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de Souza JGV, de Souza DP, da Silva CAA, Martins Sá RW, Paton JFR, da Silva MP, Moraes DJA. Electrophysiological Properties and Morphology of Cardiac and Pulmonary Motoneurons within the Dorsal Motor Nucleus of the Vagus of Rats. Neuroscience 2024; 551:153-165. [PMID: 38821242 DOI: 10.1016/j.neuroscience.2024.05.038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 05/24/2024] [Accepted: 05/27/2024] [Indexed: 06/02/2024]
Abstract
The dorsal motor nucleus of the vagus (DMV) contains parasympathetic motoneurons that project to the heart and lungs. These motoneurons control ventricular excitability/contractility and airways secretions/blood flow, respectively. However, their electrophysiological properties, morphology and synaptic input activity remain unknown. One important ionic current described in DMV motoneurons controlling their electrophysiological behaviour is the A-type mediated by voltage-dependent K+ (Kv) channels. Thus, we compared the electrophysiological properties, synaptic activity, morphology, A-type current density, and single cell expression of Kv subunits, that contribute to macroscopic A-type currents, between DMV motoneurons projecting to either the heart or lungs of adult male rats. Using retrograde labelling, we visualized distinct DMV motoneurons projecting to the heart or lungs in acutely prepared medullary slices. Subsequently, whole cell recordings, morphological reconstruction and single motoneuron qRT-PCR studies were performed. DMV pulmonary motoneurons were more depolarized, electrically excitable, presented higher membrane resistance, broader action potentials and received greater excitatory synaptic inputs compared to cardiac DMV motoneurons. These differences were in part due to highly branched dendritic complexity and lower magnitude of A-type K+ currents. By evaluating expression of channels that mediate A-type currents from single motoneurons, we demonstrated a lower level of Kv4.2 in pulmonary versus cardiac motoneurons, whereas Kv4.3 and Kv1.4 levels were similar. Thus, with the distinct electrical, morphological, and molecular properties of DMV cardiac and pulmonary motoneurons, we surmise that these cells offer a new vista of opportunities for genetic manipulation providing improvement of parasympathetic function in cardiorespiratory diseases such heart failure and asthma.
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Affiliation(s)
- Júlia G V de Souza
- School of Medicine of Ribeirão Preto, Department of Physiology, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Daniel P de Souza
- School of Medicine of Ribeirão Preto, Department of Physiology, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Carlos A A da Silva
- School of Medicine of Ribeirão Preto, Department of Physiology, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Renato W Martins Sá
- School of Medicine of Ribeirão Preto, Department of Physiology, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Julian F R Paton
- Manaaki Manawa - The Centre for Heart Research, Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Melina P da Silva
- Department of Biophysics, Paulista School of Medicine, Federal University of São Paulo, São Paulo, SP, Brazil.
| | - Davi J A Moraes
- Department of Physiology and Biophysics, Biomedical Science Institute, University of São Paulo, São Paulo, SP, Brazil.
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2
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Tsisanova E, Nobles M, Sebastian S, Ng KE, Thomas A, Weinstein LS, Munroe PB, Tinker A. The ric-8b protein (resistance to inhibitors of cholinesterase 8b) is key to preserving contractile function in the adult heart. J Biol Chem 2024; 300:107470. [PMID: 38879012 PMCID: PMC11277413 DOI: 10.1016/j.jbc.2024.107470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Revised: 05/23/2024] [Accepted: 05/26/2024] [Indexed: 07/09/2024] Open
Abstract
Resistance to inhibitors of cholinesterases (ric-8 proteins) are involved in modulating G-protein function, but little is known of their potential physiological importance in the heart. In the present study, we assessed the role of resistance to inhibitors of cholinesterase 8b (Ric-8b) in determining cardiac contractile function. We developed a murine model in which it was possible to conditionally delete ric-8b in cardiac tissue in the adult animal after the addition of tamoxifen. Deletion of ric-8b led to severely reduced contractility as measured using echocardiography days after administration of tamoxifen. Histological analysis of the ventricular tissue showed highly variable myocyte size, prominent fibrosis, and an increase in cellular apoptosis. RNA sequencing revealed transcriptional remodeling in response to cardiac ric-8b deletion involving the extracellular matrix and inflammation. Phosphoproteomic analysis revealed substantial downregulation of phosphopeptides related to myosin light chain 2. At the cellular level, the deletion of ric-8b led to loss of activation of the L-type calcium channel through the β-adrenergic pathways. Using fluorescence resonance energy transfer-based assays, we showed ric-8b protein selectively interacts with the stimulatory G-protein, Gαs. We explored if deletion of Gnas (the gene encoding Gαs) in cardiac tissue using a similar approach in the mouse led to an equivalent phenotype. The conditional deletion of the Gαs gene in the ventricle led to comparable effects on contractile function and cardiac histology. We conclude that ric-8b is essential to preserve cardiac contractile function likely through an interaction with the stimulatory G-protein and downstream phosphorylation of myosin light chain 2.
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Affiliation(s)
- Elena Tsisanova
- Department of Clinical Pharmacology and Precision Medicine, William Harvey Research Institute, Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Muriel Nobles
- Department of Clinical Pharmacology and Precision Medicine, William Harvey Research Institute, Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Sonia Sebastian
- Department of Clinical Pharmacology and Precision Medicine, William Harvey Research Institute, Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Keat-Eng Ng
- Department of Clinical Pharmacology and Precision Medicine, William Harvey Research Institute, Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Alison Thomas
- Department of Clinical Pharmacology and Precision Medicine, William Harvey Research Institute, Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, London, UK
| | | | - Patricia B Munroe
- Department of Clinical Pharmacology and Precision Medicine, William Harvey Research Institute, Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Andrew Tinker
- Department of Clinical Pharmacology and Precision Medicine, William Harvey Research Institute, Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, London, UK.
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Alvarez-Araos P, Jiménez S, Salazar-Ardiles C, Núñez-Espinosa C, Paez V, Rodriguez-Fernandez M, Raberin A, Millet GP, Iturriaga R, Andrade DC. Baroreflex and chemoreflex interaction in high-altitude exposure: possible role on exercise performance. Front Physiol 2024; 15:1422927. [PMID: 38895516 PMCID: PMC11184637 DOI: 10.3389/fphys.2024.1422927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Accepted: 05/15/2024] [Indexed: 06/21/2024] Open
Abstract
The hypoxic chemoreflex and the arterial baroreflex are implicated in the ventilatory response to exercise. It is well known that long-term exercise training increases parasympathetic and decreases sympathetic tone, both processes influenced by the arterial baroreflex and hypoxic chemoreflex function. Hypobaric hypoxia (i.e., high altitude [HA]) markedly reduces exercise capacity associated with autonomic reflexes. Indeed, a reduced exercise capacity has been found, paralleled by a baroreflex-related parasympathetic withdrawal and a pronounced chemoreflex potentiation. Additionally, it is well known that the baroreflex and chemoreflex interact, and during activation by hypoxia, the chemoreflex is predominant over the baroreflex. Thus, the baroreflex function impairment may likely facilitate the exercise deterioration through the reduction of parasympathetic tone following acute HA exposure, secondary to the chemoreflex activation. Therefore, the main goal of this review is to describe the main physiological mechanisms controlling baro- and chemoreflex function and their role in exercise capacity during HA exposure.
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Affiliation(s)
- Pablo Alvarez-Araos
- Exercise Applied Physiology Laboratory, Centro de Investigación en Fisiología y Medicina de Altura, Departamento Biomedico, Facultad de Ciencias de la Salud, Universidad de Antofagasta, Antofagasta, Chile
- Departamento de Kinesiología, Facultad de Ciencias de la Salud, Universidad de Atacama, Copiapó, Chile
| | - Sergio Jiménez
- Departamento de Kinesiología, Facultad de Ciencias de la Salud, Universidad de Atacama, Copiapó, Chile
| | - Camila Salazar-Ardiles
- Exercise Applied Physiology Laboratory, Centro de Investigación en Fisiología y Medicina de Altura, Departamento Biomedico, Facultad de Ciencias de la Salud, Universidad de Antofagasta, Antofagasta, Chile
| | - Cristian Núñez-Espinosa
- Escuela de Medicina de la Universidad de Magallanes, Punta Arenas, Chile
- Centro Asistencial de Docencia e Investigación (CADI-UMAG), Santiago, Chile
| | - Valeria Paez
- Exercise Applied Physiology Laboratory, Centro de Investigación en Fisiología y Medicina de Altura, Departamento Biomedico, Facultad de Ciencias de la Salud, Universidad de Antofagasta, Antofagasta, Chile
- Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Maria Rodriguez-Fernandez
- Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Antoine Raberin
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Gregoire P. Millet
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Rodrigo Iturriaga
- Exercise Applied Physiology Laboratory, Centro de Investigación en Fisiología y Medicina de Altura, Departamento Biomedico, Facultad de Ciencias de la Salud, Universidad de Antofagasta, Antofagasta, Chile
- Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Santiago, Chile
| | - David C. Andrade
- Exercise Applied Physiology Laboratory, Centro de Investigación en Fisiología y Medicina de Altura, Departamento Biomedico, Facultad de Ciencias de la Salud, Universidad de Antofagasta, Antofagasta, Chile
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4
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Coverdell TC, Abbott SBG, Campbell JN. Molecular cell types as functional units of the efferent vagus nerve. Semin Cell Dev Biol 2024; 156:210-218. [PMID: 37507330 PMCID: PMC10811285 DOI: 10.1016/j.semcdb.2023.07.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 07/20/2023] [Accepted: 07/20/2023] [Indexed: 07/30/2023]
Abstract
The vagus nerve vitally connects the brain and body to coordinate digestive, cardiorespiratory, and immune functions. Its efferent neurons, which project their axons from the brainstem to the viscera, are thought to comprise "functional units" - neuron populations dedicated to the control of specific vagal reflexes or organ functions. Previous research indicates that these functional units differ from one another anatomically, neurochemically, and physiologically but have yet to define their identity in an experimentally tractable way. However, recent work with genetic technology and single-cell genomics suggests that genetically distinct subtypes of neurons may be the functional units of the efferent vagus. Here we review how these approaches are revealing the organizational principles of the efferent vagus in unprecedented detail.
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Affiliation(s)
- Tatiana C Coverdell
- Biomedical Sciences Graduate Program, University of Virginia, Charlottesville, VA 22903, USA
| | - Stephen B G Abbott
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22903, USA
| | - John N Campbell
- Department of Biology, University of Virginia, Charlottesville, VA 22903, USA.
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5
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Gąsior JS, Gąsienica-Józkowy M, Młyńczak M, Rosoł M, Makuch R, Baranowski R, Werner B. Heart rate dynamics and asymmetry during sympathetic activity stimulation and post-stimulation recovery in ski mountaineers-a pilot exploratory study. Front Sports Act Living 2024; 6:1336034. [PMID: 38495673 PMCID: PMC10941344 DOI: 10.3389/fspor.2024.1336034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Accepted: 02/12/2024] [Indexed: 03/19/2024] Open
Abstract
There is a lack of studies on non-linear heart rate (HR) variability in athletes. We aimed to assess the usefulness of short-term HR dynamics and asymmetry parameters to evaluate the neural modulation of cardiac activity based on non-stationary RR interval series by studying their changes during sympathetic nervous system activity stimulation (isometric handgrip test) and post-stimulation recovery in professional ski mountaineers. The correlation between the changes in the parameters and the respiratory rate (RespRate) and also the duration of the career was analyzed. Short-term (5 min) and ultra-short-term (1 min) rates of patterns with no variations (0V), number of acceleration runs of length 1 (AR1), and short-term Porta's Index were greater, whereas Guzik's Index (GI) was smaller during sympathetic stimulation compared to rest. GI increased and the number of AR1 decreased during recovery. Greater increases in GI and RMSSD were associated with greater decreases in RespRate during recovery. Greater increases in RespRate from rest to short-term sympathetic stimulation were associated with greater increases in 0V (Max-min method) and AR1 but also with greater decreases in decelerations of short-term variance and accelerations and decelerations of long-term variance. Greater increases in 0V (Max-min method) and number of AR1 during sympathetic stimulation were associated with a shorter career duration. Greater decreases in these parameters during recovery were associated with a longer career duration. Changes in measures of HR dynamics and asymmetry, calculated based on short-term non-stationary RRi time series induced by sympathetic stimulation and post-stimulation recovery, reflected sympathovagal shift and were associated with condition-related alterations in RespRate and career duration in athletes who practice ski mountaineering.
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Affiliation(s)
- Jakub S. Gąsior
- Department of Pediatric Cardiology and General Pediatrics, Medical University of Warsaw, Warsaw, Poland
| | | | - Marcel Młyńczak
- Faculty of Mechatronics, Institute of Metrology and Biomedical Engineering, Warsaw University of Technology, Warsaw, Poland
| | - Maciej Rosoł
- Faculty of Mechatronics, Institute of Metrology and Biomedical Engineering, Warsaw University of Technology, Warsaw, Poland
| | - Robert Makuch
- Department of Physical Education, Kazimierz Pulaski University of Technology and Humanities in Radom, Radom, Poland
| | - Rafał Baranowski
- Department of Heart Rhythm Disorders, National Institute of Cardiology, Warsaw, Poland
| | - Bożena Werner
- Department of Pediatric Cardiology and General Pediatrics, Medical University of Warsaw, Warsaw, Poland
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6
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Kellett DO, Aziz Q, Humphries JD, Korsak A, Braga A, Gutierrez Del Arroyo A, Crescente M, Tinker A, Ackland GL, Gourine AV. Transcriptional response of the heart to vagus nerve stimulation. Physiol Genomics 2024; 56:167-178. [PMID: 38047311 PMCID: PMC11281814 DOI: 10.1152/physiolgenomics.00095.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 10/30/2023] [Accepted: 11/28/2023] [Indexed: 12/05/2023] Open
Abstract
Heart failure is a major clinical problem, with treatments involving medication, devices, and emerging neuromodulation therapies such as vagus nerve stimulation (VNS). Considering the ongoing interest in using VNS to treat cardiovascular disease, it is important to understand the genetic and molecular changes developing in the heart in response to this form of autonomic neuromodulation. This experimental animal (rat) study investigated the immediate transcriptional response of the ventricular myocardium to selective stimulation of vagal efferent activity using an optogenetic approach. Vagal preganglionic neurons in the dorsal motor nucleus of the vagus nerve were genetically targeted to express light-sensitive chimeric channelrhodopsin variant ChIEF and stimulated using light. RNA sequencing of the left ventricular myocardium identified 294 differentially expressed genes (false discovery rate < 0.05). Qiagen Ingenuity Pathway Analysis (IPA) highlighted 118 canonical pathways that were significantly modulated by vagal activity, of which 14 had a z score of ≥2/≤-2, including EIF-2, IL-2, integrin, and NFAT-regulated cardiac hypertrophy. IPA revealed the effect of efferent vagus stimulation on protein synthesis, autophagy, fibrosis, autonomic signaling, inflammation, and hypertrophy. IPA further predicted that the identified differentially expressed genes were the targets of 50 upstream regulators, including transcription factors (e.g., MYC and NRF1) and microRNAs (e.g., miR-335-3p and miR-338-3p). These data demonstrate that the vagus nerve has a major impact on the myocardial expression of genes involved in the regulation of key biological pathways. The transcriptional response of the ventricular myocardium induced by stimulation of vagal efferents is consistent with the beneficial effect of maintained/increased vagal activity on the heart.NEW & NOTEWORTHY This experimental animal study investigated the immediate transcriptional response of the ventricular myocardium to selective stimulation of vagal efferent activity. Vagal stimulation induced significant transcriptional changes in the heart involving the pathways controlling autonomic signaling, inflammation, fibrosis, and hypertrophy. This study provides the first direct evidence that myocardial gene expression is modulated by the activity of the autonomic nervous system.
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Affiliation(s)
- Daniel O Kellett
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
| | - Qadeer Aziz
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
- Translational Medicine and Therapeutics, William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - Jonathan D Humphries
- Department of Life Sciences, Manchester Metropolitan University, Manchester, United Kingdom
| | - Alla Korsak
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
| | - Alice Braga
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
| | - Ana Gutierrez Del Arroyo
- Translational Medicine and Therapeutics, William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - Marilena Crescente
- Department of Life Sciences, Manchester Metropolitan University, Manchester, United Kingdom
| | - Andrew Tinker
- Translational Medicine and Therapeutics, William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - Gareth L Ackland
- Translational Medicine and Therapeutics, William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - Alexander V Gourine
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
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7
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Kellett DO, Aziz Q, Humphries JD, Korsak A, Braga A, Del Arroyo AG, Crescente M, Tinker A, Ackland GL, Gourine AV. Transcriptional response of the heart to vagus nerve stimulation. Physiol Genomics 2024; 56:167-178. [PMID: 39071113 PMCID: PMC7616044 DOI: 10.6084/m9.figshare.24449590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/30/2024] Open
Abstract
Heart failure is a major clinical problem, with treatments involving medication, devices, and emerging neuromodulation therapies such as vagus nerve stimulation (VNS). Considering the ongoing interest in using VNS to treat cardiovascular disease it is important to understand the genetic and molecular changes developing in the heart in response to this form of autonomic neuromodulation. This experimental animal (rat) study investigated the immediate transcriptional response of the ventricular myocardium to selective stimulation of vagal efferent activity using an optogenetic approach. Vagal preganglionic neurons in the dorsal motor nucleus of the vagus nerve were genetically targeted to express light-sensitive chimeric channelrhodopsin variant ChIEF, and stimulated using light. RNA sequencing of left ventricular myocardium identified 294 differentially expressed genes (DEGs, false discovery rate <0.05). Qiagen Ingenuity Pathway Analysis (IPA) highlighted 118 canonical pathways that were significantly modulated by vagal activity, of which 14 had a z-score of ≥2/≤-2, including EIF-2, IL-2, Integrin, and NFAT-regulated cardiac hypertrophy. IPA revealed the effect of efferent vagus stimulation on protein synthesis, autophagy, fibrosis, autonomic signalling, inflammation, and hypertrophy. IPA further predicted that the identified DEGs were the targets of 50 upstream regulators, including transcription factors (e.g., MYC, NRF1) and microRNAs (e.g., miR-335-3p, miR-338-3p). These data demonstrate that the vagus nerve has a major impact on myocardial expression of genes involved in regulation of key biological pathways. The transcriptional response of the ventricular myocardium induced by stimulation of vagal efferents is consistent with the beneficial effect of maintained/increased vagal activity on the heart.
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Affiliation(s)
- Daniel O Kellett
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Qadeer Aziz
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
- Centre for Clinical Pharmacology and Precision Medicine, William Harvey Research Institute, Queen Mary University of London, London, UK
| | | | - Alla Korsak
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Alice Braga
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Ana Gutierrez Del Arroyo
- Centre for Clinical Pharmacology and Precision Medicine, William Harvey Research Institute, Queen Mary University of London, London, UK
| | - Marilena Crescente
- Department of Life Sciences, Manchester Metropolitan University, Manchester, UK
| | - Andrew Tinker
- Centre for Clinical Pharmacology and Precision Medicine, William Harvey Research Institute, Queen Mary University of London, London, UK
| | - Gareth L Ackland
- Translational Medicine and Therapeutics, William Harvey Research Institute, Queen Mary University of London, London, UK
| | - Alexander V Gourine
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
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James A, Bruce D, Tetlow N, Patel AB, Black E, Whitehead N, Ratcliff A, Jamie Humphreys A, MacDonald N, McDonnell G, Raobaikady R, Thirugnanasambanthar J, Ravindran JI, Whitehead N, Minto G, Abbott TE, Jhanji S, Milliken D, Ackland GL. Heart rate recovery after orthostatic challenge and cardiopulmonary exercise testing in older individuals: prospective multicentre observational cohort study. BJA OPEN 2023; 8:100238. [PMID: 38026081 PMCID: PMC10654531 DOI: 10.1016/j.bjao.2023.100238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 09/12/2023] [Accepted: 10/06/2023] [Indexed: 12/01/2023]
Abstract
Background Impaired vagal function in older individuals, quantified by the 'gold standard' delayed heart rate recovery after maximal exercise (HRRexercise), is an independent predictor of cardiorespiratory capacity and mortality (particularly when HRR ≤12 beats min-1). Heart rate also often declines after orthostatic challenge (HRRorthostatic), but the mechanism remains unclear. We tested whether HRRorthostatic reflects similar vagal autonomic characteristics as HRRexercise. Methods Prospective multicentre cohort study of subjects scheduled for cardiopulmonary exercise testing (CPET) as part of routine care. Before undergoing CPET, heart rate was measured with participants seated for 3 min, before standing for 3 min (HRRorthostatic). HRRexercise 1 min after the end of CPET was recorded. The primary outcome was the correlation between mean heart rate change every 10 s for 1 min after peak heart rate was attained on standing and after exercise for each participant. Secondary outcomes were HRRorthostatic and peak VO2 compared between individuals with HRRexercise <12 beats min-1. Results A total of 87 participants (mean age: 64 yr [95%CI: 61-66]; 48 (55%) females) completed both tests. Mean heart rate change every 10 s for 1 min after peak heart rate after standing and exercise was significantly correlated (R2=0.81; P<0.0001). HRRorthostatic was unchanged in individuals with HRRexercise ≤12 beats min-1 (n=27), but was lower when HRRexercise >12 beats min-1 (n=60; mean difference: 3 beats min-1 [95% confidence interval 1-5 beats min-1]; P<0.0001). Slower HRRorthostatic was associated with lower peak VO2 (mean difference: 3.7 ml kg-1 min-1 [95% confidence interval 0.7-6.8 ml kg-1 min-1]; P=0.039). Conclusion Prognostically significant heart rate recovery after exhaustive exercise is characterised by quantitative differences in heart rate recovery after orthostatic challenge. These data suggest that orthostatic challenge is a valid, simple test indicating vagal impairment. Clinical trial registration researchregistry6550.
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Affiliation(s)
- Aaron James
- Department of Anaesthesia, University Hospitals Plymouth NHS Trust, Plymouth, UK
| | - David Bruce
- Department of Anaesthesia, Perioperative Medicine and Critical Care, Royal Marsden Hospital, London, UK
| | - Nicholas Tetlow
- Department of Anaesthesia, Perioperative Medicine and Critical Care, Royal Marsden Hospital, London, UK
| | - Amour B.U. Patel
- Translational Medicine and Therapeutics, William Harvey Research Institute, Queen Mary, University of London, UK
| | - Ethel Black
- Department of Anaesthesia, Perioperative Medicine and Critical Care, Royal Marsden Hospital, London, UK
| | - Nicole Whitehead
- Department of Anaesthesia, Perioperative Medicine and Critical Care, Royal Marsden Hospital, London, UK
| | - Anna Ratcliff
- Department of Anaesthesia, University Hospitals Plymouth NHS Trust, Plymouth, UK
| | | | - Neil MacDonald
- Department of Anaesthesia and Perioperative Medicine, Royal London Hospital, London, UK
| | - Gayle McDonnell
- Department of Anaesthesia and Perioperative Medicine, Royal London Hospital, London, UK
| | - Ravishankar Raobaikady
- Translational Medicine and Therapeutics, William Harvey Research Institute, Queen Mary, University of London, UK
| | | | - Jeuela I. Ravindran
- Translational Medicine and Therapeutics, William Harvey Research Institute, Queen Mary, University of London, UK
| | - Nicole Whitehead
- Department of Anaesthesia, Perioperative Medicine and Critical Care, Royal Marsden Hospital, London, UK
| | - Gary Minto
- Department of Anaesthesia, University Hospitals Plymouth NHS Trust, Plymouth, UK
| | - Tom E.F. Abbott
- Translational Medicine and Therapeutics, William Harvey Research Institute, Queen Mary, University of London, UK
- Department of Anaesthesia and Perioperative Medicine, Royal London Hospital, London, UK
| | - Shaman Jhanji
- Department of Anaesthesia, Perioperative Medicine and Critical Care, Royal Marsden Hospital, London, UK
| | - Don Milliken
- Department of Anaesthesia, Perioperative Medicine and Critical Care, Royal Marsden Hospital, London, UK
| | - Gareth L. Ackland
- Translational Medicine and Therapeutics, William Harvey Research Institute, Queen Mary, University of London, UK
- Department of Anaesthesia and Perioperative Medicine, Royal London Hospital, London, UK
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9
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Porges SW. The vagal paradox: A polyvagal solution. COMPREHENSIVE PSYCHONEUROENDOCRINOLOGY 2023; 16:100200. [PMID: 38108034 PMCID: PMC10724739 DOI: 10.1016/j.cpnec.2023.100200] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 08/02/2023] [Accepted: 08/04/2023] [Indexed: 12/19/2023] Open
Abstract
Although there is a consistent literature documenting that vagal cardioinhibitory pathways support homeostatic functions, another less frequently cited literature implicates vagal cardioinhibitory pathways in compromises to survival in humans and other mammals. The latter is usually associated with threat reactions, chronic stress, and potentially lethal clinical conditions such as hypoxia. Solving this 'vagal paradox' in studies conducted in the neonatal intensive care unit served as the motivator for the Polyvagal Theory (PVT). The paradox is resolved when the different functions of vagal cardioinhibitory fibers originating in two anatomically distinguishable brainstem areas are recognized. One pathway originates in a dorsal area known as the dorsal motor nucleus of the vagus and the other in a ventral area of the brainstem known as nucleus ambiguus. Unlike mammals, in all ancestral vertebrates from which mammals evolved, cardioinhibitory vagal fibers primarily originate in the dorsal motor nucleus of the vagus. Thus, in mammals the vagus nerve is 'poly' vagal because it contains two distinct efferent pathways. Developmental and evolutionary biology identify a ventral migration of vagal cardioinhibitory fibers that culminate in an integrated circuit that has been labeled the ventral vagal complex. This complex consists of the interneuronal communication of the ventral vagus with the source nuclei involved in regulating the striated muscles of the head and face via special visceral efferent pathways. This integrated system enables the coordination of vagal regulation of the heart with sucking, swallowing, breathing, and vocalizing and forms the basis of a social engagement system that allows sociality to be a potent neuromodulator resulting in calm states that promote homeostatic function. These biobehavioral features, dependent on the maturation of the ventral vagal complex, can be compromised in preterm infants. Developmental biology informs us that in the immature mammal (e.g., fetus, preterm infant) the ventral vagus is not fully functional and myelinization is not complete; this neuroanatomical profile may potentiate the impact of vagal cardioinhibitory pathways originating in the dorsal motor nucleus of the vagus. This vulnerability is confirmed clinically in the life-threatening reactions of apnea and bradycardia in human preterm newborns, which are hypothetically mediated through chronotropic dorsal vagal pathways. Neuroanatomical research documents that the distribution of cardioinhibitory neurons representing these two distinct vagal source nuclei varies among mammals and changes during early development. By explaining the solution of the 'vagal paradox' in the preterm human, the paper highlights the functional cardioinhibitory functions of the two vagal source nuclei and provides the scientific foundation for the testing of hypotheses generated by PVT.
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Affiliation(s)
- Stephen W. Porges
- Traumatic Stress Research Consortium, Kinsey Institute, Indiana University, Bloomington, IN, USA
- University of North Carolina at Chapel Hill, Chapel Hill, USA
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10
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Korsak A, Kellett DO, Aziz Q, Anderson C, D’Souza A, Tinker A, Ackland GL, Gourine AV. Immediate and sustained increases in the activity of vagal preganglionic neurons during exercise and after exercise training. Cardiovasc Res 2023; 119:2329-2341. [PMID: 37516977 PMCID: PMC10597628 DOI: 10.1093/cvr/cvad115] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 03/31/2023] [Accepted: 05/12/2023] [Indexed: 08/01/2023] Open
Abstract
AIMS The brain controls the heart by dynamic recruitment and withdrawal of cardiac parasympathetic (vagal) and sympathetic activity. Autonomic control is essential for the development of cardiovascular responses during exercise, however, the patterns of changes in the activity of the two autonomic limbs, and their functional interactions in orchestrating physiological responses during exercise, are not fully understood. The aim of this study was to characterize changes in vagal parasympathetic drive in response to exercise and exercise training by directly recording the electrical activity of vagal preganglionic neurons in experimental animals (rats). METHODS AND RESULTS Single unit recordings were made using carbon-fibre microelectrodes from the populations of vagal preganglionic neurons of the nucleus ambiguus (NA) and the dorsal vagal motor nucleus of the brainstem. It was found that (i) vagal preganglionic neurons of the NA and the dorsal vagal motor nucleus are strongly activated during bouts of acute exercise, and (ii) exercise training markedly increases the resting activity of both populations of vagal preganglionic neurons and augments the excitatory responses of NA neurons during exercise. CONCLUSIONS These data show that central vagal drive increases during exercise and provide the first direct neurophysiological evidence that exercise training increases vagal tone. The data argue against the notion of exercise-induced central vagal withdrawal during exercise. We propose that robust increases in the activity of vagal preganglionic neurons during bouts of exercise underlie activity-dependent plasticity, leading to higher resting vagal tone that confers multiple health benefits associated with regular exercise.
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Affiliation(s)
- Alla Korsak
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London WC1E 6BT, UK
| | - Daniel O Kellett
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London WC1E 6BT, UK
| | - Qadeer Aziz
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London WC1E 6BT, UK
- Centre for Clinical Pharmacology and Precision Medicine, William Harvey Research Institute, Queen Mary University of London, London, UK
| | - Cali Anderson
- Division of Cardiovascular Sciences, University of Manchester, Manchester, UK
| | - Alicia D’Souza
- Division of Cardiovascular Sciences, University of Manchester, Manchester, UK
| | - Andrew Tinker
- Centre for Clinical Pharmacology and Precision Medicine, William Harvey Research Institute, Queen Mary University of London, London, UK
| | - Gareth L Ackland
- Translational Medicine and Therapeutics, William Harvey Research Institute, Queen Mary University of London, London, UK
| | - Alexander V Gourine
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London WC1E 6BT, UK
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11
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Booth LC, Saseetharan B, May CN, Yao ST. Selective efferent vagal stimulation in heart failure. Exp Physiol 2023. [PMID: 37755233 DOI: 10.1113/ep090866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Accepted: 09/11/2023] [Indexed: 09/28/2023]
Abstract
Patients diagnosed with heart failure have high rates of mortality and morbidity. Based on promising preclinical studies, vagal nerve stimulation has been trialled in these patients using whole nerve electrical stimulation, but the results have been mixed. This is, at least in part, due to an inability to selectively recruit the activity of specific fibres within the vagus with whole nerve electrical stimulation, as well as not knowing which the 'therapeutic' fibres are. This symposium review focuses on a population of cardiac-projecting efferent vagal fibres with cell bodies located within the dorsal motor nucleus of the vagus nerve and a new method of selectively targeting these projections as a potential treatment in heart failure. NEW FINDINGS: What is the topic of this review? Selective efferent vagal stimulation in heart failure. What advances does it highlight? Selectively targeting a population of cardiac-projecting efferent vagal fibres with cell bodies within the dorsal motor nucleus of the vagus using optogenetics slows the progression of heart failure in rats.
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Affiliation(s)
- Lindsea C Booth
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC, Australia
| | - Baagavi Saseetharan
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC, Australia
| | - Clive N May
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC, Australia
| | - Song T Yao
- Department of Anatomy and Physiology, The University of Melbourne, Melbourne, Australia
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12
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Shanks J, Pachen M, Chang JWH, George B, Ramchandra R. Cardiac Vagal Nerve Activity Increases During Exercise to Enhance Coronary Blood Flow. Circ Res 2023; 133:559-571. [PMID: 37641938 DOI: 10.1161/circresaha.123.323017] [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: 05/03/2023] [Accepted: 08/17/2023] [Indexed: 08/31/2023]
Abstract
BACKGROUND The phrase complete vagal withdrawal is often used when discussing autonomic control of the heart during exercise. However, more recent studies have challenged this assumption. We hypothesized that cardiac vagal activity increases during exercise and maintains cardiac function via transmitters other than acetylcholine. METHODS Chronic direct recordings of cardiac vagal nerve activity, cardiac output, coronary artery blood flow, and heart rate were recorded in conscious adult sheep during whole-body treadmill exercise. Cardiac innervation of the left cardiac vagal branch was confirmed with lipophilic tracer dyes (DiO). Sheep were exercised with pharmacological blockers of acetylcholine (atropine, 250 mg), VIP (vasoactive intestinal peptide; [4Cl-D-Phe6,Leu17]VIP 25 µg), or saline control, randomized on different days. In a subset of sheep, the left cardiac vagal branch was denervated. RESULTS Neural innervation from the cardiac vagal branch is seen at major cardiac ganglionic plexi, and within the fat pads associated with the coronary arteries. Directly recorded cardiac vagal nerve activity increased during exercise. Left cardiac vagal branch denervation attenuated the maximum changes in coronary artery blood flow (maximum exercise, control: 63.5±5.9 mL/min, n=8; cardiac vagal denervated: 32.7±5.6 mL/min, n=6, P=2.5×10-7), cardiac output, and heart rate during exercise. Atropine did not affect any cardiac parameters during exercise, but VIP antagonism significantly reduced coronary artery blood flow during exercise to a similar level to vagal denervation. CONCLUSIONS Our study demonstrates that cardiac vagal nerve activity actually increases and is crucial for maintaining cardiac function during exercise. Furthermore, our findings show the dynamic modulation of coronary artery blood flow during exercise is mediated by VIP.
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Affiliation(s)
- Julia Shanks
- Manaaki Manawa - The Centre for Heart Research, Department of Physiology, University of Auckland, Grafton, New Zealand
| | - Mridula Pachen
- Manaaki Manawa - The Centre for Heart Research, Department of Physiology, University of Auckland, Grafton, New Zealand
| | - Joshua W-H Chang
- Manaaki Manawa - The Centre for Heart Research, Department of Physiology, University of Auckland, Grafton, New Zealand
| | - Bindu George
- Manaaki Manawa - The Centre for Heart Research, Department of Physiology, University of Auckland, Grafton, New Zealand
| | - Rohit Ramchandra
- Manaaki Manawa - The Centre for Heart Research, Department of Physiology, University of Auckland, Grafton, New Zealand
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13
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Luck JC, Blaha C, Cauffman A, Gao Z, Arnold AC, Cui J, Sinoway LI. Autonomic and vascular function testing in collegiate athletes following SARS-CoV-2 infection: an exploratory study. Front Physiol 2023; 14:1225814. [PMID: 37528892 PMCID: PMC10389084 DOI: 10.3389/fphys.2023.1225814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 07/03/2023] [Indexed: 08/03/2023] Open
Abstract
Introduction: Recent studies suggest that SARS-CoV-2 infection alters autonomic and vascular function in young, otherwise healthy, adults. However, whether these alterations exist in young competitive athletes remains unknown. This study aimed to assess the effects of COVID-19 on cardiac autonomic control and vascular function in collegiate athletes who tested positive for COVID-19, acknowledging the limitations imposed by the early stages of the pandemic. Methods: Sixteen collegiate athletes from various sports underwent a battery of commonly used autonomic and vascular function tests (23 ± 9, range: 12-44 days post-infection). Additionally, data from 26 healthy control participants were included. Results: In response to the Valsalva maneuver, nine athletes had a reduced early phase II blood pressure response and/or reduced Valsalva ratio. A depressed respiratory sinus arrhythmia amplitude was observed in three athletes. Three athletes became presyncopal during standing and did not complete the 10-min orthostatic challenge. Brachial artery flow-mediated dilation, when allometrically scaled to account for differences in baseline diameter, was not different between athletes and controls (10.0% ± 3.5% vs. 7.1% ± 2.4%, p = 0.058). Additionally, no differences were observed between groups when FMD responses were normalized by shear rate (athletes: 0.055% ± 0.026%/s-1, controls: 0.068% ± 0.049%/s-1, p = 0.40). Discussion: Few atypical and borderline responses to autonomic function tests were observed in athletes following an acute SARS-CoV-2 infection. The most meaningful autonomic abnormality being the failure of three athletes to complete a 10-min orthostatic challenge. These findings suggest that some athletes may develop mild alterations in autonomic function in the weeks after developing COVID-19, while vascular function is not significantly impaired.
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Affiliation(s)
- J. Carter Luck
- Milton S. Hershey Medical Center, Penn State Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey, PA, United States
| | - Cheryl Blaha
- Milton S. Hershey Medical Center, Penn State Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey, PA, United States
| | - Aimee Cauffman
- Milton S. Hershey Medical Center, Penn State Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey, PA, United States
| | - Zhaohui Gao
- Milton S. Hershey Medical Center, Penn State Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey, PA, United States
| | - Amy C. Arnold
- Department of Neural and Behavioral Sciences, Pennsylvania State University College of Medicine, Hershey, PA, United States
| | - Jian Cui
- Milton S. Hershey Medical Center, Penn State Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey, PA, United States
| | - Lawrence I. Sinoway
- Milton S. Hershey Medical Center, Penn State Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey, PA, United States
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14
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Strain MM, Espinoza L, Fedorchak S, Littlejohn EL, Andrade MA, Toney GM, Boychuk CR. Early central cardiovagal dysfunction after high fat diet in a murine model. Sci Rep 2023; 13:6550. [PMID: 37085567 PMCID: PMC10121716 DOI: 10.1038/s41598-023-32492-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 03/28/2023] [Indexed: 04/23/2023] Open
Abstract
High fat diet (HFD) promotes cardiovascular disease and blunted cardiac vagal regulation. Temporal onset of loss of cardiac vagal control and its underlying mechanism are presently unclear. We tested our hypothesis that reduced central vagal regulation occurs early after HFD and contributes to poor cardiac regulation using cardiovascular testing paired with pharmacology in mice, molecular biology, and a novel bi-transgenic mouse line. Results show HFD, compared to normal fat diet (NFD), significantly blunted cardio/pulmonary chemoreflex bradycardic responses after 15 days, extending as far as tested (> 30 days). HFD produced resting tachycardia by day 3, reflected significant loss of parasympathetic tone. No differences in bradycardic responses to graded electrical stimulation of the distal cut end of the cervical vagus indicated diet-induced differences in vagal activity were centrally mediated. In nucleus ambiguus (NA), surface expression of δ-subunit containing type A gamma-aminobutyric acid receptors (GABAA(δ)R) increased at day 15 of HFD. Novel mice lacking δ-subunit expression in vagal motor neurons (ChAT-δnull) failed to exhibit blunted reflex bradycardia or resting tachycardia after two weeks of HFD. Thus, reduced parasympathetic output contributes to early HFD-induced HR dysregulation, likely through increased GABAA(δ)Rs. Results underscore need for research on mechanisms of early onset increases in GABAA(δ)R expression and parasympathetic dysfunction after HFD.
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Affiliation(s)
- Misty M Strain
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, 7703 Floyd Curl Drive, Mail Code 7746, San Antonio, TX, 78229-3901, USA
| | - Liliana Espinoza
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, 7703 Floyd Curl Drive, Mail Code 7746, San Antonio, TX, 78229-3901, USA
| | - Stephanie Fedorchak
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, 7703 Floyd Curl Drive, Mail Code 7746, San Antonio, TX, 78229-3901, USA
| | - Erica L Littlejohn
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, 7703 Floyd Curl Drive, Mail Code 7746, San Antonio, TX, 78229-3901, USA
| | - Mary Ann Andrade
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, 7703 Floyd Curl Drive, Mail Code 7746, San Antonio, TX, 78229-3901, USA
| | - Glenn M Toney
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, 7703 Floyd Curl Drive, Mail Code 7746, San Antonio, TX, 78229-3901, USA
| | - Carie R Boychuk
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, 7703 Floyd Curl Drive, Mail Code 7746, San Antonio, TX, 78229-3901, USA.
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15
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Mongin D, Chabert C, Courvoisier DS, García-Romero J, Alvero-Cruz JR. Heart rate recovery to assess fitness: comparison of different calculation methods in a large cross-sectional study. Res Sports Med 2023; 31:157-170. [PMID: 34308736 DOI: 10.1080/15438627.2021.1954513] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
We propose a cross-sectional study based on 980 maximal effort tests to quantify the effect of the calculation method of heart rate recovery (HRR) on its association with cardiorespiratory fitness (CRF). For five different time t0 after exercise cessation, HRR has been calculated as: the difference and the ratio between maximal measured heart rate and heart rate (HR) at t0HR at t0the decay time of an exponential decay encompassing the first t0 minutes of the HR recovery.The associations between HRR indices and CRF were estimated from generalized estimating equations stratified by gender and adjusted for age and body mass index. For HRR indices based on exponential regression, no significant association with CRF was found, whereas the other HRR indices are associated with CRF when t0 is at least 1 minute and is maximum for t0 = 2 minutes for females and t0 = 3 minutes for males.
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Affiliation(s)
- Denis Mongin
- Division of Rheumatology, Geneva University Hospitals, Geneva, Switzerland
| | - Clovis Chabert
- Institute for Advanced Biosciences (IAB), Grenoble Alpes University, Grenoble, France
| | | | - Jeronimo García-Romero
- Department of Human Physiology, Malaga University, Andalucía Tech, Histology, Pathological Anatomy and Physical Education, Malaga, Spain
| | - Jose Ramon Alvero-Cruz
- Department of Human Physiology, Malaga University, Andalucía Tech, Histology, Pathological Anatomy and Physical Education, Malaga, Spain
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16
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Zhou L, Zhang Y, Cao G, Zhang C, Zheng C, Meng G, Lai Y, Zhou Z, Liu Z, Liu Z, Guo F, Dong X, Liang Z, Wang Y, Guo S, Zhou X, Jiang H, Yu L. Wireless Self-Powered Optogenetic System for Long-Term Cardiac Neuromodulation to Improve Post-MI Cardiac Remodeling and Malignant Arrhythmia. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2205551. [PMID: 36698262 PMCID: PMC10037959 DOI: 10.1002/advs.202205551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Revised: 12/02/2022] [Indexed: 06/17/2023]
Abstract
Autonomic imbalance is an important characteristic of patients after myocardial infarction (MI) and adversely contributes to post-MI cardiac remodeling and ventricular arrhythmias (VAs). A previous study proved that optogenetic modulation could precisely inhibit cardiac sympathetic hyperactivity and prevent acute ischemia-induced VAs. Here, a wireless self-powered optogenetic modulation system is introduced, which achieves long-term precise cardiac neuromodulation in ambulatory canines. The wireless self-powered optical system based on a triboelectric nanogenerator is powered by energy harvested from body motion and realized the effective optical illumination that is required for optogenetic neuromodulation (ON). It is further demonstrated that long-term ON significantly mitigates MI-induced sympathetic remodeling and hyperactivity, and improves a variety of clinically relevant outcomes such as improves ventricular dysfunction, reduces infarct size, increases electrophysiological stability, and reduces susceptibility to VAs. These novel insights suggest that wireless ON holds translational potential for the clinical treatment of arrhythmia and other cardiovascular diseases related to sympathetic hyperactivity. Moreover, this innovative self-powered optical system may provide an opportunity to develop implantable/wearable and self-controllable devices for long-term optogenetic therapy.
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Affiliation(s)
- Liping Zhou
- Department of CardiologyRenmin Hospital of Wuhan UniversityHubei Key Laboratory of Autonomic Nervous System ModulationCardiac Autonomic Nervous System Research Center of Wuhan UniversityTaikang Center for Life and Medical SciencesWuhan UniversityCardiovascular Research InstituteWuhan UniversityHubei Key Laboratory of CardiologyWuhan430060P. R. China
| | - Yuanzheng Zhang
- Department of CardiologyRenmin Hospital of Wuhan UniversityHubei Key Laboratory of Autonomic Nervous System ModulationCardiac Autonomic Nervous System Research Center of Wuhan UniversityTaikang Center for Life and Medical SciencesWuhan UniversityCardiovascular Research InstituteWuhan UniversityHubei Key Laboratory of CardiologyWuhan430060P. R. China
- Hubei Yangtze Memory LaboratoriesKey Laboratory of Artificial Micro, and Nano‐structures of Ministry of EducationSchool of Physics and TechnologyWuhan UniversityWuhan430072P. R. China
| | - Gang Cao
- Biomedical CenterCollege of Veterinary MedicineHuazhong Agricultural UniversityWuhan430072P. R. China
| | - Chi Zhang
- Wuhan National Laboratory for OptoelectronicsHuazhong University of Science and TechnologyWuhan430072P. R. China
| | - Chen Zheng
- Wuhan National Laboratory for OptoelectronicsHuazhong University of Science and TechnologyWuhan430072P. R. China
| | - Guannan Meng
- Department of CardiologyRenmin Hospital of Wuhan UniversityHubei Key Laboratory of Autonomic Nervous System ModulationCardiac Autonomic Nervous System Research Center of Wuhan UniversityTaikang Center for Life and Medical SciencesWuhan UniversityCardiovascular Research InstituteWuhan UniversityHubei Key Laboratory of CardiologyWuhan430060P. R. China
| | - Yanqiu Lai
- Department of CardiologyRenmin Hospital of Wuhan UniversityHubei Key Laboratory of Autonomic Nervous System ModulationCardiac Autonomic Nervous System Research Center of Wuhan UniversityTaikang Center for Life and Medical SciencesWuhan UniversityCardiovascular Research InstituteWuhan UniversityHubei Key Laboratory of CardiologyWuhan430060P. R. China
| | - Zhen Zhou
- Department of CardiologyRenmin Hospital of Wuhan UniversityHubei Key Laboratory of Autonomic Nervous System ModulationCardiac Autonomic Nervous System Research Center of Wuhan UniversityTaikang Center for Life and Medical SciencesWuhan UniversityCardiovascular Research InstituteWuhan UniversityHubei Key Laboratory of CardiologyWuhan430060P. R. China
| | - Zhihao Liu
- Department of CardiologyRenmin Hospital of Wuhan UniversityHubei Key Laboratory of Autonomic Nervous System ModulationCardiac Autonomic Nervous System Research Center of Wuhan UniversityTaikang Center for Life and Medical SciencesWuhan UniversityCardiovascular Research InstituteWuhan UniversityHubei Key Laboratory of CardiologyWuhan430060P. R. China
| | - Zihan Liu
- Department of CardiologyRenmin Hospital of Wuhan UniversityHubei Key Laboratory of Autonomic Nervous System ModulationCardiac Autonomic Nervous System Research Center of Wuhan UniversityTaikang Center for Life and Medical SciencesWuhan UniversityCardiovascular Research InstituteWuhan UniversityHubei Key Laboratory of CardiologyWuhan430060P. R. China
| | - Fuding Guo
- Department of CardiologyRenmin Hospital of Wuhan UniversityHubei Key Laboratory of Autonomic Nervous System ModulationCardiac Autonomic Nervous System Research Center of Wuhan UniversityTaikang Center for Life and Medical SciencesWuhan UniversityCardiovascular Research InstituteWuhan UniversityHubei Key Laboratory of CardiologyWuhan430060P. R. China
| | - Xin Dong
- Wuhan National Laboratory for OptoelectronicsHuazhong University of Science and TechnologyWuhan430072P. R. China
| | - Zhizhuo Liang
- Wuhan National Laboratory for OptoelectronicsHuazhong University of Science and TechnologyWuhan430072P. R. China
| | - Yueyi Wang
- Department of CardiologyRenmin Hospital of Wuhan UniversityHubei Key Laboratory of Autonomic Nervous System ModulationCardiac Autonomic Nervous System Research Center of Wuhan UniversityTaikang Center for Life and Medical SciencesWuhan UniversityCardiovascular Research InstituteWuhan UniversityHubei Key Laboratory of CardiologyWuhan430060P. R. China
| | - Shishang Guo
- Hubei Yangtze Memory LaboratoriesKey Laboratory of Artificial Micro, and Nano‐structures of Ministry of EducationSchool of Physics and TechnologyWuhan UniversityWuhan430072P. R. China
| | - Xiaoya Zhou
- Department of CardiologyRenmin Hospital of Wuhan UniversityHubei Key Laboratory of Autonomic Nervous System ModulationCardiac Autonomic Nervous System Research Center of Wuhan UniversityTaikang Center for Life and Medical SciencesWuhan UniversityCardiovascular Research InstituteWuhan UniversityHubei Key Laboratory of CardiologyWuhan430060P. R. China
| | - Hong Jiang
- Department of CardiologyRenmin Hospital of Wuhan UniversityHubei Key Laboratory of Autonomic Nervous System ModulationCardiac Autonomic Nervous System Research Center of Wuhan UniversityTaikang Center for Life and Medical SciencesWuhan UniversityCardiovascular Research InstituteWuhan UniversityHubei Key Laboratory of CardiologyWuhan430060P. R. China
| | - Lilei Yu
- Department of CardiologyRenmin Hospital of Wuhan UniversityHubei Key Laboratory of Autonomic Nervous System ModulationCardiac Autonomic Nervous System Research Center of Wuhan UniversityTaikang Center for Life and Medical SciencesWuhan UniversityCardiovascular Research InstituteWuhan UniversityHubei Key Laboratory of CardiologyWuhan430060P. R. China
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17
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Zhong Z, Dong H, Wu Y, Zhou S, Li H, Huang P, Tian H, Li X, Xiao H, Yang T, Xiong K, Zhang G, Tang Z, Li Y, Fan X, Yuan C, Ning J, Li Y, Xie J, Li P. Remote ischemic preconditioning enhances aerobic performance by accelerating regional oxygenation and improving cardiac function during acute hypobaric hypoxia exposure. Front Physiol 2022; 13:950086. [PMID: 36160840 PMCID: PMC9500473 DOI: 10.3389/fphys.2022.950086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Accepted: 08/08/2022] [Indexed: 12/02/2022] Open
Abstract
Remote ischemic preconditioning (RIPC) may improve exercise performance. However, the influence of RIPC on aerobic performance and underlying physiological mechanisms during hypobaric hypoxia (HH) exposure remains relatively uncertain. Here, we systematically evaluated the potential performance benefits and underlying mechanisms of RIPC during HH exposure. Seventy-nine healthy participants were randomly assigned to receive sham intervention or RIPC (4 × 5 min occlusion 180 mm Hg/reperfusion 0 mm Hg, bilaterally on the upper arms) for 8 consecutive days in phases 1 (24 participants) and phase 2 (55 participants). In the phases 1, we measured the change in maximal oxygen uptake capacity (VO2max) and muscle oxygenation (SmO2) on the leg during a graded exercise test. We also measured regional cerebral oxygenation (rSO2) on the forehead. These measures and physiological variables, such as cardiovascular hemodynamic parameters and heart rate variability index, were used to evaluate the intervention effect of RIPC on the changes in bodily functions caused by HH exposure. In the phase 2, plasma protein mass spectrometry was then performed after RIPC intervention, and the results were further evaluated using ELISA tests to assess possible mechanisms. The results suggested that RIPC intervention improved VO2max (11.29%) and accelerated both the maximum (18.13%) and minimum (53%) values of SmO2 and rSO2 (6.88%) compared to sham intervention in hypobaric hypoxia exposure. Cardiovascular hemodynamic parameters (SV, SVRI, PPV% and SpMet%) and the heart rate variability index (Mean RR, Mean HR, RMSSD, pNN50, Lfnu, Hfnu, SD1, SD2/SD1, ApEn, SampEn, DFA1and DFA2) were evaluated. Protein sequence analysis showed 42 unregulated and six downregulated proteins in the plasma of the RIPC group compared to the sham group after HH exposure. Three proteins, thymosin β4 (Tβ4), heat shock protein-70 (HSP70), and heat shock protein-90 (HSP90), were significantly altered in the plasma of the RIPC group before and after HH exposure. Our data demonstrated that in acute HH exposure, RIPC mitigates the decline in VO2max and regional oxygenation, as well as physiological variables, such as cardiovascular hemodynamic parameters and the heart rate variability index, by influencing plasma Tβ4, HSP70, and HSP90. These data suggest that RIPC may be beneficial for acute HH exposure.
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Affiliation(s)
- Zhifeng Zhong
- Department of High Altitude Operational Medicine, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, China
| | - Huaping Dong
- Department of High Altitude Operational Medicine, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, China
| | - Yu Wu
- Department of High Altitude Operational Medicine, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, China
| | - Simin Zhou
- Department of High Altitude Operational Medicine, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, China
| | - Hong Li
- Department of Anesthesiology, Xinqiao Hospital, Army Medical University (Third Military Medical University), Chongqing, China
| | - Pei Huang
- Department of High Altitude Operational Medicine, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, China
| | - Huaijun Tian
- Department of High Altitude Operational Medicine, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, China
| | - Xiaoxu Li
- Key Laboratory of High Altitude Medicine, PLA, Army Medical University (Third Military Medical University), Chongqing, China
| | - Heng Xiao
- Department of High Altitude Operational Medicine, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, China
| | - Tian Yang
- Key Laboratory of High Altitude Medicine, PLA, Army Medical University (Third Military Medical University), Chongqing, China
| | - Kun Xiong
- Key Laboratory of High Altitude Medicine, PLA, Army Medical University (Third Military Medical University), Chongqing, China
| | - Gang Zhang
- Key Laboratory of High Altitude Medicine, PLA, Army Medical University (Third Military Medical University), Chongqing, China
- Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Army Medical University (Third Military Medical University), Chongqing, China
| | - Zhongwei Tang
- Key Laboratory of High Altitude Medicine, PLA, Army Medical University (Third Military Medical University), Chongqing, China
| | - Yaling Li
- Department of High Altitude Operational Medicine, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, China
| | - Xueying Fan
- Department of High Altitude Operational Medicine, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, China
| | - Chao Yuan
- Key Laboratory of High Altitude Medicine, PLA, Army Medical University (Third Military Medical University), Chongqing, China
- Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Army Medical University (Third Military Medical University), Chongqing, China
| | - Jiaolin Ning
- Department of Anesthesiology, First Affiliated Hospital, Army Medical University (Third Military Medical University), Chongqing, China
| | - Yue Li
- Department of Anesthesiology, First Affiliated Hospital, Army Medical University (Third Military Medical University), Chongqing, China
| | - Jiaxin Xie
- Department of High Altitude Operational Medicine, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, China
- *Correspondence: Jiaxin Xie, ; Peng Li,
| | - Peng Li
- Department of High Altitude Operational Medicine, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, China
- Key Laboratory of High Altitude Medicine, PLA, Army Medical University (Third Military Medical University), Chongqing, China
- Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Army Medical University (Third Military Medical University), Chongqing, China
- *Correspondence: Jiaxin Xie, ; Peng Li,
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18
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Mongin D, Chabert C, Extremera MG, Hue O, Courvoisier DS, Carpena P, Galvan PAB. Decrease of heart rate variability during exercise: An index of cardiorespiratory fitness. PLoS One 2022; 17:e0273981. [PMID: 36054204 PMCID: PMC9439241 DOI: 10.1371/journal.pone.0273981] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 08/18/2022] [Indexed: 12/04/2022] Open
Abstract
The present study proposes to measure and quantify the heart rate variability (HRV) changes during effort as a function of the heart rate and to test the capacity of the produced indices to predict cardiorespiratory fitness measures. Therefore, the beat-to-beat cardiac time interval series of 18 adolescent athletes (15.2 ± 2.0 years) measured during maximal graded effort test were detrended using a dynamical first-order differential equation model. HRV was then calculated as the standard deviation of the detrended RR intervals (SDRR) within successive windows of one minute. The variation of this measure of HRV during exercise is properly fitted by an exponential decrease of the heart rate: the SDRR is divided by 2 every increase of heart rate of 20 beats/min. The HR increase necessary to divide by 2 the HRV is linearly inversely correlated with the maximum oxygen consumption (r = -0.60, p = 0.006), the maximal aerobic power (r = -0.62, p = 0.006), and, to a lesser extent, to the power at the ventilatory thresholds (r = -0.53, p = 0.02 and r = -0.47, p = 0.05 for the first and second threshold). It indicates that the decrease of the HRV when the heart rate increases is faster among athletes with better fitness. This analysis, based only on cardiac measurements, provides a promising tool for the study of cardiac measurements generated by portable devices.
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Affiliation(s)
- Denis Mongin
- Faculty of Medicine, University of Geneva, Geneva, Switzerland
- * E-mail:
| | - Clovis Chabert
- Institute for Advanced Biosciences (IAB), Grenoble Alpes University, Grenoble, France
| | - Manuel Gomez Extremera
- Department of Applied Physics II, E.T.S.I. de Telecomunicación, University of Malaga, Malaga, Spain
| | - Olivier Hue
- ACTES laboratory, UPRES-EA 3596 UFR-STAPS, University of the French West Indies, Guadeloupe, France
| | - Delphine Sophie Courvoisier
- Faculty of Medicine, University of Geneva, Geneva, Switzerland
- Quality of Care Unit, University Hospitals of Geneva, Geneva, Switzerland
| | - Pedro Carpena
- Department of Applied Physics II, E.T.S.I. de Telecomunicación, University of Malaga, Malaga, Spain
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19
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Clinical perspectives on vagus nerve stimulation: present and future. Clin Sci (Lond) 2022; 136:695-709. [PMID: 35536161 PMCID: PMC9093220 DOI: 10.1042/cs20210507] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Revised: 04/15/2022] [Accepted: 04/22/2022] [Indexed: 12/30/2022]
Abstract
The vagus nerve, the great wanderer, is involved in numerous processes throughout the body and vagus nerve stimulation (VNS) has the potential to modulate many of these functions. This wide-reaching capability has generated much interest across a range of disciplines resulting in several clinical trials and studies into the mechanistic basis of VNS. This review discusses current preclinical and clinical evidence supporting the efficacy of VNS in different diseases and highlights recent advancements. Studies that provide insights into the mechanism of VNS are considered.
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20
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Mercier LJ, Batycky J, Campbell C, Schneider K, Smirl J, Debert CT. Autonomic dysfunction in adults following mild traumatic brain injury: A systematic review. NeuroRehabilitation 2022; 50:3-32. [PMID: 35068421 DOI: 10.3233/nre-210243] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND Increasing evidence suggests autonomic nervous system (ANS) dysfunction may occur following mild traumatic brain injury (mTBI). Measures of heart rate, heart rate variability, blood pressure and baroreceptor sensitivity can be used to evaluate ANS dysfunction following mTBI. OBJECTIVE Summarize the evidence for ANS dysfunction in adults following mTBI. METHODS A search of Embase, MEDLINE, Cochrane Central Register, PsycINFO, CINAHL and SPORTDiscus databases was conducted. Search topics included: mTBI and ANS. Identified abstracts were independently reviewed by 2 reviewers followed by full text screening. Risk of bias was assessed using a modified SIGN checklist. A structured synthesis was performed. RESULTS Thirty-nine studies (combined 1,467 participants diagnosed with mTBI) evaluating ANS function were included. ANS function was evaluated under various conditions including: rest, during exertion, cold pressor test, Valsalva maneuver, using face cooling and eyeball pressure paradigms. Short-term or ultra-short-term recordings were most common. The majority of studies (28/39) were rated as "unacceptable" for quality of evidence. CONCLUSIONS Altered parameters of ANS function have been reported in multiple conditions following mTBI, both acutely and in the post-acute/chronic stages of recovery. However, due to methodological limitations, conclusions regarding the severity and timing of ANS dysfunction following mTBI cannot be drawn.
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Affiliation(s)
- Leah J Mercier
- Department of Clinical Neurosciences, Division of Physical Medicine and Rehabilitation, University of Caglary, Calgary, AB, Canada
| | - Julia Batycky
- Department of Clinical Neurosciences, Division of Physical Medicine and Rehabilitation, University of Caglary, Calgary, AB, Canada
| | - Christina Campbell
- Department of Clinical Neurosciences, Division of Physical Medicine and Rehabilitation, University of Caglary, Calgary, AB, Canada
| | - Kathryn Schneider
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada.,Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada.,Sport Medicine Centre, Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
| | - Jonathan Smirl
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada.,Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada.,Sport Medicine Centre, Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada.,Cerebrovascular Concussion Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada.,Libin Cardiovascular Institute of Alberta, Univeristy of Calgary, Calgary, AB, Canada
| | - Chantel T Debert
- Department of Clinical Neurosciences, Division of Physical Medicine and Rehabilitation, University of Caglary, Calgary, AB, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
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21
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Sevoz-Couche C, Laborde S. Heart rate variability and slow-paced breathing:when coherence meets resonance. Neurosci Biobehav Rev 2022; 135:104576. [DOI: 10.1016/j.neubiorev.2022.104576] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 02/07/2022] [Accepted: 02/09/2022] [Indexed: 01/08/2023]
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22
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Patel ABU, 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: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [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.
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23
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Littlejohn EL, Boychuk CR. Protein Kinase C-Dependent Effects of Neurosteroids on Synaptic GABA A Receptor Inhibition Require the δ-Subunit. Front Physiol 2021; 12:742838. [PMID: 34759836 PMCID: PMC8573421 DOI: 10.3389/fphys.2021.742838] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 08/25/2021] [Indexed: 11/13/2022] Open
Abstract
The dorsal motor nucleus of the vagus (DMV) contains preganglionic motor neurons important for interpreting sensory input from the periphery, integrating that information, and coding the appropriate parasympathetic (vagal) output to target organs. Despite the critical role of hormonal regulation of vagal motor output, few studies examine the role of neurosteroids in the regulation of the DMV. Of the few examinations, no studies have investigated the potential impact of allopregnanolone (Allo), a neuroactive progesterone-derivative, in the regulation of neurotransmission on the DMV. Since DMV neuronal function is tightly regulated by GABAA receptor activity and Allo is an endogenous GABAA receptor ligand, the present study used in vitro whole cell patch clamp to investigate whether Allo alters GABAergic neurotransmission to DMV neurons. Although Allo did not influence GABAergic neurotransmission during initial application (5-20 min), a TTX-insensitive prolongment of decay time and increase in frequency of GABAergic currents was established after Allo was removed from the bath for at least 30 min (LtAllo). Inhibition of protein kinase C (PKC) abolished these effects, suggesting that PKC is largely required to mediate Allo-induced inhibition of the DMV. Using mice that lack the δ-subunit of the GABAA receptor, we further confirmed that PKC-dependent activity of LtAllo required this subunit. Allo also potentiated GABAA receptor activity after a repeated application of δ-subunit agonist, suggesting that the presence of Allo encodes stronger δ-subunit-mediated inhibition over time. Using current clamp recording, we demonstrated that LtAllo-induced inhibition is sufficient to decrease action potential firing and excitability within DMV neurons. We conclude that the effects of LtAllo on GABAergic inhibition are dependent on δ-subunit and PKC activation. Taken together, DMV neurons can undergo long lasting Allo-dependent GABAA receptor plasticity.
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Affiliation(s)
| | - Carie R. Boychuk
- Department of Cellular and Integrative Physiology, Long College of Medicine, University of Texas Health San Antonio, San Antonio, TX, United States
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24
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Westphal WP, Rault C, Robert R, Ragot S, Neau JP, Fernagut PO, Drouot X. Sleep deprivation reduces vagal tone during an inspiratory endurance task in humans. Sleep 2021; 44:zsab105. [PMID: 33895822 DOI: 10.1093/sleep/zsab105] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 04/12/2021] [Indexed: 11/13/2022] Open
Abstract
STUDY OBJECTIVES Sleep deprivation alters inspiratory endurance by reducing inspiratory motor output. Vagal tone is involved in exercise endurance. This study aimed to investigate the effect of sleep deprivation on vagal tone adaptation in healthy subjects performing an inspiratory effort. METHODS Vagal tone was assessed using Heart Rate Variability normalized units of frequency domain component HF (high frequency) before, at the start, and the end of an inspiratory loading trial performed until exhaustion by 16 volunteers after one night of sleep deprivation and one night of normal sleep, where sleep deprivation reduced the inspiratory endurance by half compared to the normal sleep condition (30 min vs 60 min). RESULTS At rest, heart rate was similar in sleep deprivation and normal sleep conditions. In normal sleep condition, heart rate increased during inspiratory loading task; this increase was greater in sleep deprivation condition. In normal sleep condition, vagal tone increased at the beginning of the trial. This vagal tone increase was absent in sleep deprivation condition. CONCLUSIONS Sleep deprivation abolished vagal tone response to inspiratory load, possibly contributing to a higher heart rate during the trial and to a reduced inspiratory endurance. CLINICAL TRIAL REGISTRATION NCT02725190.
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Affiliation(s)
- Willy-Paul Westphal
- Centre d'Investigation Clinique Inserm 1402, Team Acute Lung Injury and VEntilatory support, Centre Hospitalier Universitaire de Poitiers, France
- Université de Poitiers, INSERM, Laboratoire de Neurosciences Expérimentales et Cliniques, Team Neurodevelopment Neuroadaptation Neurodegeneration, Poitiers, France
| | - Christophe Rault
- Centre d'Investigation Clinique Inserm 1402, Team Acute Lung Injury and VEntilatory support, Centre Hospitalier Universitaire de Poitiers, France
| | - René Robert
- Centre d'Investigation Clinique Inserm 1402, Team Acute Lung Injury and VEntilatory support, Centre Hospitalier Universitaire de Poitiers, France
| | - Stéphanie Ragot
- Centre d'Investigation Clinique Inserm 1402, Team Acute Lung Injury and VEntilatory support, Centre Hospitalier Universitaire de Poitiers, France
| | - Jean-Philippe Neau
- Neurology Department, Centre Hospitalier Universitaire de Poitiers, France
| | - Pierre-Olivier Fernagut
- Université de Poitiers, INSERM, Laboratoire de Neurosciences Expérimentales et Cliniques, Team Neurodevelopment Neuroadaptation Neurodegeneration, Poitiers, France
| | - Xavier Drouot
- Centre d'Investigation Clinique Inserm 1402, Team Acute Lung Injury and VEntilatory support, Centre Hospitalier Universitaire de Poitiers, France
- Université de Poitiers, INSERM, Laboratoire de Neurosciences Expérimentales et Cliniques, Team Neurodevelopment Neuroadaptation Neurodegeneration, Poitiers, France
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25
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May SM, Chiang E, Reyes A, Martir G, Patel A, Karmali S, Patel S, West S, Del Arroyo AG, Gourine AV, Ackland GL. Neuromodulation of innate immunity by remote ischaemic conditioning in humans: Experimental cross-over study. Brain Behav Immun Health 2021; 16:100299. [PMID: 34589791 PMCID: PMC8417773 DOI: 10.1016/j.bbih.2021.100299] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 07/12/2021] [Indexed: 02/04/2023] Open
Abstract
Experimental animal studies on the mechanisms of remote ischaemic conditioning (RIC)-induced cardioprotection against ischaemia/reperfusion injury demonstrate involvement of both neuronal and humoral pathways. Autonomic parasympathetic (vagal) pathways confer organ protection through both direct innervation and/or immunomodulation, but evidence in humans is lacking. During acute inflammation, vagal release of acetylcholine suppresses CD11b expression, a critical β2-integrin regulating neutrophil adhesion to the endothelium and transmigration to sites of injury. Here, we tested the hypothesis that RIC recruits vagal activity in humans and has an anti-inflammatory effect by reducing neutrophil CD11b expression. Participants (age:50 ± 19 years; 53% female) underwent ultrasound-guided injection of local anaesthetic within the brachial plexus before applying 3 × 8 min cycles of brachial artery occlusion using a blood pressure cuff (RICblock). RIC was repeated 6 weeks later without brachial plexus block. Masked analysers quantified vagal activity (heart rate, heart rate variability (HRV)) before, and 10 min after, the last cycle of RIC. RR-interval increased after RIC (reduced heart rate) by 40 ms (95% confidence intervals (95%CI):13–66; n = 17 subjects; P = 0.003). RR-interval did not change after brachial plexus blockade (mean difference: 20 ms (95%CI:-11 to 50); P = 0.19). The high-frequency component of HRV was reduced after RICblock, but remained unchanged after RIC (P < 0.001), indicating that RIC preserved vagal activity. LPS-induced CD16+CD11b+ expression in whole blood (measured by flow cytometry) was reduced by RIC (3615 median fluorescence units (95%CI:475-6754); P = 0.026), compared with 2331 units (95%CI:-3921 to 8582); P = 0.726) after RICblock. These data suggest that in humans RIC recruits vagal cardiac and anti-inflammatory mechanisms via ischaemia/reperfusion-induced activation of sensory nerve fibres that innervate the organ undergoing RIC.
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Affiliation(s)
- Shaun M May
- William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, UK
| | - Eric Chiang
- William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, UK
| | - Anna Reyes
- University College Hospital NHS Trust, London, UK
| | | | - Amour Patel
- William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, UK
| | - Shamir Karmali
- William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, UK
| | - Sanjiv Patel
- University College Hospital NHS Trust, London, UK
| | - Simeon West
- University College Hospital NHS Trust, London, UK
| | - Ana Gutierrez Del Arroyo
- William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, UK
| | - Alexander V Gourine
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology & Pharmacology, University College London, UK
| | - Gareth L Ackland
- William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, UK
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26
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Baker J, Incognito AV, Wilson RJA, Raj SR. Syncope and silent hypoxemia in COVID-19: Implications for the autonomic field. Auton Neurosci 2021; 235:102842. [PMID: 34246957 PMCID: PMC8258030 DOI: 10.1016/j.autneu.2021.102842] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 05/22/2021] [Accepted: 06/28/2021] [Indexed: 01/08/2023]
Abstract
Coronavirus-19 (COVID-19), the infectious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus, has wreaked havoc across the globe since its emergence in December 2019. Reports of patients presenting with syncope and pre-syncope, as well as hypoxemia without symptoms of dyspnea (“silent hypoxemia”), have led researchers to speculate whether SARS-CoV-2 can alter autonomic nervous system function. As viral infections are commonly reported triggers of altered autonomic control, we must consider whether SARS-CoV-2 can also interfere with autonomic activity, at least in some patients. As we are still in the early stages of understanding COVID-19, we still do not know whether syncope and silent hypoxemia are more strongly associated with COVID-19 compared to any other viral infections that severely compromise gas exchange. Therefore, in this perspective we discuss these two intriguing clinical presentations, as they relate to autonomic nervous system function. In our discussion, we will explore COVID-specific, as well as non-COVID specific mechanisms that may affect autonomic activity and potential therapeutic targets. As we move forward in our understanding of COVID-19, well-designed prospective studies with appropriate control and comparator groups will be necessary to identify potential unique effects of COVID-19 on autonomic function.
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Affiliation(s)
- Jacquie Baker
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.
| | - Anthony V Incognito
- Hotchkiss Brain Institute and Alberta Children's Hospital Research Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Richard J A Wilson
- Hotchkiss Brain Institute and Alberta Children's Hospital Research Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Satish R Raj
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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27
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Cavalcante GL, Brognara F, Oliveira LVDC, Lataro RM, Durand MDT, Oliveira AP, Nóbrega ACL, Salgado HC, Sabino JPJ. Benefits of pharmacological and electrical cholinergic stimulation in hypertension and heart failure. Acta Physiol (Oxf) 2021; 232:e13663. [PMID: 33884761 DOI: 10.1111/apha.13663] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 03/12/2021] [Accepted: 04/06/2021] [Indexed: 12/11/2022]
Abstract
Systemic arterial hypertension and heart failure are cardiovascular diseases that affect millions of individuals worldwide. They are characterized by a change in the autonomic nervous system balance, highlighted by an increase in sympathetic activity associated with a decrease in parasympathetic activity. Most therapeutic approaches seek to treat these diseases by medications that attenuate sympathetic activity. However, there is a growing number of studies demonstrating that the improvement of parasympathetic function, by means of pharmacological or electrical stimulation, can be an effective tool for the treatment of these cardiovascular diseases. Therefore, this review aims to describe the advances reported by experimental and clinical studies that addressed the potential of cholinergic stimulation to prevent autonomic and cardiovascular imbalance in hypertension and heart failure. Overall, the published data reviewed demonstrate that the use of central or peripheral acetylcholinesterase inhibitors is efficient to improve the autonomic imbalance and hemodynamic changes observed in heart failure and hypertension. Of note, the baroreflex and the vagus nerve activation have been shown to be safe and effective approaches to be used as an alternative treatment for these cardiovascular diseases. In conclusion, pharmacological and electrical stimulation of the parasympathetic nervous system has the potential to be used as a therapeutic tool for the treatment of hypertension and heart failure, deserving to be more explored in the clinical setting.
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Affiliation(s)
- Gisele L. Cavalcante
- Graduate Program in Pharmaceutical Sciences Department of Biophysics and Physiology Federal University of Piaui Teresina PI Brazil
- Department of Pharmacology Ribeirão Preto Medical School University of São Paulo Ribeirão Preto SP Brazil
| | - Fernanda Brognara
- Department of Physiology Ribeirão Preto Medical School University of São Paulo Ribeirão Preto SP Brazil
| | - Lucas Vaz de C. Oliveira
- Graduate Program in Pharmaceutical Sciences Department of Biophysics and Physiology Federal University of Piaui Teresina PI Brazil
| | - Renata M. Lataro
- Department of Physiological Sciences Center of Biological Sciences Federal University of Santa Catarina Florianópolis SP Brazil
| | | | - Aldeidia P. Oliveira
- Graduate Program in Pharmacology Department of Biophysics and Physiology Federal University of Piaui Teresina PI Brazil
| | | | - Helio C. Salgado
- Department of Physiology Ribeirão Preto Medical School University of São Paulo Ribeirão Preto SP Brazil
| | - João Paulo J. Sabino
- Graduate Program in Pharmaceutical Sciences Department of Biophysics and Physiology Federal University of Piaui Teresina PI Brazil
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28
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Nizari S, Basalay M, Chapman P, Korte N, Korsak A, Christie IN, Theparambil SM, Davidson SM, Reimann F, Trapp S, Yellon DM, Gourine AV. Glucagon-like peptide-1 (GLP-1) receptor activation dilates cerebral arterioles, increases cerebral blood flow, and mediates remote (pre)conditioning neuroprotection against ischaemic stroke. Basic Res Cardiol 2021; 116:32. [PMID: 33942194 PMCID: PMC8093159 DOI: 10.1007/s00395-021-00873-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 04/22/2021] [Indexed: 12/12/2022]
Abstract
Stroke remains one of the most common causes of death and disability worldwide. Several preclinical studies demonstrated that the brain can be effectively protected against ischaemic stroke by two seemingly distinct treatments: remote ischaemic conditioning (RIC), involving cycles of ischaemia/reperfusion applied to a peripheral organ or tissue, or by systemic administration of glucagon-like-peptide-1 (GLP-1) receptor (GLP-1R) agonists. The mechanisms underlying RIC- and GLP-1-induced neuroprotection are not completely understood. In this study, we tested the hypothesis that GLP-1 mediates neuroprotection induced by RIC and investigated the effect of GLP-1R activation on cerebral blood vessels, as a potential mechanism of GLP-1-induced protection against ischaemic stroke. A rat model of ischaemic stroke (90 min of middle cerebral artery occlusion followed by 24-h reperfusion) was used. RIC was induced by 4 cycles of 5 min left hind limb ischaemia interleaved with 5-min reperfusion periods. RIC markedly (by ~ 80%) reduced the cerebral infarct size and improved the neurological score. The neuroprotection established by RIC was abolished by systemic blockade of GLP-1R with a specific antagonist Exendin(9-39). In the cerebral cortex of GLP-1R reporter mice, ~ 70% of cortical arterioles displayed GLP-1R expression. In acute brain slices of the rat cerebral cortex, activation of GLP-1R with an agonist Exendin-4 had a strong dilatory effect on cortical arterioles and effectively reversed arteriolar constrictions induced by metabolite lactate or oxygen and glucose deprivation, as an ex vivo model of ischaemic stroke. In anaesthetised rats, Exendin-4 induced lasting increases in brain tissue PO2, indicative of increased cerebral blood flow. These results demonstrate that neuroprotection against ischaemic stroke established by remote ischaemic conditioning is mediated by a mechanism involving GLP-1R signalling. Potent dilatory effect of GLP-1R activation on cortical arterioles suggests that the neuroprotection in this model is mediated via modulation of cerebral blood flow and improved brain perfusion.
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Affiliation(s)
- Shereen Nizari
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK
| | - Marina Basalay
- The Hatter Cardiovascular Institute, University College London, London, WC1E 6HX, UK
| | - Philippa Chapman
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK
| | - Nils Korte
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK
| | - Alla Korsak
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK
| | - Isabel N Christie
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK
| | - Shefeeq M Theparambil
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK
| | - Sean M Davidson
- The Hatter Cardiovascular Institute, University College London, London, WC1E 6HX, UK
| | - Frank Reimann
- Wellcome Trust/MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - Stefan Trapp
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK
| | - Derek M Yellon
- The Hatter Cardiovascular Institute, University College London, London, WC1E 6HX, UK
| | - Alexander V Gourine
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK.
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Sabino-Carvalho JL, Fisher JP, Vianna LC. Autonomic Function in Patients With Parkinson's Disease: From Rest to Exercise. Front Physiol 2021; 12:626640. [PMID: 33815139 PMCID: PMC8017184 DOI: 10.3389/fphys.2021.626640] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 02/24/2021] [Indexed: 12/16/2022] Open
Abstract
Parkinson’s disease (PD) is a common neurodegenerative disorder classically characterized by symptoms of motor impairment (e.g., tremor and rigidity), but also presenting with important non-motor impairments. There is evidence for the reduced activity of both the parasympathetic and sympathetic limbs of the autonomic nervous system at rest in PD. Moreover, inappropriate autonomic adjustments accompany exercise, which can lead to inadequate hemodynamic responses, the failure to match the metabolic demands of working skeletal muscle and exercise intolerance. The underlying mechanisms remain unclear, but relevant alterations in several discrete central regions (e.g., dorsal motor nucleus of the vagus nerve, intermediolateral cell column) have been identified. Herein, we critically evaluate the clinically significant and complex associations between the autonomic dysfunction, fatigue and exercise capacity in PD.
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Affiliation(s)
- Jeann L Sabino-Carvalho
- NeuroV̇ASQ̇ - Integrative Physiology Laboratory, Faculty of Physical Education, University of Brasília, Brasília, Brazil
| | - James P Fisher
- Manaaki Mānawa - The Centre for Heart Research, Department of Physiology, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Lauro C Vianna
- NeuroV̇ASQ̇ - Integrative Physiology Laboratory, Faculty of Physical Education, University of Brasília, Brasília, Brazil.,Graduate Program in Medical Sciences, Faculty of Medicine, University of Brasília, Brasília, Brazil
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30
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Espinoza L, Fedorchak S, Boychuk CR. Interplay Between Systemic Metabolic Cues and Autonomic Output: Connecting Cardiometabolic Function and Parasympathetic Circuits. Front Physiol 2021; 12:624595. [PMID: 33776789 PMCID: PMC7991741 DOI: 10.3389/fphys.2021.624595] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Accepted: 02/12/2021] [Indexed: 12/21/2022] Open
Abstract
There is consensus that the heart is innervated by both the parasympathetic and sympathetic nervous system. However, the role of the parasympathetic nervous system in controlling cardiac function has received significantly less attention than the sympathetic nervous system. New neuromodulatory strategies have renewed interest in the potential of parasympathetic (or vagal) motor output to treat cardiovascular disease and poor cardiac function. This renewed interest emphasizes a critical need to better understand how vagal motor output is generated and regulated. With clear clinical links between cardiovascular and metabolic diseases, addressing this gap in knowledge is undeniably critical to our understanding of the interaction between metabolic cues and vagal motor output, notwithstanding the classical role of the parasympathetic nervous system in regulating gastrointestinal function and energy homeostasis. For this reason, this review focuses on the central, vagal circuits involved in sensing metabolic state(s) and enacting vagal motor output to influence cardiac function. It will review our current understanding of brainstem vagal circuits and their unique position to integrate metabolic signaling into cardiac activity. This will include an overview of not only how metabolic cues alter vagal brainstem circuits, but also how vagal motor output might influence overall systemic concentrations of metabolic cues known to act on the cardiac tissue. Overall, this review proposes that the vagal brainstem circuits provide an integrative network capable of regulating and responding to metabolic cues to control cardiac function.
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Affiliation(s)
- Liliana Espinoza
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, San Antonio, TX, United States
| | - Stephanie Fedorchak
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, San Antonio, TX, United States
| | - Carie R Boychuk
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, San Antonio, TX, United States
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31
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Rangon CM, Krantic S, Moyse E, Fougère B. The Vagal Autonomic Pathway of COVID-19 at the Crossroad of Alzheimer's Disease and Aging: A Review of Knowledge. J Alzheimers Dis Rep 2020; 4:537-551. [PMID: 33532701 PMCID: PMC7835993 DOI: 10.3233/adr-200273] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/17/2020] [Indexed: 12/11/2022] Open
Abstract
Coronavirus Disease 2019 (COVID-19) pandemic-triggered mortality is significantly higher in older than in younger populations worldwide. Alzheimer's disease (AD) is related to aging and was recently reported to be among the major risk factors for COVID-19 mortality in older people. The symptomatology of COVID-19 indicates that lethal outcomes of infection rely on neurogenic mechanisms. The present review compiles the available knowledge pointing to the convergence of COVID-19 complications with the mechanisms of autonomic dysfunctions in AD and aging. The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is prone to neuroinvasion from the lung along the vagus nerve up to the brainstem autonomic nervous centers involved in the coupling of cardiovascular and respiratory rhythms. The brainstem autonomic network allows SARS-CoV-2 to trigger a neurogenic switch to hypertension and hypoventilation, which may act in synergy with aging- and AD-induced dysautonomias, along with an inflammatory "storm". The lethal outcomes of COVID-19, like in AD and unhealthy aging, likely rely on a critical hypoactivity of the efferent vagus nerve cholinergic pathway, which is involved in lowering cardiovascular pressure and systemic inflammation tone. We further discuss the emerging evidence supporting the use of 1) the non-invasive stimulation of vagus nerve as an additional therapeutic approach for severe COVID-19, and 2) the demonstrated vagal tone index, i.e., heart rate variability, via smartphone-based applications as a non-serological low-cost diagnostic of COVID-19. These two well-known medical approaches are already available and now deserve large-scale testing on human cohorts in the context of both AD and COVID-19.
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Affiliation(s)
- Claire-Marie Rangon
- Pain and Neuromodulation Unit, Division of Neurosurgery, Hôpital Fondation Ophtalmologique A. De Rothschild, Paris, France
| | - Slavica Krantic
- Sorbonne Université, St. Antoine Research Center (CRSA), Inserm UMRS-938, Hopital St-Antoine, Paris, France
| | - Emmanuel Moyse
- INRAE Centre Val-de-Loire, Physiology of Reproduction and Behavior Unit (PRC, UMR-85), Team ER2, Nouzilly, France
| | - Bertrand Fougère
- Division of Geriatric Medicine, Tours University Hospital, Tours, France
- Education, Ethics, Health (EA 7505), Tours University, Tours, France
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Abstract
The electromechanical function of the heart involves complex, coordinated activity over time and space. Life-threatening cardiac arrhythmias arise from asynchrony in these space-time events; therefore, therapies for prevention and treatment require fundamental understanding and the ability to visualize, perturb and control cardiac activity. Optogenetics combines optical and molecular biology (genetic) approaches for light-enabled sensing and actuation of electrical activity with unprecedented spatiotemporal resolution and parallelism. The year 2020 marks a decade of developments in cardiac optogenetics since this technology was adopted from neuroscience and applied to the heart. In this Review, we appraise a decade of advances that define near-term (immediate) translation based on all-optical electrophysiology, including high-throughput screening, cardiotoxicity testing and personalized medicine assays, and long-term (aspirational) prospects for clinical translation of cardiac optogenetics, including new optical therapies for rhythm control. The main translational opportunities and challenges for optogenetics to be fully embraced in cardiology are also discussed.
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Booth LC, Yao ST, Korsak A, Farmer DGS, Hood SG, McCormick D, Boesley Q, Connelly AA, McDougall SJ, Korim WS, Guild SJ, Mastitskaya S, Le P, Teschemacher AG, Kasparov S, Ackland GL, Malpas SC, McAllen RM, Allen AM, May CN, Gourine AV. Selective optogenetic stimulation of efferent fibers in the vagus nerve of a large mammal. Brain Stimul 2020; 14:88-96. [PMID: 33217609 PMCID: PMC7836098 DOI: 10.1016/j.brs.2020.11.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 10/26/2020] [Accepted: 11/11/2020] [Indexed: 12/26/2022] Open
Abstract
Background Electrical stimulation applied to individual organs, peripheral nerves, or specific brain regions has been used to treat a range of medical conditions. In cardiovascular disease, autonomic dysfunction contributes to the disease progression and electrical stimulation of the vagus nerve has been pursued as a treatment for the purpose of restoring the autonomic balance. However, this approach lacks selectivity in activating function- and organ-specific vagal fibers and, despite promising results of many preclinical studies, has so far failed to translate into a clinical treatment of cardiovascular disease. Objective Here we report a successful application of optogenetics for selective stimulation of vagal efferent activity in a large animal model (sheep). Methods and results Twelve weeks after viral transduction of a subset of vagal motoneurons, strong axonal membrane expression of the excitatory light-sensitive ion channel ChIEF was achieved in the efferent projections innervating thoracic organs and reaching beyond the level of the diaphragm. Blue laser or LED light (>10 mW mm−2; 1 ms pulses) applied to the cervical vagus triggered precisely timed, strong bursts of efferent activity with evoked action potentials propagating at speeds of ∼6 m s−1. Conclusions These findings demonstrate that in species with a large, multi-fascicled vagus nerve, it is possible to stimulate a specific sub-population of efferent fibers using light at a site remote from the vector delivery, marking an important step towards eventual clinical use of optogenetic technology for autonomic neuromodulation. Described is a method of selective efferent vagus nerve stimulation using light. Vagal preganglionic neurons are targeted to express light-sensitive channels. Specific efferent VNS by light delivery to the cervical vagus is achieved in a large animal model. Demonstrates feasibility of using optogenetic technology for autonomic neuromodulation.
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Affiliation(s)
- Lindsea C Booth
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia
| | - Song T Yao
- Florey Department of Neuroscience and Mental Health, MDHS, University of Melbourne, Melbourne, Australia
| | - Alla Korsak
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - David G S Farmer
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia; Department of Physiology, The University of Melbourne, Melbourne, Australia
| | - Sally G Hood
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia
| | - Daniel McCormick
- Department of Physiology and Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Quinn Boesley
- Department of Physiology and Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Angela A Connelly
- Department of Physiology, The University of Melbourne, Melbourne, Australia
| | - Stuart J McDougall
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia
| | - Willian S Korim
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia
| | - Sarah-Jane Guild
- Department of Physiology and Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Svetlana Mastitskaya
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Phuong Le
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia
| | - Anja G Teschemacher
- Physiology, Neuroscience and Pharmacology, University of Bristol, Bristol, UK
| | - Sergey Kasparov
- Physiology, Neuroscience and Pharmacology, University of Bristol, Bristol, UK; Baltic Federal University, Kaliningrad, Russian Federation
| | - Gareth L Ackland
- Translational Medicine and Therapeutics, William Harvey Research Institute, Queen Mary University of London, London, UK
| | - Simon C Malpas
- Department of Physiology and Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Robin M McAllen
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia
| | - Andrew M Allen
- Department of Physiology, The University of Melbourne, Melbourne, Australia
| | - Clive N May
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia.
| | - Alexander V Gourine
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK.
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Machhada A, Hosford PS, Dyson A, Ackland GL, Mastitskaya S, Gourine AV. Optogenetic Stimulation of Vagal Efferent Activity Preserves Left Ventricular Function in Experimental Heart Failure. JACC Basic Transl Sci 2020; 5:799-810. [PMID: 32875170 PMCID: PMC7452237 DOI: 10.1016/j.jacbts.2020.06.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 06/05/2020] [Accepted: 06/06/2020] [Indexed: 12/21/2022]
Abstract
This study was designed to determine the effect of selective optogenetic simulation of vagal efferent activity on left ventricular function in an animal (rat) model of MI-induced heart failure. Optogenetic stimulation of dorsal brainstem vagal pre-ganglionic neurons transduced to express light-sensitive channels preserved LV function and exercise capacity in animals with MI. The data suggest that activation of vagal efferents is critically important to deliver the therapeutic benefit of VNS in chronic heart failure.
Large clinical trials designed to test the efficacy of vagus nerve stimulation (VNS) in patients with heart failure did not demonstrate benefits with respect to the primary endpoints. The nonselective nature of VNS may account for the failure to translate promising results of preclinical and earlier clinical studies. This study showed that optogenetic stimulation of vagal pre-ganglionic neurons transduced to express light-sensitive channels preserved left ventricular function and exercise capacity in a rat model of myocardial infarction−induced heart failure. These data suggested that stimulation of vagal efferent activity is critically important to deliver the therapeutic benefit of VNS in heart failure.
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Key Words
- ABP, arterial blood pressure
- DVMN, dorsal motor nucleus of the vagus nerve
- GRK2, G-protein−coupled receptor kinase 2
- LAD, left anterior descending coronary artery
- LV dP/dtMAX, maximum rate of rise of left ventricular pressure
- LV, left ventricle
- LVEDP, left ventricular end-diastolic pressure
- LVESP, left ventricular end-systolic pressure
- LVP, left ventricular pressure
- LVV, lentiviral vector
- MI, myocardial infarction
- VNS, vagus nerve stimulation
- autonomic nervous system
- eGFP, enhanced green fluorescent protein
- heart failure
- myocardial infarction
- neuromodulation
- vagus nerve stimulation
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Affiliation(s)
- Asif Machhada
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
| | - Patrick S Hosford
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom.,Translational Medicine and Therapeutics, William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - Alex Dyson
- Clinical Physiology, Division of Medicine, University College London, London, United Kingdom
| | - Gareth L Ackland
- Translational Medicine and Therapeutics, William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - Svetlana Mastitskaya
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
| | - Alexander V Gourine
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
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Mastitskaya S, Turovsky E, Marina N, Theparambil SM, Hadjihambi A, Kasparov S, Teschemacher AG, Ramage AG, Gourine AV, Hosford PS. Astrocytes Modulate Baroreflex Sensitivity at the Level of the Nucleus of the Solitary Tract. J Neurosci 2020; 40:3052-3062. [PMID: 32132265 PMCID: PMC7141885 DOI: 10.1523/jneurosci.1438-19.2020] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Revised: 12/16/2019] [Accepted: 01/12/2020] [Indexed: 11/21/2022] Open
Abstract
Maintenance of cardiorespiratory homeostasis depends on autonomic reflexes controlled by neuronal circuits of the brainstem. The neurophysiology and neuroanatomy of these reflex pathways are well understood, however, the mechanisms and functional significance of autonomic circuit modulation by glial cells remain largely unknown. In the experiments conducted in male laboratory rats we show that astrocytes of the nucleus of the solitary tract (NTS), the brain area that receives and integrates sensory information from the heart and blood vessels, respond to incoming afferent inputs with [Ca2+]i elevations. Astroglial [Ca2+]i responses are triggered by transmitters released by vagal afferents, glutamate acting at AMPA receptors and 5-HT acting at 5-HT2A receptors. In conscious freely behaving animals blockade of Ca2+-dependent vesicular release mechanisms in NTS astrocytes by virally driven expression of a dominant-negative SNARE protein (dnSNARE) increased baroreflex sensitivity by 70% (p < 0.001). This effect of compromised astroglial function was specific to the NTS as expression of dnSNARE in astrocytes of the ventrolateral brainstem had no effect. ATP is considered the principle gliotransmitter and is released by vesicular mechanisms blocked by dnSNARE expression. Consistent with this hypothesis, in anesthetized rats, pharmacological activation of P2Y1 purinoceptors in the NTS decreased baroreflex gain by 40% (p = 0.031), whereas blockade of P2Y1 receptors increased baroreflex gain by 57% (p = 0.018). These results suggest that glutamate and 5-HT, released by NTS afferent terminals, trigger Ca2+-dependent astroglial release of ATP to modulate baroreflex sensitivity via P2Y1 receptors. These data add to the growing body of evidence supporting an active role of astrocytes in brain information processing.SIGNIFICANCE STATEMENT Cardiorespiratory reflexes maintain autonomic balance and ensure cardiovascular health. Impaired baroreflex may contribute to the development of cardiovascular disease and serves as a robust predictor of cardiovascular and all-cause mortality. The data obtained in this study suggest that astrocytes are integral components of the brainstem mechanisms that process afferent information and modulate baroreflex sensitivity via the release of ATP. Any condition associated with higher levels of "ambient" ATP in the NTS would be expected to decrease baroreflex gain by the mechanism described here. As ATP is the primary signaling molecule of glial cells (astrocytes, microglia), responding to metabolic stress and inflammatory stimuli, our study suggests a plausible mechanism of how the central component of the baroreflex is affected in pathological conditions.
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Affiliation(s)
- Svetlana Mastitskaya
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology, and Pharmacology, University College London, London WC1E 6BT, United Kingdom
| | - Egor Turovsky
- Institute of Cell Biophysics, Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Pushchino 142290, Russian Federation
| | - Nephtali Marina
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology, and Pharmacology, University College London, London WC1E 6BT, United Kingdom
| | - Shefeeq M Theparambil
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology, and Pharmacology, University College London, London WC1E 6BT, United Kingdom
| | - Anna Hadjihambi
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology, and Pharmacology, University College London, London WC1E 6BT, United Kingdom
| | - Sergey Kasparov
- Physiology, Pharmacology, and Neuroscience, University of Bristol, Bristol BS8 1TD, United Kingdom
- Baltic Federal University, Kaliningrad 236041, Russian Federation, and
| | - Anja G Teschemacher
- Physiology, Pharmacology, and Neuroscience, University of Bristol, Bristol BS8 1TD, United Kingdom
| | - Andrew G Ramage
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology, and Pharmacology, University College London, London WC1E 6BT, United Kingdom
| | - Alexander V Gourine
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology, and Pharmacology, University College London, London WC1E 6BT, United Kingdom,
| | - Patrick S Hosford
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology, and Pharmacology, University College London, London WC1E 6BT, United Kingdom,
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, United Kingdom
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Astrocytes monitor cerebral perfusion and control systemic circulation to maintain brain blood flow. Nat Commun 2020; 11:131. [PMID: 31919423 PMCID: PMC6952443 DOI: 10.1038/s41467-019-13956-y] [Citation(s) in RCA: 120] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 12/06/2019] [Indexed: 02/07/2023] Open
Abstract
Astrocytes provide neurons with essential metabolic and structural support, modulate neuronal circuit activity and may also function as versatile surveyors of brain milieu, tuned to sense conditions of potential metabolic insufficiency. Here we show that astrocytes detect falling cerebral perfusion pressure and activate CNS autonomic sympathetic control circuits to increase systemic arterial blood pressure and heart rate with the purpose of maintaining brain blood flow and oxygen delivery. Studies conducted in experimental animals (laboratory rats) show that astrocytes respond to acute decreases in brain perfusion with elevations in intracellular [Ca2+]. Blockade of Ca2+-dependent signaling mechanisms in populations of astrocytes that reside alongside CNS sympathetic control circuits prevents compensatory increases in sympathetic nerve activity, heart rate and arterial blood pressure induced by reductions in cerebral perfusion. These data suggest that astrocytes function as intracranial baroreceptors and play an important role in homeostatic control of arterial blood pressure and brain blood flow. The brain receives 20% of cardiac output, but in accord with the current knowledge lacks a specialized sensor of its own blood flow. Here, the authors show that brain astrocytes detect drops in perfusion and trigger compensatory increases in arterial pressure and heart rate to preserve brain blood flow and oxygen delivery.
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Zarbock A, Kellum JA, Gourine AV, Ackland GL. Salvaging remote ischaemic preconditioning as a therapy for perioperative acute kidney injury. Br J Anaesth 2020; 124:8-12. [PMID: 31629484 DOI: 10.1016/j.bja.2019.09.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 09/14/2019] [Indexed: 12/11/2022] Open
Affiliation(s)
- Alexander Zarbock
- Department of Anaesthesiology, Intensive Care Medicine and Pain Medicine, University Hospital Münster, Münster, Germany.
| | - John A Kellum
- Center for Critical Care Nephrology, Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Alexander V Gourine
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Gareth L Ackland
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology and Pharmacology, University College London, London, UK; Translational Medicine & 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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38
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de Paula T, Neves MF, da Silva Itaborahy A, Monteiro W, Farinatti P, Cunha FA. Acute Effect of Aerobic and Strength Exercise on Heart Rate Variability and Baroreflex Sensitivity in Men With Autonomic Dysfunction. J Strength Cond Res 2019; 33:2743-2752. [PMID: 29271835 DOI: 10.1519/jsc.0000000000002372] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
de Paula, T, Neves, MF, da Silva Itaborahy, A, Monteiro, W, Farinatti, P, and Cunha, FA. Recovery pattern of cardiac autonomic control after aerobic and strength exercises in overweight prehypertensive men. J Strength Cond Res 33(10): 2743-2752, 2019-The extent to which postexercise cardiac autonomic control depends on exercise modality remains unclear, particularly among individuals with autonomic dysfunction (cardiac autonomic dysfunction [CADysf]). This study compared heart rate variability (HRV) and baroreflex sensitivity (BRS) responses to acute aerobic exercise (AE) and strength exercise (SE) in men with CADysf. Twenty men were assigned into control (n = 10: 33.8 ± 3.0 years; 23.7 ± 1.5 kg·m) and CADysf (n = 10: 36.2 ± 9.8 years; 28.4 ± 2.6 kg·m) groups. Cardiac autonomic dysfunction underwent AE, SE, and a nonexercise control day (control session [CTL]) in a randomized, counter-balanced order. Heart rate variability and BRS were assessed in a supine position during 25 minutes of recovery after AE, SE, and CTL. Both HRV indices (p ≤ 0.05; effect size [Cohen's d]: >1.4) and BRS at rest were significantly lower in CADysf than those in controls (p < 0.01; effect size [Cohen's d]: ≥1.36). In CADysf, postexercise increases in heart rate, sympathetic activity (low-frequency [LF] band), and sympathovagal balance (LF:high-frequency [HF] ratio), as well as decreases in R-R interval, parasympathetic activity (HF band), and BRS were observed in AE (p ≤ 0.05; effect size [Cohen's d]: ≥1.31) and SE (p ≤ 0.05; effect size [Cohen's d]: ≥0.79) vs. CTL, but changes were larger after AE than SE (p ≤ 0.05; effect size [Cohen's d]: ≥0.73). In conclusion, both AE and SE elicited postexercise changes in HRV and BRS among CADysf men, primarily reflected by lowered vagal modulation, increased sympathovagal balance, and a delayed BRS recovery pattern. However, those changes seem to be more likely to occur after AE than SE.
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Affiliation(s)
- Tainah de Paula
- Post-Graduate Program in Medical Sciences, Faculty of Medical Sciences, University of Rio de Janeiro State, Rio de Janeiro, Brazil.,Laboratory of Physical Activity and Health Promotion, University of Rio de Janeiro State, Rio de Janeiro, Brazil
| | - Mario F Neves
- Post-Graduate Program in Medical Sciences, Faculty of Medical Sciences, University of Rio de Janeiro State, Rio de Janeiro, Brazil.,Department of Clinical Medicine, University of Rio de Janeiro State, Rio de Janeiro, Brazil
| | - Alex da Silva Itaborahy
- Post-Graduate Program in Medical Sciences, Faculty of Medical Sciences, University of Rio de Janeiro State, Rio de Janeiro, Brazil
| | - Walace Monteiro
- Laboratory of Physical Activity and Health Promotion, University of Rio de Janeiro State, Rio de Janeiro, Brazil.,Post-Graduate Program in Physical Activity Sciences, Salgado de Oliveira University, Rio de Janeiro, Brazil
| | - Paulo Farinatti
- Laboratory of Physical Activity and Health Promotion, University of Rio de Janeiro State, Rio de Janeiro, Brazil.,Post-Graduate Program in Physical Activity Sciences, Salgado de Oliveira University, Rio de Janeiro, Brazil.,Post-Graduate Program in Exercise Science and Sports, University of Rio de Janeiro State, Rio de Janeiro, Brazil
| | - Felipe A Cunha
- Laboratory of Physical Activity and Health Promotion, University of Rio de Janeiro State, Rio de Janeiro, Brazil.,Post-Graduate Program in Exercise Science and Sports, University of Rio de Janeiro State, Rio de Janeiro, Brazil.,Post-Graduate Program in Rehabilitation Sciences, Augusto Motta University Center (UNISUAM), Rio de Janeiro, Brazil
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Long-term stimulation of cardiac vagal preganglionic neurons reduces blood pressure in the spontaneously hypertensive rat. J Hypertens 2019; 36:2444-2452. [PMID: 30045362 DOI: 10.1097/hjh.0000000000001871] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Arterial hypertension is associated with autonomic nervous system dysfunction. Different interventional strategies have been implemented in recent years for the reduction of sympathetic activity in patients with hypertension. However, the therapeutic benefit of increasing vagal tone in hypertensive patients remains largely unexplored. OBJECTIVE Here, we describe the effects of long-term activation of vagal neural pathways on arterial pressure, heart rate arterial pressure variability and spontaneous baroreflex sensitivity in spontaneously hypertensive rats (SHR) and normotensive Wistar rats. METHODS Brainstem vagal preganglionic neurons residing in the dorsal vagal motor nucleus (DVMN) were targeted with a lentiviral vector to induce the expression of an artificial G(s) protein-coupled receptor termed designer receptors exclusively activated by designer drugs (DREADD-Gs). The transduced neurons were activated daily by systemic administration of otherwise inert ligand clozapine-n-oxide. Arterial pressure measurements were recorded in conscious freely moving animals after 21 consecutive days of DVMN stimulation. RESULTS Resting arterial pressure was significantly lower in SHRs expressing DREADD-Gs in the DVMN, compared with control SHRs expressing enhanced green fluorescent protein. No changes in arterial pressure were detected in Wistar rats expressing DREADD-Gs compared with rats expressing enhanced green fluorescent protein in the DVMN. Pharmacogenetic activation of DREADD-Gs-expressing DVMN neurons in SHRs was accompanied with increased baroreflex sensitivity and a paradoxical decrease in cardio-vagal components of heart rate and systolic arterial pressure variability in SHRs. CONCLUSION These results suggest that long-term activation of vagal parasympathetic pathways is beneficial in restoring autonomic balance in an animal model of neurogenic hypertension and might be an effective therapeutic approach for the management of hypertension.
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May SM, Reyes A, Martir G, Reynolds J, Paredes LG, Karmali S, Stephens RCM, Brealey D, Ackland GL. Acquired loss of cardiac vagal activity is associated with myocardial injury in patients undergoing noncardiac surgery: prospective observational mechanistic cohort study. Br J Anaesth 2019; 123:758-767. [PMID: 31492527 DOI: 10.1016/j.bja.2019.08.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 07/02/2019] [Accepted: 08/03/2019] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Myocardial injury is more frequent after noncardiac surgery in patients with preoperative cardiac vagal dysfunction, as quantified by delayed heart rate (HR) recovery after cessation of cardiopulmonary exercise testing. We hypothesised that serial and dynamic measures of cardiac vagal activity are also associated with myocardial injury after noncardiac surgery. METHODS Serial autonomic measurements were made before and after surgery in patients undergoing elective noncardiac surgery. Cardiac vagal activity was quantified by HR variability and HR recovery after orthostatic challenge (supine to sitting). Revised cardiac risk index (RCRI) was calculated for each patient. The primary outcome was myocardial injury (high-sensitivity troponin ≥15 ng L-1) within 48 h of surgery, masked to investigators. The exposure of interest was cardiac vagal activity (high-frequency power spectral analysis [HFLn]) and HR recovery 90 s from peak HR after the orthostatic challenge. RESULTS Myocardial injury occurred in 48/189 (25%) patients, in whom 41/48 (85%) RCRI was <2. In patients with myocardial injury, vagal activity (HFLn) declined from 5.15 (95% confidence interval [CI]: 4.58-5.72) before surgery to 4.33 (95% CI: 3.76-4.90; P<0.001) 24 h after surgery. In patients who remained free of myocardial injury, HFLn did not change (4.95 [95% CI: 4.64-5.26] before surgery vs 4.76 [95% CI: 4.44-5.08] after surgery). Before and after surgery, the orthostatic HR recovery was slower in patients with myocardial injury (5 beats min-1 [95% CI: 3-7]), compared with HR recovery in patients who remained free of myocardial injury (10 beats min-1 [95% CI: 7-12]; P=0.02). CONCLUSIONS Serial HR measures indicating loss of cardiac vagal activity are associated with perioperative myocardial injury in lower-risk patients undergoing noncardiac surgery.
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Affiliation(s)
- Shaun M May
- Translational Medicine and Therapeutics, William Harvey Research Institute, Queen Mary University of London, London, UK
| | - Anna Reyes
- University College London NHS Hospitals Trust, London, UK
| | - Gladys Martir
- University College London NHS Hospitals Trust, London, UK
| | - Joseph Reynolds
- Translational Medicine and Therapeutics, William Harvey Research Institute, Queen Mary University of London, London, UK
| | | | - Shamir Karmali
- Translational Medicine and Therapeutics, William Harvey Research Institute, Queen Mary University of London, London, UK
| | | | - David Brealey
- University College London NHS Hospitals Trust, London, UK
| | - Gareth L Ackland
- Translational Medicine and Therapeutics, William Harvey Research Institute, Queen Mary University of London, London, UK.
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Finlay M, Bhar-Amato J, Ng KE, Santos D, Orini M, Vyas V, Taggart P, Grace AA, Huang CLH, Lambiase PD, Tinker A. Autonomic modulation of the electrical substrate in mice haploinsufficient for cardiac sodium channels: a model of the Brugada syndrome. Am J Physiol Cell Physiol 2019; 317:C576-C583. [PMID: 31291141 DOI: 10.1152/ajpcell.00028.2019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
A murine line haploinsufficient in the cardiac sodium channel has been used to model human Brugada syndrome: a disease causing sudden cardiac death due to lethal ventricular arrhythmias. We explored the effects of cholinergic tone on electrophysiological parameters in wild-type and genetically modified, heterozygous, Scn5a+/- knockout mice. Scn5a+/- ventricular slices showed longer refractory periods than wild-type both at baseline and during isoprenaline challenge. Scn5a+/- hearts also showed lower conduction velocities and increased mean increase in delay than did littermate controls at baseline and blunted responses to isoprenaline challenge. Carbachol exerted limited effects but reversed the effects of isoprenaline with coapplication. Scn5a+/- mice showed a reduction in conduction reserve in that isoprenaline no longer increased conduction velocity, and this was not antagonized by muscarinic agonists.
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Affiliation(s)
- Malcolm Finlay
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Justine Bhar-Amato
- Institute of Cardiovascular Science, University College London, London, United Kingdom
| | - Keat-Eng Ng
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Diogo Santos
- Institute of Cardiovascular Science, University College London, London, United Kingdom
| | - Michele Orini
- Institute of Cardiovascular Science, University College London, London, United Kingdom
| | - Vishal Vyas
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Peter Taggart
- Institute of Cardiovascular Science, University College London, London, United Kingdom
| | - Andrew A Grace
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Christopher L-H Huang
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Pier D Lambiase
- Institute of Cardiovascular Science, University College London, London, United Kingdom
| | - Andrew Tinker
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
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The hypertension advantage and natural selection: Since type 2 diabetes associates with co-morbidities and premature death, why have the genetic variants remained in the human genome? Med Hypotheses 2019; 129:109237. [PMID: 31371084 DOI: 10.1016/j.mehy.2019.109237] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 05/18/2019] [Indexed: 12/30/2022]
Abstract
Type 2 diabetes is a major public health crisis around the world. It is estimated that more than 300 million people worldwide have type 2 diabetes. Furthermore, the World Health Organization estimates that deaths from the complications of diabetes will increase by two thirds between 2008 and 2030. Since type 2 diabetes is a major public health crisis, why have the genetic variants for diabetes not been removed from the genome by natural selection? We hypothesize that insulin resistance, a predisposition to type 2 diabetes, and the associated elevation in sympathetic nervous system activity and arterial blood pressure provided an advantage to humans who lived as hunter-gatherers. Specifically, sympathetic hyperactivity stimulates the renin-angiotensin aldosterone system, promotes sodium reabsorption, and increases blood volume, heart rate, stroke volume and peripheral vascular resistance, thus inducing hypertension. The hypertension in turn provides a hemodynamic advantage for hunter-gatherers. Specifically, sympathetic hyperactivity and increased blood pressure increases blood flow delivery to working muscles by increasing cardiac output and shunting blood from non-active tissue. This natural selection for hypertension occurred during the time in human evolutionary history when the lifespan of most individuals was probably 30-40 years, and morbidity and mortality from cardiovascular disorders was limited. Thus, the selection pressure for elevation in sympathetic nervous system activity and blood pressure provided an advantage for hunting and gathering that would be greater than the selection pressure exerted by the manifestations of cardiovascular disease in aged individuals.
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43
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Gourine AV, Ackland GL. Cardiac Vagus and Exercise. Physiology (Bethesda) 2019; 34:71-80. [PMID: 30540229 PMCID: PMC6383634 DOI: 10.1152/physiol.00041.2018] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 10/26/2018] [Accepted: 10/29/2018] [Indexed: 01/09/2023] Open
Abstract
Lower resting heart rate and high autonomic vagal activity are strongly associated with superior exercise capacity, maintenance of which is essential for general well-being and healthy aging. Recent evidence obtained in experimental studies using the latest advances in molecular neuroscience, combined with human exercise physiology, physiological modeling, and genomic data suggest that the strength of cardiac vagal activity causally determines our ability to exercise.
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Affiliation(s)
- Alexander V Gourine
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology and Pharmacology, University College London , London , United Kingdom
| | - Gareth L Ackland
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London , London , United Kingdom
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44
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Holt MK, Richards JE, Cook DR, Brierley DI, Williams DL, Reimann F, Gribble FM, Trapp S. Preproglucagon Neurons in the Nucleus of the Solitary Tract Are the Main Source of Brain GLP-1, Mediate Stress-Induced Hypophagia, and Limit Unusually Large Intakes of Food. Diabetes 2019; 68:21-33. [PMID: 30279161 PMCID: PMC6314470 DOI: 10.2337/db18-0729] [Citation(s) in RCA: 99] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 09/21/2018] [Indexed: 01/13/2023]
Abstract
Centrally administered glucagon-like peptide 1 (GLP-1) supresses food intake. Here we demonstrate that GLP-1-producing (PPG) neurons in the nucleus tractus solitarii (NTS) are the predominant source of endogenous GLP-1 within the brain. Selective ablation of NTS PPG neurons by viral expression of diphtheria toxin subunit A substantially reduced active GLP-1 concentrations in brain and spinal cord. Contrary to expectations, this loss of central GLP-1 had no significant effect on the ad libitum feeding of mice, affecting neither daily chow intake nor body weight or glucose tolerance. Only after bigger challenges to homeostasis were PPG neurons necessary for food intake control. PPG-ablated mice increased food intake after a prolonged fast and after a liquid diet preload. Consistent with our ablation data, acute inhibition of hM4Di-expressing PPG neurons did not affect ad libitum feeding; however, it increased refeeding intake after fast and blocked stress-induced hypophagia. Additionally, chemogenetic PPG neuron activation through hM3Dq caused a strong acute anorectic effect. We conclude that PPG neurons are not involved in primary intake regulation but form part of a secondary satiation/satiety circuit, which is activated by both psychogenic stress and large meals. Given their hypophagic capacity, PPG neurons might be an attractive drug target in obesity treatment.
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Affiliation(s)
- Marie K Holt
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, London, U.K
| | - James E Richards
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, London, U.K
| | - Daniel R Cook
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, London, U.K
| | - Daniel I Brierley
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, London, U.K
| | - Diana L Williams
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL
| | - Frank Reimann
- Institute of Metabolic Science and MRC Metabolic Diseases Unit, Addenbrooke's Hospital, University of Cambridge, Cambridge, U.K
| | - Fiona M Gribble
- Institute of Metabolic Science and MRC Metabolic Diseases Unit, Addenbrooke's Hospital, University of Cambridge, Cambridge, U.K
| | - Stefan Trapp
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, London, U.K.
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Abbott TEF, Pearse RM, Cuthbertson BH, Wijeysundera DN, Ackland GL. Cardiac vagal dysfunction and myocardial injury after non-cardiac surgery: a planned secondary analysis of the measurement of Exercise Tolerance before surgery study. Br J Anaesth 2018; 122:188-197. [PMID: 30686304 PMCID: PMC6354047 DOI: 10.1016/j.bja.2018.10.060] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 10/19/2018] [Accepted: 10/20/2018] [Indexed: 12/14/2022] Open
Abstract
Background The aetiology of perioperative myocardial injury is poorly understood and not clearly linked to pre-existing cardiovascular disease. We hypothesised that loss of cardioprotective vagal tone [defined by impaired heart rate recovery ≤12 beats min−1 (HRR ≤12) 1 min after cessation of preoperative cardiopulmonary exercise testing] was associated with perioperative myocardial injury. Methods We conducted a pre-defined, secondary analysis of a multi-centre prospective cohort study of preoperative cardiopulmonary exercise testing. Participants were aged ≥40 yr undergoing non-cardiac surgery. The exposure was impaired HRR (HRR≤12). The primary outcome was postoperative myocardial injury, defined by serum troponin concentration within 72 h after surgery. The analysis accounted for established markers of cardiac risk [Revised Cardiac Risk Index (RCRI), N-terminal pro-brain natriuretic peptide (NT pro-BNP)]. Results A total of 1326 participants were included [mean age (standard deviation), 64 (10) yr], of whom 816 (61.5%) were male. HRR≤12 occurred in 548 patients (41.3%). Myocardial injury was more frequent amongst patients with HRR≤12 [85/548 (15.5%) vs HRR>12: 83/778 (10.7%); odds ratio (OR), 1.50 (1.08–2.08); P=0.016, adjusted for RCRI). HRR declined progressively in patients with increasing numbers of RCRI factors. Patients with ≥3 RCRI factors were more likely to have HRR≤12 [26/36 (72.2%) vs 0 factors: 167/419 (39.9%); OR, 3.92 (1.84–8.34); P<0.001]. NT pro-BNP greater than a standard prognostic threshold (>300 pg ml−1) was more frequent in patients with HRR≤12 [96/529 (18.1%) vs HRR>12 59/745 (7.9%); OR, 2.58 (1.82–3.64); P<0.001]. Conclusions Impaired HRR is associated with an increased risk of perioperative cardiac injury. These data suggest a mechanistic role for cardiac vagal dysfunction in promoting perioperative myocardial injury.
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Affiliation(s)
- T E F Abbott
- William Harvey Research Institute, Queen Mary University of London, London, UK; University College London Hospital, London, UK
| | - R M Pearse
- William Harvey Research Institute, Queen Mary University of London, London, UK; Barts Health NHS Trust, London, UK
| | - B H Cuthbertson
- Department of Critical Care Medicine, Sunnybrook Health Sciences Centre, Toronto, ON, Canada; University of Toronto, Toronto, ON, Canada
| | - D N Wijeysundera
- University of Toronto, Toronto, ON, Canada; Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, ON, Canada; Toronto General Hospital, Toronto, ON, Canada
| | - G L Ackland
- William Harvey Research Institute, Queen Mary University of London, London, UK; Barts Health NHS Trust, London, UK.
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Ischemic preconditioning boosts post-exercise but not resting cardiac vagal control in endurance runners. Eur J Appl Physiol 2018; 119:621-632. [PMID: 30542933 DOI: 10.1007/s00421-018-4052-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 12/07/2018] [Indexed: 10/27/2022]
Abstract
PURPOSE High cardiac vagal control in endurance athletes has been generally associated with adequate recovery from training and readiness to cope high-intensity training. A method that improves cardiac vagal control in endurance athletes could therefore be advantageous. Accordingly, we sought to test whether ischemic preconditioning (IPC) could enhance cardiac vagal control in endurance runners. METHODS Fifteen subjects underwent IPC, sham ultrasound (SHAM) or control (CT), in random order. Subjects were informed both IPC and SHAM would be beneficial vs. CT (i.e., similar placebo induction), and IPC would be harmless despite ischemia sensations (i.e., nocebo avoidance). Resting cardiac vagal control was assessed via respiratory sinus arrhythmia (RSA) and heart rate variability (HRV) indexes. Post-exercise cardiac vagal control was assessed via heart rate recovery [HR time constant decay (T30) and absolute HR decay (HRR30s)] during 30-s breaks of a discontinuous incremental test. Capillary blood samples were collected for lactate threshold identification. RESULTS RSA and HRV were similar among interventions at pre- and post-intervention assessments. Lactate threshold occurred at 85 ± 4% of maximal effort. T30 was similar among interventions, but IPC increased HRR30s at 70% and 75% of maximal effort vs. SHAM and CT (70%: IPC = 31 ± 2 vs. SHAM = 26 ± 3 vs. CT = 26 ± 2 bpm, mean ± SEM, P < 0.01; 75%: IPC = 29 ± 2 vs. SHAM = 25 ± 2 vs. CT = 24 ± 2 bpm, P < 0.01). CONCLUSION IPC did not change resting cardiac vagal control, but boosted fast post-exercise cardiac vagal reactivation at exercise intensities below lactate threshold in endurance runners.
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Ang R, Mastitskaya S, Hosford PS, Basalay M, Specterman M, Aziz Q, Li Y, Orini M, Taggart P, Lambiase PD, Gourine A, Tinker A, Gourine AV. Modulation of Cardiac Ventricular Excitability by GLP-1 (Glucagon-Like Peptide-1). Circ Arrhythm Electrophysiol 2018; 11:e006740. [PMID: 30354404 PMCID: PMC6553567 DOI: 10.1161/circep.118.006740] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 09/14/2018] [Indexed: 12/25/2022]
Abstract
BACKGROUND Glucagon-like peptide-1 receptor (GLP-1R) agonists improve cardiovascular outcomes in patients with type 2 diabetes mellitus. However, systemic actions of these agents cause sympathetic activation, which is generally considered to be detrimental in cardiovascular disease. Despite significant research interest in cardiovascular biology of GLP-1, the presence of GLP-1R in ventricular cardiomyocytes remains a controversial issue, and the effects of this peptide on the electrical properties of intact ventricular myocardium are unknown. We sought to determine the effects of GLP-1R agonist exendin-4 (Ex4) on ventricular action potential duration (APD) and susceptibility to ventricular arrhythmia in the rat heart in vivo and ex vivo. METHODS Ventricular monophasic action potentials were recorded in anaesthetized (urethane) rats in vivo and isolated perfused rat hearts during sinus rhythm and ventricular pacing. RESULTS In vivo, systemic administration of Ex4 (5 μg/kg intravenously) increased heart rate, and this effect was abolished by β-adrenoceptor blockade. Despite causing sympathetic activation, Ex4 increased APD at 90% repolarization during ventricular pacing by 7% ( P=0.044; n=6) and reversed the effect of β-adrenoceptor agonist dobutamine on APD at 90% repolarization. In isolated perfused hearts, Ex4 (3 nmol/L) increased APD at 90% repolarization by 14% ( P=0.015; n=6) with no effect on heart rate. Ex4 also reduced ventricular arrhythmia inducibility in conditions of β-adrenoceptor stimulation with isoproterenol. Ex4 effects on APD and ventricular arrhythmia susceptibility were prevented in conditions of muscarinic receptor blockade or inhibition of nitric oxide synthase. CONCLUSIONS These data demonstrate that GLP-1R activation effectively opposes the effects of β-adrenoceptor stimulation on cardiac ventricular excitability and reduces ventricular arrhythmic potential. The effect of GLP-1R activation on the ventricular myocardium is indirect, mediated by acetylcholine and nitric oxide and, therefore, can be explained by stimulation of cardiac parasympathetic (vagal) neurons.
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Affiliation(s)
- Richard Ang
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology & Pharmacology, University College London, United Kingdom (R.A., S.M., P.S.H., M.B., A.V.G.)
- William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, London, United Kingdom (R.A., M.S., Q.A., Y.L., A.T.)
| | - Svetlana Mastitskaya
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology & Pharmacology, University College London, United Kingdom (R.A., S.M., P.S.H., M.B., A.V.G.)
| | - Patrick S. Hosford
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology & Pharmacology, University College London, United Kingdom (R.A., S.M., P.S.H., M.B., A.V.G.)
| | - Marina Basalay
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology & Pharmacology, University College London, United Kingdom (R.A., S.M., P.S.H., M.B., A.V.G.)
| | - Mark Specterman
- William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, London, United Kingdom (R.A., M.S., Q.A., Y.L., A.T.)
| | - Qadeer Aziz
- William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, London, United Kingdom (R.A., M.S., Q.A., Y.L., A.T.)
| | - Yiwen Li
- William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, London, United Kingdom (R.A., M.S., Q.A., Y.L., A.T.)
| | - Michele Orini
- Institute of Cardiovascular Science, University College London, United Kingdom (M.O., P.T., P.D.L.)
| | - Peter Taggart
- Institute of Cardiovascular Science, University College London, United Kingdom (M.O., P.T., P.D.L.)
| | - Pier D. Lambiase
- Institute of Cardiovascular Science, University College London, United Kingdom (M.O., P.T., P.D.L.)
| | - Andrey Gourine
- Division of Cardiology, Karolinska Institute, Stockholm, Sweden (A.G.)
| | - Andrew Tinker
- William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, London, United Kingdom (R.A., M.S., Q.A., Y.L., A.T.)
| | - Alexander V. Gourine
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology & Pharmacology, University College London, United Kingdom (R.A., S.M., P.S.H., M.B., A.V.G.)
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Lakatos BK, Kiss O, Tokodi M, Tősér Z, Sydó N, Merkely G, Babity M, Szilágyi M, Komócsin Z, Bognár C, Kovács A, Merkely B. Exercise-induced shift in right ventricular contraction pattern: novel marker of athlete's heart? Am J Physiol Heart Circ Physiol 2018; 315:H1640-H1648. [PMID: 30216120 DOI: 10.1152/ajpheart.00304.2018] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Data about the functional adaptation of the right ventricle (RV) to intense exercise are limited. Our aim was to characterize the RV mechanical pattern in top-level athletes using three-dimensional echocardiography. A total of 60 elite water polo athletes (19 ± 4 yr, 17 ± 6 h of training/wk, 50% women and 50% men) and 40 healthy sedentary control subjects were enrolled. We measured the RV end-diastolic volume index (RVEDVi) and ejection fraction (RVEF) using dedicated software. Furthermore, we determined RV global longitudinal (RV GLS) and circumferential strain (RV GCS) and the relative contribution of longitudinal ejection fraction (LEF) and radial ejection fraction (REF) to RVEF using the ReVISION method. Athletes also underwent cardiopulmonary exercise testing [O2 consumption (V̇o2)/kg]. Athletes had significantly higher RVEDVi compared with control subjects (athletes vs. control subjects, 88 ± 11 vs. 65 ± 10 ml/m2, P < 0.001); however, they also demonstrated lower RVEF (56 ± 4% vs. 61 ± 5%, P < 0.001). RV GLS was comparable between the two groups (-22 ± 5% vs. -23 ± 5%, P = 0.24), whereas RV GCS was significantly lower in athletes (-21 ± 4% vs. -26 ± 7%, P < 0.001). Athletes had higher LEF and lower REF contribution to RVEF (LEF/RVEF: 0.50 ± 0.07 vs. 0.42 ± 0.07, P < 0.001; REF/RVEF: 0.33 ± 0.08 vs. 0.45 ± 0.08, P < 0.001). Moreover, the pattern of RV functional shift correlated with V̇o2/kg (LEF/RVEF: r = 0.30, P < 0.05; REF/RVEF: r = -0.27, P < 0.05). RV mechanical adaptation to long-term intense exercise implies a functional shift; the relative contribution of longitudinal motion to global function was increased, whereas the radial shortening was significantly decreased, in athletes. Moreover, this functional pattern correlates with aerobic exercise performance, representing a potential new resting marker of an athlete's heart. NEW & NOTEWORTHY Intensive regular physical exercise results in significant changes of right ventricular morphology and function. By separate quantification of the right ventricular longitudinal and radial function, a relative dominance of longitudinal motion and a decrease in radial motion can be observed compared with sedentary controls. Moreover, this contraction pattern correlates with cardiopulmonary fitness. According to these results, this functional shift of the right ventricle may represent a novel marker of an athlete's heart.
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Affiliation(s)
| | - Orsolya Kiss
- Semmelweis University Heart and Vascular Center , Budapest , Hungary
| | - Márton Tokodi
- Semmelweis University Heart and Vascular Center , Budapest , Hungary
| | | | - Nóra Sydó
- Semmelweis University Heart and Vascular Center , Budapest , Hungary
| | - Gergő Merkely
- Semmelweis University Heart and Vascular Center , Budapest , Hungary.,Department of Orthopaedics, Uzsoki Hospital , Budapest , Hungary
| | - Máté Babity
- Semmelweis University Heart and Vascular Center , Budapest , Hungary
| | - Mónika Szilágyi
- Semmelweis University Heart and Vascular Center , Budapest , Hungary
| | | | - Csaba Bognár
- Semmelweis University Heart and Vascular Center , Budapest , Hungary
| | - Attila Kovács
- Semmelweis University Heart and Vascular Center , Budapest , Hungary
| | - Béla Merkely
- Semmelweis University Heart and Vascular Center , Budapest , Hungary
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49
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Gourine AV, Deuchars SA. Autonomic rhythms in health and disease. Exp Physiol 2018; 103:324-325. [PMID: 29493055 DOI: 10.1113/ep086800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 12/15/2017] [Indexed: 11/08/2022]
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50
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Astrocytes modulate brainstem respiratory rhythm-generating circuits and determine exercise capacity. Nat Commun 2018; 9:370. [PMID: 29371650 PMCID: PMC5785528 DOI: 10.1038/s41467-017-02723-6] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 12/19/2017] [Indexed: 11/29/2022] Open
Abstract
Astrocytes are implicated in modulation of neuronal excitability and synaptic function, but it remains unknown if these glial cells can directly control activities of motor circuits to influence complex behaviors in vivo. This study focused on the vital respiratory rhythm-generating circuits of the preBötzinger complex (preBötC) and determined how compromised function of local astrocytes affects breathing in conscious experimental animals (rats). Vesicular release mechanisms in astrocytes were disrupted by virally driven expression of either the dominant-negative SNARE protein or light chain of tetanus toxin. We show that blockade of vesicular release in preBötC astrocytes reduces the resting breathing rate and frequency of periodic sighs, decreases rhythm variability, impairs respiratory responses to hypoxia and hypercapnia, and dramatically reduces the exercise capacity. These findings indicate that astrocytes modulate the activity of CNS circuits generating the respiratory rhythm, critically contribute to adaptive respiratory responses in conditions of increased metabolic demand and determine the exercise capacity. Circuits of the preBötzinger complex generate rhythms needed for breathing. Here, the authors provide evidence, using a combination of chemogenetic approaches and approaches to inhibit vesicular release, that astrocytes play a role in regulating respiratory rate.
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