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Telias I, Beitler JR. Reverse Triggering, the Rhythm Dyssynchrony: Potential Implications for Lung and Diaphragm Protection. Am J Respir Crit Care Med 2021; 203:5-6. [PMID: 32841572 PMCID: PMC7781145 DOI: 10.1164/rccm.202008-3172ed] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Affiliation(s)
- Irene Telias
- Interdepartmental Division of Critical Care Medicine University of Toronto Toronto, Ontario, Canada.,Li Ka Shing Knowledge Institute St. Michael's Hospital Toronto, Ontario, Canada.,Department of Medicine University Health Network and Sinai Health System Toronto, Ontario, Canada
| | - Jeremy R Beitler
- Division of Pulmonary, Allergy, and Critical Care Medicine Columbia University New York, New York and.,Center for Acute Respiratory Failure New York-Presbyterian Hospital New York, New York
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2
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Abstract
Variability in cardiovascular spectra was first described by Stephan Hales in 1733. Traube and Hering initially noted respirophasic variation of the arterial pressure waveform in 1865 and Sigmund Mayer noted a lower frequency oscillation of the same in anesthetized rabbits in 1876. Very low frequency oscillations were noted by Barcroft and Nisimaru in 1932, likely representing vasogenic autorhythmicity. While the origins of Traube Hering and very low frequency oscillatory variability in cardiovascular spectra are well described, genesis mechanisms and functional significance of Mayer waves remain in controversy. Various theories have posited baroreflex and central supraspinal mechanisms for genesis of Mayer waves. Several studies have demonstrated the persistence of Mayer waves following high cervical transection, indicating a spinal capacity for genesis of these oscillations. We suggest a general tendency for central sympathetic neurons to oscillate at the Mayer wave frequency, the presence of multiple Mayer wave oscillators throughout the brainstem and spinal cord, and possible contemporaneous genesis by baroreflex and vasomotor mechanisms.
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Affiliation(s)
- George Zaki Ghali
- United States Environmental Protection Agency, Arlington, VA; Department of Toxicology, Purdue University, West Lafayette, IN, USA
| | - Michael George Zaki Ghali
- Department of Neurological Surgery, Houston Methodist Hospital, Houston, TX; Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Emil Zaki Ghali
- Department of Medicine, Inova Alexandria Hospital, Alexandria, VA, USA; Department of Cardiothoracic Surgery, El Gomhoureya General Hospital, Alexandria, Egypt
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3
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Cregg JM, Chu KA, Hager LE, Maggard RSJ, Stoltz DR, Edmond M, Alilain WJ, Philippidou P, Landmesser LT, Silver J. A Latent Propriospinal Network Can Restore Diaphragm Function after High Cervical Spinal Cord Injury. Cell Rep 2017; 21:654-665. [PMID: 29045834 PMCID: PMC5687843 DOI: 10.1016/j.celrep.2017.09.076] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 08/08/2017] [Accepted: 09/24/2017] [Indexed: 10/18/2022] Open
Abstract
Spinal cord injury (SCI) above cervical level 4 disrupts descending axons from the medulla that innervate phrenic motor neurons, causing permanent paralysis of the diaphragm. Using an ex vivo preparation in neonatal mice, we have identified an excitatory spinal network that can direct phrenic motor bursting in the absence of medullary input. After complete cervical SCI, blockade of fast inhibitory synaptic transmission caused spontaneous, bilaterally coordinated phrenic bursting. Here, spinal cord glutamatergic neurons were both sufficient and necessary for the induction of phrenic bursts. Direct stimulation of phrenic motor neurons was insufficient to evoke burst activity. Transection and pharmacological manipulations showed that this spinal network acts independently of medullary circuits that normally generate inspiration, suggesting a distinct non-respiratory function. We further show that this "latent" network can be harnessed to restore diaphragm function after high cervical SCI in adult mice and rats.
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Affiliation(s)
- Jared M Cregg
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Kevin A Chu
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Lydia E Hager
- Spinal Cord and Brain Injury Research Center, Department of Neuroscience, University of Kentucky College of Medicine, Lexington, KY 40536, USA
| | - Rachel S J Maggard
- Spinal Cord and Brain Injury Research Center, Department of Neuroscience, University of Kentucky College of Medicine, Lexington, KY 40536, USA
| | - Daimen R Stoltz
- Spinal Cord and Brain Injury Research Center, Department of Neuroscience, University of Kentucky College of Medicine, Lexington, KY 40536, USA
| | - Michaela Edmond
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Warren J Alilain
- Spinal Cord and Brain Injury Research Center, Department of Neuroscience, University of Kentucky College of Medicine, Lexington, KY 40536, USA
| | - Polyxeni Philippidou
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Lynn T Landmesser
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Jerry Silver
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH 44106, USA.
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4
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Delisle S, Charbonney E, Albert M, Ouellet P, Marsolais P, Rigollot M, Savary D, Richard JCM, Serri K. Patient–Ventilator Asynchrony due to Reverse Triggering Occurring in Brain-Dead Patients: Clinical Implications and Physiological Meaning. Am J Respir Crit Care Med 2016; 194:1166-1168. [DOI: 10.1164/rccm.201603-0483le] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Ghali MGZ, Marchenko V. Patterns of Phrenic Nerve Discharge after Complete High Cervical Spinal Cord Injury in the Decerebrate Rat. J Neurotrauma 2016; 33:1115-27. [DOI: 10.1089/neu.2015.4034] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Michael George Zaki Ghali
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania
| | - Vitaliy Marchenko
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania
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6
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Marchenko V, Ghali MGZ, Rogers RF. The role of spinal GABAergic circuits in the control of phrenic nerve motor output. Am J Physiol Regul Integr Comp Physiol 2015; 308:R916-26. [PMID: 25833937 DOI: 10.1152/ajpregu.00244.2014] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Accepted: 03/26/2015] [Indexed: 01/20/2023]
Abstract
While supraspinal mechanisms underlying respiratory pattern formation are well characterized, the contribution of spinal circuitry to the same remains poorly understood. In this study, we tested the hypothesis that intraspinal GABAergic circuits are involved in shaping phrenic motor output. To this end, we performed bilateral phrenic nerve recordings in anesthetized adult rats and observed neurogram changes in response to knocking down expression of both isoforms (65 and 67 kDa) of glutamate decarboxylase (GAD65/67) using microinjections of anti-GAD65/67 short-interference RNA (siRNA) in the phrenic nucleus. The number of GAD65/67-positive cells was drastically reduced on the side of siRNA microinjections, especially in the lateral aspects of Rexed's laminae VII and IX in the ventral horn of cervical segment C4, but not contralateral to microinjections. We hypothesize that intraspinal GABAergic control of phrenic output is primarily phasic, but also plays an important role in tonic regulation of phrenic discharge. Also, we identified respiration-modulated GABAergic interneurons (both inspiratory and expiratory) located slightly dorsal to the phrenic nucleus. Our data provide the first direct evidence for the existence of intraspinal GABAergic circuits contributing to the formation of phrenic output. The physiological role of local intraspinal inhibition, independent of descending direct bulbospinal control, is discussed.
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Affiliation(s)
- Vitaliy Marchenko
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania
| | - Michael G Z Ghali
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania
| | - Robert F Rogers
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania
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7
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Alilain WJ, Silver J. Shedding light on restoring respiratory function after spinal cord injury. Front Mol Neurosci 2009; 2:18. [PMID: 19893756 PMCID: PMC2773153 DOI: 10.3389/neuro.02.018.2009] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2009] [Accepted: 10/01/2009] [Indexed: 11/13/2022] Open
Abstract
Loss of respiratory function is one of the leading causes of death following spinal cord injury. Because of this, much work has been done in studying ways to restore respiratory function following spinal cord injury (SCI) – including pharmacological and regeneration strategies. With the emergence of new and powerful tools from molecular neuroscience, new therapeutically relevant alternatives to these approaches have become available, including expression of light sensitive proteins called channelrhodopsins. In this article we briefly review the history of various attempts to restore breathing after C2 hemisection, and focus on our recent work using the activation of light sensitive channels to restore respiratory function after experimental SCI. We also discuss how such light-induced activity can help shed light on the inner workings of the central nervous system respiratory circuitry that controls diaphragmatic function.
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Affiliation(s)
- Warren J Alilain
- Department of Neurosciences, Case Western Reserve University School of Medicine Cleveland, OH, USA
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Respiratory neuroplasticity and cervical spinal cord injury: translational perspectives. Trends Neurosci 2008; 31:538-47. [PMID: 18775573 DOI: 10.1016/j.tins.2008.07.002] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2008] [Revised: 07/10/2008] [Accepted: 07/17/2008] [Indexed: 12/18/2022]
Abstract
Paralysis of the diaphragm is a severe consequence of cervical spinal cord injury. This condition can be experimentally modeled by lateralized, high cervical lesions that interrupt descending inspiratory drive to the corresponding phrenic nucleus. Although partial recovery of ipsilateral diaphragm function occurs over time, recent findings show persisting chronic deficits in ventilation and phrenic motoneuron activity. Some evidence suggests, however, that spontaneous recovery can be enhanced by modulating neural pathways to phrenic motoneurons via synaptic circuitries which appear more complex than previously envisioned. The present review highlights these and other recent experimental multidisciplinary findings pertaining to respiratory neuroplasticity in the rat. Translational considerations are also emphasized, with specific attention directed at the clinical and interpretational strengths of different lesion models and outcome measures.
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