1
|
Viemari JC. Isoproterenol modulates expiratory activities in the brainstem spinal cord preparation in neonatal mice in vitro. Respir Physiol Neurobiol 2024; 324:104241. [PMID: 38417565 DOI: 10.1016/j.resp.2024.104241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 02/12/2024] [Accepted: 02/23/2024] [Indexed: 03/01/2024]
Abstract
Motor behaviors such as breathing required temporal coordination of different muscle groups to insured efficient ventilation and provide oxygen to the body. This action is the result of interactions between neural networks located within the brainstem. Inspiration and expiration depend at least in part on interactions between two separate oscillators: inspiration is driven by a neural network located in the preBötzinger complex (PreBötC) and active expiration is driven by a network in the parafacial respiratory group (pFRG). Neurons of the pFRG are silent at rest and become active when the respiratory drive increased. This study investigated the temporal coordination between the brainstem respiratory network and the lumbar spinal network that generates spontaneous activities that is different of the induced fictive locomotion. The remaining question is how these activities coordinate early during the development. Results of this study show that brainstem networks contribute to the temporal coordination of the lumbar spontaneous activity during inspiration since lumbar motor activity occurs exclusively during the expiratory time. This study also investigated the role of the β-noradrenergic modulation on the respiratory activities. β-noradrenergic receptors activation increased the frequency of the double bursts and increased expiratory activity at the lumbar level. These results suggest interactions between brainstem and spinal networks and reveal a descending drive that may contribute to the coordination of the respiratory and lumbar spontaneous activities.
Collapse
Affiliation(s)
- Jean-Charles Viemari
- Aix-Marseille Univ, Inserm, MMG, Marseille, France; Aix-Marseille Univ, CNRS, INT, Marseille, France.
| |
Collapse
|
2
|
Ding WH, Lu YF, Xu MX, Yu RS. Compare image quality of T2-weighted imaging with different phase acceleration factors. Medicine (Baltimore) 2023; 102:e33234. [PMID: 36897710 PMCID: PMC9997765 DOI: 10.1097/md.0000000000033234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 02/16/2023] [Indexed: 03/11/2023] Open
Abstract
Previous studies demonstrated that adjusting the phase acceleration (PA) factors could influence image quality. To improve image quality and decrease respiratory artifacts of lesions in the liver on T2-weighted image by adjusting PA factor and number of excitation (NEX). Sixty consecutive patients with hepatic lesions were enrolled in this prospective research between May 2020 and June 2020. All patients had 3.0T magnetic resonance imaging with 4 sequences (combining PA factors and NEXs, the former was 2 and 3, the latter were 1.5 and 2, respectively, with the same other scanning parameters). Two readers used 5-point quality scales to assess image quality. The signal intensity was measured by drawing regions of interest in the liver, spleen, and background on the T2-weighted imaging. Artifacts, overall image impression, and vascular conspicuity were better when the PA factor was 3 than 2. Artifacts and vascular conspicuity were better when NEX was 2 than 1.5. PA factor 3 and NEX 2 got a higher score in 5-point quality scales and less scan time than the other 3 sequences. Meanwhile, the signal-to-noise ratio of PA factor 3 and NEX 2 was best among these 4 sequences. PA factor and NEX could influence the imaging quality and lesion-to-hepatic contrast in detecting hepatic lesions on T2-weighted images. PA factor 3 and NEX 2 may have a positive effect in the clinic, especially for those with irregular respiration, as it decreased artifacts and reduced scan time.
Collapse
Affiliation(s)
- Wen-Hong Ding
- Department of Radiology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yuan-Fei Lu
- Department of Radiology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Meng-Xi Xu
- Department of Radiology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Ri-Sheng Yu
- Department of Radiology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| |
Collapse
|
3
|
Abstract
Breathing is a vital rhythmic motor behavior with a surprisingly broad influence on the brain and body. The apparent simplicity of breathing belies a complex neural control system, the breathing central pattern generator (bCPG), that exhibits diverse operational modes to regulate gas exchange and coordinate breathing with an array of behaviors. In this review, we focus on selected advances in our understanding of the bCPG. At the core of the bCPG is the preBötzinger complex (preBötC), which drives inspiratory rhythm via an unexpectedly sophisticated emergent mechanism. Synchronization dynamics underlying preBötC rhythmogenesis imbue the system with robustness and lability. These dynamics are modulated by inputs from throughout the brain and generate rhythmic, patterned activity that is widely distributed. The connectivity and an emerging literature support a link between breathing, emotion, and cognition that is becoming experimentally tractable. These advances bring great potential for elucidating function and dysfunction in breathing and other mammalian neural circuits.
Collapse
Affiliation(s)
- Sufyan Ashhad
- Department of Neurobiology, University of California at Los Angeles, Los Angeles, California, USA;
| | - Kaiwen Kam
- Department of Cell Biology and Anatomy, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, USA
| | | | - Jack L Feldman
- Department of Neurobiology, University of California at Los Angeles, Los Angeles, California, USA;
| |
Collapse
|
4
|
Hypoxic and Hypercapnic Responses in Transgenic Murine Model of Alzheimer’s Disease Overexpressing Human AβPP: The Effects of Pretreatment with Memantine and Rivastigmine. Int J Mol Sci 2022; 23:ijms23116004. [PMID: 35682682 PMCID: PMC9180806 DOI: 10.3390/ijms23116004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 05/24/2022] [Accepted: 05/25/2022] [Indexed: 12/03/2022] Open
Abstract
Despite the severe respiratory problems reducing the quality of life for Alzheimer’s disease (AD) patients, their causes are poorly understood. We aimed to investigate hypoxic and hypercapnic respiratory responses in a transgenic mouse model of AD (AβPP V717I) overexpressing AβPP and mimicking early-onset AD. The cholinesterase inhibitor rivastigmine and the NMDA receptor antagonist memantine were used to investigate the effects of drugs, used to treat AD cognitive dysfunction, on breathing in hypoxia and hypercapnia. We found a significant increase in the respiratory response to hypercapnia and no difference in the hypoxic response in APP+ mice, compared with the control group (APP−). Memantine had no effect on respiration in either group, including responses to hypoxia and hypercapnia. Rivastigmine depressed resting ventilation and response to hypercapnia irrespective of the mice genotype. Reduction in hypoxia-augmented ventilation by rivastigmine was observed only in APP+ mice, which exhibited lower acetylcholinesterase activity in the hippocampus. Treatment with rivastigmine reduced the enzyme activity in both groups equally in the hippocampus and brainstem. The increased ventilatory response to hypercapnia in transgenic mice may indicate alterations in chemoreceptive respiratory nuclei, resulting in increased CO2 sensitivity. Rivastigmine is a potent reductant of normoxic and hypercapnic respiration in APP+ and APP− mice.
Collapse
|
5
|
Patterns of cardio-respiratory motor outputs during acute and subacute exposure to chlorpyrifos in an ex-vivo in situ preparation in rats. Toxicol Appl Pharmacol 2022; 436:115862. [PMID: 34998853 DOI: 10.1016/j.taap.2022.115862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 12/08/2021] [Accepted: 01/02/2022] [Indexed: 10/19/2022]
Abstract
While a considerable body of literature has characterized the clinical features induced by organophosphate pesticides, the field lacks scrutiny into cardio-respiratory changes in different phases of poisoning. Herein, we evaluated the impact of chlorpyrifos (CPF) and its active metabolite chlorpyrifos-oxon (CPO) on the cardiorespiratory system during acute and subacute phases of poisoning using an in situ experimental rodent model. CPF (30 mg/kg) was injected intraperitoneally to rats beforehand (24 h) whereas CPO (15 mg/kg) was added into the perfusate reservoir to evaluate the effects on the motor outputs throughout the three phases of the respiratory cycle: inspiration, post-inspiration and late expiration. Phrenic, recurrent laryngeal (RLN) and thoracic sympathetic nerve activity (tSNA) were recorded. Heart rate was derived from the electrocardiogram (ECG) and the baro- and chemo-reflexes tested. CPF and CPO led to a time-dependent change in cardiorespiratory motor outputs. In the acute phase, the CPO induced bradypnea, transiently reduced the inspiratory time (TI), and increased the amplitude of phrenic. Post-inspiratory (PI) discharge recorded from the RLN was progressively reduced while tSNA was increased. CPO significantly depressed the chemoreflex but had no effect on baroreflex. During subacute phase, CPF prolongated TI with no effect on respiratory rate. Both the RLN PI discharge, the chemoreflex and the baroreflex sympathetic gain were reduced. In addition, both CPF and CPO shifted the cardiac sympatho-vagal balance towards sympathetic dominance. Our data show that different phases of poisoning are associated with specific changes in the cardio-respiratory system and might therefore demand distinct approaches by health care providers.
Collapse
|
6
|
Vafaee F, Shirzad S, Shamsi F, Boskabady MH. Neuroscience and treatment of asthma, new therapeutic strategies and future aspects. Life Sci 2021; 292:120175. [PMID: 34826435 DOI: 10.1016/j.lfs.2021.120175] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 11/11/2021] [Accepted: 11/19/2021] [Indexed: 12/14/2022]
Abstract
AIMS Asthma is an airway inflammatory disease that is affected by neurological and psychological factors. The aim of present review is to investigating the relationship between neural functions and neurobiological changes and asthma symptoms. MAIN METHODS The information in this article is provided from articles published in English and reputable database using appropriate keywords from 1970 to October 2020. KEY FINDINGS The symptoms of asthma such as cough, difficult breathing, and mucus secretion get worse when a person is suffering from stress, anxiety, and depression. The function of the insula, anterior cingulate cortex, and hypothalamic-pituitary-adrenal axis changes in response to stress and psychological disease; then the stress hormones are produced from neuroendocrine system, which leads to asthma exacerbation. The evidence represents that psychological therapies or neurological rehabilitation reduces the inflammation through modulating the activity of neurocircuitry and the function of brain centers involved in asthma. Moreover, the neurotrophins and neuropeptides are the key mediators in the neuro-immune interactions, which secrete from the airway nerves in response to brain signals, and they could be the target of many new therapies in asthma. SIGNIFICANCE This review provides an insight into the vital role of the central and peripheral nervous system in development and exacerbation of asthma and provides practical approaches and strategies on neural networks to improve the airway inflammation and asthma severity.
Collapse
Affiliation(s)
- Farzaneh Vafaee
- Neuroscience Research Center, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Neuroscience, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Shima Shirzad
- Neuroscience Research Center, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Neuroscience, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Fatemeh Shamsi
- Department of Neuroscience, School of Advanced Medical Sciences and Technologies, Shiraz University of Medical Sciences, Shiraz, Iran; Neuroscience Laboratory (Brain, Cognition and Behavior), Department of Neuroscience, School of Advanced Medical Sciences and Technologies, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mohammad Hossein Boskabady
- Applied Biomedical Research Center, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Physiology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
| |
Collapse
|
7
|
Magalhães KS, da Silva MP, Mecawi AS, Paton JFR, Machado BH, Moraes DJA. Intrinsic and synaptic mechanisms controlling the expiratory activity of excitatory lateral parafacial neurones of rats. J Physiol 2021; 599:4925-4948. [PMID: 34510468 DOI: 10.1113/jp281545] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 09/07/2021] [Indexed: 12/21/2022] Open
Abstract
Active expiration is essential for increasing pulmonary ventilation during high chemical drive (hypercapnia). The lateral parafacial (pFL ) region, which contains expiratory neurones, drives abdominal muscles during active expiration in response to hypercapnia. However, the electrophysiological properties and synaptic mechanisms determining the activity of pFL expiratory neurones, as well as the specific conditions for their emergence, are not fully understood. Using whole cell electrophysiology and single cell quantitative RT-PCR techniques, we describe the intrinsic electrophysiological properties, the phenotype and the respiratory-related synaptic inputs to the pFL expiratory neurones, as well as the mechanisms for the expression of their expiratory activity under conditions of hypercapnia-induced active expiration, using in situ preparations of juvenile rats. We also evaluated whether these neurones possess intrinsic CO2 /[H+ ] sensitivity and burst generating properties. GABAergic and glycinergic inhibition during inspiration and expiration suppressed the activity of glutamatergic pFL expiratory neurones in normocapnia. In hypercapnia, these neurones escape glycinergic inhibition and generate burst discharges at the end of expiration. Evidence for the contribution of post-inhibitory rebound, CaV 3.2 isoform of T-type Ca2+ channels and intracellular [Ca2+ ] is presented. Neither intrinsic bursting properties, mediated by persistent Na+ current, nor CO2 /[H+ ] sensitivity or expression of CO2 /[H+ ] sensitive ion channels/receptors (TASK or GPR4) were observed. On the other hand, hyperpolarisation-activated cyclic nucleotide-gated and twik-related K+ leak channels were recorded. Post-synaptic disinhibition and the intrinsic electrophysiological properties of glutamatergic neurones play important roles in the generation of the expiratory oscillations in the pFL region during hypercapnia in rats. KEY POINTS: Hypercapnia induces active expiration in rats and the recruitment of a specific population of expiratory neurones in the lateral parafacial (pFL ) region. Post-synaptic GABAergic and glycinergic inhibition both suppress the activity of glutamatergic pFL neurones during inspiratory and expiratory phases in normocapnia. Hypercapnia reduces glycinergic inhibition during expiration leading to burst generation by pFL neurones; evidence for a contribution of post-inhibitory rebound, voltage-gated Ca2+ channels and intracellular [Ca2+ ] is presented. pFL glutamatergic expiratory neurones are neither intrinsic burster neurones, nor CO2 /[H+ ] sensors, and do not express CO2 /[H+ ] sensitive ion channels or receptors. Post-synaptic disinhibition and the intrinsic electrophysiological properties of glutamatergic neurones both play important roles in the generation of the expiratory oscillations in the pFL region during hypercapnia in rats.
Collapse
Affiliation(s)
- Karolyne S Magalhães
- Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Melina P da Silva
- Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - André S Mecawi
- Department of Biophysics, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Julian F R Paton
- Department of Physiology, Faculty of Medical & Health Sciences, University of Auckland, Park Road, Grafton, Auckland, New Zealand
| | - Benedito H Machado
- Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Davi J A Moraes
- Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| |
Collapse
|
8
|
Elias GJB, Loh A, Gwun D, Pancholi A, Boutet A, Neudorfer C, Germann J, Namasivayam A, Gramer R, Paff M, Lozano AM. Deep brain stimulation of the brainstem. Brain 2021; 144:712-723. [PMID: 33313788 DOI: 10.1093/brain/awaa374] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 07/31/2020] [Accepted: 08/17/2020] [Indexed: 01/02/2023] Open
Abstract
Deep brain stimulation (DBS) of the subthalamic nucleus, pallidum, and thalamus is an established therapy for various movement disorders. Limbic targets have also been increasingly explored for their application to neuropsychiatric and cognitive disorders. The brainstem constitutes another DBS substrate, although the existing literature on the indications for and the effects of brainstem stimulation remains comparatively sparse. The objective of this review was to provide a comprehensive overview of the pertinent anatomy, indications, and reported stimulation-induced acute and long-term effects of existing white and grey matter brainstem DBS targets. We systematically searched the published literature, reviewing clinical trial articles pertaining to DBS brainstem targets. Overall, 164 studies describing brainstem DBS were identified. These studies encompassed 10 discrete structures: periaqueductal/periventricular grey (n = 63), pedunculopontine nucleus (n = 48), ventral tegmental area (n = 22), substantia nigra (n = 9), mesencephalic reticular formation (n = 7), medial forebrain bundle (n = 8), superior cerebellar peduncles (n = 3), red nucleus (n = 3), parabrachial complex (n = 2), and locus coeruleus (n = 1). Indications for brainstem DBS varied widely and included central neuropathic pain, axial symptoms of movement disorders, headache, depression, and vegetative state. The most promising results for brainstem DBS have come from targeting the pedunculopontine nucleus for relief of axial motor deficits, periaqueductal/periventricular grey for the management of central neuropathic pain, and ventral tegmental area for treatment of cluster headaches. Brainstem DBS has also acutely elicited numerous motor, limbic, and autonomic effects. Further work involving larger, controlled trials is necessary to better establish the therapeutic potential of DBS in this complex area.
Collapse
Affiliation(s)
- Gavin J B Elias
- Division of Neurosurgery, Department of Surgery, University Health Network and University of Toronto, Toronto, Canada
| | - Aaron Loh
- Division of Neurosurgery, Department of Surgery, University Health Network and University of Toronto, Toronto, Canada
| | - Dave Gwun
- Division of Neurosurgery, Department of Surgery, University Health Network and University of Toronto, Toronto, Canada
| | - Aditya Pancholi
- Division of Neurosurgery, Department of Surgery, University Health Network and University of Toronto, Toronto, Canada
| | - Alexandre Boutet
- Division of Neurosurgery, Department of Surgery, University Health Network and University of Toronto, Toronto, Canada.,Joint Department of Medical Imaging, University of Toronto, Toronto, Canada
| | - Clemens Neudorfer
- Division of Neurosurgery, Department of Surgery, University Health Network and University of Toronto, Toronto, Canada
| | - Jürgen Germann
- Division of Neurosurgery, Department of Surgery, University Health Network and University of Toronto, Toronto, Canada
| | - Andrew Namasivayam
- Division of Neurosurgery, Department of Surgery, University Health Network and University of Toronto, Toronto, Canada
| | - Robert Gramer
- Division of Neurosurgery, Department of Surgery, University Health Network and University of Toronto, Toronto, Canada
| | - Michelle Paff
- Division of Neurosurgery, Department of Surgery, University Health Network and University of Toronto, Toronto, Canada
| | - Andres M Lozano
- Division of Neurosurgery, Department of Surgery, University Health Network and University of Toronto, Toronto, Canada
| |
Collapse
|
9
|
Hammer M, Schwale C, Brankačk J, Draguhn A, Tort ABL. Theta-gamma coupling during REM sleep depends on breathing rate. Sleep 2021; 44:6326772. [PMID: 34297128 DOI: 10.1093/sleep/zsab189] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 06/23/2021] [Indexed: 11/12/2022] Open
Abstract
Temporal coupling between theta and gamma oscillations is a hallmark activity pattern of several cortical networks and becomes especially prominent during REM sleep. In a parallel approach, nasal breathing has been recently shown to generate phase-entrained network oscillations which also modulate gamma. Both slow rhythms (theta and respiration-entrained oscillations) have been suggested to aid large-scale integration but they differ in frequency, display low coherence, and modulate different gamma sub-bands. Respiration and theta are therefore believed to be largely independent. In the present work, however, we report an unexpected but robust relation between theta-gamma coupling and respiration in mice. Interestingly, this relation takes place not through the phase of individual respiration cycles, but through respiration rate: the strength of theta-gamma coupling exhibits an inverted V-shaped dependence on breathing rate, leading to maximal coupling at breathing frequencies of 4-6 Hz. Noteworthy, when subdividing sleep epochs into phasic and tonic REM patterns, we find that breathing differentially relates to theta-gamma coupling in each state, providing new evidence for their physiological distinctiveness. Altogether, our results reveal that breathing correlates with brain activity not only through phase-entrainment but also through rate-dependent relations with theta-gamma coupling. Thus, the link between respiration and other patterns of cortical network activity is more complex than previously assumed.
Collapse
Affiliation(s)
- Maximilian Hammer
- Institute for Physiology and Pathophysiology, Heidelberg University, 69120 Heidelberg, Germany
| | - Chrysovalandis Schwale
- Institute for Physiology and Pathophysiology, Heidelberg University, 69120 Heidelberg, Germany.,Department of General Internal Medicine and Psychosomatics, Heidelberg University, 69120 Heidelberg, Germany
| | - Jurij Brankačk
- Institute for Physiology and Pathophysiology, Heidelberg University, 69120 Heidelberg, Germany
| | - Andreas Draguhn
- Institute for Physiology and Pathophysiology, Heidelberg University, 69120 Heidelberg, Germany
| | - Adriano B L Tort
- Brain Institute, Federal University of Rio Grande do Norte, Natal, RN 59056-450, Brazil
| |
Collapse
|
10
|
Katsuki S, Ikeda K, Onimaru H, Dohi K, Izumizaki M. Effects of acetylcholine on hypoglossal and C4 nerve activity in brainstem-spinal cord preparations from newborn rat. Respir Physiol Neurobiol 2021; 293:103737. [PMID: 34229065 DOI: 10.1016/j.resp.2021.103737] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Revised: 06/17/2021] [Accepted: 07/01/2021] [Indexed: 11/17/2022]
Abstract
Effects of acetylcholine (ACh) on respiratory activity have been an intriguing theme especially in relation to central chemoreception and the control of hypoglossal nerve activity. We studied the effects of ACh on hypoglossal and phrenic (C4) nerve activities and inspiratory and pre-inspiratory neurons in the rostral ventrolateral medulla in brainstem-spinal cord preparations from newborn rats. ACh application increased respiratory rhythm, decreased inspiratory hypoglossal and C4 nerve burst amplitude, and enhanced pre-inspiratory hypoglossal activity. ACh induced membrane depolarization of pre-inspiratory neurons that might be involved in facilitation of respiratory rhythm by ACh. Effects of ACh on hypoglossal and C4 nerve activity were partially reversed by a nicotinic receptor blocker, mecamylamine. Further application of a muscarinic receptor antagonist, oxybutynin, resulted in slight increase of hypoglossal (but not C4) burst amplitude. Thus, ACh induced different effects on hypoglossal and C4 nerve activity in the brainstem-spinal cord preparation.
Collapse
Affiliation(s)
- Shino Katsuki
- Department of Physiology, Showa University School of Medicine, Tokyo 142-8555, Japan; Department of Emergency, Disaster and Critical Care Medicine, Showa University, Tokyo 142-8555, Japan
| | - Keiko Ikeda
- Department of Oral Physiology, Showa University School of Dentistry, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan
| | - Hiroshi Onimaru
- Department of Physiology, Showa University School of Medicine, Tokyo 142-8555, Japan.
| | - Kenji Dohi
- Department of Emergency, Disaster and Critical Care Medicine, Showa University, Tokyo 142-8555, Japan
| | - Masahiko Izumizaki
- Department of Physiology, Showa University School of Medicine, Tokyo 142-8555, Japan
| |
Collapse
|
11
|
Tort AB, Hammer M, Zhang J, Brankačk J, Draguhn A. Temporal Relations between Cortical Network Oscillations and Breathing Frequency during REM Sleep. J Neurosci 2021; 41:5229-5242. [PMID: 33963051 PMCID: PMC8211551 DOI: 10.1523/jneurosci.3067-20.2021] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Revised: 03/29/2021] [Accepted: 04/27/2021] [Indexed: 11/21/2022] Open
Abstract
Nasal breathing generates a rhythmic signal which entrains cortical network oscillations in widespread brain regions on a cycle-to-cycle time scale. It is unknown, however, how respiration and neuronal network activity interact on a larger time scale: are breathing frequency and typical neuronal oscillation patterns correlated? Is there any directionality or temporal relationship? To address these questions, we recorded field potentials from the posterior parietal cortex of mice together with respiration during REM sleep. In this state, the parietal cortex exhibits prominent θ and γ oscillations while behavioral activity is minimal, reducing confounding signals. We found that the instantaneous breathing frequency strongly correlates with the instantaneous frequency and amplitude of both θ and γ oscillations. Cross-correlograms and Granger causality revealed specific directionalities for different rhythms: changes in θ activity precede and Granger-cause changes in breathing frequency, suggesting control by the functional state of the brain. On the other hand, the instantaneous breathing frequency Granger causes changes in γ frequency, suggesting that γ is influenced by a peripheral reafference signal. These findings show that changes in breathing frequency temporally relate to changes in different patterns of rhythmic brain activity. We hypothesize that such temporal relations are mediated by a common central drive likely to be located in the brainstem.
Collapse
Affiliation(s)
- Adriano B.L. Tort
- Brain Institute, Federal University of Rio Grande do Norte, Natal, RN 59056-450, Brazil
| | - Maximilian Hammer
- Institute for Physiology and Pathophysiology, Heidelberg University, Heidelberg, 69120, Germany
| | - Jiaojiao Zhang
- Institute for Physiology and Pathophysiology, Heidelberg University, Heidelberg, 69120, Germany
| | - Jurij Brankačk
- Institute for Physiology and Pathophysiology, Heidelberg University, Heidelberg, 69120, Germany
| | - Andreas Draguhn
- Institute for Physiology and Pathophysiology, Heidelberg University, Heidelberg, 69120, Germany
| |
Collapse
|
12
|
Gnoni V, Drakatos P, Higgins S, Duncan I, Wasserman D, Kabiljo R, Mutti C, Halasz P, Goadsby PJ, Leschziner GD, Rosenzweig I. Cyclic alternating pattern in obstructive sleep apnea: A preliminary study. J Sleep Res 2021; 30:e13350. [PMID: 33939202 DOI: 10.1111/jsr.13350] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 03/10/2021] [Accepted: 03/18/2021] [Indexed: 11/29/2022]
Abstract
Obstructive sleep apnea is linked to cardiovascular disease, metabolic disorders and dementia. The precise nature of the association between respiratory events in obstructive sleep apnea, cortical or subcortical arousals, and cognitive, autonomic and oxidative stress consequences remains incompletely elucidated. Previous studies have aimed to understand the relationship between obstructive sleep apnea and arousal patterns, as defined by the cyclic alternating pattern, but results have been inconsistent, in part likely due to the presence of associated comorbidities. To better define this relationship, we analysed cyclic alternating patterns in patients with obstructive sleep apnea without any additional comorbidities. We identified 18 adult male, non-obese subjects with obstructive sleep apnea and no other comorbidities or medication history, who underwent whole-night electroencephalography and polysomnography. Cyclic alternating pattern analysis was performed and verified by certified somnologists. Pairwise linear regression analysis demonstrated an inverse relationship between obstructive sleep apnea severity and cyclic alternating pattern subtype A1, and a direct correlation with cyclic alternating pattern subtype A3. Cyclic alternating pattern subtypes A1 prevail in milder obstructive sleep apnea phenotype, whilst cyclic alternating pattern subtypes A2 and A3 overcome among moderate-to-severe obstructive sleep apnea patients. The milder obstructive sleep apnea group also presented higher sleep efficiency, and increased percentages of non-rapid eye movement stage 3 and rapid eye movement sleep, as well as longer cyclic alternating pattern sequences in N3, while severe obstructive sleep apnea patients spent more time in lighter sleep stages. These results imply/suggest a balance between cyclic alternating pattern's adaptive and maladaptive arousal processes in obstructive sleep apnea of differing severities. In milder obstructive sleep apnea (apnea-hypopnea index < 20), sleep continuity may be reinforced by cyclic alternating pattern subtype A1, whereas in more severe obstructive sleep apnea, decompensation of these sleep-stabilizing mechanisms may occur and more intrusive cyclic alternating pattern fluctuations disrupt sleep circuitry.
Collapse
Affiliation(s)
- Valentina Gnoni
- Department of Neuroimaging, Sleep and Brain Plasticity Centre, Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King's College London, UK.,Sleep Disorders Centre, Guy's and St Thomas NHS Foundation Trust, London, UK
| | - Panagis Drakatos
- Department of Neuroimaging, Sleep and Brain Plasticity Centre, Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King's College London, UK.,Sleep Disorders Centre, Guy's and St Thomas NHS Foundation Trust, London, UK.,Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Sean Higgins
- Department of Neuroimaging, Sleep and Brain Plasticity Centre, Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King's College London, UK.,Sleep Disorders Centre, Guy's and St Thomas NHS Foundation Trust, London, UK
| | - Iain Duncan
- Department of Neuroimaging, Sleep and Brain Plasticity Centre, Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King's College London, UK.,Sleep Disorders Centre, Guy's and St Thomas NHS Foundation Trust, London, UK
| | - Danielle Wasserman
- Department of Neuroimaging, Sleep and Brain Plasticity Centre, Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King's College London, UK
| | - Renata Kabiljo
- Department of Neuroimaging, Sleep and Brain Plasticity Centre, Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King's College London, UK
| | - Carlotta Mutti
- Neurology Unit, Department of General Medicine, Parma University Hospital, Parma, Italy
| | - Peter Halasz
- National Institute of Clinical Neuroscience, Budapest, Hungary
| | - Peter J Goadsby
- NIHR-Wellcome Trust King's Clinical Research Facility, King's College London, London, UK
| | - Guy D Leschziner
- Department of Neuroimaging, Sleep and Brain Plasticity Centre, Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King's College London, UK.,Sleep Disorders Centre, Guy's and St Thomas NHS Foundation Trust, London, UK.,Department of Neurology, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Ivana Rosenzweig
- Department of Neuroimaging, Sleep and Brain Plasticity Centre, Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King's College London, UK.,Sleep Disorders Centre, Guy's and St Thomas NHS Foundation Trust, London, UK
| |
Collapse
|
13
|
Takakura AC, Malheiros-Lima MR, Moreira TS. Excitatory and inhibitory modulation of parafacial respiratory neurons in the control of active expiration. Respir Physiol Neurobiol 2021; 289:103657. [PMID: 33781931 DOI: 10.1016/j.resp.2021.103657] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 02/22/2021] [Accepted: 03/21/2021] [Indexed: 01/21/2023]
Abstract
In order to increase ventilation, the respiratory system engages active expiration through recruitment of abdominal muscles. Here, we reviewed the new advances in the modulation of parafacial respiratory (pF) region to trigger active expiration. In addition, we also made a comprehensive discussion of experiments indicating that the lateral aspect of the pF (pFL) is anatomically and functionally distinct from the adjacent and partially overlapping chemosensitive neurons of the ventral aspect of the pF (pFV) also named the retrotrapezoid nucleus. Recent evidence suggest a complex network responsible for the generation of active expiration and neuromodulatory systems that influence its activity. The activity of the pFL is tonically inhibited by inhibitory inputs and also receives excitatory inputs from chemoreceptors (central x peripheral) as well as from catecholaminergic C1 neurons. Therefore, the modulatory inputs and the physiological conditions under which these mechanisms are used to recruit active expiration and increase ventilation need further investigation.
Collapse
Affiliation(s)
- Ana C Takakura
- Department of Pharmacology, Instituto de Ciencias Biomedicas, Universidade de Sao Paulo, 05508-000, São Paulo, SP, Brazil.
| | - Milene R Malheiros-Lima
- Department of Physiology and Biophysics, Instituto de Ciencias Biomedicas, Universidade de Sao Paulo, 05508-000, São Paulo, SP, Brazil
| | - Thiago S Moreira
- Department of Physiology and Biophysics, Instituto de Ciencias Biomedicas, Universidade de Sao Paulo, 05508-000, São Paulo, SP, Brazil.
| |
Collapse
|
14
|
Moreira TS, Sobrinho CR, Falquetto B, Oliveira LM, Lima JD, Mulkey DK, Takakura AC. The retrotrapezoid nucleus and the neuromodulation of breathing. J Neurophysiol 2020; 125:699-719. [PMID: 33427575 DOI: 10.1152/jn.00497.2020] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Breathing is regulated by a host of arousal and sleep-wake state-dependent neuromodulators to maintain respiratory homeostasis. Modulators such as acetylcholine, norepinephrine, histamine, serotonin (5-HT), adenosine triphosphate (ATP), substance P, somatostatin, bombesin, orexin, and leptin can serve complementary or off-setting functions depending on the target cell type and signaling mechanisms engaged. Abnormalities in any of these modulatory mechanisms can destabilize breathing, suggesting that modulatory mechanisms are not overly redundant but rather work in concert to maintain stable respiratory output. The present review focuses on the modulation of a specific cluster of neurons located in the ventral medullary surface, named retrotrapezoid nucleus, that are activated by changes in tissue CO2/H+ and regulate several aspects of breathing, including inspiration and active expiration.
Collapse
Affiliation(s)
- Thiago S Moreira
- Department of Physiology and Biophysics, Instituto de Ciencias Biomedicas, Universidade de Sao Paulo (USP), São Paulo, Brazil
| | - Cleyton R Sobrinho
- Department of Physiology and Biophysics, Instituto de Ciencias Biomedicas, Universidade de Sao Paulo (USP), São Paulo, Brazil
| | - Barbara Falquetto
- Department of Pharmacology, Instituto de Ciencias Biomedicas, Universidade de Sao Paulo (USP), São Paulo, Brazil
| | - Luiz M Oliveira
- Department of Pharmacology, Instituto de Ciencias Biomedicas, Universidade de Sao Paulo (USP), São Paulo, Brazil
| | - Janayna D Lima
- Department of Physiology and Biophysics, Instituto de Ciencias Biomedicas, Universidade de Sao Paulo (USP), São Paulo, Brazil
| | - Daniel K Mulkey
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut
| | - Ana C Takakura
- Department of Pharmacology, Instituto de Ciencias Biomedicas, Universidade de Sao Paulo (USP), São Paulo, Brazil
| |
Collapse
|
15
|
Biancardi V, Saini J, Pageni A, Prashaad M. H, Funk GD, Pagliardini S. Mapping of the excitatory, inhibitory, and modulatory afferent projections to the anatomically defined active expiratory oscillator in adult male rats. J Comp Neurol 2020; 529:853-884. [DOI: 10.1002/cne.24984] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 06/29/2020] [Accepted: 07/05/2020] [Indexed: 01/21/2023]
Affiliation(s)
- Vivian Biancardi
- Department of Physiology University of Alberta Edmonton Canada
- Women and Children's Health Research Institute, Faculty of Medicine and Dentistry University of Alberta Edmonton Canada
| | - Jashan Saini
- Department of Physiology University of Alberta Edmonton Canada
| | - Anileen Pageni
- Department of Physiology University of Alberta Edmonton Canada
| | | | - Gregory D. Funk
- Department of Physiology University of Alberta Edmonton Canada
- Women and Children's Health Research Institute, Faculty of Medicine and Dentistry University of Alberta Edmonton Canada
- Neuroscience and Mental Health Institute University of Alberta Edmonton Canada
| | - Silvia Pagliardini
- Department of Physiology University of Alberta Edmonton Canada
- Women and Children's Health Research Institute, Faculty of Medicine and Dentistry University of Alberta Edmonton Canada
- Neuroscience and Mental Health Institute University of Alberta Edmonton Canada
| |
Collapse
|
16
|
Pisanski A, Ding X, Koch NA, Pagliardini S. Chemogenetic modulation of the parafacial respiratory group influences the recruitment of abdominal activity during REM sleep. Sleep 2020; 43:5634373. [PMID: 31747042 DOI: 10.1093/sleep/zsz283] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 11/01/2019] [Indexed: 12/21/2022] Open
Abstract
Current theories on respiratory control postulate that the respiratory rhythm is generated by oscillatory networks in the medulla: preBötzinger complex (preBötC) is the master oscillator responsible for generating inspiration, while parafacial respiratory group (pFRG) drives active expiration through recruitment of expiratory abdominal (ABD) muscle activity. Research addressing the role of pFRG in ventilation and rhythm generation across sleep states is limited. We recently reported the occurrence of ABD recruitment occurring despite the induction of muscle paralysis during REM sleep. This ABD recruitment was associated with increased tidal volume and regularization of the respiratory period in rats. As pFRG generates active expiration through the engagement of ABD muscles, we hypothesized that the expiratory oscillator is also responsible for the ABD recruitment observed during REM sleep. To test this hypothesis, we inhibited and activated pFRG using chemogenetics (i.e. designer receptors exclusively activated by designer drugs) while recording EEG and respiratory muscle EMG activities across sleep-wake cycles in male Sprague-Dawley rats. Our results suggest that inhibition of pFRG reduced the number of REM events expressing ABD recruitment, in addition to the intensity and prevalence of these events. Conversely, activation of pFRG resulted in an increase in the number of REM events in which ABD recruitment was observed, as well as the intensity and prevalence of ABD recruitment. Interestingly, modulation of pFRG activity did not affect ABD recruitment during NREM sleep or wakefulness. These results suggest that the occurrence of ABD recruitment during sleep is dependent on pFRG activity and is state dependent.
Collapse
Affiliation(s)
- Annette Pisanski
- Department of Physiology, University of Alberta, Edmonton, Alberta, Canada.,Women and Children's Health Research Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Xiuqing Ding
- Department of Physiology, University of Alberta, Edmonton, Alberta, Canada
| | - Nils A Koch
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Silvia Pagliardini
- Department of Physiology, University of Alberta, Edmonton, Alberta, Canada.,Women and Children's Health Research Institute, University of Alberta, Edmonton, Alberta, Canada.,Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada
| |
Collapse
|
17
|
O'Halloran KD. Pontine noradrenergic neurons facilitate pulmonary ventilation during hypercapnic stress: fight or flight - and breathe! Exp Physiol 2019; 105:5-6. [PMID: 31782170 DOI: 10.1113/ep088283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 11/26/2019] [Indexed: 11/08/2022]
Affiliation(s)
- Ken D O'Halloran
- Department of Physiology, School of Medicine, College of Medicine & Health, University College Cork, Cork, Ireland
| |
Collapse
|
18
|
Participation of GABA B Receptors of Parafacial Respiratory Group in the Regulation of Respiration in Rats. Bull Exp Biol Med 2019; 168:24-27. [PMID: 31745683 DOI: 10.1007/s10517-019-04637-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Indexed: 10/25/2022]
Abstract
The respiratory effects of microinjections of baclofen and 2-hydroxysaclofen into the parafacial respiratory group were studied in experiments on rats. It was shown that activation of GABAB receptors of the parafacial respiratory group suppressed external respiration due to a decrease in the tidal volume and inspiratory flow rate. In parallel, we observed a decrease in the amplitude and an increase in the duration of inspiratory bursts of the diaphragm. Injection of GABAB receptor blocker into the parafacial respiratory group increased pulmonary ventilation due to an increase in volumetric parameters of the inspiratory phase. This effect was accompanied by prolongation of expiration and lengthening of the intervals between the inspiratory bursts of the diaphragm. These results suggest that GABAB receptors of the parafacial respiratory group are an important element of the central mechanisms regulating the volumetric respiratory parameters and are involved in the regulation of the phases of the respiratory cycle.
Collapse
|
19
|
Magalhães KS, de Britto AA, Paton JFR, Moraes DJA. A6 neurons simultaneously modulate active expiration and upper airway resistance in rats. Exp Physiol 2019; 105:53-64. [PMID: 31675759 DOI: 10.1113/ep088164] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 10/23/2019] [Indexed: 12/30/2022]
Abstract
NEW FINDINGS What is the central question of this study? Do A6 neurons modulate active expiratory and airway responses evoked by hypercapnia/acidosis? What is the main finding and its importance? Acute inhibition of A6 neurons reduced active expiratory, inspiratory and the associated oropharyngeal and laryngeal motor responses to hypercapnia/acidosis. A6 neurons provide excitatory synaptic drive contributing to the central generation of inspiratory and expiratory motor activity as well as the control of upper airway resistance. ABSTRACT During rest, inspiration is an active phenomenon, whereas expiration is passive. Under conditions of high chemical drive, such as hypercapnia/acidosis, there is an increase in inspiratory activity, expiration becomes active and upper airway resistance is reduced. The locus coeruleus noradrenergic neurons (A6 neurons) are activated when exposed to elevated CO2 /[H+ ] levels and modulate respiratory brainstem neurons regulating ventilation. However, the role of A6 neurons in the control of upper airway resistance is not fully understood. We tested the hypothesis that A6 neurons contribute to the central generation of active inspiratory and expiratory responses and the associated changes in the motor nerves controlling upper airway resistance during hypercapnia/acidosis in rats. Using a perfused brainstem-spinal cord preparation, we inhibited A6 neurons using pharmacogenetics and evaluated the active expiratory (abdominal nerve), laryngeal (cervical vagus nerve), oropharyngeal (hypoglossal nerve) and inspiratory (phrenic nerve) motor nerve responses to hypercapnia/acidosis. Acute inhibition of A6 neurons did not produce significant changes in the respiratory pattern in normocapnia. However, the hypercapnia/acidosis-induced active expiratory response and the associated changes in the motor nerves responsible for control of oropharyngeal and laryngeal resistance, as well as the inspiratory response were all reduced after inhibition of A6 neurons. Our data demonstrate that A6 neurons exert an important excitatory synaptic drive to the central generation of both active inspiratory and expiratory activities and modulate the control of upper airway resistance during hypercapnia/acidosis.
Collapse
Affiliation(s)
- Karolyne S Magalhães
- School of Medicine of Ribeirão Preto, Department of Physiology, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Alan A de Britto
- School of Medicine of Ribeirão Preto, Department of Physiology, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Julian F R Paton
- Cardiovascular Autonomic Research Cluster, Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Davi J A Moraes
- School of Medicine of Ribeirão Preto, Department of Physiology, University of São Paulo, Ribeirão Preto, SP, Brazil
| |
Collapse
|
20
|
Balanced cholinergic modulation of spinal locomotor circuits via M2 and M3 muscarinic receptors. Sci Rep 2019; 9:14051. [PMID: 31575899 PMCID: PMC6773880 DOI: 10.1038/s41598-019-50452-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 09/12/2019] [Indexed: 01/05/2023] Open
Abstract
Neuromodulation ensures that neural circuits produce output that is flexible whilst remaining within an optimal operational range. The neuromodulator acetylcholine is released during locomotion to regulate spinal motor circuits. However, the range of receptors and downstream mechanisms by which acetylcholine acts have yet to be fully elucidated. We therefore investigated metabotropic acetylcholine receptor-mediated modulation by using isolated spinal cord preparations from neonatal mice in which locomotor-related output can be induced pharmacologically. We report that M2 receptor blockade decreases the frequency and amplitude of locomotor-related activity, whilst reducing its variability. In contrast, M3 receptor blockade destabilizes locomotor-related bursting. Motoneuron recordings from spinal cord slices revealed that activation of M2 receptors induces an outward current, decreases rheobase, reduces the medium afterhyperpolarization, shortens spike duration and decreases synaptic inputs. In contrast, M3 receptor activation elicits an inward current, increases rheobase, extends action potential duration and increases synaptic inputs. Analysis of miniature postsynaptic currents support that M2 and M3 receptors modulate synaptic transmission via different mechanisms. In summary, we demonstrate that M2 and M3 receptors have opposing modulatory actions on locomotor circuit output, likely reflecting contrasting cellular mechanisms of action. Thus, intraspinal cholinergic systems mediate balanced, multimodal control of spinal motor output.
Collapse
|
21
|
Silva JN, Oliveira LM, Souza FC, Moreira TS, Takakura AC. Distinct pathways to the parafacial respiratory group to trigger active expiration in adult rats. Am J Physiol Lung Cell Mol Physiol 2019; 317:L402-L413. [DOI: 10.1152/ajplung.00467.2018] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Active expiration (AE) is part of the breathing phase; it is conditional and occurs when we increase our metabolic demand, such as during hypercapnia, hypoxia, or exercise. The parafacial respiratory group (pFRG) is involved in AE. Data from the literature suggest that excitatory and the absence of inhibitory inputs to the pFRG are necessary to determine AE. However, the source of the inputs to the pFRG that trigger AE remains unclear. We show in adult urethane-anesthetized Wistar rats that the pharmacological inhibition of the medial aspect of the nucleus of the solitary tract (mNTS) or the rostral aspect of the pedunculopontine tegmental nucleus (rPPTg) is able to generate AE. In addition, direct inhibitory projection from the mNTS or indirect cholinergic projection from the rPPTg is able to contact pFRG to trigger AE. The inhibition of the mNTS or the rPPTg under conditions of high metabolic demand, such as hypercapnia (9–10% CO2), did not affect the AE. The present results suggest for the first time that inhibitory sources from the mNTS and a cholinergic pathway from the rPPTg, involving M2/M4 muscarinic receptors, could be important sources to modulate and sustain AE.
Collapse
Affiliation(s)
- Josiane N. Silva
- Department of Pharmacology, Institute of Biomedical Science, University of São Paulo, Sao Paulo, Brazil
| | - Luiz M. Oliveira
- Department of Pharmacology, Institute of Biomedical Science, University of São Paulo, Sao Paulo, Brazil
| | - Felipe C. Souza
- Department of Pharmacology, Institute of Biomedical Science, University of São Paulo, Sao Paulo, Brazil
| | - Thiago S. Moreira
- Department of Physiology and Biophysics, Institute of Biomedical Science, University of São Paulo, Sao Paulo, Brazil
| | - Ana C. Takakura
- Department of Pharmacology, Institute of Biomedical Science, University of São Paulo, Sao Paulo, Brazil
| |
Collapse
|
22
|
Abstract
Breathing is a well-described, vital and surprisingly complex behaviour, with behavioural and physiological outputs that are easy to directly measure. Key neural elements for generating breathing pattern are distinct, compact and form a network amenable to detailed interrogation, promising the imminent discovery of molecular, cellular, synaptic and network mechanisms that give rise to the behaviour. Coupled oscillatory microcircuits make up the rhythmic core of the breathing network. Primary among these is the preBötzinger Complex (preBötC), which is composed of excitatory rhythmogenic interneurons and excitatory and inhibitory pattern-forming interneurons that together produce the essential periodic drive for inspiration. The preBötC coordinates all phases of the breathing cycle, coordinates breathing with orofacial behaviours and strongly influences, and is influenced by, emotion and cognition. Here, we review progress towards cracking the inner workings of this vital core.
Collapse
|
23
|
Benarroch EE. Control of the cardiovascular and respiratory systems during sleep. Auton Neurosci 2019; 218:54-63. [DOI: 10.1016/j.autneu.2019.01.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 01/28/2019] [Accepted: 01/28/2019] [Indexed: 01/01/2023]
|
24
|
Lima JD, Sobrinho CR, Falquetto B, Santos LK, Takakura AC, Mulkey DK, Moreira TS. Cholinergic neurons in the pedunculopontine tegmental nucleus modulate breathing in rats by direct projections to the retrotrapezoid nucleus. J Physiol 2019; 597:1919-1934. [PMID: 30724347 DOI: 10.1113/jp277617] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Accepted: 02/04/2019] [Indexed: 12/14/2022] Open
Abstract
KEY POINTS Cholinergic projections from the pedunculopontine tegmental nucleus (PPTg) to the retrotrapezoid nucleus (RTN) are considered to be important for sleep-wake state-dependent control of breathing. The RTN also receives cholinergic input from the postinspiratory complex. Stimulation of the PPTg increases respiratory output under control conditions but not when muscarinic receptors in the RTN are blocked. The data obtained in the present study support the possibility that arousal-dependent modulation of breathing involves recruitment of cholinergic projections from the PPTg to the RTN. ABSTRACT The pedunculopontine tegmental nucleus (PPTg) in the mesopontine region has important physiological functions, including breathing control. The PPTg contains a variety of cell types, including cholinergic neurons that project to the rostral aspect of the ventrolateral medulla. In addition, cholinergic signalling in the retrotrapezoid nucleus (RTN), a region that contains neurons that regulate breathing in response to changes in CO2 /H+ , has been shown to activate chemosensitive neurons and increase inspiratory activity. The present study aimed to identify the source of cholinergic input to the RTN and determine whether cholinergic signalling in this region influences baseline breathing or the ventilatory response to CO2 in conscious male Wistar rats. Retrograde tracer Fluoro-Gold injected into the RTN labelled a subset of cholinergic PPTg neurons that presumably project directly to the chemosensitive region of the RTN. In unrestrained awake rats, unilateral injection of the glutamate (10 mm/100 nL) in the PPTg decreased tidal volume (VT ) but otherwise increased respiratory rate (fR ) and net respiratory output as indicated by an increase in ventilation (VE ). All respiratory responses elicited by PPTg stimulation were blunted by prior injection of methyl-atropine (5 mm/50-75 nL) into the RTN. These results show that stimulation of the PPTg can increase respiratory activity in part by cholinergic activation of chemosensitive elements of the RTN. Based on previous evidence that cholinergic PPTg projections may simultaneously activate expiratory output from the pFRG, we speculate that cholinergic signalling at the level of RTN region could also be involved in breathing regulation.
Collapse
Affiliation(s)
- Janayna D Lima
- Department of Physiology and Biophysics, University of São Paulo, São Paulo, SP, Brazil
| | - Cleyton R Sobrinho
- Department of Physiology and Biophysics, University of São Paulo, São Paulo, SP, Brazil
| | - Barbara Falquetto
- Department of Pharmacology, University of São Paulo, São Paulo, SP, Brazil
| | - Leonardo K Santos
- Department of Physiology and Biophysics, University of São Paulo, São Paulo, SP, Brazil
| | - Ana C Takakura
- Department of Pharmacology, University of São Paulo, São Paulo, SP, Brazil
| | - Daniel K Mulkey
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, USA
| | - Thiago S Moreira
- Department of Physiology and Biophysics, University of São Paulo, São Paulo, SP, Brazil
| |
Collapse
|
25
|
Ramirez JM, Baertsch N. Defining the Rhythmogenic Elements of Mammalian Breathing. Physiology (Bethesda) 2019; 33:302-316. [PMID: 30109823 DOI: 10.1152/physiol.00025.2018] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Breathing's remarkable ability to adapt to changes in metabolic, environmental, and behavioral demands stems from a complex integration of its rhythm-generating network within the wider nervous system. Yet, this integration complicates identification of its specific rhythmogenic elements. Based on principles learned from smaller rhythmic networks of invertebrates, we define criteria that identify rhythmogenic elements of the mammalian breathing network and discuss how they interact to produce robust, dynamic breathing.
Collapse
Affiliation(s)
- Jan-Marino Ramirez
- Center for Integrative Brain Research, Seattle Children's Research Institute, University of Washington School of Medicine , Seattle, Washington
| | - Nathan Baertsch
- Center for Integrative Brain Research, Seattle Children's Research Institute, University of Washington School of Medicine , Seattle, Washington
| |
Collapse
|
26
|
Benarroch EE. Brainstem integration of arousal, sleep, cardiovascular, and respiratory control. Neurology 2018; 91:958-966. [PMID: 30355703 DOI: 10.1212/wnl.0000000000006537] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
|
27
|
Magalhães KS, Spiller PF, da Silva MP, Kuntze LB, Paton JFR, Machado BH, Moraes DJA. Locus Coeruleus as a vigilance centre for active inspiration and expiration in rats. Sci Rep 2018; 8:15654. [PMID: 30353035 PMCID: PMC6199338 DOI: 10.1038/s41598-018-34047-w] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 10/08/2018] [Indexed: 01/05/2023] Open
Abstract
At rest, inspiration is an active process while expiration is passive. However, high chemical drive (hypercapnia or hypoxia) activates central and peripheral chemoreceptors triggering reflex increases in inspiration and active expiration. The Locus Coeruleus contains noradrenergic neurons (A6 neurons) that increase their firing frequency when exposed to hypercapnia and hypoxia. Using recently developed neuronal hyperpolarising technology in conscious rats, we tested the hypothesis that A6 neurons are a part of a vigilance centre for controlling breathing under high chemical drive and that this includes recruitment of active inspiration and expiration in readiness for flight or fight. Pharmacogenetic inhibition of A6 neurons was without effect on resting and on peripheral chemoreceptors-evoked inspiratory, expiratory and ventilatory responses. On the other hand, the number of sighs evoked by systemic hypoxia was reduced. In the absence of peripheral chemoreceptors, inhibition of A6 neurons during hypercapnia did not affect sighing, but reduced both the magnitude and incidence of active expiration, and the frequency and amplitude of inspiration. These changes reduced pulmonary ventilation. Our data indicated that A6 neurons exert a CO2-dependent modulation of expiratory drive. The data also demonstrate that A6 neurons contribute to the CO2-evoked increases in the inspiratory motor output and hypoxia-evoked sighing.
Collapse
Affiliation(s)
- Karolyne S Magalhães
- School of Medicine of Ribeirão Preto, Department of Physiology, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Pedro F Spiller
- School of Medicine of Ribeirão Preto, Department of Physiology, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Melina P da Silva
- School of Medicine of Ribeirão Preto, Department of Physiology, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Luciana B Kuntze
- School of Medicine of Ribeirão Preto, Department of Physiology, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Julian F R Paton
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences, University of Bristol, Bristol, UK.,Cardiovascular Autonomic Research Cluster, Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Benedito H Machado
- School of Medicine of Ribeirão Preto, Department of Physiology, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Davi J A Moraes
- School of Medicine of Ribeirão Preto, Department of Physiology, University of São Paulo, Ribeirão Preto, SP, Brazil.
| |
Collapse
|
28
|
Rajani V, Zhang Y, Jalubula V, Rancic V, SheikhBahaei S, Zwicker JD, Pagliardini S, Dickson CT, Ballanyi K, Kasparov S, Gourine AV, Funk GD. Release of ATP by pre-Bötzinger complex astrocytes contributes to the hypoxic ventilatory response via a Ca 2+ -dependent P2Y 1 receptor mechanism. J Physiol 2018; 596:3245-3269. [PMID: 28678385 PMCID: PMC6068109 DOI: 10.1113/jp274727] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 06/27/2017] [Indexed: 01/03/2023] Open
Abstract
KEY POINTS The ventilatory response to reduced oxygen (hypoxia) is biphasic, comprising an initial increase in ventilation followed by a secondary depression. Our findings indicate that, during hypoxia, astrocytes in the pre-Bötzinger complex (preBötC), a critical site of inspiratory rhythm generation, release a gliotransmitter that acts via P2Y1 receptors to stimulate ventilation and reduce the secondary depression. In vitro analyses reveal that ATP excitation of the preBötC involves P2Y1 receptor-mediated release of Ca2+ from intracellular stores. By identifying a role for gliotransmission and the sites, P2 receptor subtype, and signalling mechanisms via which ATP modulates breathing during hypoxia, these data advance our understanding of the mechanisms underlying the hypoxic ventilatory response and highlight the significance of purinergic signalling and gliotransmission in homeostatic control. Clinically, these findings are relevant to conditions in which hypoxia and respiratory depression are implicated, including apnoea of prematurity, sleep disordered breathing and congestive heart failure. ABSTRACT The hypoxic ventilatory response (HVR) is biphasic, consisting of a phase I increase in ventilation followed by a secondary depression (to a steady-state phase II) that can be life-threatening in premature infants who suffer from frequent apnoeas and respiratory depression. ATP released in the ventrolateral medulla oblongata during hypoxia attenuates the secondary depression. We explored a working hypothesis that vesicular release of ATP by astrocytes in the pre-Bötzinger Complex (preBötC) inspiratory rhythm-generating network acts via P2Y1 receptors to mediate this effect. Blockade of vesicular exocytosis in preBötC astrocytes bilaterally (using an adenoviral vector to specifically express tetanus toxin light chain in astrocytes) reduced the HVR in anaesthetized rats, indicating that exocytotic release of a gliotransmitter within the preBötC contributes to the hypoxia-induced increases in ventilation. Unilateral blockade of P2Y1 receptors in the preBötC via local antagonist injection enhanced the secondary respiratory depression, suggesting that a significant component of the phase II increase in ventilation is mediated by ATP acting at P2Y1 receptors. In vitro responses of the preBötC inspiratory network, preBötC inspiratory neurons and cultured preBötC glia to purinergic agents demonstrated that the P2Y1 receptor-mediated increase in fictive inspiratory frequency involves Ca2+ recruitment from intracellular stores leading to increases in intracellular Ca2+ ([Ca2+ ]i ) in inspiratory neurons and glia. These data suggest that ATP is released by preBötC astrocytes during hypoxia and acts via P2Y1 receptors on inspiratory neurons (and/or glia) to evoke Ca2+ release from intracellular stores and an increase in ventilation that counteracts the hypoxic respiratory depression.
Collapse
Affiliation(s)
- Vishaal Rajani
- Department of Physiology, Neuroscience and Mental Health Institute (NMHI), Women and Children's Health Research Institute (WCHRI), Faculty of Medicine and DentistryUniversity of AlbertaEdmontonAlbertaCanada
- Present address: Neurosciences & Mental Health, Peter Gilgan Centre for Research and Learning (PGCRL)The Hospital for Sick ChildrenTorontoOntarioCanada
| | - Yong Zhang
- Department of Physiology, Neuroscience and Mental Health Institute (NMHI), Women and Children's Health Research Institute (WCHRI), Faculty of Medicine and DentistryUniversity of AlbertaEdmontonAlbertaCanada
| | - Venkatesh Jalubula
- Department of Physiology, Neuroscience and Mental Health Institute (NMHI), Women and Children's Health Research Institute (WCHRI), Faculty of Medicine and DentistryUniversity of AlbertaEdmontonAlbertaCanada
| | - Vladimir Rancic
- Department of Physiology, Neuroscience and Mental Health Institute (NMHI), Women and Children's Health Research Institute (WCHRI), Faculty of Medicine and DentistryUniversity of AlbertaEdmontonAlbertaCanada
| | - Shahriar SheikhBahaei
- Cellular and Systems Neurobiology Section, National Institute of Neurological Disorders and Stroke (NINDS)National Institutes of Health (NIH)BethesdaMDUSA
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology & PharmacologyUniversity College LondonLondonUK
| | - Jennifer D. Zwicker
- Department of Physiology, Neuroscience and Mental Health Institute (NMHI), Women and Children's Health Research Institute (WCHRI), Faculty of Medicine and DentistryUniversity of AlbertaEdmontonAlbertaCanada
| | - Silvia Pagliardini
- Department of Physiology, Neuroscience and Mental Health Institute (NMHI), Women and Children's Health Research Institute (WCHRI), Faculty of Medicine and DentistryUniversity of AlbertaEdmontonAlbertaCanada
| | - Clayton T. Dickson
- Department of Psychology, Neuroscience and Mental Health Institute (NMHI)Faculty of ScienceEdmontonAlbertaCanada
| | - Klaus Ballanyi
- Department of Physiology, Neuroscience and Mental Health Institute (NMHI), Women and Children's Health Research Institute (WCHRI), Faculty of Medicine and DentistryUniversity of AlbertaEdmontonAlbertaCanada
| | - Sergey Kasparov
- Department of Physiology, Pharmacology and NeuroscienceUniversity of BristolBristolUK
| | - Alexander V. Gourine
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology & PharmacologyUniversity College LondonLondonUK
| | - Gregory D. Funk
- Department of Physiology, Neuroscience and Mental Health Institute (NMHI), Women and Children's Health Research Institute (WCHRI), Faculty of Medicine and DentistryUniversity of AlbertaEdmontonAlbertaCanada
| |
Collapse
|
29
|
Pisanski A, Pagliardini S. The parafacial respiratory group and the control of active expiration. Respir Physiol Neurobiol 2018; 265:153-160. [PMID: 29933053 DOI: 10.1016/j.resp.2018.06.010] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 06/11/2018] [Accepted: 06/18/2018] [Indexed: 11/16/2022]
Abstract
Breathing at rest is typically characterized by three phases: active inspiration, post-inspiration (or stage 1 expiration), and passive expiration (or stage 2 expiration). Breathing during periods of increased respiratory demand, on the other hand, engages active expiration through recruitment of abdominal muscles in order to increase ventilation. It is currently hypothesized that different phases of the respiratory rhythm are driven by three coupled oscillators: the preBötzinger Complex, driving inspiration, the parafacial respiratory group (pFRG), driving active expiration and the post-inspiratory Complex, driving post-inspiration. In this paper we review advances in the understanding of the pFRG and its role in the generation of active expiration across different developmental stages and vigilance states. Recent experiments suggest that the abdominal recruitment varies across development depending on the vigilance state, possibly following the maturation of the network responsible for the generation of active expiration and neuromodulatory systems that influence its activity. The activity of the pFRG is tonically inhibited by GABAergic inputs and strongly recruited by cholinergic systems. However, the sources of these modulatory inputs and the physiological conditions under which these mechanisms are used to recruit active expiration and increase ventilation need further investigation. Some evidence suggests that active expiration during hypercapnia is evoked through disinhibition, while during hypoxia it is elicited through activation of catecholaminergic C1 neurons. Finally, a discussion of experiments indicating that the pFRG is anatomically and functionally distinct from the adjacent and partially overlapping chemosensitive neurons of the retrotrapezoid nucleus is also presented.
Collapse
Affiliation(s)
- Annette Pisanski
- Department of Physiology, University of Alberta, Edmonton, AB, Canada; Women and Children's Research Institute, University of Alberta, Edmonton, AB, Canada
| | - Silvia Pagliardini
- Department of Physiology, University of Alberta, Edmonton, AB, Canada; Women and Children's Research Institute, University of Alberta, Edmonton, AB, Canada; Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada.
| |
Collapse
|
30
|
Inhibitory modulation of the cough reflex by acetylcholine in the caudal nucleus tractus solitarii of the rabbit. Respir Physiol Neurobiol 2018; 257:93-99. [PMID: 29369803 DOI: 10.1016/j.resp.2018.01.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Revised: 01/08/2018] [Accepted: 01/15/2018] [Indexed: 12/16/2022]
Abstract
A cholinergic system has been described in the nucleus tractus solitarii (NTS). However, no information is available on the role played by acetylcholine (ACh) in the modulation of the cough reflex within the caudal NTS that has an important function in cough regulation. We addressed this issue making use of bilateral microinjections (30-50 nl) of 10 mM ACh combined with 5 mM physostigmine as well as of 10 mM mecamylamine or 10 mM scopolamine into the caudal NTS of pentobarbital sodium-anesthetized, spontaneously breathing rabbits. Microinjections of ACh/physostigmine caused depressant effects on the cough reflex induced by mechanical and chemical stimulation of the tracheobronchial tree. They also elicited transient increases in respiratory frequency and decreases in abdominal activity. These effects were prevented by scopolamine, but not by mecamylamine. The results show for the first time that ACh exerts an inhibitory modulation of the cough reflex through muscarinic receptors within the caudal NTS. They also may provide hints for novel antitussive approaches.
Collapse
|
31
|
Leirão IP, Silva CA, Gargaglioni LH, da Silva GSF. Hypercapnia-induced active expiration increases in sleep and enhances ventilation in unanaesthetized rats. J Physiol 2017; 596:3271-3283. [PMID: 28776683 DOI: 10.1113/jp274726] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2017] [Accepted: 08/01/2017] [Indexed: 12/13/2022] Open
Abstract
KEY POINTS Expiratory muscles (abdominal and thoracic) can be recruited when respiratory drive increases under conditions of increased respiratory demand such as hypercapnia. Studying hypercapnia-induced active expiration in unanaesthetized rats importantly contributes to the understanding of how the control system is integrated in vivo in freely moving animals. In unanaesthetized rats, hypercapnia-induced active expiration was not always recruited either in wakefulness or in sleep, suggesting that additional factors influence the recruitment of active expiration. The pattern of abdominal muscle recruitment varied in a state-dependent manner with active expiration being more predominant in the sleep state than in quiet wakefulness. Pulmonary ventilation was enhanced in periods with active expiration compared to periods without it. ABSTRACT Expiration is passive at rest but becomes active through recruitment of abdominal muscles under increased respiratory drive. Hypercapnia-induced active expiration has not been well explored in unanaesthetized rats. We hypothesized that (i) CO2 -evoked active expiration is recruited in a state-dependent manner, i.e. differently in sleep or wakefulness, and (ii) recruitment of active expiration enhances ventilation, hence having an important functional role in meeting metabolic demand. To test these hypotheses, Wistar rats (280-330 g) were implanted with electrodes for EEG and electromyography EMG of the neck, diaphragm (DIA) and abdominal (ABD) muscles. Active expiratory events were considered as rhythmic ABDEMG activity interposed to DIAEMG . Animals were exposed to room air followed by hypercapnia (7% CO2 ) with EEG, EMG and ventilation ( V̇E ) recorded throughout the experimental protocol. No active expiration was observed during room air exposure. During hypercapnia, CO2 -evoked active expiration was predominantly recruited during non-rapid eye movement sleep. Its increased occurrence during sleep was evidenced by the decreased DIA-to-ADB ratio (1:1 ratio means that each DIA event is followed by an ABD event, indicating a high occurrence of ABD activity). Moreover, V̇E was also enhanced (P < 0.05) in periods with active expiration. V̇E had a positive correlation (P < 0.05) with the peak amplitude of ABDEMG activity. The data demonstrate strongly that hypercapnia-induced active expiration increases during sleep and provides an important functional role to support V̇E in conditions of increased respiratory demand.
Collapse
Affiliation(s)
- Isabela P Leirão
- Department of Animal Morphology and Physiology, College of Agricultural and Veterinary Sciences, São Paulo State University (FCAV-UNESP), Jaboticabal, SP, Brazil
| | - Carlos A Silva
- Department of Animal Morphology and Physiology, College of Agricultural and Veterinary Sciences, São Paulo State University (FCAV-UNESP), Jaboticabal, SP, Brazil
| | - Luciane H Gargaglioni
- Department of Animal Morphology and Physiology, College of Agricultural and Veterinary Sciences, São Paulo State University (FCAV-UNESP), Jaboticabal, SP, Brazil
| | - Glauber S F da Silva
- Department of Animal Morphology and Physiology, College of Agricultural and Veterinary Sciences, São Paulo State University (FCAV-UNESP), Jaboticabal, SP, Brazil
| |
Collapse
|
32
|
Brainstem mechanisms underlying the cough reflex and its regulation. Respir Physiol Neurobiol 2017; 243:60-76. [DOI: 10.1016/j.resp.2017.05.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 05/16/2017] [Accepted: 05/17/2017] [Indexed: 12/12/2022]
|
33
|
Affiliation(s)
- Ken D O'Halloran
- Department of Physiology, School of Medicine, University College Cork, Ireland
| |
Collapse
|