1
|
Krohn F, Novello M, van der Giessen RS, De Zeeuw CI, Pel JJM, Bosman LWJ. The integrated brain network that controls respiration. eLife 2023; 12:83654. [PMID: 36884287 PMCID: PMC9995121 DOI: 10.7554/elife.83654] [Citation(s) in RCA: 29] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 01/29/2023] [Indexed: 03/09/2023] Open
Abstract
Respiration is a brain function on which our lives essentially depend. Control of respiration ensures that the frequency and depth of breathing adapt continuously to metabolic needs. In addition, the respiratory control network of the brain has to organize muscular synergies that integrate ventilation with posture and body movement. Finally, respiration is coupled to cardiovascular function and emotion. Here, we argue that the brain can handle this all by integrating a brainstem central pattern generator circuit in a larger network that also comprises the cerebellum. Although currently not generally recognized as a respiratory control center, the cerebellum is well known for its coordinating and modulating role in motor behavior, as well as for its role in the autonomic nervous system. In this review, we discuss the role of brain regions involved in the control of respiration, and their anatomical and functional interactions. We discuss how sensory feedback can result in adaptation of respiration, and how these mechanisms can be compromised by various neurological and psychological disorders. Finally, we demonstrate how the respiratory pattern generators are part of a larger and integrated network of respiratory brain regions.
Collapse
Affiliation(s)
- Friedrich Krohn
- Department of Neuroscience, Erasmus MC, Rotterdam, Netherlands
| | - Manuele Novello
- Department of Neuroscience, Erasmus MC, Rotterdam, Netherlands
| | | | - Chris I De Zeeuw
- Department of Neuroscience, Erasmus MC, Rotterdam, Netherlands.,Netherlands Institute for Neuroscience, Royal Academy of Arts and Sciences, Amsterdam, Netherlands
| | - Johan J M Pel
- Department of Neuroscience, Erasmus MC, Rotterdam, Netherlands
| | | |
Collapse
|
2
|
Shandybina ND, Kuropatenko MV, Moshonkina TR. Regulation of Human Respiration by Electrical Stimulation. J EVOL BIOCHEM PHYS+ 2022; 58:1879-1891. [PMID: 36573159 PMCID: PMC9773692 DOI: 10.1134/s0022093022060175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 09/28/2022] [Accepted: 09/29/2022] [Indexed: 12/24/2022]
Abstract
The review addresses modern methods of electrical stimulation used to regulate the function of external respiration in humans. The methods include abdominal functional stimulation of respiratory muscles, diaphragmatic stimulation, phrenic nerve stimulation, epidural and transcutaneous spinal cord stimulation. The physiological rationale of their application is described along with the examples of their use in clinical practice, including stimulation parameters and electrode placement diagrams for each of the methods. We analyze the effectiveness of each of the methods in patients with respiratory muscle paresis and the features of their use depending on the level of spinal cord injury. Special attention is paid to the method of epidural spinal cord stimulation because this technique is widely used in electrophysiological studies on animal models, providing deeper insight into the spinal levels of the functional control of external respiration. The review substantiates the great potential of using the method of transcutaneous electrical spinal cord stimulation both in fundamental studies of external respiration and in clinical practice.
Collapse
Affiliation(s)
- N. D. Shandybina
- Pavlov Institute of Physiology, Russian Academy of Sciences, St. Petersburg, Russia
- Institute of Experimental Medicine, St. Petersburg, Russia
| | | | - T. R. Moshonkina
- Pavlov Institute of Physiology, Russian Academy of Sciences, St. Petersburg, Russia
| |
Collapse
|
3
|
Michel-Flutot P, Mansart A, Deramaudt TB, Jesus I, Lee KZ, Bonay M, Vinit S. Permanent diaphragmatic deficits and spontaneous respiratory plasticity in a mouse model of incomplete cervical spinal cord injury. Respir Physiol Neurobiol 2021; 284:103568. [DOI: 10.1016/j.resp.2020.103568] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 10/21/2020] [Accepted: 10/25/2020] [Indexed: 12/21/2022]
|
4
|
Kumar D, Talluri TR, Selokar NL, Hyder I, Kues WA. Perspectives of pluripotent stem cells in livestock. World J Stem Cells 2021; 13:1-29. [PMID: 33584977 PMCID: PMC7859985 DOI: 10.4252/wjsc.v13.i1.1] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 09/28/2020] [Accepted: 11/09/2020] [Indexed: 02/06/2023] Open
Abstract
The recent progress in derivation of pluripotent stem cells (PSCs) from farm animals opens new approaches not only for reproduction, genetic engineering, treatment and conservation of these species, but also for screening novel drugs for their efficacy and toxicity, and modelling of human diseases. Initial attempts to derive PSCs from the inner cell mass of blastocyst stages in farm animals were largely unsuccessful as either the cells survived for only a few passages, or lost their cellular potency; indicating that the protocols which allowed the derivation of murine or human embryonic stem (ES) cells were not sufficient to support the maintenance of ES cells from farm animals. This scenario changed by the innovation of induced pluripotency and by the development of the 3 inhibitor culture conditions to support naïve pluripotency in ES cells from livestock species. However, the long-term culture of livestock PSCs while maintaining the full pluripotency is still challenging, and requires further refinements. Here, we review the current achievements in the derivation of PSCs from farm animals, and discuss the potential application areas.
Collapse
Affiliation(s)
- Dharmendra Kumar
- Animal Physiology and Reproduction Division, ICAR-Central Institute for Research on Buffaloes, Hisar 125001, India.
| | - Thirumala R Talluri
- Equine Production Campus, ICAR-National Research Centre on Equines, Bikaner 334001, India
| | - Naresh L Selokar
- Animal Physiology and Reproduction Division, ICAR-Central Institute for Research on Buffaloes, Hisar 125001, India
| | - Iqbal Hyder
- Department of Physiology, NTR College of Veterinary Science, Gannavaram 521102, India
| | - Wilfried A Kues
- Department of Biotechnology, Friedrich-Loeffler-Institute, Federal Institute of Animal Health, Neustadt 31535, Germany
| |
Collapse
|
5
|
Trawczynski M, Liu G, David BT, Fessler RG. Restoring Motor Neurons in Spinal Cord Injury With Induced Pluripotent Stem Cells. Front Cell Neurosci 2019; 13:369. [PMID: 31474833 PMCID: PMC6707336 DOI: 10.3389/fncel.2019.00369] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 07/29/2019] [Indexed: 12/14/2022] Open
Abstract
Spinal cord injury (SCI) is a devastating neurological disorder that damages motor, sensory, and autonomic pathways. Recent advances in stem cell therapy have allowed for the in vitro generation of motor neurons (MNs) showing electrophysiological and synaptic activity, expression of canonical MN biomarkers, and the ability to graft into spinal lesions. Clinical translation, especially the transplantation of MN precursors in spinal lesions, has thus far been elusive because of stem cell heterogeneity and protocol variability, as well as a hostile microenvironment such as inflammation and scarring, which yield inconsistent pre-clinical results without a consensus best-practice therapeutic strategy. Induced pluripotent stem cells (iPSCs) in particular have lower ethical and immunogenic concerns than other stem cells, which could make them more clinically applicable. In this review, we focus on the differentiation of iPSCs into neural precursors, MN progenitors, mature MNs, and MN subtype fates. Previous reviews have summarized MN development and differentiation, but an up-to-date summary of technological and experimental advances holding promise for bench-to-bedside translation, especially those targeting individual MN subtypes in SCI, is currently lacking. We discuss biological mechanisms of MN lineage, recent experimental protocols and techniques for MN differentiation from iPSCs, and transplantation of neural precursors and MN lineage cells in spinal cord lesions to restore motor function. We emphasize efficient, clinically safe, and personalized strategies for the application of MN and their subtypes as therapy in spinal lesions.
Collapse
Affiliation(s)
- Matthew Trawczynski
- Department of Neurosurgery, Rush University Medical Center, Chicago, IL, United States
| | - Gele Liu
- Department of Neurosurgery, Rush University Medical Center, Chicago, IL, United States
| | - Brian T David
- Department of Neurosurgery, Rush University Medical Center, Chicago, IL, United States
| | - Richard G Fessler
- Department of Neurosurgery, Rush University Medical Center, Chicago, IL, United States
| |
Collapse
|
6
|
Ghali MGZ. The bulbospinal network controlling the phrenic motor system: Laterality and course of descending projections. Neurosci Res 2017; 121:7-17. [PMID: 28389264 DOI: 10.1016/j.neures.2017.03.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 03/06/2017] [Indexed: 11/17/2022]
Abstract
The respiratory rhythm is generated by the parafacial respiratory group, Bötzinger complex, and pre-Bötzinger complex and relayed to pre-motor neurons, which in turn project to and control respiratory motor outputs in the brainstem and spinal cord. The phrenic nucleus is one such target, containing phrenic motoneurons (PhMNs), which supply the diaphragm, the primary inspiratory muscle in mammals. While some investigators have demonstrated both ipsi- and contralateral bulbophrenic projections, there exists controversy regarding the relative physiological contribution of each to phasic and tonic drive to PhMNs and at which levels decussations occur. Following C1- or C2 spinal cord hemisection-induced silencing of the ipsilateral phrenic/diaphragm activity, respiratory stressor-induced, as well as spontaneous, recovery of crossed phrenic activity is observed, suggesting an important contribution of pathways crossing below the level of injury in driving phrenic motor output. The precise mechanisms underlying this recovery are debated. In this review, we seek to present a comprehensive discussion of the organization of the bulbospinal network controlling PhMNs, a thorough appreciation of which is necessary for understanding neural respiratory control, accurate interpretation of studies investigating respiratory recovery following spinal cord injury, and targeted development of therapies for respiratory neurorehabilitation in patients sustaining high cervical cord injury.
Collapse
Affiliation(s)
- Michael George Zaki Ghali
- Department of Neurobiology & Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, USA.
| |
Collapse
|
7
|
Abstract
The cervical spine is the most common site of traumatic vertebral column injuries. Respiratory insufficiency constitutes a significant proportion of the morbidity burden and is the most common cause of mortality in these patients. In seeking to enhance our capacity to treat specifically the respiratory dysfunction following spinal cord injury, investigators have studied the "crossed phrenic phenomenon", wherein contraction of a hemidiaphragm paralyzed by a complete hemisection of the ipsilateral cervical spinal cord above the phrenic nucleus can be induced by respiratory stressors and recovers spontaneously over time. Strengthening of latent contralateral projections to the phrenic nucleus and sprouting of new descending axons have been proposed as mechanisms contributing to the observed recovery. We have recently demonstrated recovery of spontaneous crossed phrenic activity occurring over minutes to hours in C1-hemisected unanesthetized decerebrate rats. The specific neurochemical and molecular pathways underlying crossed phrenic activity following injury require further clarification. A thorough understanding of these is necessary in order to develop targeted therapies for respiratory neurorehabilitation following spinal trauma. Animal studies provide preliminary evidence for the utility of neuropharmacological manipulation of serotonergic and adenosinergic pathways, nerve grafts, olfactory ensheathing cells, intraspinal microstimulation and a possible role for dorsal rhizotomy in recovering phrenic activity following spinal cord injury.
Collapse
|
8
|
Clinical potential of human-induced pluripotent stem cells : Perspectives of induced pluripotent stem cells. Cell Biol Toxicol 2016; 33:99-112. [PMID: 27900567 DOI: 10.1007/s10565-016-9370-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 11/18/2016] [Indexed: 02/06/2023]
Abstract
The recent establishment of induced pluripotent stem (iPS) cells promises the development of autologous cell therapies for degenerative diseases, without the ethical concerns associated with human embryonic stem (ES) cells. Initially, iPS cells were generated by retroviral transduction of somatic cells with core reprogramming genes. To avoid potential genotoxic effects associated with retroviral transfection, more recently, alternative non-viral gene transfer approaches were developed. Before a potential clinical application of iPS cell-derived therapies can be planned, it must be ensured that the reprogramming to pluripotency is not associated with genome mutagenesis or epigenetic aberrations. This may include direct effects of the reprogramming method or "off-target" effects associated with the reprogramming or the culture conditions. Thus, a rigorous safety testing of iPS or iPS-derived cells is imperative, including long-term studies in model animals. This will include not only rodents but also larger mammalian model species to allow for assessing long-term stability of the transplanted cells, functional integration into the host tissue, and freedom from undifferentiated iPS cells. Determination of the necessary cell dose is also critical; it is assumed that a minimum of 1 billion transplantable cells is required to achieve a therapeutic effect. This will request medium to long-term in vitro cultivation and dozens of cell divisions, bearing the risk of accumulating replication errors. Here, we review the clinical potential of human iPS cells and evaluate which are the most suitable approaches to overcome or minimize risks associated with the application of iPS cell-derived cell therapies.
Collapse
|
9
|
Neuroprotective and Neurorestorative Processes after Spinal Cord Injury: The Case of the Bulbospinal Respiratory Neurons. Neural Plast 2016; 2016:7692602. [PMID: 27563469 PMCID: PMC4987469 DOI: 10.1155/2016/7692602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 06/29/2016] [Indexed: 11/18/2022] Open
Abstract
High cervical spinal cord injuries interrupt the bulbospinal respiratory pathways projecting to the cervical phrenic motoneurons resulting in important respiratory defects. In the case of a lateralized injury that maintains the respiratory drive on the opposite side, a partial recovery of the ipsilateral respiratory function occurs spontaneously over time, as observed in animal models. The rodent respiratory system is therefore a relevant model to investigate the neuroplastic and neuroprotective mechanisms that will trigger such phrenic motoneurons reactivation by supraspinal pathways. Since part of this recovery is dependent on the damaged side of the spinal cord, the present review highlights our current understanding of the anatomical neuroplasticity processes that are developed by the surviving damaged bulbospinal neurons, notably axonal sprouting and rerouting. Such anatomical neuroplasticity relies also on coordinated molecular mechanisms at the level of the axotomized bulbospinal neurons that will promote both neuroprotection and axon growth.
Collapse
|
10
|
Abstract
Basic experimental stem cell research has opened up the possibility of many diverse clinical applications; however, translation to clinical trials has been restricted to only a few diseases. To broaden this clinical scope, pluripotent stem cell derivatives provide a uniquely scalable source of functional differentiated cells that can potentially repair damaged or diseased tissues to treat a wide spectrum of diseases and injuries. However, gathering sound data on their distribution, longevity, function and mechanisms of action in host tissues is imperative to realizing their clinical benefit. The large-scale availability of treatments involving pluripotent stem cells remains some years away, because of the long and demanding regulatory pathway that is needed to ensure their safety.
Collapse
|
11
|
Keomani E, Deramaudt TB, Petitjean M, Bonay M, Lofaso F, Vinit S. A murine model of cervical spinal cord injury to study post-lesional respiratory neuroplasticity. J Vis Exp 2014. [PMID: 24894020 DOI: 10.3791/51235] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
A cervical spinal cord injury induces permanent paralysis, and often leads to respiratory distress. To date, no efficient therapeutics have been developed to improve/ameliorate the respiratory failure following high cervical spinal cord injury (SCI). Here we propose a murine pre-clinical model of high SCI at the cervical 2 (C2) metameric level to study diverse post-lesional respiratory neuroplasticity. The technique consists of a surgical partial injury at the C2 level, which will induce a hemiparalysis of the diaphragm due to a deafferentation of the phrenic motoneurons from the respiratory centers located in the brainstem. The contralateral side of the injury remains intact and allows the animal recovery. Unlike other SCIs which affect the locomotor function (at the thoracic and lumbar level), the respiratory function does not require animal motivation and the quantification of the deficit/recovery can be easily performed (diaphragm and phrenic nerve recordings, whole body ventilation). This pre-clinical C2 SCI model is a powerful, useful, and reliable pre-clinical model to study various respiratory and non-respiratory neuroplasticity events at different levels (molecular to physiology) and to test diverse putative therapeutic strategies which might improve the respiration in SCI patients.
Collapse
Affiliation(s)
- Emilie Keomani
- UFR des sciences de la santé - Simone Veil, Université de Versailles Saint-Quentin-en-Yvelines
| | - Thérèse B Deramaudt
- UFR des sciences de la santé - Simone Veil, Université de Versailles Saint-Quentin-en-Yvelines
| | - Michel Petitjean
- UFR des sciences de la santé - Simone Veil, Université de Versailles Saint-Quentin-en-Yvelines; Service de Physiologie - Explorations fonctionnelles, Hôpital Ambroise Paré
| | - Marcel Bonay
- UFR des sciences de la santé - Simone Veil, Université de Versailles Saint-Quentin-en-Yvelines; Service de Physiologie - Explorations fonctionnelles, Hôpital Ambroise Paré
| | - Frédéric Lofaso
- UFR des sciences de la santé - Simone Veil, Université de Versailles Saint-Quentin-en-Yvelines; Services de Physiologie, Explorations Fonctionnelles, Réanimation Médicale et Centre d'Investigation Clinique et d'Innovation Technologique (Unité Inserm 805), Université de Versailles Saint-Quentin-en-Yvelines
| | - Stéphane Vinit
- UFR des sciences de la santé - Simone Veil, Université de Versailles Saint-Quentin-en-Yvelines;
| |
Collapse
|
12
|
Basoglu H, Kurtoglu T, Cetin NK, Bilgin MD, Kiylioglu N. Assessment of in vivo spinal cord conduction velocity in rats in an experimental model of ischemic spinal cord injury. Spinal Cord 2013; 51:616-22. [DOI: 10.1038/sc.2013.40] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Revised: 03/22/2013] [Accepted: 04/02/2013] [Indexed: 11/09/2022]
|
13
|
Diaphragm activation via high frequency spinal cord stimulation in a rodent model of spinal cord injury. Exp Neurol 2013; 247:689-93. [PMID: 23499833 DOI: 10.1016/j.expneurol.2013.03.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Revised: 03/01/2013] [Accepted: 03/04/2013] [Indexed: 01/25/2023]
Abstract
As demonstrated in a canine model, high frequency spinal cord stimulation (HF-SCS) is a novel and more physiologic method of electrical activation of the inspiratory muscles compared to current techniques. The dog model, however, has significant limitations due to cost and societal concerns. Since the rodent respiratory system is also a relevant model for the study of neuronal circuitry function, the aims of the present study were to a) assess the effects of HF-SCS and b) determine the methodology of application of this technique in rats. In 9 Sprague Dawley rats, diaphragm multiunit and single motor unit EMG activity were assessed during spontaneous breathing and HF-SCS applied on the ventral epidural surface of the spinal cord at the T2 level following C1 spinal section. As in dogs, HF-SCS results in the activation of the diaphragm at physiological firing frequencies and the generation of large inspired volumes. Mean maximum firing frequencies of the diaphragm during spontaneous breathing and HF-SCS were 23.3 ± 1.4 Hz (range: 9.8-51.6 Hz) and 26.6 ± 1.3 Hz; range: 12.0-72.9 Hz, respectively, at comparable inspired volumes. Moreover, HF-SCS was successful in pacing these animals over a 60-min period without evidence of system fatigue. Our results suggest that, similar to the dog model, HF-SCS in the rat results in the activation of spinal cord tracts which synapse with the phrenic motoneuron pool, allowing the processing of the stimulus and consequent physiologic activation of the inspiratory muscles. The rat may be a useful model for further studies evaluating phrenic motoneuron physiology.
Collapse
|
14
|
Extensive respiratory plasticity after cervical spinal cord injury in rats: Axonal sprouting and rerouting of ventrolateral bulbospinal pathways. Exp Neurol 2012; 236:88-102. [DOI: 10.1016/j.expneurol.2012.04.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Revised: 03/14/2012] [Accepted: 04/11/2012] [Indexed: 01/10/2023]
|
15
|
Reier PJ, Lane MA, Hall ED, Teng YD, Howland DR. Translational spinal cord injury research: preclinical guidelines and challenges. HANDBOOK OF CLINICAL NEUROLOGY 2012; 109:411-33. [PMID: 23098728 PMCID: PMC4288927 DOI: 10.1016/b978-0-444-52137-8.00026-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Advances in the neurobiology of spinal cord injury (SCI) have prompted increasing attention to opportunities for moving experimental strategies towards clinical applications. Preclinical studies are the centerpiece of the translational process. A major challenge is to establish strategies for achieving optimal translational progression while minimizing potential repetition of previous disappointments associated with clinical trials. This chapter reviews and expands upon views pertaining to preclinical design reported in recently published opinion surveys. Subsequent discussion addresses other preclinical considerations more specifically related to current and potentially imminent cellular and pharmacological approaches to acute/subacute and chronic SCI. Lastly, a retrospective and prospective analysis examines how guidelines currently under discussion relate to select examples of past, current, and future clinical translations. Although achieving definition of the "perfect" preclinical scenario is difficult to envision, this review identifies therapeutic robustness and independent replication of promising experimental findings as absolutely critical prerequisites for clinical translation. Unfortunately, neither has been fully embraced thus far. Accordingly, this review challenges the notion "everything works in animals and nothing in humans", since more rigor must first be incorporated into the bench-to-bedside translational process by all concerned, whether in academia, clinical medicine, or corporate circles.
Collapse
Affiliation(s)
- Paul J Reier
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, FL, USA.
| | | | | | | | | |
Collapse
|
16
|
Wewetzer K, Radtke C, Kocsis J, Baumgärtner W. Species-specific control of cellular proliferation and the impact of large animal models for the use of olfactory ensheathing cells and Schwann cells in spinal cord repair. Exp Neurol 2011; 229:80-7. [DOI: 10.1016/j.expneurol.2010.08.029] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Accepted: 08/22/2010] [Indexed: 10/19/2022]
|
17
|
Cormier CM, Mukhida K, Walker G, Marsh DR. Development of Autonomic Dysreflexia after Spinal Cord Injury Is Associated with a Lack of Serotonergic Axons in the Intermediolateral Cell Column. J Neurotrauma 2010; 27:1805-18. [PMID: 20698759 DOI: 10.1089/neu.2010.1441] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Christen M. Cormier
- Department of Anatomy and Neurobiology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Karim Mukhida
- Department of Anatomy and Neurobiology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Greg Walker
- Department of Anatomy and Neurobiology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Daniel R. Marsh
- Department of Anatomy and Neurobiology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| |
Collapse
|
18
|
Sandhu M, Dougherty B, Lane M, Bolser D, Kirkwood P, Reier P, Fuller D. Respiratory recovery following high cervical hemisection. Respir Physiol Neurobiol 2009; 169:94-101. [PMID: 19560562 PMCID: PMC2783827 DOI: 10.1016/j.resp.2009.06.014] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2009] [Revised: 06/09/2009] [Accepted: 06/19/2009] [Indexed: 01/16/2023]
Abstract
In this paper we review respiratory recovery following C2 spinal cord hemisection (C2HS) and introduce evidence for ipsilateral (IL) and contralateral (CL) phrenic motor neuron (PhrMN) synchrony post-C2HS. Rats have rapid, shallow breathing after C2HS but ventilation ( logical or (E)) is maintained. logical or (E) deficits occur during hypercapnic challenge reflecting reduced tidal volume (VT), but modest recovery occurs by 12 wks post-injury. IL PhrMN activity recovers in a time-dependent manner after C2HS, and neuroanatomical evidence suggests that this may involve both mono- and polysynaptic pathways. Accordingly, we used cross-correlation to examine IL and CL PhrMN synchrony after C2HS. Uninjured rats showed correlogram peaks consistent with synchronous activity and common synaptic input. Correlogram peaks were absent at 2 wks post-C2HS, but by 12 wks 50% of rats showed peaks occurring with a 1.1+/-0.19ms lag from zero on the abscissa. These data are consistent with prolonged conduction time to IL (vs. CL) PhrMNs and the possibility of polysynaptic inputs to IL PhrMNs after chronic C2HS.
Collapse
Affiliation(s)
- M.S. Sandhu
- Department of Physical Therapy College of Public Health and Health Professions McKnight Brain Institute University of Florida P.O. Box 100154, 100 S. Newell Drive Gainesville, FL 32610, USA
| | - B.J. Dougherty
- Department of Physical Therapy College of Public Health and Health Professions McKnight Brain Institute University of Florida P.O. Box 100154, 100 S. Newell Drive Gainesville, FL 32610, USA
- Department of Neuroscience College of Medicine McKnight Brain Institute University of Florida PO Box 100244 100 Newell Dr Gainesville FL 32610−0244, USA
| | - M.A. Lane
- Department of Neuroscience College of Medicine McKnight Brain Institute University of Florida PO Box 100244 100 Newell Dr Gainesville FL 32610−0244, USA
| | - D.C. Bolser
- Department of Physiological Sciences College of Veterinary Medicine PO Box 100144, 1600 SW Archer Rd Gainesville, FL 32610−0144, USA
| | - P.A. Kirkwood
- Sobell Dept for Motor Neuroscience and Movement Disorders UCL Institute of Neurology Queen Square, London WC1N 3BG United Kingdom
| | - P.J. Reier
- Department of Neuroscience College of Medicine McKnight Brain Institute University of Florida PO Box 100244 100 Newell Dr Gainesville FL 32610−0244, USA
| | - D.D. Fuller
- Department of Physical Therapy College of Public Health and Health Professions McKnight Brain Institute University of Florida P.O. Box 100154, 100 S. Newell Drive Gainesville, FL 32610, USA
| |
Collapse
|
19
|
Authier S, Legaspi M, Gauvin D, Troncy E. Respiratory safety pharmacology: Positive control drug responses in Sprague–Dawley rats, Beagle dogs and cynomolgus monkeys. Regul Toxicol Pharmacol 2009; 55:229-35. [DOI: 10.1016/j.yrtph.2009.07.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2009] [Revised: 07/23/2009] [Accepted: 07/24/2009] [Indexed: 11/28/2022]
|
20
|
Vinit S, Kastner A. Descending bulbospinal pathways and recovery of respiratory motor function following spinal cord injury. Respir Physiol Neurobiol 2009; 169:115-22. [PMID: 19682608 DOI: 10.1016/j.resp.2009.08.004] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2009] [Revised: 07/20/2009] [Accepted: 08/06/2009] [Indexed: 12/14/2022]
Abstract
The rodent respiratory system is a relevant model for study of the intrinsic post-lesion mechanisms of neuronal plasticity and resulting recovery after high cervical spinal cord injury. An unilateral cervical injury (hemisection, lateral section or contusion) interrupts unilaterally bulbospinal respiratory pathways to phrenic motor neurons innervating the diaphragm and leads to important respiratory defects on the injured side. However, the ipsilateral phrenic nerve exhibits a spontaneous and progressive recovery with post-lesion time. Shortly after a lateral injury, this partial recovery depends on the activation of contralateral pathways that cross the spinal midline caudal to the injury. Activation of these crossed phrenic pathways after the injury depends on the integrity of phrenic sensory afferents. These pathways are located principally in the lateral part of the spinal cord and involve 30% of the medullary respiratory neurons. By contrast, in chronic post-lesion conditions, the medial part of the spinal cord becomes sufficient to trigger substantial ipsilateral respiratory drive. Thus, after unilateral cervical spinal cord injury, respiratory reactivation is associated with a time-dependent anatomo-functional reorganization of the bulbospinal respiratory descending pathways, which represents an adaptative strategy for functional compensation.
Collapse
Affiliation(s)
- Stéphane Vinit
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI 53706-1102, USA.
| | | |
Collapse
|
21
|
Vinit S, Lovett-Barr MR, Mitchell GS. Intermittent hypoxia induces functional recovery following cervical spinal injury. Respir Physiol Neurobiol 2009; 169:210-7. [PMID: 19651247 DOI: 10.1016/j.resp.2009.07.023] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2009] [Revised: 07/20/2009] [Accepted: 07/27/2009] [Indexed: 12/13/2022]
Abstract
Respiratory-related complications are the leading cause of death in spinal cord injury (SCI) patients. Few effective SCI treatments are available after therapeutic interventions are performed in the period shortly after injury (e.g. spine stabilization and prevention of further spinal damage). In this review we explore the capacity to harness endogenous spinal plasticity induced by intermittent hypoxia to optimize function of surviving (spared) neural pathways associated with breathing. Two primary questions are addressed: (1) does intermittent hypoxia induce plasticity in spinal synaptic pathways to respiratory motor neurons following experimental SCI? and (2) can this plasticity improve respiratory function? In normal rats, intermittent hypoxia induces serotonin-dependent plasticity in spinal pathways to respiratory motor neurons. Early experiments suggest that intermittent hypoxia also enhances respiratory motor output in experimental models of cervical SCI (cervical hemisection) and that the capacity to induce functional recovery is greater with longer durations post-injury. Available evidence suggests that intermittent hypoxia-induced spinal plasticity has considerable therapeutic potential to treat respiratory insufficiency following chronic cervical spinal injury.
Collapse
Affiliation(s)
- Stéphane Vinit
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI 53706-1102, USA.
| | | | | |
Collapse
|
22
|
Fuller DD, Sandhu MS, Doperalski NJ, Lane MA, White TE, Bishop MD, Reier PJ. Graded unilateral cervical spinal cord injury and respiratory motor recovery. Respir Physiol Neurobiol 2008; 165:245-53. [PMID: 19150658 DOI: 10.1016/j.resp.2008.12.010] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2007] [Revised: 12/16/2008] [Accepted: 12/17/2008] [Indexed: 10/21/2022]
Abstract
We examined the potential contribution of ventromedial (VM) tissue sparing to respiratory recovery following chronic (1 mo) unilateral C2 spinal cord injury (SCI) in rats. Preserved white matter ipsilateral to the injury was quantitatively expressed relative to contralateral white matter. The ipsilateral-to-contralateral white matter ratio was 0 after complete C2 hemisection (C2HS) and 0.23+/-0.04 with minimal VM sparing. Inspiratory (breath min(-1)) and phrenic frequency (burst min(-1)), measured by plethysmography (conscious rats) and phrenic neurograms (anesthetized rats) respectively, were both lower with minimal VM sparing (p<0.05 vs. C2HS). Tidal volume also was greater in minimal VM sparing rats during a hypercapnic challenge (p<0.05 vs. C2HS). In other C2 hemilesioned rats with more extensive VM matter sparing (ipsilateral-to-contralateral white matter ratio=0.55+/-0.05), respiratory deficits were indicated at 1 mo post-injury by reduced ventilation during hypercapnic challenge (p<0.05 vs. uninjured). Anterograde (ventral respiratory column-to-spinal cord) neuroanatomical tracing studies showed that descending respiratory projections from the brainstem are present in VM tissue. We conclude that even relatively minimal sparing of VM tissue after C2 hemilesion can alter respiratory outcomes. In addition, respiratory deficits can emerge in the adult rat after high cervical SCI even when relatively extensive VM sparing occurs.
Collapse
Affiliation(s)
- D D Fuller
- Department of Physical Therapy, College of Public Health and Health Professions, McKnight Brain Institute, University of Florida, P.O. Box 100154, 100 S. Newell Drive, Gainesville, FL 32610, USA.
| | | | | | | | | | | | | |
Collapse
|