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Kaur S, Lynch N, Sela Y, Lima JD, Thomas RC, Bandaru SS, Saper CB. Lateral parabrachial FoxP2 neurons regulate respiratory responses to hypercapnia. Nat Commun 2024; 15:4475. [PMID: 38796568 PMCID: PMC11128025 DOI: 10.1038/s41467-024-48773-5] [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: 04/26/2023] [Accepted: 05/10/2024] [Indexed: 05/28/2024] Open
Abstract
About half of the neurons in the parabrachial nucleus (PB) that are activated by CO2 are located in the external lateral (el) subnucleus, express calcitonin gene-related peptide (CGRP), and cause forebrain arousal. We report here, in male mice, that most of the remaining CO2-responsive neurons in the adjacent central lateral (PBcl) and Kölliker-Fuse (KF) PB subnuclei express the transcription factor FoxP2 and many of these neurons project to respiratory sites in the medulla. PBclFoxP2 neurons show increased intracellular calcium during wakefulness and REM sleep and in response to elevated CO2 during NREM sleep. Photo-activation of the PBclFoxP2 neurons increases respiration, whereas either photo-inhibition of PBclFoxP2 or genetic deletion of PB/KFFoxP2 neurons reduces the respiratory response to CO2 stimulation without preventing awakening. Thus, augmenting the PBcl/KFFoxP2 response to CO2 in patients with sleep apnea in combination with inhibition of the PBelCGRP neurons may avoid hypoventilation and minimize EEG arousals.
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Affiliation(s)
- Satvinder Kaur
- Department of Neurology, Division of Sleep Medicine, and Program in Neuroscience, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Nicole Lynch
- Department of Neurology, Division of Sleep Medicine, and Program in Neuroscience, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Yaniv Sela
- Department of Neurology, Division of Sleep Medicine, and Program in Neuroscience, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Janayna D Lima
- Department of Neurology, Division of Sleep Medicine, and Program in Neuroscience, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Renner C Thomas
- Department of Neurology, Division of Sleep Medicine, and Program in Neuroscience, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Sathyajit S Bandaru
- Department of Neurology, Division of Sleep Medicine, and Program in Neuroscience, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Clifford B Saper
- Department of Neurology, Division of Sleep Medicine, and Program in Neuroscience, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
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Wright MD, Mann LM, Doherty CJ, Thompson BP, Angus SA, Chang JC, Dominelli PB. Peripheral hypercapnic chemosensitivity at rest and progressive exercise intensities in males and females. J Appl Physiol (1985) 2024; 136:274-282. [PMID: 38126093 DOI: 10.1152/japplphysiol.00578.2023] [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: 08/21/2023] [Revised: 12/04/2023] [Accepted: 12/13/2023] [Indexed: 12/23/2023] Open
Abstract
Peripheral hypercapnic chemosensitivity (PHC) is the ventilatory response to hypercapnia and is enhanced with acute whole body exercise. However, little is known about the mechanism(s) responsible for the exercise-related increase in PHC and if progressive exercise leads to further augmentation. We hypothesized that unloaded cycle exercise (0 W) would increase PHC but progressively increasing the intensity would not further augment the response. Twenty healthy subjects completed two testing days. Day 1 was a maximal exercise test on a cycle ergometer to determine peak power output (Wmax). Day 2 consisted of six 12-min stages: 1) rest on chair, 2) rest on bike, 3) 0 W unloaded cycling, 4) 25% Wmax, 5) 50% Wmax, and 6) ∼70% Wmax with ∼10 min of rest between each exercise stage. In each stage, PHC was assessed via two breaths of 10% CO2 (∼21% O2) repeated five times with ∼45 s between each to ensure end-tidal CO2 ([Formula: see text]) and ventilation returned to baseline. Prestimulus [Formula: see text] was not different between rest and unloaded cycling (P = 0.478). There was a significant increase in PHC between seated rest and 25% Wmax (0.71 ± 0.37 vs. 1.03 ± 0.52 L·mmHg-1·min-1, respectively, P = 0.0006) and between seated rest and unloaded cycling (0.71 ± 0.37 vs. 1.04 ± 0.4 L·mmHg-1·min-1, respectively, P = 0.0017). There was no effect of exercise intensity on PHC (1.03 ± 0.52 vs. 0.95 ± 0.58 vs. 1.01 ± 0.65 L·mmHg-1·min-1 for 25, 50, and 70% Wmax, P = 0.44). The increased PHC response from seated rest to unloaded and 25% Wmax, but no effect of exercise intensity suggests a possible feedforward/feedback mechanism causing increased PHC sensitivity through the act of cycling.NEW & NOTEWORTHY Unloaded exercise significantly increased the peripheral hypercapnic ventilatory response (HCVR) compared with rest. However, increases in exercise intensity did not further augment peripheral HCVR. Males had a greater peripheral HCVR compared with females, but there was no interaction between sex and intensity. The lack of sex interactions suggests the mechanism augmenting the peripheral HCVR with exercise is independent of sex. The increase in peripheral HCVR with exercise is likely due to central command.
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Affiliation(s)
- Madeline D Wright
- Department of Kinesiology and Health Sciences, University of Waterloo, Waterloo, Ontario, Canada
| | - Leah M Mann
- Department of Kinesiology and Health Sciences, University of Waterloo, Waterloo, Ontario, Canada
| | - Connor J Doherty
- Department of Kinesiology and Health Sciences, University of Waterloo, Waterloo, Ontario, Canada
| | - Benjamin P Thompson
- Department of Kinesiology and Health Sciences, University of Waterloo, Waterloo, Ontario, Canada
| | - Sarah A Angus
- Department of Kinesiology and Health Sciences, University of Waterloo, Waterloo, Ontario, Canada
| | - Jou-Chung Chang
- Department of Kinesiology and Health Sciences, University of Waterloo, Waterloo, Ontario, Canada
| | - Paolo B Dominelli
- Department of Kinesiology and Health Sciences, University of Waterloo, Waterloo, Ontario, Canada
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Hérent C, Diem S, Usseglio G, Fortin G, Bouvier J. Upregulation of breathing rate during running exercise by central locomotor circuits in mice. Nat Commun 2023; 14:2939. [PMID: 37217517 DOI: 10.1038/s41467-023-38583-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 05/02/2023] [Indexed: 05/24/2023] Open
Abstract
While respiratory adaptation to exercise is compulsory to cope with the increased metabolic demand, the neural signals at stake remain poorly identified. Using neural circuit tracing and activity interference strategies in mice, we uncover here two systems by which the central locomotor network can enable respiratory augmentation in relation to running activity. One originates in the mesencephalic locomotor region (MLR), a conserved locomotor controller. Through direct projections onto the neurons of the preBötzinger complex that generate the inspiratory rhythm, the MLR can trigger a moderate increase of respiratory frequency, prior to, or even in the absence of, locomotion. The other is the lumbar enlargement of the spinal cord containing the hindlimb motor circuits. When activated, and through projections onto the retrotrapezoid nucleus (RTN), it also potently upregulates breathing rate. On top of identifying critical underpinnings for respiratory hyperpnea, these data also expand the functional implication of cell types and pathways that are typically regarded as "locomotor" or "respiratory" related.
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Affiliation(s)
- Coralie Hérent
- Université Paris-Saclay, CNRS, Institut des Neurosciences Paris-Saclay, 91400, Saclay, France
- Champalimaud Research, Champalimaud Foundation, 1400-038, Lisbon, Portugal
| | - Séverine Diem
- Université Paris-Saclay, CNRS, Institut des Neurosciences Paris-Saclay, 91400, Saclay, France
- Institute of Functional Genomics, University of Montpellier, CNRS, INSERM, 34094, Montpellier, France
| | - Giovanni Usseglio
- Université Paris-Saclay, CNRS, Institut des Neurosciences Paris-Saclay, 91400, Saclay, France
| | - Gilles Fortin
- Institut de Biologie de l'École Normale Supérieure (IBENS), École Normale Supérieure, CNRS, INSERM, PSL Research University, 75005, Paris, France
| | - Julien Bouvier
- Université Paris-Saclay, CNRS, Institut des Neurosciences Paris-Saclay, 91400, Saclay, France.
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Juvin L, Colnot E, Barrière G, Thoby-Brisson M, Morin D. Neurogenic mechanisms for locomotor-respiratory coordination in mammals. Front Neuroanat 2022; 16:953746. [PMID: 35968158 PMCID: PMC9365938 DOI: 10.3389/fnana.2022.953746] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 07/06/2022] [Indexed: 11/13/2022] Open
Abstract
Central motor rhythm-generating networks controlling different functions are generally considered to operate mostly independently from one another, each controlling the specific behavioral task to which it is assigned. However, under certain physiological circumstances, central pattern generators (CPGs) can exhibit strong uni- or bidirectional interactions that render them closely inter-dependent. One of the best illustrations of such an inter-CPG interaction is the functional relationship that may occur between rhythmic locomotor and respiratory functions. It is well known that in vertebrates, lung ventilatory rates accelerate at the onset of physical exercise in order to satisfy the accompanying rapid increase in metabolism. Part of this acceleration is sustained by a coupling between locomotion and ventilation, which most often results in a periodic drive of the respiratory cycle by the locomotor rhythm. In terrestrial vertebrates, the likely physiological significance of this coordination is that it serves to reduce the mechanical interference between the two motor systems, thereby producing an energetic benefit and ultimately, enabling sustained aerobic activity. Several decades of studies have shown that locomotor-respiratory coupling is present in most species, independent of the mode of locomotion employed. The present article aims to review and discuss mechanisms engaged in shaping locomotor-respiratory coupling (LRC), with an emphasis on the role of sensory feedback inputs, the direct influences between CPG networks themselves, and finally on spinal cellular candidates that are potentially involved in the coupling of these two vital motor functions.
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Affiliation(s)
- Laurent Juvin
- University of Bordeaux, Centre National de la Recherche Scientifique, Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, Unité Mixte de Recherche 5287, Bordeaux, France
| | - Eloïse Colnot
- University of Bordeaux, Centre National de la Recherche Scientifique, Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, Unité Mixte de Recherche 5287, Bordeaux, France
| | - Grégory Barrière
- University of Bordeaux, Centre National de la Recherche Scientifique, Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, Unité Mixte de Recherche 5287, Bordeaux, France
| | - Muriel Thoby-Brisson
- University of Bordeaux, Centre National de la Recherche Scientifique, Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, Unité Mixte de Recherche 5287, Bordeaux, France
| | - Didier Morin
- University of Bordeaux, Centre National de la Recherche Scientifique, Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, Unité Mixte de Recherche 5287, Bordeaux, France
- Department of Health, Safety & Environment, Bordeaux Institute of Technology, Bordeaux, France
- *Correspondence: Didier Morin
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5
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Koppula A, Barra RR, Sridharan KS. Effects of exercise anticipation on cardiorespiratory coherence. Physiol Rep 2022; 10:e15381. [PMID: 35883224 PMCID: PMC9325975 DOI: 10.14814/phy2.15381] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 05/23/2022] [Accepted: 06/17/2022] [Indexed: 11/24/2022] Open
Abstract
In this study, we explored the role of feedforward mechanisms in triggering cardiorespiratory adjustments before the onset of exercise. To isolate the feedforward aspects, we examined the effect of exercise anticipation on cardiorespiratory coherence. Twenty-nine healthy males (age = 18.8 [0.96] years) were subjected to bicycle (BE) and handgrip exercise (H) at two different intensities, viz., low and high. Bicycle exercise was performed in a unilateral (left- and right-sided) or bilateral mode, whereas handgrip was performed only in a unilateral mode. Single-lead ECG and respiratory rhythm, measured in the 5 min of anticipation phase before the onset of exercise, were used for analysis. Coherence was computed between ECG-derived instantaneous heart rate and respiratory signal. Average coherence in the high-frequency band (0.15-0.4 Hz) was used to estimate respiratory sinus arrhythmia (RSA). We found that coherence decreased with the anticipation of exercise relative to baseline (baseline = 0.54 [0.16], BE = 0.41 [0.12], H = 0.39 [0.12], p < 0.001). The decrease was greater for high intensity exercise (low = 0.42 [0.11], high = 0.37 [0.1], p < 0.001). The fall of coherence with intensity was stronger for bicycle exercise (BE: low = 0.44 [0.12], high = 0.37 [0.12], H: low = 0.4 [0.12], high = 0.37 [0.12], p = 0.00433). The expectation of bilateral exercise resulted in lower coherence compared to unilateral exercise (right-sided = 0.45 [0.16], left-sided = 0.4 [0.16], bilateral = 0.36 [0.15], unilateral vs. bilateral: p < 0.001), and the left-sided exercise had lower coherence compared to that of the right (left-sided vs. right-sided: p = 0.00925). Handgrip exercise showed similar trend (right-sided = 0.4 [0.15], left-sided = 0.37 [0.14], p = 0.0056). In conclusion, feedforward RSA adjustments in anticipation of exercise covaried with subsequent exercise-related features like intensity, muscle mass (unilateral vs. bilateral), and the exercise side (left vs. right). The left versus the right difference in coherence indicates autonomic asymmetry. Feedforward changes in RSA are like those seen during actual exercise and might facilitate the rapid phase transition between rest and exercise.
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Affiliation(s)
- Aditya Koppula
- Department of Biomedical Engineering, Neurotech Lab, Indian Institute of Technology, Hyderabad, India
| | - Ram Reddy Barra
- Department of Physiology, Apollo Institute of Medical Sciences and Research, Hyderabad, India
| | - Kousik Sarathy Sridharan
- Department of Biomedical Engineering, Neurotech Lab, Indian Institute of Technology, Hyderabad, India
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Assadpour E, Ivry I, Wasef S, Adeyinka B, Murray KR, Edgell H. Oral contraceptives and menstrual cycle influence autonomic reflex function. Physiol Rep 2021; 8:e14550. [PMID: 32889781 PMCID: PMC7507440 DOI: 10.14814/phy2.14550] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 07/29/2020] [Indexed: 12/31/2022] Open
Abstract
Progesterone and its analogues are known to influence ventilation. Therefore, the purpose of this study was to investigate the role of endogenous and pharmaceutical female sex hormones in ventilatory control during the activation of the metaboreflex, mechanoreflex, and CO2 chemoreflex. Women aged 18–30 taking (n = 14) or not taking (n = 12) oral contraceptives (OC and NOC, respectively) were tested in the low hormone (LH) and high hormone (HH) conditions corresponding to the early follicular and mid‐luteal phases (NOC) or placebo and high‐dose pills (OC). Women underwent three randomized trials: (a) 3 min of passive leg movement (PLM), (b) 2 min of 40% maximal voluntary handgrip exercise followed by 2 min of post‐exercise circulatory occlusion (PECO), and (c) 5 min of breathing 5% CO2. We primarily measured hemodynamics and ventilation. During PLM, the OC group had a smaller pressor response (p = .012). During PECO, the OC group similarly exhibited a smaller pressor response (p = .043) and also exhibited a greater ventilatory response (p = .024). Lastly, in response to breathing 5% CO2, women in the HH phase had a greater ventilatory response (p = .022). We found that OC use attenuates the pressor response to both the metaboreflex and mechanoreflex while increasing the ventilatory response to metaboreflex activation. We also found evidence of an enhanced CO2 chemoreflex in the HH phase. We hypothesize that OC effects are from the chronic upregulation of pulmonary and vascular β‐adrenergic receptors. We further suggest that the increased cyclic progesterone in the HH phase enhances the chemoreflex.
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Affiliation(s)
- Elnaz Assadpour
- School of Kinesiology and Health Science, York University, Toronto, ON, Canada
| | - Ilana Ivry
- School of Kinesiology and Health Science, York University, Toronto, ON, Canada
| | - Sara Wasef
- School of Kinesiology and Health Science, York University, Toronto, ON, Canada
| | - Baithat Adeyinka
- School of Kinesiology and Health Science, York University, Toronto, ON, Canada
| | - Kevin R Murray
- School of Kinesiology and Health Science, York University, Toronto, ON, Canada
| | - Heather Edgell
- School of Kinesiology and Health Science, York University, Toronto, ON, Canada
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Bergelt M, Fung Yuan V, O’Brien R, Middleton LE, Martins dos Santos W. Moderate aerobic exercise, but not anticipation of exercise, improves cognitive control. PLoS One 2020; 15:e0242270. [PMID: 33186396 PMCID: PMC7665798 DOI: 10.1371/journal.pone.0242270] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 10/29/2020] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Evidence suggests a single bout of exercise can improve cognitive control. However, many studies only include assessments after exercise. It is unclear whether exercise changes as a result, or in anticipation, of exercise. OBJECTIVE To examine changes in cognitive control due to moderate aerobic exercise, and anticipation of such exercise. METHODS Thirty-one young healthy adults (mean age 22 years; 55% women) completed three conditions (randomized order): 1) exercise (participants anticipated and completed exercise); 2) anticipation (participants anticipated exercise but completed rest); and 3) rest (participants anticipated and completed rest). Cognitive control was assessed with a modified Flanker task at three timepoints: (1) early (20 min pre-intervention, pre-reveal in anticipation session); (2) pre-intervention (after reveal); and (3) post-intervention. An accuracy-weighted response time (RTLISAS) was the primary outcome, analyzed with a linear mixed effects modeling approach. RESULTS There was an interaction between condition and time (p = 0.003) and between session and time (p = 0.015). RTLISAS was better post-exercise than post-rest and post-deception, but was similar across conditions at other timepoints. RTLISAS improved across time in session 1 and session 2, but did not improve over time in session 3. There were also main effects of condition (p = 0.024), session (p = 0.005), time (p<0.001), and congruency (p<0.001). CONCLUSIONS Cognitive control improved after moderate aerobic exercise, but not in anticipation of exercise. Improvements on a Flanker task were also observed across sessions and time, indicative of a learning effect that should be considered in study design and analyses.
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Affiliation(s)
| | - Vanessa Fung Yuan
- Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada
- Department of Kinesiology, Brock University, St. Catharines, ON, Canada
| | - Richard O’Brien
- Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada
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Sarlabous L, Aquino-Esperanza J, Magrans R, de Haro C, López-Aguilar J, Subirà C, Batlle M, Rué M, Gomà G, Ochagavia A, Fernández R, Blanch L. Development and validation of a sample entropy-based method to identify complex patient-ventilator interactions during mechanical ventilation. Sci Rep 2020; 10:13911. [PMID: 32807815 PMCID: PMC7431581 DOI: 10.1038/s41598-020-70814-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 08/05/2020] [Indexed: 11/28/2022] Open
Abstract
Patient-ventilator asynchronies can be detected by close monitoring of ventilator screens by clinicians or through automated algorithms. However, detecting complex patient-ventilator interactions (CP-VI), consisting of changes in the respiratory rate and/or clusters of asynchronies, is a challenge. Sample Entropy (SE) of airway flow (SE-Flow) and airway pressure (SE-Paw) waveforms obtained from 27 critically ill patients was used to develop and validate an automated algorithm for detecting CP-VI. The algorithm's performance was compared versus the gold standard (the ventilator's waveform recordings for CP-VI were scored visually by three experts; Fleiss' kappa = 0.90 (0.87-0.93)). A repeated holdout cross-validation procedure using the Matthews correlation coefficient (MCC) as a measure of effectiveness was used for optimization of different combinations of SE settings (embedding dimension, m, and tolerance value, r), derived SE features (mean and maximum values), and the thresholds of change (Th) from patient's own baseline SE value. The most accurate results were obtained using the maximum values of SE-Flow (m = 2, r = 0.2, Th = 25%) and SE-Paw (m = 4, r = 0.2, Th = 30%) which report MCCs of 0.85 (0.78-0.86) and 0.78 (0.78-0.85), and accuracies of 0.93 (0.89-0.93) and 0.89 (0.89-0.93), respectively. This approach promises an improvement in the accurate detection of CP-VI, and future study of their clinical implications.
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Affiliation(s)
- Leonardo Sarlabous
- Critical Care Center, Hospital Universitari Parc Taulí, Institut d'Investigació i Innovació Parc Taulí I3PT, Universitat Autònoma de Barcelona, Parc Taulí 1, 08208, Sabadell, Barcelona, Spain.
- Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Instituto de Salud Carlos III, Madrid, Spain.
| | - José Aquino-Esperanza
- Critical Care Center, Hospital Universitari Parc Taulí, Institut d'Investigació i Innovació Parc Taulí I3PT, Universitat Autònoma de Barcelona, Parc Taulí 1, 08208, Sabadell, Barcelona, Spain
- Biomedical Research Networking Center in Respiratory Disease (CIBERES), Instituto de Salud Carlos III, Madrid, Spain
- Facultat de Medicina, Universitat de Barcelona, Barcelona, Spain
| | | | - Candelaria de Haro
- Critical Care Center, Hospital Universitari Parc Taulí, Institut d'Investigació i Innovació Parc Taulí I3PT, Universitat Autònoma de Barcelona, Parc Taulí 1, 08208, Sabadell, Barcelona, Spain
- Biomedical Research Networking Center in Respiratory Disease (CIBERES), Instituto de Salud Carlos III, Madrid, Spain
| | - Josefina López-Aguilar
- Critical Care Center, Hospital Universitari Parc Taulí, Institut d'Investigació i Innovació Parc Taulí I3PT, Universitat Autònoma de Barcelona, Parc Taulí 1, 08208, Sabadell, Barcelona, Spain
- Biomedical Research Networking Center in Respiratory Disease (CIBERES), Instituto de Salud Carlos III, Madrid, Spain
| | - Carles Subirà
- Department of Intensive Care, Fundació Althaia, Universitat Internacional de Catalunya , Manresa, Spain
| | - Montserrat Batlle
- Department of Intensive Care, Fundació Althaia, Universitat Internacional de Catalunya , Manresa, Spain
| | - Montserrat Rué
- Department of Basic Medical Sciences, Universitat de Lleida-IRBLLEIDA, Lleida, Spain
| | - Gemma Gomà
- Critical Care Center, Hospital Universitari Parc Taulí, Institut d'Investigació i Innovació Parc Taulí I3PT, Universitat Autònoma de Barcelona, Parc Taulí 1, 08208, Sabadell, Barcelona, Spain
| | - Ana Ochagavia
- Critical Care Center, Hospital Universitari Parc Taulí, Institut d'Investigació i Innovació Parc Taulí I3PT, Universitat Autònoma de Barcelona, Parc Taulí 1, 08208, Sabadell, Barcelona, Spain
- Biomedical Research Networking Center in Respiratory Disease (CIBERES), Instituto de Salud Carlos III, Madrid, Spain
| | - Rafael Fernández
- Biomedical Research Networking Center in Respiratory Disease (CIBERES), Instituto de Salud Carlos III, Madrid, Spain
- Department of Intensive Care, Fundació Althaia, Universitat Internacional de Catalunya , Manresa, Spain
| | - Lluís Blanch
- Critical Care Center, Hospital Universitari Parc Taulí, Institut d'Investigació i Innovació Parc Taulí I3PT, Universitat Autònoma de Barcelona, Parc Taulí 1, 08208, Sabadell, Barcelona, Spain
- Biomedical Research Networking Center in Respiratory Disease (CIBERES), Instituto de Salud Carlos III, Madrid, Spain
- BetterCare S.L, Sabadell, Spain
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Le Gal JP, Colnot E, Cardoit L, Bacqué-Cazenave J, Thoby-Brisson M, Juvin L, Morin D. Modulation of respiratory network activity by forelimb and hindlimb locomotor generators. Eur J Neurosci 2020; 52:3181-3195. [PMID: 32150780 DOI: 10.1111/ejn.14717] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 02/05/2020] [Accepted: 03/03/2020] [Indexed: 01/22/2023]
Abstract
Early at the onset of exercise, breathing rate accelerates in order to anticipate the increasing metabolic demand resulting from the extra effort produced. Accordingly, the respiratory neural networks are the target of various input signals originating either centrally or peripherally. For example, during locomotion, the activation of muscle sensory afferents is able to entrain and thereby increase the frequency of spontaneous respiratory rhythmogenesis. Moreover, the lumbar spinal networks engaged in generating hindlimb locomotor rhythms are also capable of activating the medullary respiratory generators through an ascending excitatory command. However, in the context of quadrupedal locomotion, the influence of other spinal cord regions, such as cervical and thoracic segments, remains unknown. Using isolated brainstem-spinal cord preparations from neonatal rats and mice, we show that cervicothoracic circuitry may also contribute to locomotion-induced acceleration of respiratory cycle frequency. As previously observed for the hindlimb CPGs, the pharmacological activation of forelimb locomotor networks produces episodes of fictive locomotion that in turn increase the ongoing respiratory rhythm. Thoracic neuronal circuitry may also participate indirectly in this modulation via the activation of both cervical and lumbar CPG neurons. Furthermore, using light stimulation of CHR2-expressing glutamatergic neurons, we found that the modulation of the respiratory rate during locomotion involves lumbar glutamatergic circuitry. Our results demonstrate that during locomotion, the respiratory rhythm-generating networks receive excitatory ascending inputs from the spinal circuits responsible for generating and coordinating fore- and hindlimb movements. This constitutes a distributed central mechanism that contributes to matching breathing rate to the speed of locomotion.
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Affiliation(s)
- Jean-Patrick Le Gal
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, Unité Mixte de Recherche, Centre National de la Recherche Scientifique, Université de Bordeaux, Bordeaux, France
| | - Eloïse Colnot
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, Unité Mixte de Recherche, Centre National de la Recherche Scientifique, Université de Bordeaux, Bordeaux, France
| | - Laura Cardoit
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, Unité Mixte de Recherche, Centre National de la Recherche Scientifique, Université de Bordeaux, Bordeaux, France
| | - Julien Bacqué-Cazenave
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, Unité Mixte de Recherche, Centre National de la Recherche Scientifique, Université de Bordeaux, Bordeaux, France
| | - Muriel Thoby-Brisson
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, Unité Mixte de Recherche, Centre National de la Recherche Scientifique, Université de Bordeaux, Bordeaux, France
| | - Laurent Juvin
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, Unité Mixte de Recherche, Centre National de la Recherche Scientifique, Université de Bordeaux, Bordeaux, France
| | - Didier Morin
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, Unité Mixte de Recherche, Centre National de la Recherche Scientifique, Université de Bordeaux, Bordeaux, France
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Spinelli E, Mauri T, Beitler JR, Pesenti A, Brodie D. Respiratory drive in the acute respiratory distress syndrome: pathophysiology, monitoring, and therapeutic interventions. Intensive Care Med 2020; 46:606-618. [PMID: 32016537 PMCID: PMC7224136 DOI: 10.1007/s00134-020-05942-6] [Citation(s) in RCA: 144] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 01/16/2020] [Indexed: 12/18/2022]
Abstract
Neural respiratory drive, i.e., the activity of respiratory centres controlling breathing, is an overlooked physiologic variable which affects the pathophysiology and the clinical outcome of acute respiratory distress syndrome (ARDS). Spontaneous breathing may offer multiple physiologic benefits in these patients, including decreased need for sedation, preserved diaphragm activity and improved cardiovascular function. However, excessive effort to breathe due to high respiratory drive may lead to patient self-inflicted lung injury (P-SILI), even in the absence of mechanical ventilation. In the present review, we focus on the physiological and clinical implications of control of respiratory drive in ARDS patients. We summarize the main determinants of neural respiratory drive and the mechanisms involved in its potentiation, in health and ARDS. We also describe potential and pitfalls of the available bedside methods for drive assessment and explore classical and more “futuristic” interventions to control drive in ARDS patients.
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Affiliation(s)
- Elena Spinelli
- Dipartimento di Anestesia, Rianimazione ed Emergenza-Urgenza, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Università Degli Studi Di Milano, Via F. Sforza 35, 20122, Milan, Italy
| | - Tommaso Mauri
- Dipartimento di Anestesia, Rianimazione ed Emergenza-Urgenza, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Università Degli Studi Di Milano, Via F. Sforza 35, 20122, Milan, Italy. .,Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy.
| | - Jeremy R Beitler
- Center for Acute Respiratory Failure, Division of Pulmonary, Allergy, and Critical Care Medicine, Columbia University College of Physicians and Surgeons/New York-Presbyterian Hospital, New York, NY, USA
| | - Antonio Pesenti
- Dipartimento di Anestesia, Rianimazione ed Emergenza-Urgenza, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Università Degli Studi Di Milano, Via F. Sforza 35, 20122, Milan, Italy.,Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
| | - Daniel Brodie
- Center for Acute Respiratory Failure, Division of Pulmonary, Allergy, and Critical Care Medicine, Columbia University College of Physicians and Surgeons/New York-Presbyterian Hospital, New York, NY, USA
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Cintineo HP, Arent SM. Anticipatory Salivary Cortisol and State Anxiety Before Competition Predict Match Outcome in Division I Collegiate Wrestlers. J Strength Cond Res 2020; 33:2905-2908. [PMID: 31490432 DOI: 10.1519/jsc.0000000000003376] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Cintineo, HP and Arent, SM. Anticipatory salivary cortisol and state anxiety before competition predict match outcome in Division I collegiate wrestlers. J Strength Cond Res 33(11): 2905-2908, 2019-Anticipation of exercise and other stressors has been shown to result in physiological and psychological changes, which include increased levels of cortisol and anxiety. Combat sports, in particular, typically elicit robust anticipatory responses because of the distinct nature of these sports. Therefore, the purpose of this investigation was to examine the relationship between state anxiety scores, anticipatory cortisol response, and performance outcomes in college wrestlers. A secondary purpose was to determine the correlation between anticipatory cortisol and state anxiety scores. Twenty-six collegiate wrestlers were recruited to undergo saliva collection and to complete the State Anxiety Inventory before a wrestling match and again on a rest day in a time-matched, control session. Univariate analyses revealed that both salivary cortisol and anxiety were greater before competition than on a rest day. In addition, it was found that losers had higher levels of anticipatory cortisol and anxiety compared with winners. A significant correlation between salivary cortisol and anxiety was found as well. These data show that higher cortisol and anxiety may negatively affect performance. Athletes and coaches should work together to determine optimal levels of arousal and should aim to replicate this during both training and competition to ensure consistently high levels of performance through appropriate preparation.
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Affiliation(s)
- Harry P Cintineo
- IFNH Center for Health and Human Performance, Rutgers University, New Brunswick, New Jersey.,Department of Exercise Science, University of South Carolina, Columbia, South Carolina
| | - Shawn M Arent
- IFNH Center for Health and Human Performance, Rutgers University, New Brunswick, New Jersey.,Department of Exercise Science, University of South Carolina, Columbia, South Carolina
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Vidotto LS, Carvalho CRFD, Harvey A, Jones M. Dysfunctional breathing: what do we know? ACTA ACUST UNITED AC 2019; 45:e20170347. [PMID: 30758427 PMCID: PMC6534396 DOI: 10.1590/1806-3713/e20170347] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 02/17/2018] [Indexed: 11/26/2022]
Abstract
Dysfunctional breathing (DB) is a respiratory condition characterized by irregular breathing patterns that occur either in the absence of concurrent diseases or secondary to cardiopulmonary diseases. Although the primary symptom is often dyspnea or “air hunger”, DB is also associated with nonrespiratory symptoms such as dizziness and palpitations. DB has been identified across all ages. Its prevalence among adults in primary care in the United Kingdom is approximately 9.5%. In addition, among individuals with asthma, a positive diagnosis of DB is found in a third of women and a fifth of men. Although DB has been investigated for decades, it remains poorly understood because of a paucity of high-quality clinical trials and validated outcome measures specific to this population. Accordingly, DB is often underdiagnosed or misdiagnosed, given the similarity of its associated symptoms (dyspnea, tachycardia, and dizziness) to those of other common cardiopulmonary diseases such as COPD and asthma. The high rates of misdiagnosis of DB suggest that health care professionals do not fully understand this condition and may therefore fail to provide patients with an appropriate treatment. Given the multifarious, psychophysiological nature of DB, a holistic, multidimensional assessment would seem the most appropriate way to enhance understanding and diagnostic accuracy. The present narrative review was developed as a means of summarizing the available evidence about DB, as well as improving understanding of the condition by researchers and practitioners.
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Affiliation(s)
- Laís Silva Vidotto
- . Department of Clinical Sciences, Brunel University London, United Kingdom
| | | | - Alex Harvey
- . Department of Clinical Sciences, Brunel University London, United Kingdom
| | - Mandy Jones
- . Department of Clinical Sciences, Brunel University London, United Kingdom
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Korsak A, Sheikhbahaei S, Machhada A, Gourine AV, Huckstepp RTR. The Role Of Parafacial Neurons In The Control Of Breathing During Exercise. Sci Rep 2018; 8:400. [PMID: 29321559 PMCID: PMC5762684 DOI: 10.1038/s41598-017-17412-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 11/24/2017] [Indexed: 02/07/2023] Open
Abstract
Neuronal cell groups residing within the retrotrapezoid nucleus (RTN) and C1 area of the rostral ventrolateral medulla oblongata contribute to the maintenance of resting respiratory activity and arterial blood pressure, and play an important role in the development of cardiorespiratory responses to metabolic challenges (such as hypercapnia and hypoxia). In rats, acute silencing of neurons within the parafacial region which includes the RTN and the rostral aspect of the C1 circuit (pFRTN/C1), transduced to express HM4D (Gi-coupled) receptors, was found to dramatically reduce exercise capacity (by 60%), determined by an intensity controlled treadmill running test. In a model of simulated exercise (electrical stimulation of the sciatic or femoral nerve in urethane anaesthetised spontaneously breathing rats) silencing of the pFRTN/C1 neurons had no effect on cardiovascular changes, but significantly reduced the respiratory response during steady state exercise. These results identify a neuronal cell group in the lower brainstem which is critically important for the development of the respiratory response to exercise and, determines exercise capacity.
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Affiliation(s)
- Alla Korsak
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology and Pharmacology, University College London, London, WC1E 6BT, United Kingdom
| | - Shahriar Sheikhbahaei
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology and Pharmacology, University College London, London, WC1E 6BT, United Kingdom
| | - Asif Machhada
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology and Pharmacology, University College London, London, WC1E 6BT, United Kingdom
| | - Alexander V Gourine
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology and Pharmacology, University College London, London, WC1E 6BT, United Kingdom.
| | - Robert T R Huckstepp
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology and Pharmacology, University College London, London, WC1E 6BT, United Kingdom. .,School of Life Sciences, University of Warwick, Coventry, CV4 7AL, United Kingdom.
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Respiratory Changes in Response to Cognitive Load: A Systematic Review. Neural Plast 2016; 2016:8146809. [PMID: 27403347 PMCID: PMC4923594 DOI: 10.1155/2016/8146809] [Citation(s) in RCA: 96] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 04/18/2016] [Accepted: 05/10/2016] [Indexed: 11/17/2022] Open
Abstract
When people focus attention or carry out a demanding task, their breathing changes. But which parameters of respiration vary exactly and can respiration reliably be used as an index of cognitive load? These questions are addressed in the present systematic review of empirical studies investigating respiratory behavior in response to cognitive load. Most reviewed studies were restricted to time and volume parameters while less established, yet meaningful parameters such as respiratory variability have rarely been investigated. The available results show that respiratory behavior generally reflects cognitive processing and that distinct parameters differ in sensitivity: While mentally demanding episodes are clearly marked by faster breathing and higher minute ventilation, respiratory amplitude appears to remain rather stable. The present findings further indicate that total variability in respiratory rate is not systematically affected by cognitive load whereas the correlated fraction decreases. In addition, we found that cognitive load may lead to overbreathing as indicated by decreased end-tidal CO2 but is also accompanied by elevated oxygen consumption and CO2 release. However, additional research is needed to validate the findings on respiratory variability and gas exchange measures. We conclude by outlining recommendations for future research to increase the current understanding of respiration under cognitive load.
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Zaman J, Van den Bergh O, Fannes S, Van Diest I. Reprint of "Learning to breathe? Feedforward regulation of the inspiratory motor drive". Respir Physiol Neurobiol 2014; 204:93-8. [PMID: 25288353 DOI: 10.1016/j.resp.2014.09.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Claims have been made that breathing is in part controlled by feedforward regulation. In a classical conditioning paradigm, we investigated anticipatory increases in the inspiratory motor drive as measured by inspiratory occlusion pressure (P100). In an acquisition phase, an experimental group (N = 13) received a low-intensity resistive load (5 cmH2O/l/s) for three consecutive inspirations as Conditioned Stimulus (CS), preceding a load of a stronger intensity (20 cmH2O/l/s) for three subsequent inspirations as unconditioned stimulus (US). The control group (N = 11) received the low-intensity load for six consecutive inspirations. In a post-acquisition phase both groups received the low-intensity load for six consecutive inspirations. Responses to the CS-load only differed between groups during the first acquisition trials and a strong increase in P100 during the US-loads was observed, which habituated across the experiment. Our results suggest that the disruption caused by adding low to moderate resistive loads to three consecutive inspirations results in a short-lasting anticipatory increase in inspiratory motor drive.
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Affiliation(s)
- Jonas Zaman
- Research Group on Health Psychology University of Leuven, Tiensestraat 102, Box 3726, B-3000 Leuven, Belgium
| | - Omer Van den Bergh
- Research Group on Health Psychology University of Leuven, Tiensestraat 102, Box 3726, B-3000 Leuven, Belgium
| | - Stien Fannes
- Research Group on Health Psychology University of Leuven, Tiensestraat 102, Box 3726, B-3000 Leuven, Belgium
| | - Ilse Van Diest
- Research Group on Health Psychology University of Leuven, Tiensestraat 102, Box 3726, B-3000 Leuven, Belgium.
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Zaman J, Van den Bergh O, Fannes S, Van Diest I. Learning to breathe? Feedforward regulation of the inspiratory motor drive. Respir Physiol Neurobiol 2014; 201:1-6. [DOI: 10.1016/j.resp.2014.05.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 05/23/2014] [Accepted: 05/26/2014] [Indexed: 11/25/2022]
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Remote control of respiratory neural network by spinal locomotor generators. PLoS One 2014; 9:e89670. [PMID: 24586951 PMCID: PMC3930745 DOI: 10.1371/journal.pone.0089670] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Accepted: 01/21/2014] [Indexed: 12/03/2022] Open
Abstract
During exercise and locomotion, breathing rate rapidly increases to meet the suddenly enhanced oxygen demand. The extent to which direct central interactions between the spinal networks controlling locomotion and the brainstem networks controlling breathing are involved in this rhythm modulation remains unknown. Here, we show that in isolated neonatal rat brainstem-spinal cord preparations, the increase in respiratory rate observed during fictive locomotion is associated with an increase in the excitability of pre-inspiratory neurons of the parafacial respiratory group (pFRG/Pre-I). In addition, this locomotion-induced respiratory rhythm modulation is prevented both by bilateral lesion of the pFRG region and by blockade of neurokinin 1 receptors in the brainstem. Thus, our results assign pFRG/Pre-I neurons a new role as elements of a previously undescribed pathway involved in the functional interaction between respiratory and locomotor networks, an interaction that also involves a substance P-dependent modulating mechanism requiring the activation of neurokinin 1 receptors. This neurogenic mechanism may take an active part in the increased respiratory rhythmicity produced at the onset and during episodes of locomotion in mammals.
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Tobin MJ, Laghi F, Jubran A. Ventilatory failure, ventilator support, and ventilator weaning. Compr Physiol 2013; 2:2871-921. [PMID: 23720268 DOI: 10.1002/cphy.c110030] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The development of acute ventilatory failure represents an inability of the respiratory control system to maintain a level of respiratory motor output to cope with the metabolic demands of the body. The level of respiratory motor output is also the main determinant of the degree of respiratory distress experienced by such patients. As ventilatory failure progresses and patient distress increases, mechanical ventilation is instituted to help the respiratory muscles cope with the heightened workload. While a patient is connected to a ventilator, a physician's ability to align the rhythm of the machine with the rhythm of the patient's respiratory centers becomes the primary determinant of the level of rest accorded to the respiratory muscles. Problems of alignment are manifested as failure to trigger, double triggering, an inflationary gas-flow that fails to match inspiratory demands, and an inflation phase that persists after a patient's respiratory centers have switched to expiration. With recovery from disorders that precipitated the initial bout of acute ventilatory failure, attempts are made to discontinue the ventilator (weaning). About 20% of weaning attempts fail, ultimately, because the respiratory controller is unable to sustain ventilation and this failure is signaled by development of rapid shallow breathing. Substantial advances in the medical management of acute ventilatory failure that requires ventilator assistance are most likely to result from research yielding novel insights into the operation of the respiratory control system.
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Affiliation(s)
- Martin J Tobin
- Division of Pulmonary and Critical Care Medicine, Edward Hines Jr. Veterans Affairs Hospital and Loyola University of Chicago Stritch School of Medicine, Hines, Illinois, USA.
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Izumizaki M, Iwase M, Tsuchiya N, Homma I. Hyperpnoeic response independent of limb movements at exercise onset in mice. Respir Physiol Neurobiol 2013; 185:319-31. [DOI: 10.1016/j.resp.2012.09.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Revised: 09/20/2012] [Accepted: 09/21/2012] [Indexed: 10/27/2022]
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Jutand L, Tremoureux L, Pichon A, Delpech N, Denjean A, Raux M, Straus C, Similowski T. Ventilatory response to exercise does not evidence electroencephalographical respiratory-related activation of the cortical premotor circuitry in healthy humans. Acta Physiol (Oxf) 2012; 205:356-62. [PMID: 22356255 DOI: 10.1111/j.1748-1716.2012.02427.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2011] [Revised: 10/10/2011] [Accepted: 02/12/2012] [Indexed: 11/26/2022]
Abstract
AIM The neural structures responsible for the coupling between ventilatory control and pulmonary gas exchange during exercise have not been fully identified. Suprapontine mechanisms have been hypothesized but not formally evidenced. Because the involvement of a premotor circuitry in the compensation of inspiratory mechanical loads has recently been described, we looked for its implication in exercise-induced hyperpnea. METHODS Electroencephalographical recordings were performed to identify inspiratory premotor potentials (iPPM) in eight physically fit normal men during cycling at 40 and 70% of their maximal oxygen consumption ((V)·O(2max) ). Relaxed pedalling (0 W) and voluntary sniff manoeuvres were used as negative and positive controls respectively. RESULTS Voluntary sniffs were consistently associated with iPPMs. This was also the case with voluntarily augmented breathing at rest (in three subjects tested). During the exercise protocol, no respiratory-related activity was observed whilst performing bouts of relaxed pedalling. Exercise-induced hyperpnea was also not associated with iPPMs, except in one subject. CONCLUSION We conclude that if there are cortical mechanisms involved in the ventilatory adaptation to exercise in physically fit humans, they are distinct from the premotor mechanisms activated by inspiratory load compensation.
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Affiliation(s)
| | | | - A. Pichon
- Université Paris 13; UFR SMBH, STAPS, UPRES EA 2363; Laboratoire Réponses Cellulaires et Fonctionnelles à l'Hypoxie; 74 rue Marcel Cachin; 93017; Bobigny; France
| | - N. Delpech
- Université de Poitiers; Laboratoire des Adaptations Physiologiques aux Activités Physiques; Faculté des Sciences du Sport; UPRES EA 3813; 4 Allée Jean Monnet; 86000; Poitiers; France
| | - A. Denjean
- Assistance Publique - Hôpitaux de Paris; Hôpital Robert Debré; Service de physiologie, Explorations Fonctionnelles; 75019; Paris; France
| | | | | | - T. Similowski
- Assistance Publique - Hôpitaux de Paris; Groupe Hospitalier Pitié-Salpêtrière; Service de Pneumologie et Réanimation; 75013; Paris; France
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21
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Abstract
When animals move, respiration increases to adapt for increased energy demands; the underlying mechanisms are still not understood. We investigated the neural substrates underlying the respiratory changes in relation to movement in lampreys. We showed that respiration increases following stimulation of the mesencephalic locomotor region (MLR) in an in vitro isolated preparation, an effect that persists in the absence of the spinal cord and caudal brainstem. By using electrophysiological and anatomical techniques, including whole-cell patch recordings, we identified a subset of neurons located in the dorsal MLR that send direct inputs to neurons in the respiratory generator. In semi-intact preparations, blockade of this region with 6-cyano-7-nitroquinoxaline-2,3-dione and (2R)-amino-5-phosphonovaleric acid greatly reduced the respiratory increases without affecting the locomotor movements. These results show that neurons in the respiratory generator receive direct glutamatergic connections from the MLR and that a subpopulation of MLR neurons plays a key role in the respiratory changes linked to movement.
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Gariépy JF, Missaghi K, Dubuc R. The interactions between locomotion and respiration. PROGRESS IN BRAIN RESEARCH 2010; 187:173-88. [DOI: 10.1016/b978-0-444-53613-6.00012-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Liatsi D, Tsapas B, Pampori S, Tsagourias M, Pneumatikos I, Matamis D. Respiratory, metabolic and hemodynamic effects of clonidine in ventilated patients presenting with withdrawal syndrome. Intensive Care Med 2008; 35:275-81. [PMID: 18709354 DOI: 10.1007/s00134-008-1251-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2008] [Accepted: 07/18/2008] [Indexed: 11/24/2022]
Abstract
OBJECTIVE To investigate the respiratory, metabolic and hemodynamic effects of clonidine in ventilated patients presenting with withdrawal syndrome after sedation interruption. DESIGN Prospective, interventional, single-center study in 30 ventilated ICU patients. INTERVENTIONS Metabolic [oxygen consumption (VO(2)), CO(2) production (VCO(2)), resting energy expenditure (REE)], respiratory [minute ventilation (V (E)), tidal volume (V (T)), respiratory rate (RR)] and hemodynamic (HR, SAP, MAP) parameters were measured in 30 ventilated ICU patients. Measurements were performed first under sedation with remifentanil-propofol, then after sedation interruption, and finally after clonidine administration (0.9-1.8 mg of clonidine in two doses of 10 min interval). RESULTS Sedation interruption produced significant increases in the hemodynamic parameters (SAP and MAP by 33%, HR by 37%), and metabolic rate (increase in VO(2) by 70%, VCO(2) by 88% and REE by 74%), leading to high respiratory demands (increase in V (E) from 9 to 15 l/min). The V (E) was increased due to a twofold increase in the RR; V (T) remained constant. In 25 out of 30 patients, clonidine administration decreased the hemodynamic (SAP, MAP and HR), metabolic (VO(2), VCO(2), REE) and respiratory parameters to values close to those observed with sedation. Clonidine induced mild sedation and patients became more cooperative with the ventilator. All patients responding to clonidine were weaned from the ventilator in 2 days (median, range 1-18 days). CONCLUSION Patients with withdrawal syndrome had significantly elevated hemodynamic, metabolic and respiratory demands. Clonidine significantly decreased these demands, induced mild sedation and facilitated patient cooperation with the ventilator, enabling ventilator weaning.
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Affiliation(s)
- Domniki Liatsi
- ICU, Papageorgiou General Hospital, Thessaloniki, Greece
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Poon CS, Tin C, Yu Y. Homeostasis of exercise hyperpnea and optimal sensorimotor integration: the internal model paradigm. Respir Physiol Neurobiol 2007; 159:1-13; discussion 14-20. [PMID: 17416554 PMCID: PMC2225386 DOI: 10.1016/j.resp.2007.02.020] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2007] [Revised: 02/28/2007] [Accepted: 02/28/2007] [Indexed: 11/16/2022]
Abstract
Homeostasis is a basic tenet of biomedicine and an open problem for many physiological control systems. Among them, none has been more extensively studied and intensely debated than the dilemma of exercise hyperpnea - a paradoxical homeostatic increase of respiratory ventilation that is geared to metabolic demands instead of the normal chemoreflex mechanism. Classical control theory has led to a plethora of "feedback/feedforward control" or "set point" hypotheses for homeostatic regulation, yet so far none of them has proved satisfactory in explaining exercise hyperpnea and its interactions with other respiratory inputs. Instead, the available evidence points to a far more sophisticated respiratory controller capable of integrating multiple afferent and efferent signals in adapting the ventilatory pattern toward optimality relative to conflicting homeostatic, energetic and other objectives. This optimality principle parsimoniously mimics exercise hyperpnea, chemoreflex and a host of characteristic respiratory responses to abnormal gas exchange or mechanical loading/unloading in health and in cardiopulmonary diseases - all without resorting to a feedforward "exercise stimulus". Rather, an emergent controller signal encoding the projected metabolic level is predicted by the principle as an exercise-induced 'mental percept' or 'internal model', presumably engendered by associative learning (operant conditioning or classical conditioning) which achieves optimality through continuous identification of, and adaptation to, the causal relationship between respiratory motor output and resultant chemical-mechanical afferent feedbacks. This internal model self-tuning adaptive control paradigm opens a new challenge and exciting opportunity for experimental and theoretical elucidations of the mechanisms of respiratory control - and of homeostatic regulation and sensorimotor integration in general.
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Affiliation(s)
- Chi-Sang Poon
- Harvard-MIT Division of Health Sciences and Technology, Bldg. 56-046, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA.
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Abstract
INTRODUCTION What are the nature and the neural substrate of voluntary force perception? STATE OF ART Experimental findings demonstrate that efferent signals related to motor command play a dominant role in perceiving voluntary muscular force. This suggests that voluntary force perception is provided through a sense of effort and not through a sense of intramuscular tension. Nevertheless, experimental data show that the contribution of sensory input to effort awareness must not be dismissed. Sensory signals are not involved in generating a signal of effort but rather in calibrating and modulating its magnitude. Neuroimaging and neuropsychological studies revealed that many cortical structures are activated during tasks of voluntary muscular force perception. PERSPECTIVES AND CONCLUSION In such tasks, the basal ganglia might support the coherence of cortical activity.
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Affiliation(s)
- G Lafargue
- URECA (EA 1059), Université Charles de Gaulle, Lille III, Villeneuve d'Ascq.
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Masaoka Y, Homma I. Amygdala and emotional breathing in humans. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2005; 551:9-14. [PMID: 15602938 DOI: 10.1007/0-387-27023-x_2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Affiliation(s)
- Yuri Masaoka
- Department of Physiology II, Showa University School of Medicine, Shinagawa-ku, Tokyo, Japan
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Masaoka Y, Homma I. The effect of anticipatory anxiety on breathing and metabolism in humans. RESPIRATION PHYSIOLOGY 2001; 128:171-7. [PMID: 11812381 DOI: 10.1016/s0034-5687(01)00278-x] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Respiratory patterns are influenced by cortical and limbic factors and generated by a complex interaction between metabolic requirements and their behavioral effects. Our previous results showed that the temporal pole and the amygdala in the limbic system are related to anxiety and associated with an increase of respiratory frequency, especially in high trait anxiety subjects. The purpose of this study was to investigate the relationship between respiratory patterns and metabolic output during the production of anticipatory anxiety. In all subjects, fR increased without changes in V(O(2)), V(CO(2)) and HR; and PET(CO(2)) decreased during anticipatory anxiety. In the subjects with high trait anxiety, the increase of fR and the decrease of TE were larger than those in the subjects with low trait anxiety. These results suggest that an increase in respiratory frequency is not related to metabolic factors and is consistent with a mechanism involving the limbic system modulating respiratory drive.
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Affiliation(s)
- Y Masaoka
- Second Department of Physiology, Showa University School of Medicine, Hatanodai 1-5-8, Shinagawa-ku, 142-8555, Tokyo, Japan
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Dallimore K, Jenkins S, Tucker B. Respiratory and cardiovascular responses to manual chest percussion in normal subjects. THE AUSTRALIAN JOURNAL OF PHYSIOTHERAPY 2001; 44:267-274. [PMID: 11676742 DOI: 10.1016/s0004-9514(14)60386-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The respiratory and cardiovascular responses to manual chest percussion were studied in seven naive healthy subjects. Percussion during quiet breathing, percussion with thoracic expansion exercises (TEE) and TEE alone were applied to subjects in side-lying. Inspired volume, oxygen consumption, oxygen saturation, heart rate and blood pressure were measured before, during and after each technique. Significant increases in inspired volume and heart rate occurred with all three techniques (p < 0.01). Oxygen consumption increased with all three techniques however only the increases during percussion with TEE, and TEE alone were significant (p < 0.01). Oxygen saturation increased with percussion with TEE and TEE alone (p < 0.01). No significant changes in blood pressure were observed.
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Affiliation(s)
- Kate Dallimore
- Physiotherapy Department, Fremantle Hospital, Fremantle, WA, 6160, Australia.
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30
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Abstract
In this article, it is argued that learning participates to fulfill the metabolic requirements by adapting respiratory control to changing internal and external states. Recent classical-conditioning experiments in newborn mice or adult rats show the close link between conditioned respiratory and arousal responses. The conditioned fear model may be a suitable and largely unexplored model of emotionally induced hyperventilation. The parabrachial nucleus and periacqueducal grey may play a pivotal role in the ventilatory component of conditioned fear. The sensitivity of breathing to conditioning in newborn and adult animals suggests that learning processes may shape breathing pattern throughout life.
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31
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Abstract
Respiration and heart rates were recorded in normal subjects watching effortful actions produced by an actor in front of them. Subjects remained immobile throughout. Two experiments were performed. In experiment 1, subjects watched a weight-lifting performance, either static or dynamic, with increasing weights. In experiment 2, they watched a walking/running performance on a treadmill moving at increasing speed. In both experiments, no change was found in observers' heart rate. By contrast, consistent changes were found in respiration rate. These changes tended to follow the exercise rhythm of the actor, specially during accelerated running (from 2.5 to 10 km/h) where respiration rate increased linearly with speed of the treadmill. Average maximum increase ranged between 25 and 30% above resting rate. This finding demonstrates activation of central mechanisms related to action performance during observation of effortful actions. It could represent a basis for understanding and imitating actions performed by other people.
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Affiliation(s)
- C Paccalin
- Institut des Sciences Cognitives, 67 Boulevard Pinel, 69675, Bron, France
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32
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Masaoka Y, Homma I. Expiratory time determined by individual anxiety levels in humans. J Appl Physiol (1985) 1999; 86:1329-36. [PMID: 10194219 DOI: 10.1152/jappl.1999.86.4.1329] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We have previously found that individual anxiety levels influence respiratory rates in physical load and mental stress (Y. Masaoka and I. Homma. Int. J. Psychophysiol. 27: 153-159, 1997). On the basis of that study, in the present study we investigated the metabolic outputs during tests and analyzed the respiratory timing relationship between inspiration and expiration, taking into account individual anxiety levels. Disregarding anxiety levels, there were correlations between O2 consumption (VO2) and minute ventilation (VE) and between VO2 and tidal volume in the physical load test, but no correlations were observed in the noxious audio stimulation test. There was a volume-based increase in respiratory patterns in physical load; however, VE increased not only for the adjustment of metabolic needs but also for individual mental factors; anxiety participated in this increase. In the high-anxiety group, the VE-to-VO2 ratio, indicating ventilatory efficiency, increased in both tests. In the high-anxiety group, increases in respiratory rate contributed to a VE increase, and there were negative correlations between expiratory time and anxiety scores in both tests. In an awake state, the higher neural structure may dominantly affect the mechanism of respiratory rhythm generation. We focus on the relationship between expiratory time and anxiety and show diagrams of respiratory output, allowing for individual personality.
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Affiliation(s)
- Y Masaoka
- Second Department of Physiology, Showa University School of Medicine, Tokyo 142, Japan
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33
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Wientjes CJ, Grossman P, Gaillard AW. Influence of drive and timing mechanisms on breathing pattern and ventilation during mental task performance. Biol Psychol 1998. [DOI: 10.1016/s0301-0511(98)00026-x] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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34
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Nsegbe E, Vardon G, Perruchet P, Gallego J. Classic conditioning of the ventilatory responses in rats. J Appl Physiol (1985) 1997; 83:1174-83. [PMID: 9338426 DOI: 10.1152/jappl.1997.83.4.1174] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Recent authors have stressed the role of conditioning in the control of breathing, but experimental evidence of this role is still sparse and contradictory. To establish that classic conditioning of the ventilatory responses can occur in rats, we performed a controlled experiment in which a 1-min tone [conditioned stimulus (CS)] was paired with a hypercapnic stimulus [8.5% CO2, unconditioned stimulus (US)]. The experimental group (n = 9) received five paired CS-US presentations, followed by one CS alone to test conditioning. This sequence was repeated six times. The control group (n = 7) received the same number of CS and US, but each US was delivered 3 min after the CS. We observed that after the CS alone, breath duration was significantly longer in the experimental than in the control group and mean ventilation was significantly lower, thus showing inhibitory conditioning. This conditioning may have resulted from the association between the CS and the inhibitory and aversive effects of CO2. The present results confirmed the high sensitivity of the respiratory controller to conditioning processes.
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Affiliation(s)
- E Nsegbe
- Laboratoire de Neurologie et Physiologie du Développement, Hôpital Robert-Debré, Université de Paris-7, 75019 Paris, France
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35
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Masaoka Y, Homma I. Anxiety and respiratory patterns: their relationship during mental stress and physical load. Int J Psychophysiol 1997; 27:153-9. [PMID: 9342646 DOI: 10.1016/s0167-8760(97)00052-4] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In the present study we investigated the effect of mental stress on respiration using unpleasant sounds. To compare the center output of each stimuli, subjects took part in one session divided into two phases: a mental stress test and a physical loading test. The purpose of this study was not only to investigate ventilatory response in emotions caused by mental stress and physical load, but also to determine the relationship between respiratory pattern and personality. Ten normal subjects were measured for VE (minute ventilation), VT (tidal volume), RR (respiratory rate), Vo2 (O2 consumption), Vco2 (CO2 production) and FETco2 (end-tidal CO2 concentration) on a breath-by-breath basis; the subjects were given Spielberger's State Trait Anxiety Inventory (STAI) before beginning this experiment. Unpleasant emotions caused by mental stress altered the breathing pattern. VE increase was achieved by the combination of VT and RR disregarding the subjects' personality. However, subjects with high anxiety RR increased more than VT resulting in a positive correlation between the trait anxiety score and RR. We found that a dominant RR increase was observed not only in the mental stress test but also in the physical loading test. In the physical load, there was a positive correlation between the state anxiety score and RR. These results indicate that respiratory patterns are related to personality anxiety. These findings may provide important evidence relating respiratory function to psychological aspects.
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Affiliation(s)
- Y Masaoka
- Second Department of Physiology, School of Medicine, Showa University, Tokyo, Japan
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36
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Wuyam B, Moosavi SH, Decety J, Adams L, Lansing RW, Guz A. Imagination of dynamic exercise produced ventilatory responses which were more apparent in competitive sportsmen. J Physiol 1995; 482 ( Pt 3):713-24. [PMID: 7738860 PMCID: PMC1157796 DOI: 10.1113/jphysiol.1995.sp020554] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
1. The cardiorespiratory response to imagination of previously performed treadmill exercise was measured in six competitive sportsmen and six non-athletic males. This was compared with the response to a control task (imaging letters) and a task not involving imagination ('treadmill sound only'). 2. In athletes, imagined exercise produced increases in ventilation which varied within and between subjects. The mean maximal increase (11.71 min-1) was approximately 20% of the ventilatory response to actual exercise. This was primarily due to treadmill speed-related increases in respiratory frequency (mean maximal increase, 14.8 breaths min-1) and resulted in significant reductions in end-tidal PCO2 (mean maximal fall, 7 mmHg). These effects were greater (P < 0.01) than any observed during the control tasks. 3. Changes in heart rate (mean increase, 12 beats min-1) were not significantly different from those observed during the control tasks (P > 0.2). 4. In non-athletes, imagination of exercise produced no changes in cardiorespiratory variables. No significant differences were detected in subjective assessments of movement imagery ability between athletes and non-athletes (P = 0.17). 5. This study demonstrates that ventilatory effects, when observed, are specific to imagination of exercise. The greater likelihood of generating ventilatory responses in highly trained athletes, experienced in 'rhythmic' sports, may be related to awareness of breathing and its role in exercise imagination strategy. A volitional component of the response cannot be discounted.
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Affiliation(s)
- B Wuyam
- Department of Medicine, Charing Cross and Westminster Medical School, London, UK
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37
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Gallego J, Benammou S, Miramand JL, Vardon G, el-Massioui N, Pacteau C, Perruchet P. Ventilatory conditioning by self-stimulation in rats: a pilot study. BIOFEEDBACK AND SELF-REGULATION 1994; 19:171-80. [PMID: 7918754 DOI: 10.1007/bf01776489] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
This article describes an experimental attempt to condition breathing pattern in rats. In this experiment, a freely moving rat was first rewarded by an electrical stimulation of the medial forebrain bundle whenever inspiratory duration (TI) exceeded 300 ms. A bidirectional control was then used: TIs longer than 400 ms were rewarded, and then TIs shorter than 300 ms were rewarded. The frequency of TIs longer than 300 ms increased when this event was rewarded, further increased when TIs above 400 ms were rewarded, and decreased during reversal conditioning (TI < 300 ms). At the beginning of the experiment, stimulation caused increased arousal and motor activity, but after prolonged conditioning, the brain stimulation was associated with quiet wakefulness. Although the general procedure appears to be well-suited to the experimental study of voluntary breathing, some possible improvements are suggested for further, more extensive investigations.
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Affiliation(s)
- J Gallego
- Faculté de Médecine de Paris-Sud, Laboratoire de Physiologie, Le Kremlin-Bicêtre, France
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38
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Weisman IM, Zeballos RJ. AN INTEGRATED APPROACH TO THE INTERPRETATION OF CARDIOPULMONARY EXERCISE TESTING. Clin Chest Med 1994. [DOI: 10.1016/s0272-5231(21)01082-0] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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39
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Hida W, Okabe S, Miki H, Kikuchi Y, Taguchi O, Takishima T, Shirato K. Effects of submental stimulation for several consecutive nights in patients with obstructive sleep apnoea. Thorax 1994; 49:446-52. [PMID: 8016764 PMCID: PMC474864 DOI: 10.1136/thx.49.5.446] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND It has previously been reported that short term submental stimulation can reduce the frequency of apnoea and improve sleep architecture in patients with obstructive sleep apnoea. The effects of submental stimulation during consecutive nights on apnoea or on daytime sleepiness have not, however, been studied. METHODS Patients with obstructive sleep apnoea were studied by polysomnography on a control night, for five consecutive nights of submental stimulation, and on three following nights (n = 8). A multiple sleep latency test (MSLT) (n = 8) and measurement of the upper airway resistance (n = 5) were performed during the day after the polysomnographic study, on the control night, and on the fifth stimulation night. In an additional five patients with obstructive sleep apnoea, matched for age, sex, and weight, the effects of two nights of stimulation were examined for comparison. Submental stimulation began when an apnoea lasted for five seconds and stopped with the resumption of breathing as detected by oronasal flow. RESULTS The apnoea index, the number of times per hour that SaO2 dropped below 85% (SaO2 < 85%/hour), and the total apnoea duration expressed as a percentage of total sleep time during stimulation nights decreased to approximately 50% of the corresponding values on the control night. This improvement persisted for at least two nights after the five consecutive stimulation nights, but not after the two consecutive stimulation nights. Sleep architecture and MSLT following the stimulation nights improved but upper airway resistance did not change. CONCLUSIONS Submental stimulation for five consecutive nights in patients with obstructive sleep apnoea improved the breathing disturbance, sleep quality, and daytime sleepiness. The effect lasted for the following two nights, but did not completely abolish the sleep disordered breathing.
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Affiliation(s)
- W Hida
- First Department of Internal Medicine, Tohoku University School of Medicine, Sendai, Japan
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40
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Blanc-Gras N, Estève F, Benchetrit G, Gallego J. Performance and learning during voluntary control of breath patterns. Biol Psychol 1994; 37:147-59. [PMID: 8003590 DOI: 10.1016/0301-0511(94)90028-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Fourteen subjects learned to adjust their breath pattern to two target breaths displayed on a video screen, by using visual feedback, during two sessions 24 h apart. These two targets were respectively the smallest and the largest breaths of a ten-breath sample previously recorded from each subject's resting spontaneous breathing. Performances were significantly better for the large than for the small target breath. This cannot be directly inferred from current knowledge related to the control of movement time and amplitude, but rather it may be inferred from the periodic character of breathing, to the higher mental load during the small breath task, or to the presumably different frequencies of target breaths in the whole span of spontaneous breathing. In the second session, performance on the two targets levelled out as a result of learning.
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Affiliation(s)
- N Blanc-Gras
- Laboratoire de Physiologie, Faculté de Médecine de Grenoble, La Tronche, France
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41
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Shea SA, Andres LP, Paydarfar D, Banzett RB, Shannon DC. Effect of mental activity on breathing in congenital central hypoventilation syndrome. RESPIRATION PHYSIOLOGY 1993; 94:251-63. [PMID: 8108605 DOI: 10.1016/0034-5687(93)90022-3] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Congenital central hypoventilation syndrome (CCHS) is associated with hypoventilation during sleep, but breathing can be adequate during wakefulness. It has been assumed that in awake CCHS patients breathing is activated by the forebrain, even voluntarily (i.e. Ondine's Curse). We tested whether or not an abnormal breathing pattern can be provoked by intense mental concentration in CCHS patients as this would be expected to disturb any voluntary control over breathing if present. Breathing (inductance plethysmography), end-tidal PCO2) (PETCO2), arterial oxygen saturation (SaO2) and EEG were measured in 5 children with CCHS (aged 8-17 years) and 5 controls during 5 min periods while resting; reading; performing mental arithmetic and playing a hand-held "Nintendo" game. There were no significant differences between controls and CCHS (unpaired t-tests, P > 0.05) in mean breath duration, tidal volume, ventilation, SaO2 or PETCO2 during REST or the conditions of mental stimulation. Both groups increased ventilation during mental stimulation. Respiratory variability was not greater in CCHS in any condition. These data provide indirect evidence that CCHS patients do not require voluntary activation of every breath (they do not have Ondine's Curse) and suggest that mental concentration might stimulate the respiratory complex as part of a generalised CNS arousal.
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Affiliation(s)
- S A Shea
- Physiology Program, Harvard School of Public Health, Boston, MA 02115
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42
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Abstract
1. To test the hypothesis that repeated associations of exercise and increased respiratory dead space elicit mechanisms that augment future ventilatory responses to exercise alone, experiments were conducted on normal adult goats familiarized with experimental procedures. 2. Measurements of ventilation, arterial blood gases and CO2 production were made at rest, during mild steady-state exercise (4 km h-1; 5% grade) and with increased dead space at rest in seven goats before and after training. In Series I experiments, training consisted of fourteen to twenty exercise trials explicitly paired with increased dead space (0.8 l) over 2 days. Increased dead space predominantly represents a CO2 chemoreceptor stimulus with only mild hypoxic stimulation. Post-training measurements were made 1-6 h and 1 week after training was completed. 3. The same goats repeated a slightly modified protocol several months later (Series II; 6 trials per day for 4 days) to determine if responses were both repeatable and reversible, and to investigate training effects on dynamic ventilatory responses at the onset of exercise. 4. In Series I experiments, resting minute ventilation and breathing frequency were elevated 1-6 h post-training compared to baseline (44 and 74% respectively), whereas resting tidal volume decreased (14%). One week post-training, resting values had returned to baseline. Series II training had no significant effects on resting measurements. 5. Relative to baseline, arterial partial pressure of CO2 (Pa,CO2) values decreased significantly more from rest to exercise 1-6 h post-training in both Series I (2.7 +/- 0.2 vs. 1.8 +/- 0.9 mmHg) and Series II (3.4 +/- 0.6 vs. 2.0 +/- 0.6 mmHg). The exercise ventilatory response increased 25-28% 1-6 h post-training (both series), largely due to a greater exercise frequency response, but returned to baseline 1 week post-training. Training had no effect on ventilatory responses to CO2 at rest, suggesting that decreases in CO2 chemoreceptor responsiveness did not cause the greater exercise ventilatory response. Model estimates indicate that the net feedforward exercise ventilatory stimulus was increased 40-50% by training. 6. Training had no discernable effects on ventilatory dynamics at the onset of exercise. However, post-training differences in Pa,CO2 regulation and ventilation were established early in exercise, prior to steady state. 7. Collectively, these experiments suggest a previously unsuspected degree of repeatable and reversible plasticity in the control system subserving the exercise ventilatory response. Such plasticity may contribute to the development of normal exercise hyperpnoea and to adaptive responses of the ventilatory control system in adult animals.
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Affiliation(s)
- P A Martin
- Department of Comparative Biosciences, University of Wisconsin, Madison 53706
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43
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Abstract
An adaptive neural network model that exhibits the optimality and homeostasis characteristics of the respiratory control system is described. Based upon the Hopfield network structure and a postulated Hebb-like respiratory synapse with correlational short-term potentiation, the model is capable of mimicking the normal ventilatory responses to exercise and CO2 inputs without the need for an explicit exercise stimulus. Results suggest the possibility of an adaptive neuronal mechanism that effects optimal homeostatic regulation of respiration in mammals.
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Affiliation(s)
- C S Poon
- Harvard-MIT Division of Health Sciences and Technology, Cambridge 02139
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44
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Ramsay SC, Adams L, Murphy K, Corfield DR, Grootoonk S, Bailey DL, Frackowiak RS, Guz A. Regional cerebral blood flow during volitional expiration in man: a comparison with volitional inspiration. J Physiol 1993; 461:85-101. [PMID: 8350282 PMCID: PMC1175247 DOI: 10.1113/jphysiol.1993.sp019503] [Citation(s) in RCA: 115] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
1. Positron emission tomographic (PET) imaging of regional cerebral blood flow (rCBF), using a new 3-dimensional technique of data collection, was used to identify areas of neuronal activation associated with volitional inspiration and separately with volitional expiration in five normal male subjects. A comparison of the activated areas was also undertaken to isolate regions specific for one or other active task. 2. Scans were performed during intravenous infusion of H2(15)O under conditions of (a) volitional inspiration with passive expiration, (b) passive inspiration with volitional expiration and (c) passive inspiration with passive expiration. Four measurements in these three conditions were performed in each subject. Breathing pattern was well matched between conditions. 3. Regional increases in brain blood flow, due to increased neural activity associated with either active inspiration or active expiration, were derived using a pixel by pixel comparison of images obtained during the volitional and passive ventilation phases. Data were pooled from all runs in all subjects and were then processed to detect statistically significant (P < 0.05) increases in rCBF comparing active inspiration with passive inspiration and active expiration with passive expiration. 4. During active inspiration significant increases in rCBF were found bilaterally in the primary motor cortex dorsally just lateral to the vertex, in the supplementary motor area, in the right lateral pre-motor cortex and in the left ventrolateral thalamus. 5. In active expiration significant increases in rCBF were found in the right and left primary motor cortices dorsally just lateral to the vertex, the right and left primary motor cortices more ventrolaterally, the supplementary motor area, the right lateral pre-motor cortex, the ventrolateral thalamus bilaterally, and the cerebellum. 6. Using this modified and more sensitive PET technique, these findings essentially replicate those for volitional inspiration obtained in a previous study. For volitional expiration the areas activated are more extensive, but overlap with those involved in volitional inspiration. 7. The technique used has been successful in demonstrating the regions of the brain involved in the generation of volitional breathing, and probably in the volitional modulation of automatic breathing patterns such as would be required for the production of speech.
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Affiliation(s)
- S C Ramsay
- MRC Cyclotron Unit, Hammersmith Hospital, London
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45
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Martin TW, Zeballos RJ, Weisman IM. Gas exchange during maximal upper extremity exercise. Chest 1991; 99:420-5. [PMID: 1989805 DOI: 10.1378/chest.99.2.420] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
STUDY OBJECTIVE to characterize gas exchange and cardiopulmonary performance during maximal progressive arm crank exercise. DESIGN Cardiopulmonary variables were measured and arterial blood gases were determined in blood samples obtained from an indwelling radial arterial catheter during arm crank exercise (34 watts/min). Arm crank exercise was compared to maximal leg exercise performed by a different but comparable group of subjects from a previous study. PARTICIPANTS 19 healthy young (mean +/- SEM: 20 +/- 1 yr) black males. RESULTS Peak arm crank exercise resulted in lower values compared to peak leg exercise for: power (129 +/- 2 vs 253 +/- 10 W), VO2 (2.17 +/- 0.04 vs 3.26 +/- 0.14 L/min); VCO2 (2.9 +/- 0.11 vs 4.32 +/- 0.17 L/min); HR (168 +/- 3 vs 189 +/- 3 beats/min); AT (1.15 +/- 0.05 vs 1.83 +/- 0.07 L/min); and VE (101 +/- 2 vs 144 +/- 8 L/min), respectively. Arm crank exercise (baseline vs peak) elicited an impressive improvement in PaO2 (85 +/- 1 to 97 +/- 1 mm Hg), no change in SaO2 (96 +/- 0.2 to 96 +/- 0.2 percent), no significant increase in P(A-a)O2 (3 +/- 0.7 to 5 +/- 0.9 mm Hg) and an appropriate trending decrease in VD/VT (0.22 +/- 0.01 to 0.17 +/- 0.01). Peak arm crank values were significantly different from peak cycle exercise for PaO2 (82 +/- 2.2 mm Hg), SaO2 (93 +/- 0.4 percent), P(A-a)O2 (21 +/- 1.9 mm Hg) and VD/VT (0.08 +/- 0.01). At comparable levels of VO2 for arm crank and cycle exercise (2.17 +/- 0.04 vs 2.26 +/- 0.08 L/min), significant differences were observed for PaO2 (97 +/- 1.4 vs 81 +/- 1.9 mm Hg); SaO2 (96 +/- 0.2 vs 94 +/- 0.4 percent); P(A-a)O2 (5 +/- 0.9 vs 14 +/- 1.5 mm Hg); and VD/VT (0.17 +/- 0.01 vs 0.08 +/- 0.01), respectively. CONCLUSIONS Maximal arm crank exercise represents a submaximal cardiopulmonary stress compared to maximal leg exercise. The differences in gas exchange observed at peak exercise between arm crank and leg exercise for the most part reflect the lower VO2 achieved. However, the persistence of these gas exchange differences even at a comparable level of VO2 suggests that factors other than VO2 may be operative. These factors may include differences in alveolar ventilation, CO2 production, ventilation-perfusion inequality, diffusion, and control of breathing.
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Affiliation(s)
- T W Martin
- Department of Clinical Investigation, William Beaumont Army Medical Center, El Paso, TX
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46
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Abstract
Changes in orientation of attention and ventilatory data were examined in three normal volunteers who practiced a learned ventilatory pattern over eight training sessions. The breathing task was a voluntary increase of inspiratory duration up to a given target with the aid of informative feedback on this variable. The orientation of attention was investigated through reaction time (RT) to auditory stimuli presented at different points in inspiration and expiration, during either automatic or voluntary control of breathing. Findings show that RTs are longer during voluntary than automatic breathing throughout the experiment, and that they decrease across sessions in both conditions. In the first sessions, RTs were longer during expiration than inspiration but this difference cancels out in the last sessions. The results are discussed in terms of attentional demands of control of breathing, automatization, and the connection between automatic and voluntary control of breathing. This work shows that after eight practice sessions, the orientation of attention displays significant changes; however, the control of breathing remains attention demanding.
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Affiliation(s)
- J Gallego
- Laboratoire de Physiologie Respiratoire, Université Pierre-et-Marie Curie U. F. R. Broussais-Hôtel-Dieu, Paris, France
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47
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Decety J, Jeannerod M, Germain M, Pastene J. Vegetative response during imagined movement is proportional to mental effort. Behav Brain Res 1991; 42:1-5. [PMID: 2029340 DOI: 10.1016/s0166-4328(05)80033-6] [Citation(s) in RCA: 220] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Measurement of cardiac and respiratory activity during mental simulation of locomotion at increasing speed revealed a covariation of heart rate and pulmonary ventilation with the degree of imagined effort. The degree of vegetative activation of a subject mentally running at 12 km/h was comparable to that of a subject actually walking at 5 km/h. This effect cannot be explained by an increase in peripheral (e.g. muscular) metabolic demands. Indeed, oxygen uptake decreased during motor imagery. This finding is suggestive of a commonality of neural structures responsible for mental imagery of movement and those responsible for programming actual movement. In addition, it provides an quantifiable way of testing mental imagery in relation to movement by using easily accessible biological markers.
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Affiliation(s)
- J Decety
- Vision et Motricité, INSERM U94, Bron, France
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48
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Tallarida G, Peruzzi G, Raimondi G. The role of chemosensitive muscle receptors in cardiorespiratory regulation during exercise. JOURNAL OF THE AUTONOMIC NERVOUS SYSTEM 1990; 30 Suppl:S155-61. [PMID: 2212481 DOI: 10.1016/0165-1838(90)90123-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Several possible mechanisms leading to the cardiorespiratory adjustments to muscular exercise can be considered. Activation of the cardiovascular and respiratory centers may result from: (1) direct or reflex action of circulating metabolites (humoral control); (2) cortical influxes (central drive); (3) nervous impulses from receptors in the contracting muscles (peripheral drive). Information presently available focuses most of the interest upon the muscular drive. Our studies on anesthetized animals (rabbits, dogs) have demonstrated that different types of exercise (dynamic and static) produce two different types of adjustments reflexly elicited by activation of sensory endings of somatic afferents in muscles. Dynamic exercise produces a vasodilatory effect with a decrease in blood pressure and heart rate and an increase in breathing frequency; static exercise provokes an increase in blood pressure, heart rate and depth of breathing. These two patterns of adjustments to exercise are also reproducible, in anesthetized animals, by injecting chemical substances into muscular arteries. Injections of bradykinin, K+ ions and acid solutions evoke cardiorespiratory responses analogous to those produced by dynamic contractions; injections of hypertonic NaCl or glucose evoke an excitatory pattern closely similar to that elicited by isometric contractions. These research studies lead to the hypothesis that two functionally distinct types of chemosensitive receptors (K and P) exist in the skeletal muscles which are activated in proportionally different measures during different types of muscular activity, thus evoking coordinated changes in the cardiovascular and respiratory functions. These studies also strongly support the important role of the peripheral reflex mechanism in governing the circulatory and respiratory systems to perfectly match cardiorespiratory changes to the muscular metabolic needs during exercise.
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Affiliation(s)
- G Tallarida
- Dipartimento di Medicina Interna, II Universita degli Studi di Roma Tor Vergata, Italy
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49
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Concu A. Contribution of central and reflex nervous activity to the rapid increase in pulmonary ventilation at the start of muscular exercise in man. EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY AND OCCUPATIONAL PHYSIOLOGY 1989; 59:10-5. [PMID: 2583137 DOI: 10.1007/bf02396573] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
To investigate the relative contributions of the central and peripheral neural drive to hyperventilation at the onset of muscular exercise, five volunteers were tested during the first ten breaths while performing both voluntary (VM) and passive (PM) ankle rotations with a frequency of 1 Hz and through an angle of 10 degrees. Resulting breathing patterns for the two movements were compared. Hypocapnic hyperventilation, found in both PM and VM, indicated its neural origin. Respiratory changes were higher in VM than in PM. In both experimental conditions, increases in ventilation (VE) depended more on respiratory frequency (f) than on tidal volume (VT). Moreover, increases in VT adapted, breath-by-breath, to values lower than the initial ones, while increases in f rose progressively. Expiratory time was reduced more than inspiratory time (TI); increases in inspiratory flow (VT/TI) depended to the same extent on changes in both TI and VT. Increases in expiratory tidal volume were initially higher than in inspiratory tidal volume, thereby producing a reduction in functional residual capacity. Because PM respiratory changes could be considered to be of nervous reflex origin only, the identical breathing patterns in PM and VM indicated that the hyperventilation found also in VM was mainly of reflex origin. The increase in VE was considered to be dependent on a greater stimulus from muscle proprioreceptors.
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Affiliation(s)
- A Concu
- Istituto di Fisiologia Umana, Facoltà di Medicina e Chirurgia, Università di Cagliari, Italy
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Grucza R, Nakazono Y, Miyamoto Y. Cardiorespiratory response to absolute and relative work intensity in untrained men. EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY AND OCCUPATIONAL PHYSIOLOGY 1989; 59:59-67. [PMID: 2583151 DOI: 10.1007/bf02396581] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Twenty young, untrained men performed two tests on cycle ergometer in order to verify whether the kinetics of the cardiorespiratory reactions exhibit any relation to maximal oxygen uptake (VO2max) in the untrained state. On the 1st day, the subjects exercised at work intensities of 50 and 100 W, the increase as a step function, for periods of 10 min each. The next day, they performed exercise at a relative intensity of 50% VO2max for 10 min. Respiratory frequency, tidal volume, minute ventilation (VE), heart rate (HR), stroke volume (SV), and cardiac output (Q) were measured continuously. The SV was measured by impedance plethysmography. All the cardiorespiratory variables increased rapidly at the onset of both absolute and relative intensity of work, with a faster response for Q than for VE. The increase in absolute intensity of work from 50 to 100 W caused a significantly slower cardiorespiratory reaction than at the beginning of exercise. The SV increased by 20 ml during first 20 s of both absolute and relative intensities of work and then began to decrease after 6 and 4 min of the exercise, respectively. The decrease in SV was associated with an increase in HR and a stable value of Q. Acceleration at the beginning of, and deceleration during recovery from, the relative intensity of work for VE, HR, and Q were well correlated with individual levels of VO2max in the tested men. It is concluded that the kinetics of cardiorespiratory reaction to a constant, relative intensity of work is related to VO2max in untrained men, and that the kinetics probably constitute a physiological feature of an individual.
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Affiliation(s)
- R Grucza
- Department of Applied Physiology, Polish Academy of Sciences, Warsaw
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