to generate power spectra. In the hypertensive rats, total spectral power was 400% (P < 0.01) and power at the heart rate frequency was 50% (P < 0.01) greater while phase and time differences were shorter (both P < 0.001) than in Wistar rats. Brachial nerve stimulation increased total power in Wistar and hypertensive rats (P < 0.05), but importantly, power at the heart rate frequency was decreased by 80% in Wistar whereas there was a 20% (P < 0.05) increase in hypertensive rats, while phase and time differences were raised only in hypertensive rats (P < 0.05). Bilateral cervical vagotomy of the hypertensive rats had minimal actions on most variables but phase and time differences were doubled compared to intact hypertensive animals, but brachial nerve stimulation decreased power at the heart rate frequency (P < 0.05) which was a very different response from intact rats. Resting blood pressure, heart rate, total power and power at the heart rate frequency in the carotid sinus denervated animals were lower than in intact hypertensive rats, between 17 and 71%, respectively, but increased during brachial nerve stimulation. These experiments demonstrated that whereas somatic sensory input can modulate the pattern of sympathetic nerve activity to the kidney under normal conditions, this does not occur in the hypertensive rat. This appears to be related to afferent information carried by the vagus which suppresses the normal response; the carotid sinus baroreceptors are devoted to organising the nerve activity in relation to the blood pressure pulse wave.
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Affiliation(s)
- G Davis
- Department of Physiology, Medical School, University of Birmingham, UK
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40
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Thurston CL, Helton ES. Effects of intravenous phenylephrine on blood pressure, nociception, and neural activity in the rostral ventral medulla in rats. Brain Res 1996; 717:81-90. [PMID: 8738257 DOI: 10.1016/0006-8993(96)00007-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Acute or chronic increases in arterial blood pressure are associated with decreases in nociception. In addition, acute increases in arterial blood pressure inhibit ON cells and excite OFF cells of the rostral ventral medulla (RVM). The current study tested whether the antinociception produced by increases in blood pressure is dependent on changes in the activity of ON and/or OFF cells. Single unit activity of ON or OFF cells was recorded in the RVM during increases in blood pressure produced by intravenous infusion of phenylephrine (1, 2.5, or 10 micrograms/min for 21 min) in lightly anesthetized rats. Nociception was measured using the tail flick test. Phenylephrine dose-dependently increased mean arterial pressure and tail flick latency, but had inconsistent effects on neural activity in the RVM. In a second study, the effects of phenylephrine infusion on tail flick latency was determined before and after saline or lidocaine microinjections into the RVM. Lidocaine had no effect on the ability of phenylephrine to inhibit the tail flick reflex. These data suggest that the RVM, and therefore ON and OFF cells, is not required for phenylephrine-induced antinociception.
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Affiliation(s)
- C L Thurston
- Department of Biomedical Sciences, University of South Alabama, Mobile 36688, USA
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41
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Bossut DF, Maixner W. Effects of cardiac vagal afferent electrostimulation on the responses of trigeminal and trigeminothalamic neurons to noxious orofacial stimulation. Pain 1996; 65:101-109. [PMID: 8826496 DOI: 10.1016/0304-3959(95)00166-2] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We have previously reported that electrical stimulation of cardiac vagal afferents produces an inhibition of the feline's digastric reflex evoked by tooth-pulp stimulation. In the present study, we evaluated whether cardiac vagal afferent stimulation (CVAS) alters the responses of trigeminal sensory neurons to noxious orofacial stimulation in alpha-chloralose-anesthetized cats. A total of 37 trigeminal and trigeminothalamic neurons were recorded from trigeminal nucleus caudalis and trigeminal nucleus oralis. Thirty-five of these 37 neurons were classified as wide-dynamic-range (WDR) neurons because they had cutaneous receptive fields and responded to both noxious heat and non-noxious tactile stimuli. The effects of continuous CVAS (5 Hz, 3 msec, 2 mA) on heat-evoked responses (6 sec 50 degrees C heat pulse) were examined on 32 WDR neurons. CVAS inhibited (21 of 32 neurons), facilitated (5 of 32 neurons) or did not affect neuronal responses (6 of 32 neurons) to noxious heat. The effects of CVAS on heat-evoked responses of trigeminal and trigeminothalamic neurons were equivalent. The effects of intermittent CVAS (7 pulses at 333 Hz, 5 mA, delivered 200 msec prior to the test stimulus) on the responses to electrical test stimuli delivered to the center of a neuron's cutaneous receptive field or to the tooth pulp were also examined. Intermittent CVAS inhibited (15 of 24 neurons), facilitated (4 of 24 neurons) or had no effect (5 of 24 neurons) on A delta-mediated responses evoked by the electrical stimulation of facial skin. Intermittent CVAS either inhibited (8 of 12 neurons) or had no effect (4 of 12 neurons) on C-fiber-mediated responses evoked by electrical stimulation of the facial skin. Eight cells were recorded that received tooth-pulp input. Six of these 8 cells also received afferent input from facial skin, the remaining 2 cells responded only to tooth-pulp stimulation. Intermittent CVAS either inhibited (7 of 8 neurons) or had no effect (1 of 8 neurons) on A delta-mediated responses evoked by electrical stimulation of the tooth pulp. The modulatory actions of intermittent CVAS on trigeminal and trigeminothalamic neuronal responses to convergent afferent input from both skin and tooth pulp were equivalent. The outcomes of this study provide additional evidence that cardiopulmonary vagal afferent stimulation modulates neuronal responses to noxious stimulation and suggest that alterations in cardiopulmonary dynamics may modulate nociception.
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Affiliation(s)
- D F Bossut
- Dental Research Center and the Departments of Endodontics and Pharmacology, University of North Carolina, Chapel Hill, NC 27599-7455 USA
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Komisaruk BR, Bianca R, Sansone G, Gómez LE, Cueva-Rolón R, Beyer C, Whipple B. Brain-mediated responses to vaginocervical stimulation in spinal cord-transected rats: role of the vagus nerves. Brain Res 1996; 708:128-34. [PMID: 8720868 DOI: 10.1016/0006-8993(95)01312-1] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The present study was designed to ascertain whether the vagus nerves convey functional sensory activity from the reproductive tract in rats. Previously, vaginocervical mechanostimulation (VS) was shown to increase pupil diameter (PD) and the threshold of vocalization to tail shock (Voc-T). These responses were attenuated but not abolished by combined bilateral transection of the 'genito-spinal' nerves (i.e. pelvic, hypogastric and pudendal). Subsequent bilateral vagotomy further reduced or abolished the residual responses. In the present study, spinal cord transection above the known level of entry of the genito-spinal nerves was combined with bilateral vagotomy. In ovariectomized rats, after spinal cord transection at thoracic 7 (T7X), lumbar 5 (L5X) levels, or sham surgery (Sh), responses to VS were measured, the vagus nerves were then transected bilaterally, and responses to VS were again measured. VS significantly increased Voc-T and PD after sham procedure or spinal cord transection at either level. Subsequent bilateral vagotomy abolished the VS-induced increase in PD in the T7X group. Due to low survival rate, the effect of vagotomy on Voc-T could not be determined. Consequently, we performed a second experiment. In non-ovariectomized rats, VS significantly increased PD but reduced Voc-T in the T7X group compared to the Sh group, and subsequent bilateral vagotomy abolished both responses. These findings provide evidence that, in the rat, the vagus nerves provide a functional sensory pathway from the reproductive tract directly to the medulla oblongata of the brain, bypassing the spinal cord.
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Affiliation(s)
- B R Komisaruk
- Institute of Animal Behavior, Rutgers, State University of New Jersey, Newark, 07102, USA
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Gentle MJ, Hunter LN, Sterling RJ. Projections of ankle joint afferents to the spinal cord and brainstem of the chicken (Gallus g. domesticus). J Comp Neurol 1995; 361:669-80. [PMID: 8576421 DOI: 10.1002/cne.903610409] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The projections of the ankle joint capsule afferents were studied by transganglionic transport of horseradish peroxidase injected directly into the ankle joint. The number and size of the labelled dorsal root ganglion cells were measured from synsacral nerves 2-9. In the dorsal root ganglia, all sizes of sensory neurones were labelled, and the largest number of labelled cells was in ganglia 5-7. The extensive sympathetic innervation of the ankle joint was identified by the large number of cell bodies labelled in the sympathetic ganglia of the paravertebral chain. Labelled afferent fibres projected to the spinal cord from the 2nd to the 8th synsacral nerves, with the rostral projection mainly via Lissauer's tract and the dorsal funiculus. Terminal labelling in the dorsal horn was identified in laminae I-III and VI, with a slight projection to V. Two areas of dense labelling, which did not correspond with the largest number of labelled dorsal root ganglion cells, were identified. A rostral area with the highest density of label was observed at the level of synsacral nerves 3-4 and a second slightly less dense area between synsacral nerves 7-8. In the caudal medulla, diffuse terminal labelling was observed in the nucleus gracilis et cuneatus, nucleus of the tractus solitarius, and the nucleus cuneatus externus. These results are discussed in a comparative context to identify similarities and differences between different primary afferent projections in birds and mammals and to highlight the possible functional significance of the avian articular afferent projection.
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Affiliation(s)
- M J Gentle
- Roslin Institute (Edinburgh), Midlothian, Scotland, United Kingdom
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Thurston CL, Randich A. Responses of on and off cells in the rostral ventral medulla to stimulation of vagal afferents and changes in mean arterial blood pressure in intact and cardiopulmonary deafferented rats. Pain 1995; 62:19-38. [PMID: 7478705 DOI: 10.1016/0304-3959(94)00223-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The relationships between mean arterial blood pressure (MAP) and the activity of putative pain modulatory neurons of the rostroventral medulla (ON and OFF cells) were determined in intact and cardiopulmonary deafferented rats. A total of 173 neurons were recorded from 97 rats as follows: 32 ON cells and 25 OFF cells from 39 intact rats; 32 ON cells and 20 OFF cells from 24 rats with bilateral sino-aortic deafferentation (SAD); 12 ON cells and 20 OFF cells from 19 rats with bilateral cervical vagotomy (CVAG); and 20 ON cells and 12 OFF cells from 15 rats with both SAD and CVAG. ON and OFF cells showed spontaneous fluctuations in activity such that ON cell activity was negatively correlated with MAP whereas OFF cell activity was positively correlated with MAP under conditions of no applied stimuli. These correlations were present in both intact and cardiopulmonary deafferented rats. Further, experimentally induced increases in MAP decreased ON cell activity and increased OFF cell activity in intact rats, but not in rats with SAD, CVAG, or the combination of SAD and CVAG. Experimentally induced decreases in MAP decreased OFF cell activity in intact rats and rats with CVAG, but not in rats with SAD or the combination of SAD and CVAG. These findings indicate that ON and OFF cells are modulated by baroreceptor activity, but baroreceptor input is not necessary for the spontaneous fluctuations in ON and OFF cell activity. Electrical stimulation of vagal afferents (VAS) inhibited 60% of the OFF cells studied, excited 4%, and produced biphasic effects consisting of excitation at low intensities and inhibition at greater intensities in 28% of all OFF cells. In general, VAS excited the majority of the ON cells studied, although there were significant differences between effects in intact and cardiopulmonary deafferented rats. Greater intensities of VAS that inhibited OFF cells and excited ON cells also inhibited the tail flick. Thus, inhibition of OFF cells and excitation of ON cells was correlated with antinociception. The effects of intravenous (i.v.) administration of 1.0 mg/kg morphine on neuronal activity did not differ between intact and cardiopulmonary deafferented rats.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- C L Thurston
- Department of Biomedical Sciences, University of South Alabama, Mobile, AL 36688 USA Department of Psychology, University of Alabama at Birmingham, Birmingham, AL 35294 USA
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Menescal-de-Oliveira L, Hoffmann A. Temporal modulation of antinociception by reciprocal connections between the dorsomedial medulla and parabrachial region. Brain Res Bull 1995; 37:467-74. [PMID: 7633895 DOI: 10.1016/0361-9230(95)00026-b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Microinjection of carbachol into the dorsal parabrachial regio (PBRd) of guinea pigs induces analgesia from the 5th to the 15th min postinjection, as evaluated by the reduction of the vocalization in response to an electric shock applied to one paw. When reversible blockade of the dorsomedial medulla or specifically of the nucleus tractus solitarius (NTS) is performed with xylocaine 5 min after microinjection of carbachol into the PBRd, the analgesic effect continues up to the 45th and to the 60th min, respectively. Blockade of the dorsomedial medulla is achieved by topical application of xylocaine to the area postrema (AP) or microinjection of the drug into the NTS. A prolongation of the duration of the analgesic effect also occurs after the inverse procedure, i.e., after reversible blockade of the PBRd 5 min after topical application of carbachol (1 microgram/microliter)to the AP or microinjection of carbachol into the NTS. In this case, the analgesic action, which lasted up to 30 min when carbachol was applied to the AP and 60 min when microinjected into the NTS, was prolonged up to 60 min and to 80 min, respectively, after reversible blockade of PBR. The present data suggest that the reciprocal connections between the different regions of the dorsomedial medulla and the PBR play an important role in the modulation of the duration of the analgesic effect, and that this fact may be of adaptive importance in the defensive analgesia that occurs in the confrontation between prey and predator.
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Affiliation(s)
- L Menescal-de-Oliveira
- Department of Physiology, Faculty of Medicine of Ribeiräo Preto, University of Säo Paulo, Brazil
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Parent MB, McGaugh JL. Posttraining infusion of lidocaine into the amygdala basolateral complex impairs retention of inhibitory avoidance training. Brain Res 1994; 661:97-103. [PMID: 7834391 DOI: 10.1016/0006-8993(94)91186-x] [Citation(s) in RCA: 105] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The present experiment examined the role of the central nucleus and basolateral complex in the retention of inhibitory avoidance training by reversibly inactivating these regions with lidocaine immediately following training. Male Sprague-Dawley rats were surgically implanted bilaterally with cannulae aimed at the central nucleus or the basolateral complex. One week later, they received one trial inhibitory avoidance training (0.45 mA; 1 s), followed immediately by infusions of lidocaine hydrochloride or buffer (10 micrograms/0.25 microliters). Retention was tested 2 days after training. Immediate posttraining infusions of lidocaine into the central nucleus did not affect retention performance; in contrast, immediate posttraining infusions of lidocaine into the basolateral complex significantly impaired retention performance. In addition, the effect of posttraining infusions of lidocaine into the basolateral complex was time-dependent: infusions administered 6 h after training also impaired memory, but infusions administered 24 h after training had no effect. Immediate posttraining infusions of lidocaine also impaired the retention performance of rats trained with a more intense footshock (0.75 mA). However, at the higher footshock intensity, administration of lidocaine 6 h after training had no effect on retention performance. The time- and footshock-dependent retrograde impairment of memory produced by posttraining reversible inactivation of the basolateral complex suggests that this region of the amygdala is involved in the consolidation of memory for inhibitory avoidance training.
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Affiliation(s)
- M B Parent
- Center for the Neurobiology of Learning and Memory, University of California, Irvine 92717-3800
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Granata AR. Rostral ventrolateral medulla descending neurons excited by nucleus tractus solitarii inputs. Brain Res 1994; 648:299-305. [PMID: 7922545 DOI: 10.1016/0006-8993(94)91131-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Neurons in the rostral ventrolateral medulla (RVLM) were electrophysiologically characterized and anatomically identified using an intracellular recording technique in vivo. Of 49 neurons recorded, 7 were antidromically activated from the dorsolateral funiculus in the thoracic spinal cord, with axonal conduction velocities ranging from 16.6 to 55.0 m/s. The RVLM-spinal neurons were spontaneously active and non-bursting. Additionally, they demonstrated a flat post-R-wave histogram and a flat average of the neuronal membrane potential triggered by the pulsatile arterial pressure. Therefore their activity was not related to cardiac rhythm. Electrical stimulation of the nucleus tractus solitarii (NTS) at the level of the obex evoked monosynaptic excitatory postsynaptic potential (EPSP) on 3 RVLM-spinal neurons; median latency was 1.5 ms. The recorded neurons, intracellularly labeled with horseradish peroxidase (HRP) or biocytin, were located in the rostral pole of the RVLM, between 0.3 and 0.7 mm from the ventral medullary surface and in many cases close to the neurons containing phenylethanolamine-N-methyltransferase (PNMT). These findings are discussed in relation to the physiological role in cardiovascular and nociceptive functional regulation played by the neurons analyzed in this study.
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Affiliation(s)
- A R Granata
- Department of Pharmacology, College of Medicine, University of Tennessee, Memphis 38163
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Esteves F, Lima D, Coimbra A. Structural types of spinal cord marginal (lamina I) neurons projecting to the nucleus of the tractus solitarius in the rat. Somatosens Mot Res 1993; 10:203-16. [PMID: 8328233 DOI: 10.3109/08990229309028832] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The structural types of spinal cord marginal (lamina I) neurons projecting to the nucleus of the tractus solitarius (NTS) were studied. Upon injections of cholera toxin subunit B (CTb) into the caudal part of the NTS, including its lateral and medial portions, labeled cells occurred bilaterally in laminae I, IV-VII, and X, and the lateral spinal nucleus (LSN). After injections into the lateral portion alone, only a few cells were labeled in laminae V, VII, and X, and the LSN, and none in the superficial dorsal horn. Of 1882 labeled marginal cells, 38% belonged to the flattened type, 37% to the pyramidal type, and 25% to the fusiform type. Flattened and pyramidal cells were labeled in considerably greater numbers than those reported when other supraspinal targets of these cells were injected with CTb. Since cells in the NTS are known to be under marked gamma-aminobutyric acidergic (GABA-ergic) inhibition, it is possible that only strong input conveyed by great numbers of flattened and pyramidal cells is capable of overcoming that barrier. Fusiform cells were labeled in numbers similar to those observed previously after tracer injections into the two other targets of this neuronal type, the parabrachial nuclei and the lateral reticular nucleus. Considering that these regions, as well as the NTS, control cardiovascular and respiratory functions, it is suggested that fusiform cells transmit noxious input that will influence autonomic reflexes processed in the three nuclei.
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Affiliation(s)
- F Esteves
- Institute of Histology and Embryology, Faculty of Medicine, University of Oporto, Porto, Portugal
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Thurston CL, Randich A. Electrical stimulation of the subdiaphragmatic vagus in rats: inhibition of heat-evoked responses of spinal dorsal horn neurons and central substrates mediating inhibition of the nociceptive tail flick reflex. Pain 1992; 51:349-365. [PMID: 1491862 DOI: 10.1016/0304-3959(92)90221-v] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Electrical stimulation of the subdiaphragmatic branch of the vagus nerve (SDVAS) inhibits the nociceptive tail flick (TF) reflex. The present experiments examined (1) the central substrates mediating SDVAS-produced inhibition of the TF reflex and (2) the effects of SDVAS on either background or noxious heat-evoked responses of spinal dorsal horn neurons. Microinjections of ibotenic acid in the ipsilateral nucleus tractus solitarius (NTS), nucleus raphe magnus (NRM), or bilateral locus coeruleus/subcoeruleus (LC/SC) significantly increased the intensity of SDVAS required to inhibit the TF reflex in lightly anesthetized rats. In studies of class-2 spinal dorsal horn neurons, SDVAS produced significant intensity-dependent inhibition of noxious heat-evoked responses of 17/25 (68%) units, facilitation of 4/25 (16%) units, and no effect on 4/25 (16%) units. In studies of class-3 spinal dorsal horn neurons, SDVAS produced significant intensity-dependent inhibition of noxious heat-evoked responses of 8/9 (89%) units. Noxious heat-evoked responses of 1/9 (11%) unit were facilitated by SDVAS. In general, the background activity of either class-2 or class-3 units was not significantly affected by SDVAS. SDVAS produced a significant rightward, parallel shift in the stimulus response function (SRF) of class-2 neurons to noxious, graded heat stimuli ranging from 40 to 52 degrees C, while SDVAS produced a significant increase in the threshold and a significant reduction in the slope of the SRF of class-3 neurons. These data indicate that SDVAS generally inhibits noxious heat-evoked responses of lumbosacral spinal dorsal horn neurons in the rat, but does not significantly affect background activity of the same neurons. Furthermore, the inhibition of the TF reflex produced by SDVAS depends on central relays in the ipsilateral NTS, NRM, and bilateral LC/SC.
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Affiliation(s)
- C L Thurston
- Department of Psychology, University of Alabama at Birmingham, Birmingham, AL 35294 USA
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Williams CL, McGaugh JL. Reversible inactivation of the nucleus of the solitary tract impairs retention performance in an inhibitory avoidance task. BEHAVIORAL AND NEURAL BIOLOGY 1992; 58:204-10. [PMID: 1456942 DOI: 10.1016/0163-1047(92)90482-j] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Several peripherally acting hormones and drugs are known to modulate memory storage processes, yet the mechanisms which permit these agents to influence memory is not well understood since they do not freely enter the brain. The nucleus of the solitary tract (NTS) is one brainstem structure which receives important neural input from the periphery. Therefore, the objective of this experiment was to determine whether the NTS is involved in modulating processes contributing to memory formation. Male Sprague-Dawley rats were trained in a one-trial inhibitory avoidance task (0.35 mA, 0.5 s footshock). Immediately or 2 h after training microinjections of 2% lidocaine hydrochloride (20 mg/kg) or a phosphate buffer solution were administered bilaterally into the NTS. Two other groups received microinjections of lidocaine into the fourth ventricle or cerebellum. On retention tests given 48 h after training the latency to reenter the dark compartment of the apparatus was recorded. The retention latencies of rats receiving bilateral microinjections of 0.5 microliter of lidocaine hydrochloride into the NTS were significantly shorter than those of animals given injections of a buffer solution (0.5 microliter), delayed injections of buffer or lidocaine, or control injections of lidocaine into the cerebellum or fourth ventricle. These findings suggest that memory storage processes are impaired by reversible inactivation of the NTS after training. The implications of these findings in terms of a possible role of the NTS in modulating brain processes involved in memory storage are discussed.
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Affiliation(s)
- C L Williams
- Center for the Neurobiology of Learning and Memory, University of California, Irvine 92717
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