1
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Eilfort AM, Rasenack M, Zörner B, Curt A, Filli L. Evidence for reticulospinal plasticity underlying motor recovery in Brown-Séquard-plus Syndrome: a case report. Front Neurol 2024; 15:1335795. [PMID: 38895696 PMCID: PMC11183277 DOI: 10.3389/fneur.2024.1335795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Accepted: 05/10/2024] [Indexed: 06/21/2024] Open
Abstract
Brown-Séquard Syndrome (BSS) is a rare neurological condition caused by a unilateral spinal cord injury (SCI). Upon initial ipsilesional hemiplegia, patients with BSS typically show substantial functional recovery over time. Preclinical studies on experimental BSS demonstrated that spontaneous neuroplasticity in descending motor systems is a key mechanism promoting functional recovery. The reticulospinal (RS) system is one of the main descending motor systems showing a remarkably high ability for neuroplastic adaptations after incomplete SCI. In humans, little is known about the contribution of RS plasticity to functional restoration after SCI. Here, we investigated RS motor drive to different muscles in a subject with Brown-Séquard-plus Syndrome (BSPS) five months post-injury using the StartReact paradigm. RS drive was compared between ipsi- and contralesional muscles, and associated with measures of functional recovery. Additionally, corticospinal (CS) drive was investigated using transcranial magnetic stimulation (TMS) in a subset of muscles. The biceps brachii showed a substantial enhancement of RS drive on the ipsi- vs. contralesional side, whereas no signs of CS plasticity were found ipsilesionally. This finding implies that motor recovery of ipsilesional elbow flexion is primarily driven by the RS system. Results were inversed for the ipsilesional tibialis anterior, where RS drive was not augmented, but motor-evoked potentials recovered over six months post-injury, suggesting that CS plasticity contributed to improvements in ankle dorsiflexion. Our findings indicate that the role of RS and CS plasticity in motor recovery differs between muscles, with CS plasticity being essential for the restoration of distal extremity motor function, and RS plasticity being important for the functional recovery of proximal flexor muscles after SCI in humans.
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Affiliation(s)
- Antonia Maria Eilfort
- Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
- Department of Health Science and Technology, ETH Zurich, Zurich, Switzerland
| | - Maria Rasenack
- Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
| | - Björn Zörner
- Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
- Swiss Paraplegic Center and Swiss Paraplegic Research, Nottwil, Switzerland
| | - Armin Curt
- Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
| | - Linard Filli
- Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
- Swiss Center for Movement Analysis, Balgrist Campus AG, Zurich, Switzerland
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2
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Mi X, Chen ABY, Duarte D, Carey E, Taylor CR, Braaker PN, Bright M, Almeida RG, Lim JX, Ruetten VMS, Zheng W, Wang M, Reitman ME, Wang Y, Poskanzer KE, Lyons DA, Nimmerjahn A, Ahrens MB, Yu G. Fast, Accurate, and Versatile Data Analysis Platform for the Quantification of Molecular Spatiotemporal Signals. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.02.592259. [PMID: 38766026 PMCID: PMC11100599 DOI: 10.1101/2024.05.02.592259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Optical recording of intricate molecular dynamics is becoming an indispensable technique for biological studies, accelerated by the development of new or improved biosensors and microscopy technology. This creates major computational challenges to extract and quantify biologically meaningful spatiotemporal patterns embedded within complex and rich data sources, many of which cannot be captured with existing methods. Here, we introduce Activity Quantification and Analysis (AQuA2), a fast, accurate, and versatile data analysis platform built upon advanced machine learning techniques. It decomposes complex live imaging-based datasets into elementary signaling events, allowing accurate and unbiased quantification of molecular activities and identification of consensus functional units. We demonstrate applications across a wide range of biosensors, cell types, organs, animal models, and imaging modalities. As exemplar findings, we show how AQuA2 identified drug-dependent interactions between neurons and astroglia, and distinct sensorimotor signal propagation patterns in the mouse spinal cord.
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Affiliation(s)
- Xuelong Mi
- Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Arlington, VA 22203, USA
- These authors contributed equally
| | - Alex Bo-Yuan Chen
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
- Graduate Program in Neuroscience, Harvard Medical School, Boston, MA 02115, USA
- These authors contributed equally
| | - Daniela Duarte
- Waitt Advanced Biophotonics Center, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Erin Carey
- Waitt Advanced Biophotonics Center, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Charlotte R. Taylor
- Department of Biochemistry & Biophysics, University of California, San Francisco, CA, USA
- Neuroscience Graduate Program, University of California, San Francisco, CA, USA
| | - Philipp N. Braaker
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh BioQuarter, Edinburgh EH16 4SB, UK
| | - Mark Bright
- Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Arlington, VA 22203, USA
| | - Rafael G. Almeida
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh BioQuarter, Edinburgh EH16 4SB, UK
| | - Jing-Xuan Lim
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Virginia M. S. Ruetten
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
- Gatsby Computational Neuroscience Unit, UCL, London W1T 4JG, USA
| | - Wei Zheng
- Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Arlington, VA 22203, USA
| | - Mengfan Wang
- Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Arlington, VA 22203, USA
| | - Michael E. Reitman
- Department of Biochemistry & Biophysics, University of California, San Francisco, CA, USA
- Neuroscience Graduate Program, University of California, San Francisco, CA, USA
| | - Yizhi Wang
- Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Arlington, VA 22203, USA
| | - Kira E. Poskanzer
- Department of Biochemistry & Biophysics, University of California, San Francisco, CA, USA
- Neuroscience Graduate Program, University of California, San Francisco, CA, USA
- Kavli Institute for Fundamental Neuroscience, San Francisco, CA, USA
| | - David A. Lyons
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh BioQuarter, Edinburgh EH16 4SB, UK
| | - Axel Nimmerjahn
- Waitt Advanced Biophotonics Center, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Misha B. Ahrens
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Guoqiang Yu
- Department of Automation, Tsinghua University, Beijing 100084, China
- IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China
- Lead contact
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3
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He Y, Xu Y, Hai M, Feng Y, Liu P, Chen Z, Duan W. Exoskeleton-Assisted Rehabilitation and Neuroplasticity in Spinal Cord Injury. World Neurosurg 2024; 185:45-54. [PMID: 38320651 DOI: 10.1016/j.wneu.2024.01.167] [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: 10/23/2023] [Revised: 01/29/2024] [Accepted: 01/30/2024] [Indexed: 02/08/2024]
Abstract
Spinal cord injury (SCI) results in neurological deficits below the level of injury, causing motor dysfunction and various severe multisystem complications. Rehabilitative training plays a crucial role in the recovery of individuals with SCI, and exoskeleton serves as an emerging and promising tool for rehabilitation, especially in promoting neuroplasticity and alleviating SCI-related complications. This article reviews the classifications and research progresses of medical exoskeletons designed for SCI patients and describes their performances in practical application separately. Meanwhile, we discuss their mechanisms for enhancing neuroplasticity and functional remodeling, as well as their palliative impacts on secondary complications. The potential trends in exoskeleton design are raised according to current progress and requirements on SCI rehabilitation.
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Affiliation(s)
- Yana He
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China; School of Basic Medical Sciences, Capital Medical University, Beijing, China
| | - Yuxuan Xu
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China; School of Basic Medical Sciences, Capital Medical University, Beijing, China
| | - Minghang Hai
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China; School of Basic Medical Sciences, Capital Medical University, Beijing, China
| | - Yang Feng
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China; School of Basic Medical Sciences, Capital Medical University, Beijing, China
| | - Penghao Liu
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China; Lab of Spinal Cord Injury and Functional Reconstruction, China International Neuroscience Institute(CHINA-INI), Beijing, China
| | - Zan Chen
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China; Lab of Spinal Cord Injury and Functional Reconstruction, China International Neuroscience Institute(CHINA-INI), Beijing, China
| | - Wanru Duan
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China; Lab of Spinal Cord Injury and Functional Reconstruction, China International Neuroscience Institute(CHINA-INI), Beijing, China.
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4
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Dominguez-Bajo A, Clotman F. Potential Roles of Specific Subclasses of Premotor Interneurons in Spinal Cord Function Recovery after Traumatic Spinal Cord Injury in Adults. Cells 2024; 13:652. [PMID: 38667267 PMCID: PMC11048910 DOI: 10.3390/cells13080652] [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: 03/01/2024] [Revised: 04/04/2024] [Accepted: 04/05/2024] [Indexed: 04/28/2024] Open
Abstract
The differential expression of transcription factors during embryonic development has been selected as the main feature to define the specific subclasses of spinal interneurons. However, recent studies based on single-cell RNA sequencing and transcriptomic experiments suggest that this approach might not be appropriate in the adult spinal cord, where interneurons show overlapping expression profiles, especially in the ventral region. This constitutes a major challenge for the identification and direct targeting of specific populations that could be involved in locomotor recovery after a traumatic spinal cord injury in adults. Current experimental therapies, including electrical stimulation, training, pharmacological treatments, or cell implantation, that have resulted in improvements in locomotor behavior rely on the modulation of the activity and connectivity of interneurons located in the surroundings of the lesion core for the formation of detour circuits. However, very few publications clarify the specific identity of these cells. In this work, we review the studies where premotor interneurons were able to create new intraspinal circuits after different kinds of traumatic spinal cord injury, highlighting the difficulties encountered by researchers, to classify these populations.
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Affiliation(s)
- Ana Dominguez-Bajo
- Université catholique de Louvain, Louvain Institute of Biomolecular Science and Technology (LIBST), Animal Molecular and Cellular Biology Group (AMCB), Place Croix du Sud 4–5, 1348 Louvain la Neuve, Belgium
| | - Frédéric Clotman
- Université catholique de Louvain, Louvain Institute of Biomolecular Science and Technology (LIBST), Animal Molecular and Cellular Biology Group (AMCB), Place Croix du Sud 4–5, 1348 Louvain la Neuve, Belgium
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Scheuber MI, Guidolin C, Martins S, Sartori AM, Hofer AS, Schwab ME. Electrical stimulation of the cuneiform nucleus enhances the effects of rehabilitative training on locomotor recovery after incomplete spinal cord injury. Front Neurosci 2024; 18:1352742. [PMID: 38595973 PMCID: PMC11002271 DOI: 10.3389/fnins.2024.1352742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 03/13/2024] [Indexed: 04/11/2024] Open
Abstract
Most human spinal cord injuries are anatomically incomplete, leaving some fibers still connecting the brain with the sublesional spinal cord. Spared descending fibers of the brainstem motor control system can be activated by deep brain stimulation (DBS) of the cuneiform nucleus (CnF), a subnucleus of the mesencephalic locomotor region (MLR). The MLR is an evolutionarily highly conserved structure which initiates and controls locomotion in all vertebrates. Acute electrical stimulation experiments in female adult rats with incomplete spinal cord injury conducted in our lab showed that CnF-DBS was able to re-establish a high degree of locomotion five weeks after injury, even in animals with initially very severe functional deficits and white matter lesions up to 80-95%. Here, we analyzed whether CnF-DBS can be used to support medium-intensity locomotor training and long-term recovery in rats with large but incomplete spinal cord injuries. Rats underwent rehabilitative training sessions three times per week in an enriched environment, either with or without CnF-DBS supported hindlimb stepping. After 4 weeks, animals that trained under CnF-DBS showed a higher level of locomotor performance than rats that trained comparable distances under non-stimulated conditions. The MLR does not project to the spinal cord directly; one of its main output targets is the gigantocellular reticular nucleus in the medulla oblongata. Long-term electrical stimulation of spared reticulospinal fibers after incomplete spinal cord injury via the CnF could enhance reticulospinal anatomical rearrangement and in this way lead to persistent improvement of motor function. By analyzing the spared, BDA-labeled giganto-spinal fibers we found that their gray matter arborization density after discontinuation of CnF-DBS enhanced training was lower in the lumbar L2 and L5 spinal cord in stimulated as compared to unstimulated animals, suggesting improved pruning with stimulation-enhanced training. An on-going clinical study in chronic paraplegic patients investigates the effects of CnF-DBS on locomotor capacity.
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Affiliation(s)
- Myriam I. Scheuber
- Institute for Regenerative Medicine, University of Zurich, Schlieren, Switzerland
- ETH Phenomics Center, ETH Zurich, Zurich, Switzerland
| | - Carolina Guidolin
- Institute for Regenerative Medicine, University of Zurich, Schlieren, Switzerland
- ETH Phenomics Center, ETH Zurich, Zurich, Switzerland
| | - Suzi Martins
- Institute for Regenerative Medicine, University of Zurich, Schlieren, Switzerland
- ETH Phenomics Center, ETH Zurich, Zurich, Switzerland
| | - Andrea M. Sartori
- Institute for Regenerative Medicine, University of Zurich, Schlieren, Switzerland
- ETH Phenomics Center, ETH Zurich, Zurich, Switzerland
| | - Anna-Sophie Hofer
- Institute for Regenerative Medicine, University of Zurich, Schlieren, Switzerland
- ETH Phenomics Center, ETH Zurich, Zurich, Switzerland
- Department of Neurosurgery, University Hospital Zurich, Zurich, Switzerland
| | - Martin E. Schwab
- Institute for Regenerative Medicine, University of Zurich, Schlieren, Switzerland
- ETH Phenomics Center, ETH Zurich, Zurich, Switzerland
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6
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Brown BL, Anil N, States G, Whittemore SR, Magnuson DSK. Long ascending propriospinal neurons are heterogenous and subject to spinal cord injury induced anatomic plasticity. Exp Neurol 2024; 373:114631. [PMID: 38070723 PMCID: PMC10922963 DOI: 10.1016/j.expneurol.2023.114631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 11/15/2023] [Accepted: 11/29/2023] [Indexed: 12/21/2023]
Abstract
Long ascending propriospinal neurons (LAPNs) are a subset of spinal interneurons that provide direct connectivity between distant spinal segments. Here, we focus specifically on an anatomically defined population of "inter-enlargement" LAPNs with cell bodies at L2/3 and terminals at C5/6. Previous studies showed that silencing LAPNs in awake and freely moving animals disrupted interlimb coordination of the hindlimbs, forelimbs, and heterolateral limb pairs. Surprisingly, despite a proportion of LAPNs being anatomically intact post- spinal cord injury (SCI), silencing them improved locomotor function but only influenced coordination of the hindlimb pair. Given the functional significance of LAPNs pre- and post-SCI, we characterized their anatomy and SCI-induced anatomical plasticity. This detailed anatomical characterization revealed three morphologically distinct subsets of LAPNs that differ in soma size, neurite complexity and/or neurite orientation. Following a mild thoracic contusive SCI there was a marked shift in neurite orientation in two of the LAPN subsets to a more dorsoventral orientation, and collateral densities decreased in the cervical enlargement but increased just caudal to the injury epicenter. These post-SCI anatomical changes potentially reflect maladaptive plasticity and an effort to establish new functional inputs from sensory afferents that sprout post-SCI to achieve circuitry homeostasis.
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Affiliation(s)
- Brandon L Brown
- Interdisciplinary Program in Translational Neuroscience, University of Louisville, Louisville, KY, United States; Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, KY, United States; Department of Anatomical Sciences and Neurobiology, School of Medicine, University of Louisville, Louisville, KY, United States
| | - Neha Anil
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, KY, United States; Department of Bioengineering, J.B. Speed School of Engineering, University of Louisville, Louisville, KY, United States
| | - Gregory States
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, KY, United States; Department of Anatomical Sciences and Neurobiology, School of Medicine, University of Louisville, Louisville, KY, United States
| | - Scott R Whittemore
- Interdisciplinary Program in Translational Neuroscience, University of Louisville, Louisville, KY, United States; Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, KY, United States; Department of Anatomical Sciences and Neurobiology, School of Medicine, University of Louisville, Louisville, KY, United States; Department of Neurological Surgery, School of Medicine, University of Louisville, Louisville, KY, United States
| | - David S K Magnuson
- Interdisciplinary Program in Translational Neuroscience, University of Louisville, Louisville, KY, United States; Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, KY, United States; Department of Anatomical Sciences and Neurobiology, School of Medicine, University of Louisville, Louisville, KY, United States; Department of Bioengineering, J.B. Speed School of Engineering, University of Louisville, Louisville, KY, United States; Department of Neurological Surgery, School of Medicine, University of Louisville, Louisville, KY, United States.
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7
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Lemieux M, Karimi N, Bretzner F. Functional plasticity of glutamatergic neurons of medullary reticular nuclei after spinal cord injury in mice. Nat Commun 2024; 15:1542. [PMID: 38378819 PMCID: PMC10879492 DOI: 10.1038/s41467-024-45300-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 01/17/2024] [Indexed: 02/22/2024] Open
Abstract
Spinal cord injury disrupts the descending command from the brain and causes a range of motor deficits. Here, we use optogenetic tools to investigate the functional plasticity of the glutamatergic reticulospinal drive of the medullary reticular formation after a lateral thoracic hemisection in female mice. Sites evoking stronger excitatory descending drive in intact conditions are the most impaired after injury, whereas those associated with a weaker drive are potentiated. After lesion, pro- and anti-locomotor activities (that is, initiation/acceleration versus stop/deceleration) are overall preserved. Activating the descending reticulospinal drive improves stepping ability on a flat surface of chronically impaired injured mice, and its priming enhances recovery of skilled locomotion on a horizontal ladder. This study highlights the resilience and capacity for reorganization of the glutamatergic reticulospinal command after injury, along with its suitability as a therapeutical target to promote functional recovery.
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Affiliation(s)
- Maxime Lemieux
- Centre de Recherche du CHU de Québec, CHUL-Neurosciences, 2705 Boul. Laurier, Québec, QC, G1V 4G2, Canada
| | - Narges Karimi
- Centre de Recherche du CHU de Québec, CHUL-Neurosciences, 2705 Boul. Laurier, Québec, QC, G1V 4G2, Canada
- Faculty of Medicine, Department of Psychiatry and Neurosciences, Université Laval, Québec, QC, G1V 4G2, Canada
| | - Frederic Bretzner
- Centre de Recherche du CHU de Québec, CHUL-Neurosciences, 2705 Boul. Laurier, Québec, QC, G1V 4G2, Canada.
- Faculty of Medicine, Department of Psychiatry and Neurosciences, Université Laval, Québec, QC, G1V 4G2, Canada.
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Calderone A, Cardile D, De Luca R, Quartarone A, Corallo F, Calabrò RS. Brain Plasticity in Patients with Spinal Cord Injuries: A Systematic Review. Int J Mol Sci 2024; 25:2224. [PMID: 38396902 PMCID: PMC10888628 DOI: 10.3390/ijms25042224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 02/09/2024] [Accepted: 02/11/2024] [Indexed: 02/25/2024] Open
Abstract
A spinal cord injury (SCI) causes changes in brain structure and brain function due to the direct effects of nerve damage, secondary mechanisms, and long-term effects of the injury, such as paralysis and neuropathic pain (NP). Recovery takes place over weeks to months, which is a time frame well beyond the duration of spinal shock and is the phase in which the spinal cord remains unstimulated below the level of injury and is associated with adaptations occurring throughout the nervous system, often referred to as neuronal plasticity. Such changes occur at different anatomical sites and also at different physiological and molecular biological levels. This review aims to investigate brain plasticity in patients with SCIs and its influence on the rehabilitation process. Studies were identified from an online search of the PubMed, Web of Science, and Scopus databases. Studies published between 2013 and 2023 were selected. This review has been registered on OSF under (n) 9QP45. We found that neuroplasticity can affect the sensory-motor network, and different protocols or rehabilitation interventions can activate this process in different ways. Exercise rehabilitation training in humans with SCIs can elicit white matter plasticity in the form of increased myelin water content. This review has demonstrated that SCI patients may experience plastic changes either spontaneously or as a result of specific neurorehabilitation training, which may lead to positive outcomes in functional recovery. Clinical and experimental evidence convincingly displays that plasticity occurs in the adult CNS through a variety of events following traumatic or non-traumatic SCI. Furthermore, efficacy-based, pharmacological, and genetic approaches, alone or in combination, are increasingly effective in promoting plasticity.
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Affiliation(s)
- Andrea Calderone
- Graduate School of Health Psychology, Department of Clinical and Experimental Medicine, University of Messina, 98122 Messina, Italy;
| | - Davide Cardile
- IRCCS Centro Neurolesi Bonino-Pulejo, S.S. 113 Via Palermo, C.da Casazza, 98124 Messina, Italy
| | - Rosaria De Luca
- IRCCS Centro Neurolesi Bonino-Pulejo, S.S. 113 Via Palermo, C.da Casazza, 98124 Messina, Italy
| | - Angelo Quartarone
- IRCCS Centro Neurolesi Bonino-Pulejo, S.S. 113 Via Palermo, C.da Casazza, 98124 Messina, Italy
| | - Francesco Corallo
- IRCCS Centro Neurolesi Bonino-Pulejo, S.S. 113 Via Palermo, C.da Casazza, 98124 Messina, Italy
| | - Rocco Salvatore Calabrò
- IRCCS Centro Neurolesi Bonino-Pulejo, S.S. 113 Via Palermo, C.da Casazza, 98124 Messina, Italy
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Shepard CT, Brown BL, Van Rijswijck MA, Zalla RM, Burke DA, Morehouse JR, Riegler AS, Whittemore SR, Magnuson DSK. Silencing long-descending inter-enlargement propriospinal neurons improves hindlimb stepping after contusive spinal cord injuries. eLife 2023; 12:e82944. [PMID: 38099572 PMCID: PMC10776087 DOI: 10.7554/elife.82944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 12/13/2023] [Indexed: 01/10/2024] Open
Abstract
Spinal locomotor circuitry is comprised of rhythm generating centers, one for each limb, that are interconnected by local and long-distance propriospinal neurons thought to carry temporal information necessary for interlimb coordination and gait control. We showed previously that conditional silencing of the long ascending propriospinal neurons (LAPNs) that project from the lumbar to the cervical rhythmogenic centers (L1/L2 to C6), disrupts right-left alternation of both the forelimbs and hindlimbs without significantly disrupting other fundamental aspects of interlimb and speed-dependent coordination (Pocratsky et al., 2020). Subsequently, we showed that silencing the LAPNs after a moderate thoracic contusive spinal cord injury (SCI) resulted in better recovered locomotor function (Shepard et al., 2021). In this research advance, we focus on the descending equivalent to the LAPNs, the long descending propriospinal neurons (LDPNs) that have cell bodies at C6 and terminals at L2. We found that conditional silencing of the LDPNs in the intact adult rat resulted in a disrupted alternation of each limb pair (forelimbs and hindlimbs) and after a thoracic contusion SCI significantly improved locomotor function. These observations lead us to speculate that the LAPNs and LDPNs have similar roles in the exchange of temporal information between the cervical and lumbar rhythm generating centers, but that the partial disruption of the pathway after SCI limits the independent function of the lumbar circuitry. Silencing the LAPNs or LDPNs effectively permits or frees-up the lumbar circuitry to function independently.
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Affiliation(s)
- Courtney T Shepard
- Interdisciplinary Program in Translational Neuroscience, School of Interdisciplinary and Graduate Studies, University of LouisvilleLouisvilleUnited States
- Department of Anatomical Sciences and Neurobiology, University of LouisvilleLouisvilleUnited States
- Kentucky Spinal Cord Injury Research Center, University of LouisvilleLouisvilleUnited States
| | - Brandon L Brown
- Interdisciplinary Program in Translational Neuroscience, School of Interdisciplinary and Graduate Studies, University of LouisvilleLouisvilleUnited States
- Department of Anatomical Sciences and Neurobiology, University of LouisvilleLouisvilleUnited States
- Kentucky Spinal Cord Injury Research Center, University of LouisvilleLouisvilleUnited States
| | - Morgan A Van Rijswijck
- Kentucky Spinal Cord Injury Research Center, University of LouisvilleLouisvilleUnited States
- Speed School of Engineering, University of LouisvilleLouisvilleUnited States
| | - Rachel M Zalla
- Kentucky Spinal Cord Injury Research Center, University of LouisvilleLouisvilleUnited States
- Speed School of Engineering, University of LouisvilleLouisvilleUnited States
| | - Darlene A Burke
- Kentucky Spinal Cord Injury Research Center, University of LouisvilleLouisvilleUnited States
| | - Johnny R Morehouse
- Kentucky Spinal Cord Injury Research Center, University of LouisvilleLouisvilleUnited States
| | - Amberly S Riegler
- Kentucky Spinal Cord Injury Research Center, University of LouisvilleLouisvilleUnited States
| | - Scott R Whittemore
- Interdisciplinary Program in Translational Neuroscience, School of Interdisciplinary and Graduate Studies, University of LouisvilleLouisvilleUnited States
- Department of Anatomical Sciences and Neurobiology, University of LouisvilleLouisvilleUnited States
- Kentucky Spinal Cord Injury Research Center, University of LouisvilleLouisvilleUnited States
- Department of Neurological Surgery, University of LouisvilleLouisvilleUnited States
| | - David SK Magnuson
- Interdisciplinary Program in Translational Neuroscience, School of Interdisciplinary and Graduate Studies, University of LouisvilleLouisvilleUnited States
- Department of Anatomical Sciences and Neurobiology, University of LouisvilleLouisvilleUnited States
- Kentucky Spinal Cord Injury Research Center, University of LouisvilleLouisvilleUnited States
- Speed School of Engineering, University of LouisvilleLouisvilleUnited States
- Department of Neurological Surgery, University of LouisvilleLouisvilleUnited States
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10
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Li J, Shangguan Z, Ye X, Wang Z, Liu W, Chen G. Modified FGF Hydrogel for Effective Axon Formation by Enhanced Regeneration of Myelin Sheath of Schwann Cells Using Rat Model. Int J Nanomedicine 2023; 18:7225-7236. [PMID: 38076728 PMCID: PMC10710222 DOI: 10.2147/ijn.s417723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 11/09/2023] [Indexed: 12/18/2023] Open
Abstract
Introduction An acute spinal cord injury (SCI) is a debilitating event for which there is no targeted or effective treatment. Previous studies have shown that fibroblast growth factor (bFGF) and Schwann cells (SC) exert a protective effect on the injured tissues. Because of their easy injectability and strength, hydrogels are considered to be ideal candidates for creating loadable tissues. However, the application and mechanism of bFGF-hydrogels have not been explored. Methods We synthesized a new class of bFGF-hydrosol and evaluated its safety and biocompatibility in vitro and in vivo. Next, an SCI rat model was established to evaluate the effect of the hydrosol on an SCI by detecting various pro-inflammatory markers and evaluating the injury. The ability of hydrosol to promote axon formation was evaluated by detecting corresponding indexes, and its ability to promote remyelination was evaluated by detecting the corresponding indexes in Schwann cells. Results A novel in situ injectable hydrogel containing bFGF (HA-bFGF) was synthesized and found to have better biocompatibility than other gels. HA-bFGF helped to repair tissue damage after an SCI in vivo. Our mechanistic investigation also showed that HA-bFGF improved axon formation after an SCI by facilitating the regeneration of myelin sheath of Schwann cells. Conclusion In this study, we found that HA-bFGF could promote neural restoration and tissue recovery after an SCI. Our results indicate that hydrogels loaded with bFGF can alleviate a spinal cord injury by promoting the remyelination of Schwann cells, reducing inflammation at the injured site, and ultimately promoting axon generation.
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Affiliation(s)
- Jiandong Li
- Department of Orthopaedics, Fujian Medical University Union Hospital, Fuzhou, China
- Union Clinical College, Fujian Medical University, Fuzhou, China
| | - Zhitao Shangguan
- Department of Orthopaedics, Fujian Medical University Union Hospital, Fuzhou, China
- Union Clinical College, Fujian Medical University, Fuzhou, China
| | - Xiaoqing Ye
- Department of Orthopaedics, Fujian Medical University Union Hospital, Fuzhou, China
- Union Clinical College, Fujian Medical University, Fuzhou, China
| | - Zhenyu Wang
- Department of Orthopaedics, Fujian Medical University Union Hospital, Fuzhou, China
- Union Clinical College, Fujian Medical University, Fuzhou, China
| | - Wenge Liu
- Department of Orthopaedics, Fujian Medical University Union Hospital, Fuzhou, China
- Union Clinical College, Fujian Medical University, Fuzhou, China
| | - Gang Chen
- Department of Orthopaedics, Fujian Medical University Union Hospital, Fuzhou, China
- Union Clinical College, Fujian Medical University, Fuzhou, China
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11
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Xie Y, Zhang L, Guo S, Peng R, Gong H, Yang M. Changes in respiratory structure and function after traumatic cervical spinal cord injury: observations from spinal cord and brain. Front Neurol 2023; 14:1251833. [PMID: 37869136 PMCID: PMC10587692 DOI: 10.3389/fneur.2023.1251833] [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: 07/02/2023] [Accepted: 09/18/2023] [Indexed: 10/24/2023] Open
Abstract
Respiratory difficulties and mortality following severe cervical spinal cord injury (CSCI) result primarily from malfunctions of respiratory pathways and the paralyzed diaphragm. Nonetheless, individuals with CSCI can experience partial recovery of respiratory function through respiratory neuroplasticity. For decades, researchers have revealed the potential mechanism of respiratory nerve plasticity after CSCI, and have made progress in tissue healing and functional recovery. While most existing studies on respiratory plasticity after spinal cord injuries have focused on the cervical spinal cord, there is a paucity of research on respiratory-related brain structures following such injuries. Given the interconnectedness of the spinal cord and the brain, traumatic changes to the former can also impact the latter. Consequently, are there other potential therapeutic targets to consider? This review introduces the anatomy and physiology of typical respiratory centers, explores alterations in respiratory function following spinal cord injuries, and delves into the structural foundations of modified respiratory function in patients with CSCI. Additionally, we propose that magnetic resonance neuroimaging holds promise in the study of respiratory function post-CSCI. By studying respiratory plasticity in the brain and spinal cord after CSCI, we hope to guide future clinical work.
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Affiliation(s)
- Yongqi Xie
- School of Rehabilitation Medicine, Capital Medical University, Beijing, China
| | - Liang Zhang
- School of Rehabilitation Medicine, Capital Medical University, Beijing, China
| | - Shuang Guo
- School of Rehabilitation Medicine, Capital Medical University, Beijing, China
- Department of Rehabilitation, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Run Peng
- School of Rehabilitation Medicine, Capital Medical University, Beijing, China
| | - Huiming Gong
- School of Rehabilitation Medicine, Capital Medical University, Beijing, China
- Department of Spinal and Neural Functional Reconstruction, China Rehabilitation Research Center, Beijing, China
| | - Mingliang Yang
- School of Rehabilitation Medicine, Capital Medical University, Beijing, China
- Department of Spinal and Neural Functional Reconstruction, China Rehabilitation Research Center, Beijing, China
- Center of Neural Injury and Repair, Beijing Institute for Brain Disorders, Beijing, China
- Beijing Key Laboratory of Neural Injury and Rehabilitation, Beijing, China
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12
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Danner SM, Shepard CT, Hainline C, Shevtsova NA, Rybak IA, Magnuson DSK. Spinal control of locomotion before and after spinal cord injury. Exp Neurol 2023; 368:114496. [PMID: 37499972 PMCID: PMC10529867 DOI: 10.1016/j.expneurol.2023.114496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Revised: 07/10/2023] [Accepted: 07/23/2023] [Indexed: 07/29/2023]
Abstract
Thoracic spinal cord injury affects long propriospinal neurons that interconnect the cervical and lumbar enlargements. These neurons are crucial for coordinating forelimb and hindlimb locomotor movements in a speed-dependent manner. However, recovery from spinal cord injury is usually studied over a very limited range of speeds that may not fully expose circuitry dysfunction. To overcome this limitation, we investigated overground locomotion in rats trained to move over an extended distance with a wide range of speeds both pre-injury and after recovery from thoracic hemisection or contusion injuries. In this experimental context, intact rats expressed a speed-dependent continuum of alternating (walk and trot) and non-alternating (canter, gallop, half-bound gallop, and bound) gaits. After a lateral hemisection injury, rats recovered the ability to locomote over a wide range of speeds but lost the ability to use the highest-speed gaits (half-bound gallop and bound) and predominantly used the limb contralateral to the injury as lead during canter and gallop. A moderate contusion injury caused a greater reduction in maximal speed, loss of all non-alternating gaits, and emergence of novel alternating gaits. These changes resulted from weak fore-hind coupling together with appropriate control of left-right alternation. After hemisection, animals expressed a subset of intact gaits with appropriate interlimb coordination even on the side of the injury, where the long propriospinal connections were severed. These observations highlight how investigating locomotion over the full range of speeds can reveal otherwise hidden aspects of spinal locomotor control and post-injury recovery.
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Affiliation(s)
- Simon M Danner
- Department of Neurobiology and Anatomy, College of Medicine, Drexel University, Philadelphia, PA, USA.
| | - Courtney T Shepard
- Interdisciplinary Program in Translational Neuroscience, University of Louisville School of Medicine, Health Sciences Campus, Louisville, KY, USA
| | - Casey Hainline
- Speed School of Engineering, University of Louisville School of Medicine, Health Sciences Campus, Louisville, KY, USA
| | - Natalia A Shevtsova
- Department of Neurobiology and Anatomy, College of Medicine, Drexel University, Philadelphia, PA, USA
| | - Ilya A Rybak
- Department of Neurobiology and Anatomy, College of Medicine, Drexel University, Philadelphia, PA, USA
| | - David S K Magnuson
- Department of Neurological Surgery, University of Louisville School of Medicine, Health Sciences Campus, Louisville, KY, USA; Kentucky Spinal Cord Injury Research Center, University of Louisville School of Medicine, Health Sciences Campus, Louisville, KY, USA
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13
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Duguay M, Bonizzato M, Delivet-Mongrain H, Fortier-Lebel N, Martinez M. Uncovering and leveraging the return of voluntary motor programs after paralysis using a bi-cortical neuroprosthesis. Prog Neurobiol 2023; 228:102492. [PMID: 37414352 DOI: 10.1016/j.pneurobio.2023.102492] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 06/26/2023] [Accepted: 06/26/2023] [Indexed: 07/08/2023]
Abstract
Rehabilitative and neuroprosthetic approaches after spinal cord injury (SCI) aim to reestablish voluntary control of movement. Promoting recovery requires a mechanistic understanding of the return of volition over action, but the relationship between re-emerging cortical commands and the return of locomotion is not well established. We introduced a neuroprosthesis delivering targeted bi-cortical stimulation in a clinically relevant contusive SCI model. In healthy and SCI cats, we controlled hindlimb locomotor output by tuning stimulation timing, duration, amplitude, and site. In intact cats, we unveiled a large repertoire of motor programs. After SCI, the evoked hindlimb lifts were highly stereotyped, yet effective in modulating gait and alleviating bilateral foot drag. Results suggest that the neural substrate underpinning motor recovery had traded-off selectivity for efficacy. Longitudinal tests revealed that the return of locomotion after SCI was correlated with recovery of the descending drive, which advocates for rehabilitation interventions directed at the cortical target.
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Affiliation(s)
- Maude Duguay
- Département de Neurosciences and Centre interdisciplinaire de recherche sur le cerveau et l'apprentissage (CIRCA), Université de Montréal, Québec, Canada; CIUSSS du Nord-de-l'Île-de-Montréal, Québec, Canada
| | - Marco Bonizzato
- Département de Neurosciences and Centre interdisciplinaire de recherche sur le cerveau et l'apprentissage (CIRCA), Université de Montréal, Québec, Canada; CIUSSS du Nord-de-l'Île-de-Montréal, Québec, Canada; Department of Electrical Engineering, Polytechnique Montréal, Québec, Canada
| | - Hugo Delivet-Mongrain
- Département de Neurosciences and Centre interdisciplinaire de recherche sur le cerveau et l'apprentissage (CIRCA), Université de Montréal, Québec, Canada
| | - Nicolas Fortier-Lebel
- Département de Neurosciences and Centre interdisciplinaire de recherche sur le cerveau et l'apprentissage (CIRCA), Université de Montréal, Québec, Canada
| | - Marina Martinez
- Département de Neurosciences and Centre interdisciplinaire de recherche sur le cerveau et l'apprentissage (CIRCA), Université de Montréal, Québec, Canada; CIUSSS du Nord-de-l'Île-de-Montréal, Québec, Canada.
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14
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Toro CA, Hansen J, Siddiq MM, Johnson K, Cao J, Pero A, Iyengar R, Cai D, Cardozo CP. Synaptojanin 1 Modulates Functional Recovery After Incomplete Spinal Cord Injury in Male Apolipoprotein E Epsilon 4 Mice. Neurotrauma Rep 2023; 4:464-477. [PMID: 37528868 PMCID: PMC10389254 DOI: 10.1089/neur.2023.0023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/03/2023] Open
Abstract
Apolipoprotein E epsilon 4 (ApoE4) is the second most common variant of ApoE, being present in ∼14% of the population. Clinical reports identify ApoE4 as a genetic risk factor for poor outcomes after traumatic spinal cord injury (SCI) and spinal cord diseases such as cervical myelopathy. To date, there is no intervention to promote recovery of function after SCI/spinal cord diseases that is specifically targeted at ApoE4-associated impairment. Studies in the human and mouse brain link ApoE4 to elevated levels of synaptojanin 1 (synj1), a lipid phosphatase that degrades phosphoinositol 4,5-bisphosphate (PIP2) into inositol 4-monophosphate. Synj1 regulates rearrangements of the cytoskeleton as well as endocytosis and trafficking of synaptic vesicles. We report here that, as compared to ApoE3 mice, levels of synj1 messenger RNA and protein were elevated in spinal cords of healthy ApoE4 mice associated with lower PIP2 levels. Using a moderate-severity model of contusion SCI in mice, we found that genetic reduction of synj1 improved locomotor function recovery at 14 days after SCI in ApoE4 mice without altering spared white matter. Genetic reduction of synj1 did not alter locomotor recovery of ApoE3 mice after SCI. Bulk RNA sequencing revealed that at 14 days after SCI in ApoE4 mice, genetic reduction of synj1 upregulated genes involved in glutaminergic synaptic transmission just above and below the lesion. Overall, our findings provide evidence for a link between synj1 to poor outcomes after SCI in ApoE4 mice, up to 14 days post-injury, through mechanisms that may involve the function of excitatory glutaminergic neurons.
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Affiliation(s)
- Carlos A. Toro
- Spinal Cord Damage Research Center, James J. Peters VA Medical Center, Bronx, New York, USA
- Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Jens Hansen
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Mustafa M. Siddiq
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Kaitlin Johnson
- Spinal Cord Damage Research Center, James J. Peters VA Medical Center, Bronx, New York, USA
| | - Jiqing Cao
- Research and Development, James J. Peters VA Medical Center, Bronx, New York, USA
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Adriana Pero
- Research and Development, James J. Peters VA Medical Center, Bronx, New York, USA
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Ravi Iyengar
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Dongming Cai
- Neurology Service, James J. Peters VA Medical Center, Bronx, New York, USA
- Research and Development, James J. Peters VA Medical Center, Bronx, New York, USA
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Christopher P. Cardozo
- Spinal Cord Damage Research Center, James J. Peters VA Medical Center, Bronx, New York, USA
- Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Department of Rehabilitative Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
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15
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Germann M, Baker SN. Testing a Novel Wearable Device for Motor Recovery of the Elbow Extensor Triceps Brachii in Chronic Spinal Cord Injury. eNeuro 2023; 10:ENEURO.0077-23.2023. [PMID: 37460228 PMCID: PMC10399611 DOI: 10.1523/eneuro.0077-23.2023] [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: 02/22/2023] [Revised: 05/24/2023] [Accepted: 05/30/2023] [Indexed: 07/29/2023] Open
Abstract
After corticospinal tract damage, reticulospinal connections to motoneurons strengthen preferentially to flexor muscles. This could contribute to the disproportionately poor recovery of extensors often seen after spinal cord injury (SCI) and stroke. In this study, we paired electrical stimulation over the triceps muscle with auditory clicks, using a wearable device to deliver stimuli over a prolonged period of time. Healthy human volunteers wore the stimulation device for ∼6 h and a variety of electrophysiological assessments were used to measure changes in triceps motor output. In contrast to previous results in the biceps muscle, paired stimulation: (1) did not increase the StartReact effect; (2) did not decrease the suppression of responses to transcranial magnetic brain stimulation (TMS) following a loud sound; (3) did not enhance muscle responses elicited by a TMS coil oriented to induce anterior-posterior current. In a second study, chronic cervical SCI survivors wore the stimulation device for ∼4 h every day for four weeks; this was compared with a four-week period without wearing the device. Functional and electrophysiological assessments were repeated at week 0, week 4, and week 8. No significant changes were observed in electrophysiological assessments after paired stimulation. Functional measurements such as maximal force and variability and speed of trajectories made during a planar reaching task also remained unchanged. Our results suggest that the triceps muscle shows less potential for plasticity than biceps; pairing clicks with muscle stimulation does not seem beneficial in enhancing triceps recovery after SCI.
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Affiliation(s)
- Maria Germann
- Institute of Biosciences, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, United Kingdom
| | - Stuart N Baker
- Institute of Biosciences, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, United Kingdom
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16
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Cheng J, Guan NN. A fresh look at propriospinal interneurons plasticity and intraspinal circuits remodeling after spinal cord injury. IBRO Neurosci Rep 2023. [DOI: 10.1016/j.ibneur.2023.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023] Open
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17
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Danner SM, Shepard CT, Hainline C, Shevtsova NA, Rybak IA, Magnuson DS. Spinal control of locomotion before and after spinal cord injury. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.22.533794. [PMID: 36993490 PMCID: PMC10055332 DOI: 10.1101/2023.03.22.533794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
Abstract
Thoracic spinal cord injury affects long propriospinal neurons that interconnect the cervical and lumbar enlargements. These neurons are crucial for coordinating forelimb and hindlimb movements in a speed-dependent manner. At the same time, recovery from spinal cord injury is usually studied over a very limited range of speeds. To overcome this limitation, we investigated overground locomotion in rats over the full range of speeds pre-injury and after recovery from thoracic hemisection or contusion injuries. Intact rats expressed a speed-dependent continuum of alternating (walk and trot) and non-alternating (canter, gallop, half-bound gallop, and bound) gaits. After a lateral hemisection injury, rats recovered the ability to locomote over a wide range of speeds but lost the ability to move using the highest-speed gaits (half-bound gallop and bound) and predominantly used the limb contralateral to injury as lead during canter and gallop. A moderate contusion injury resulted in a greater reduction in maximal speed, loss of non-alternating gaits, and emergence of novel alternating gaits. Analysis of the gait structure in phase space and the variability of limb coupling suggests substantial reorganization of intraspinal pathways mediating interlimb coordination following recovery of locomotion after lateral hemisection or midline contusion injuries. This reorganization appears as an increased reliance on local enlargement circuitry and suggests that speed-dependent gait changes in the forelimbs rely on ascending information from the lumbar circuitry that is impaired post-injury. These observations highlight how investigating the full repertoire of locomotor speeds can reveal otherwise hidden aspects of spinal circuitry and post-injury reorganization.
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Affiliation(s)
- Simon M. Danner
- Department of Neurobiology and Anatomy, College of Medicine, Drexel University, Philadelphia, PA, USA
- For correspondence:
| | - Courtney T. Shepard
- Interdisciplinary Program in Translational Neuroscience, University of Louisville School of Medicine, Health Sciences Campus, Louisville, Kentucky, USA
| | - Casey Hainline
- Speed School of Engineering, University of Louisville School of Medicine, Health Sciences Campus, Louisville, Kentucky, USA
| | - Natalia A. Shevtsova
- Department of Neurobiology and Anatomy, College of Medicine, Drexel University, Philadelphia, PA, USA
| | - Ilya A. Rybak
- Department of Neurobiology and Anatomy, College of Medicine, Drexel University, Philadelphia, PA, USA
| | - David S.K. Magnuson
- Department of Neurological Surgery, University of Louisville School of Medicine, Health Sciences Campus, Louisville, Kentucky, USA
- Kentucky Spinal Cord Injury Research Center, University of Louisville School of Medicine, Health Sciences Campus, Louisville, Kentucky, USA
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18
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Roussel M, Lafrance-Zoubga D, Josset N, Lemieux M, Bretzner F. Functional contribution of mesencephalic locomotor region nuclei to locomotor recovery after spinal cord injury. Cell Rep Med 2023; 4:100946. [PMID: 36812893 PMCID: PMC9975330 DOI: 10.1016/j.xcrm.2023.100946] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 12/09/2022] [Accepted: 01/23/2023] [Indexed: 02/23/2023]
Abstract
Spinal cord injury (SCI) results in a disruption of information between the brain and the spinal circuit. Electrical stimulation of the mesencephalic locomotor region (MLR) can promote locomotor recovery in acute and chronic SCI rodent models. Although clinical trials are currently under way, there is still debate about the organization of this supraspinal center and which anatomic correlate of the MLR should be targeted to promote recovery. Combining kinematics, electromyographic recordings, anatomic analysis, and mouse genetics, our study reveals that glutamatergic neurons of the cuneiform nucleus contribute to locomotor recovery by enhancing motor efficacy in hindlimb muscles, and by increasing locomotor rhythm and speed on a treadmill, over ground, and during swimming in chronic SCI mice. In contrast, glutamatergic neurons of the pedunculopontine nucleus slow down locomotion. Therefore, our study identifies the cuneiform nucleus and its glutamatergic neurons as a therapeutical target to improve locomotor recovery in patients living with SCI.
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Affiliation(s)
- Marie Roussel
- Centre de Recherche du CHU de Québec, CHUL-Neurosciences, 2705 Boul. Laurier, Québec, QC G1V 4G2, Canada
| | - David Lafrance-Zoubga
- Centre de Recherche du CHU de Québec, CHUL-Neurosciences, 2705 Boul. Laurier, Québec, QC G1V 4G2, Canada
| | - Nicolas Josset
- Centre de Recherche du CHU de Québec, CHUL-Neurosciences, 2705 Boul. Laurier, Québec, QC G1V 4G2, Canada
| | - Maxime Lemieux
- Centre de Recherche du CHU de Québec, CHUL-Neurosciences, 2705 Boul. Laurier, Québec, QC G1V 4G2, Canada
| | - Frederic Bretzner
- Centre de Recherche du CHU de Québec, CHUL-Neurosciences, 2705 Boul. Laurier, Québec, QC G1V 4G2, Canada; Faculty of Medicine, Department of Psychiatry and Neurosciences, Université Laval, Québec, QC G1V 4G2, Canada.
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19
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Anderson MA, Squair JW, Gautier M, Hutson TH, Kathe C, Barraud Q, Bloch J, Courtine G. Natural and targeted circuit reorganization after spinal cord injury. Nat Neurosci 2022; 25:1584-1596. [PMID: 36396975 DOI: 10.1038/s41593-022-01196-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 10/05/2022] [Indexed: 11/18/2022]
Abstract
A spinal cord injury disrupts communication between the brain and the circuits in the spinal cord that regulate neurological functions. The consequences are permanent paralysis, loss of sensation and debilitating dysautonomia. However, the majority of circuits located above and below the injury remain anatomically intact, and these circuits can reorganize naturally to improve function. In addition, various neuromodulation therapies have tapped into these processes to further augment recovery. Emerging research is illuminating the requirements to reconstitute damaged circuits. Here, we summarize these natural and targeted reorganizations of circuits after a spinal cord injury. We also advocate for new concepts of reorganizing circuits informed by multi-omic single-cell atlases of recovery from injury. These atlases will uncover the molecular logic that governs the selection of 'recovery-organizing' neuronal subpopulations, and are poised to herald a new era in spinal cord medicine.
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Affiliation(s)
- Mark A Anderson
- NeuroX Institute, School of Life Sciences, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland.,Department of Clinical Neuroscience, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland.,Defitech Center for Interventional Neurotherapies (NeuroRestore), EPFL/CHUV/UNIL, Lausanne, Switzerland.,Wyss Center for Bio and Neuroengineering, Geneva, Switzerland
| | - Jordan W Squair
- NeuroX Institute, School of Life Sciences, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland.,Department of Clinical Neuroscience, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland.,Defitech Center for Interventional Neurotherapies (NeuroRestore), EPFL/CHUV/UNIL, Lausanne, Switzerland
| | - Matthieu Gautier
- NeuroX Institute, School of Life Sciences, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland.,Department of Clinical Neuroscience, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland.,Defitech Center for Interventional Neurotherapies (NeuroRestore), EPFL/CHUV/UNIL, Lausanne, Switzerland
| | - Thomas H Hutson
- NeuroX Institute, School of Life Sciences, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland.,Department of Clinical Neuroscience, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland.,Defitech Center for Interventional Neurotherapies (NeuroRestore), EPFL/CHUV/UNIL, Lausanne, Switzerland.,Wyss Center for Bio and Neuroengineering, Geneva, Switzerland
| | - Claudia Kathe
- NeuroX Institute, School of Life Sciences, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland.,Department of Clinical Neuroscience, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland.,Defitech Center for Interventional Neurotherapies (NeuroRestore), EPFL/CHUV/UNIL, Lausanne, Switzerland
| | - Quentin Barraud
- NeuroX Institute, School of Life Sciences, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland.,Department of Clinical Neuroscience, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland.,Defitech Center for Interventional Neurotherapies (NeuroRestore), EPFL/CHUV/UNIL, Lausanne, Switzerland
| | - Jocelyne Bloch
- NeuroX Institute, School of Life Sciences, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland.,Department of Clinical Neuroscience, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland.,Defitech Center for Interventional Neurotherapies (NeuroRestore), EPFL/CHUV/UNIL, Lausanne, Switzerland
| | - Grégoire Courtine
- NeuroX Institute, School of Life Sciences, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland. .,Department of Clinical Neuroscience, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland. .,Defitech Center for Interventional Neurotherapies (NeuroRestore), EPFL/CHUV/UNIL, Lausanne, Switzerland.
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20
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Lecomte CG, Mari S, Audet J, Merlet AN, Harnie J, Beaulieu C, Abdallah K, Gendron L, Rybak IA, Prilutsky BI, Frigon A. Modulation of the gait pattern during split-belt locomotion after lateral spinal cord hemisection in adult cats. J Neurophysiol 2022; 128:1593-1616. [PMID: 36382895 PMCID: PMC9744650 DOI: 10.1152/jn.00230.2022] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 11/10/2022] [Accepted: 11/10/2022] [Indexed: 11/17/2022] Open
Abstract
Most previous studies investigated the recovery of locomotion in animals and people with incomplete spinal cord injury (SCI) during relatively simple tasks (e.g., walking in a straight line on a horizontal surface or a treadmill). We know less about the recovery of locomotion after incomplete SCI in left-right asymmetric conditions, such as turning or stepping along circular trajectories. To investigate this, we collected kinematic and electromyography data during split-belt locomotion at different left-right speed differences before and after a right thoracic lateral spinal cord hemisection in nine adult cats. After hemisection, although cats still performed split-belt locomotion, we observed several changes in the gait pattern compared with the intact state at early (1-2 wk) and late (7-8 wk) time points. Cats with larger lesions showed new coordination patterns between the fore- and hindlimbs, with the forelimbs taking more steps. Despite this change in fore-hind coordination, cats maintained consistent phasing between the fore- and hindlimbs. Adjustments in cycle and phase (stance and swing) durations between the slow and fast sides allowed animals to maintain 1:1 left-right coordination. Periods of triple support involving the right (ipsilesional) hindlimb decreased in favor of quad support and triple support involving the other limbs. Step and stride lengths decreased with concurrent changes in the right fore- and hindlimbs, possibly to avoid interference. The above adjustments in the gait pattern allowed cats to retain the ability to locomote in asymmetric conditions after incomplete SCI. We discuss potential plastic neuromechanical mechanisms involved in locomotor recovery in these conditions.NEW & NOTEWORTHY Everyday locomotion often involves left-right asymmetries, when turning, walking along circular paths, stepping on uneven terrains, etc. To show how incomplete spinal cord injury affects locomotor control in asymmetric conditions, we collected data before and after a thoracic lateral spinal hemisection on a split-belt treadmill with one side stepping faster than the other. We show that adjustments in kinematics and muscle activity allowed cats to retain the ability to perform asymmetric locomotion after hemisection.
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Affiliation(s)
- Charly G Lecomte
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Stephen Mari
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Johannie Audet
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Angèle N Merlet
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Jonathan Harnie
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Claudie Beaulieu
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Khaled Abdallah
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Louis Gendron
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Ilya A Rybak
- Department of Neurobiology and Anatomy, College of Medicine, Drexel University, Philadelphia, Pennsylvania
| | - Boris I Prilutsky
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia
| | - Alain Frigon
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec, Canada
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21
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Sanganahalli BG, Pavuluri S, Chitturi J, Herman P, Elkabes S, Heary R, Hyder F, Kannurpatti SS. Lateralized Supraspinal Functional Connectivity Correlate with Pain and Motor Dysfunction in Rat Hemicontusion Cervical Spinal Cord Injury. Neurotrauma Rep 2022; 3:421-432. [PMID: 36337081 PMCID: PMC9622206 DOI: 10.1089/neur.2022.0040] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Afferent nociceptive activity in the reorganizing spinal cord after SCI influences supraspinal regions to establish pain. Clinical evidence of poor motor functional recovery in SCI patients with pain, led us to hypothesize that sensory-motor integration transforms into sensory-motor interference to manifest pain. This was tested by investigating supraspinal changes in a rat model of hemicontusion cervical SCI. Animals displayed ipsilateral forelimb motor dysfunction and pain, which persisted at 6 weeks after SCI. Using resting state fMRI at 8 weeks after SCI, RSFC across 14 ROIs involved in nociception, indicated lateral differences with a relatively weaker right-right connectivity (deafferented-contralateral) compared to left-left (unaffected-ipsilateral). However, the sensory (S1) and motor (M1/M2) networks showed greater RSFC using right hemisphere ROI seeds when compared to left. Voxel seeds from the somatosensory forelimb (S1FL) and M1/M2 representations reproduced the SCI-induced sensory and motor RSFC enhancements observed using the ROI seeds. Larger local connectivity occurred in the right sensory and motor networks amidst a decreasing overall local connectivity. This maladaptive reorganization of the right (deafferented) hemisphere localized the sensory component of pain emerging from the ipsilateral forepaw. A significant expansion of the sensory and motor network s overlap occurred globally after SCI when compared to sham, supporting the hypothesis that sensory and motor interference manifests pain. Voxel-seed based analysis revealed greater sensory and motor network overlap in the left hemisphere when compared to the right. This left predominance of the overlap suggested relatively larger pain processing in the unaffected hemisphere, when compared to the deafferented side.
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Affiliation(s)
- Basavaraju G. Sanganahalli
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Swathi Pavuluri
- Department of Radiology, Rutgers Biomedical and Health Sciences–New Jersey Medical School, Newark, New Jersey, USA
| | - Jyothsna Chitturi
- Department of Radiology, Rutgers Biomedical and Health Sciences–New Jersey Medical School, Newark, New Jersey, USA
| | - Peter Herman
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Stella Elkabes
- Department of Neurosurgery, Rutgers Biomedical and Health Sciences–New Jersey Medical School, Newark, New Jersey, USA
| | - Robert Heary
- Hackensack Meridian School of Medicine, Mountainside Medical Center, Montclair, New Jersey, USA
| | - Fahmeed Hyder
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Sridhar S. Kannurpatti
- Department of Radiology, Rutgers Biomedical and Health Sciences–New Jersey Medical School, Newark, New Jersey, USA.,Address correspondence to: Sridhar S. Kannurpatti, PhD, Department of Radiology, RUTGERS–New Jersey Medical School, MSB, F-506, 185 South Orange Avenue, Newark, NJ 07103, USA.
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22
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Samejima S, Henderson R, Pradarelli J, Mondello SE, Moritz CT. Activity-dependent plasticity and spinal cord stimulation for motor recovery following spinal cord injury. Exp Neurol 2022; 357:114178. [PMID: 35878817 DOI: 10.1016/j.expneurol.2022.114178] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 06/22/2022] [Accepted: 07/16/2022] [Indexed: 02/07/2023]
Abstract
Spinal cord injuries lead to permanent physical impairment despite most often being anatomically incomplete disruptions of the spinal cord. Remaining connections between the brain and spinal cord create the potential for inducing neural plasticity to improve sensorimotor function, even many years after injury. This narrative review provides an overview of the current evidence for spontaneous motor recovery, activity-dependent plasticity, and interventions for restoring motor control to residual brain and spinal cord networks via spinal cord stimulation. In addition to open-loop spinal cord stimulation to promote long-term neuroplasticity, we also review a more targeted approach: closed-loop stimulation. Lastly, we review mechanisms of spinal cord neuromodulation to promote sensorimotor recovery, with the goal of advancing the field of rehabilitation for physical impairments following spinal cord injury.
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Affiliation(s)
- Soshi Samejima
- International Collaboration on Repair Discoveries, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada; Department of Medicine, Division of Physical Medicine and Rehabilitation, Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Richard Henderson
- Department of Electrical and Computer Engineering, University of Washington, Seattle, WA, USA; Department of Rehabilitation Medicine, University of Washington, Seattle, WA, USA
| | - Jared Pradarelli
- Department of Rehabilitation Medicine, University of Washington, Seattle, WA, USA
| | - Sarah E Mondello
- Department of Rehabilitation Medicine, University of Washington, Seattle, WA, USA
| | - Chet T Moritz
- Department of Electrical and Computer Engineering, University of Washington, Seattle, WA, USA; Department of Rehabilitation Medicine, University of Washington, Seattle, WA, USA; Center for Neurotechnology, Seattle, WA, USA; Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA.
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23
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Wang Z, Romanski A, Mehra V, Wang Y, Brannigan M, Campbell BC, Petsko GA, Tsoulfas P, Blackmore MG. Brain-wide analysis of the supraspinal connectome reveals anatomical correlates to functional recovery after spinal injury. eLife 2022; 11:76254. [PMID: 35838234 PMCID: PMC9345604 DOI: 10.7554/elife.76254] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 07/12/2022] [Indexed: 11/15/2022] Open
Abstract
The supraspinal connectome is essential for normal behavior and homeostasis and consists of numerous sensory, motor, and autonomic projections from brain to spinal cord. Study of supraspinal control and its restoration after damage has focused mostly on a handful of major populations that carry motor commands, with only limited consideration of dozens more that provide autonomic or crucial motor modulation. Here, we assemble an experimental workflow to rapidly profile the entire supraspinal mesoconnectome in adult mice and disseminate the output in a web-based resource. Optimized viral labeling, 3D imaging, and registration to a mouse digital neuroanatomical atlas assigned tens of thousands of supraspinal neurons to 69 identified regions. We demonstrate the ability of this approach to clarify essential points of topographic mapping between spinal levels, measure population-specific sensitivity to spinal injury, and test the relationships between region-specific neuronal sparing and variability in functional recovery. This work will spur progress by broadening understanding of essential but understudied supraspinal populations.
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Affiliation(s)
- Zimei Wang
- Department of Biomedical Sciences, Marquette University, Milwaukee, United States
| | - Adam Romanski
- Department of Biomedical Sciences, Marquette University, Milwaukee, United States
| | - Vatsal Mehra
- Department of Biomedical Sciences, Marquette University, Milwaukee, United States
| | - Yunfang Wang
- Department of Neurological Surgery, University of Miami, Miami, United States
| | - Matthew Brannigan
- Department of Biomedical Sciences, Marquette University, Milwaukee, United States
| | - Benjamin C Campbell
- Helen and Robert Appel Alzheimer's Disease Research Institute, Cornell University, New York, United States
| | - Gregory A Petsko
- Helen and Robert Appel Alzheimer's Disease Research Institute, Cornell University, New York, United States
| | - Pantelis Tsoulfas
- Department of Neurological Surgery, University of Miami, Miami, United States
| | - Murray G Blackmore
- Department of Biomedical Sciences, Marquette University, Milwaukee, United States
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24
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Hofer AS, Scheuber MI, Sartori AM, Good N, Stalder SA, Hammer N, Fricke K, Schalbetter SM, Engmann AK, Weber RZ, Rust R, Schneider MP, Russi N, Favre G, Schwab ME. Stimulation of the cuneiform nucleus enables training and boosts recovery after spinal cord injury. Brain 2022; 145:3681-3697. [PMID: 35583160 PMCID: PMC9586551 DOI: 10.1093/brain/awac184] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Revised: 04/07/2022] [Accepted: 05/04/2022] [Indexed: 11/15/2022] Open
Abstract
Severe spinal cord injuries result in permanent paraparesis in spite of the frequent sparing of small portions of white matter. Spared fibre tracts are often incapable of maintaining and modulating the activity of lower spinal motor centres. Effects of rehabilitative training thus remain limited. Here, we activated spared descending brainstem fibres by electrical deep brain stimulation of the cuneiform nucleus of the mesencephalic locomotor region, the main control centre for locomotion in the brainstem, in adult female Lewis rats. We show that deep brain stimulation of the cuneiform nucleus enhances the weak remaining motor drive in highly paraparetic rats with severe, incomplete spinal cord injuries and enables high-intensity locomotor training. Stimulation of the cuneiform nucleus during rehabilitative aquatraining after subchronic (n = 8 stimulated versus n = 7 unstimulated versus n = 7 untrained rats) and chronic (n = 14 stimulated versus n = 9 unstimulated versus n = 9 untrained rats) spinal cord injury re-established substantial locomotion and improved long-term recovery of motor function. We additionally identified a safety window of stimulation parameters ensuring context-specific locomotor control in intact rats (n = 18) and illustrate the importance of timing of treatment initiation after spinal cord injury (n = 14). This study highlights stimulation of the cuneiform nucleus as a highly promising therapeutic strategy to enhance motor recovery after subchronic and chronic incomplete spinal cord injury with direct clinical applicability.
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Affiliation(s)
- Anna-Sophie Hofer
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland.,Institute for Regenerative Medicine, University of Zurich, 8952 Schlieren, Switzerland.,Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Myriam I Scheuber
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland.,Institute for Regenerative Medicine, University of Zurich, 8952 Schlieren, Switzerland.,Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Andrea M Sartori
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland.,Institute for Regenerative Medicine, University of Zurich, 8952 Schlieren, Switzerland.,Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Nicolas Good
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland.,Institute for Regenerative Medicine, University of Zurich, 8952 Schlieren, Switzerland.,Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Stephanie A Stalder
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland.,Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Nicole Hammer
- Institute for Regenerative Medicine, University of Zurich, 8952 Schlieren, Switzerland.,Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Kai Fricke
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland.,Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Sina M Schalbetter
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland.,Institute for Regenerative Medicine, University of Zurich, 8952 Schlieren, Switzerland.,Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Anne K Engmann
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland.,Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Rebecca Z Weber
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland.,Institute for Regenerative Medicine, University of Zurich, 8952 Schlieren, Switzerland.,Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Ruslan Rust
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland.,Institute for Regenerative Medicine, University of Zurich, 8952 Schlieren, Switzerland.,Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Marc P Schneider
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland.,Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Natalie Russi
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland.,Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Giacomin Favre
- Department of Economics, University of Zurich, 8032 Zurich, Switzerland
| | - Martin E Schwab
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland.,Institute for Regenerative Medicine, University of Zurich, 8952 Schlieren, Switzerland.,Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
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25
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Progression in translational research on spinal cord injury based on microenvironment imbalance. Bone Res 2022; 10:35. [PMID: 35396505 PMCID: PMC8993811 DOI: 10.1038/s41413-022-00199-9] [Citation(s) in RCA: 60] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Revised: 11/14/2021] [Accepted: 12/22/2021] [Indexed: 02/07/2023] Open
Abstract
Spinal cord injury (SCI) leads to loss of motor and sensory function below the injury level and imposes a considerable burden on patients, families, and society. Repair of the injured spinal cord has been recognized as a global medical challenge for many years. Significant progress has been made in research on the pathological mechanism of spinal cord injury. In particular, with the development of gene regulation, cell sequencing, and cell tracing technologies, in-depth explorations of the SCI microenvironment have become more feasible. However, translational studies related to repair of the injured spinal cord have not yielded significant results. This review summarizes the latest research progress on two aspects of SCI pathology: intraneuronal microenvironment imbalance and regenerative microenvironment imbalance. We also review repair strategies for the injured spinal cord based on microenvironment imbalance, including medications, cell transplantation, exosomes, tissue engineering, cell reprogramming, and rehabilitation. The current state of translational research on SCI and future directions are also discussed. The development of a combined, precise, and multitemporal strategy for repairing the injured spinal cord is a potential future direction.
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26
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Atkinson DA, Steele AG, Manson GA, Sheynin J, Oh J, Gerasimenko YP, Sayenko DG. Characterization of interlimb interaction via transcutaneous spinal stimulation of cervical and lumbar spinal enlargements. J Neurophysiol 2022; 127:1075-1085. [PMID: 35320019 PMCID: PMC8993515 DOI: 10.1152/jn.00456.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 03/17/2022] [Accepted: 03/21/2022] [Indexed: 11/22/2022] Open
Abstract
The use of transcutaneous electrical spinal stimulation (TSS) to modulate sensorimotor networks after neurological insult has garnered much attention from both researchers and clinicians in recent years. Although many different stimulation paradigms have been reported, the interlimb effects of these neuromodulation techniques have been little studied. The effects of multisite TSS on interlimb sensorimotor function are of particular interest in the context of neurorehabilitation, as these networks have been shown to be important for functional recovery after neurological insult. The present study utilized a condition-test paradigm to investigate the effects of interenlargement TSS on spinal motor excitability in both cervical and lumbosacral motor pools. Additionally, comparison was made between the conditioning effects of lumbosacral and cervical TSS and peripheral stimulation of the fibular nerve and ulnar nerve, respectively. In 16/16 supine, relaxed participants, facilitation of spinally evoked motor responses (sEMRs) in arm muscles was seen in response to lumbosacral TSS or fibular nerve stimulation, whereas facilitation of sEMRs in leg muscles was seen in response to cervical TSS or ulnar nerve stimulation. The decreased latency between TSS- and peripheral nerve-evoked conditioning implicates interlimb networks in the observed facilitation of motor output. The results demonstrate the ability of multisite TSS to engage interlimb networks, resulting in the bidirectional influence of cervical and lumbosacral motor output. The engagement of interlimb networks via TSS of the cervical and lumbosacral enlargements represents a feasible method for engaging spinal sensorimotor networks in clinical populations with compromised motor function.NEW & NOTEWORTHY Bidirectional interlimb modulation of spinal motor excitability can be evoked by transcutaneous spinal stimulation over the cervical and lumbosacral enlargements. Multisite transcutaneous spinal stimulation engages spinal sensorimotor networks thought to be important in the recovery of function after spinal cord injury.
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Affiliation(s)
- D. A. Atkinson
- Doctor of Physical Therapy program, University of St. Augustine for Health Sciences, Austin, Texas
- Department of Neurosurgery, Center for Neuroregeneration, Houston Methodist Research Institute, Houston, Texas
| | - A. G. Steele
- Department of Neurosurgery, Center for Neuroregeneration, Houston Methodist Research Institute, Houston, Texas
- Department of Electrical and Computer Engineering, University of Houston, Houston, Texas
| | - G. A. Manson
- Department of Neurosurgery, Center for Neuroregeneration, Houston Methodist Research Institute, Houston, Texas
- School of Kinesiology and Health Studies, Queen’s University, Kingston, Ontario, Canada
| | - J. Sheynin
- Department of Psychiatry and Behavioral Science, Texas A&M University Health Science Center, Houston, Texas
| | - J. Oh
- Department of Neurosurgery, Center for Neuroregeneration, Houston Methodist Research Institute, Houston, Texas
| | - Y. P. Gerasimenko
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky
- Department of Physiology, University of Louisville, Louisville, Kentucky
- Pavlov Institute of Physiology, St. Petersburg, Russia
| | - D. G. Sayenko
- Department of Neurosurgery, Center for Neuroregeneration, Houston Methodist Research Institute, Houston, Texas
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27
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Ren X, Zhang W, Mo J, Qin J, Chen Y, Han J, Feng X, Han L, Feng S, Liang H, Cen L, Wu X, Huang C, Deng H, Cao Z, Yao H, Lan R, Wang X, Ren S. Partial Restoration of Spinal Cord Neural Continuity via Sural Nerve Transplantation Using a Technique of Spinal Cord Fusion. Front Neurosci 2022; 16:808983. [PMID: 35237120 PMCID: PMC8882688 DOI: 10.3389/fnins.2022.808983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 01/24/2022] [Indexed: 11/13/2022] Open
Abstract
BackgroundSpinal cord injury (SCI) can cause paralysis and serious chronic morbidity, and there is no effective treatment. Based on our previous experimental results of spinal cord fusion (SCF) in mice, rats, beagles, and monkeys, we developed a surgical protocol of SCF for paraplegic human patients. We designed a novel surgical procedure of SCF, called sural nerve transplantation (SNT), for human patients with lower thoracic SCI and distal cord dysfunction.MethodsWe conducted a clinical trial (ChiCTR2000030788) and performed SNT in 12 fully paraplegic patients due to SCI between T1 and T12. We assessed pre- and postoperative central nerve pain, motor function, sensory function, and autonomic nerve function. Conduction of action potentials across the sural nerve transplant was evaluated. Neural continuity was also examined by diffusion tensor imaging (DTI).ResultsAmong the 12 paraplegic patients enrolled in this clinical trial, seven patients demonstrated improved autonomic nerve functions. Seven patients had clinically significant relief of their symptoms of cord central pain. One patient, however, developed postoperative cord central pain (VAS: 4). Five patients had varying degrees of recovered sensory and/or motor functions below the single neurologic level 1 month after surgery. One patient showed recovery of electrophysiologic, motor-evoked potentials 6 months after the operation. At 6 months after surgery, DTI indicated fusion and nerve connections of white cord and sural nerves in seven patients.ConclusionSNT was able to fuse the axonal stumps of white cord and sural nerve and at least partially improve the cord central pain in most patients. Although SNT did not restore the spinal cord continuity in white matter in some patients, SNT could restore spinal cord continuity in the cortico-trunco-reticulo-propriospinal pathway, thereby restoring in part some motor and sensory functions. SNT may therefore be a safe, feasible, and effective method to treat paraplegic patients with SCI. Future clinical trials should be performed to optimize the type/technique of nerve transplantation, reduce surgical damage, and minimize postoperative scar formation and adhesion, to avoid postoperative cord central pain.Clinical Trial Registration[http://www.chictr.org.cn/showproj.aspx?proj=50526], identifier [ChiCTR2000030788].
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Affiliation(s)
- Xiaoping Ren
- Department of Orthopedics, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China
- Institute of Orthopedics, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China
- Global Initiative to Cure Paralysis (GICUP), Columbus, OH, United States
- *Correspondence: Xiaoping Ren, ;
| | - Weihua Zhang
- Department of Orthopedics, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China
- Institute of Orthopedics, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China
- Global Initiative to Cure Paralysis (GICUP), Columbus, OH, United States
| | - Jian Mo
- Department of Orthopedics, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China
| | - Jie Qin
- Department of Orthopedics, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China
- Institute of Orthopedics, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China
| | - Yi Chen
- Department of Orthopedics, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China
| | - Jie Han
- Department of Orthopedics, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China
| | - Xinjian Feng
- Department of Orthopedics, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China
| | - Linxuan Han
- Department of Orthopedics, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China
- Institute of Orthopedics, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China
| | - Sitan Feng
- Department of Orthopedics, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China
| | - Haibo Liang
- Department of Orthopedics, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China
| | - Liangjue Cen
- Department of Orthopedics, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China
| | - Xiaofei Wu
- Department of Orthopedics, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China
- Institute of Orthopedics, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China
| | - Chunxing Huang
- Department of Orthopedics, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China
| | - Haixuan Deng
- Department of Imaging, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China
| | - Zhenbin Cao
- Department of Imaging, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China
| | - Huihui Yao
- Department of Electrophysiology, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China
| | - Rongyu Lan
- Department of Orthopedics, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China
- Institute of Orthopedics, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China
| | - Xiaogang Wang
- Department of Orthopedics, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China
| | - Shuai Ren
- Global Initiative to Cure Paralysis (GICUP), Columbus, OH, United States
- Department of Orthopedics, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
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28
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Deng L, Ravenscraft B, Xu XM. Exploring propriospinal neuron-mediated neural circuit plasticity using recombinant viruses after spinal cord injury. Exp Neurol 2021; 349:113962. [PMID: 34953895 DOI: 10.1016/j.expneurol.2021.113962] [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: 06/07/2021] [Revised: 12/16/2021] [Accepted: 12/19/2021] [Indexed: 11/04/2022]
Abstract
Propriospinal neurons (PSNs) play a crucial role in motor control and sensory processing and contribute to plastic reorganization of spinal circuits responsible for recovery from spinal cord injury (SCI). Due to their scattered distribution and various intersegmental projection patterns, it is challenging to dissect the function of PSNs within the neuronal network. New genetically encoded tools, particularly cell-type-specific transgene expression methods using recombinant viral vectors combined with other genetic, pharmacologic, and optogenetic approaches, have enormous potential for visualizing PSNs in the neuronal circuits and monitoring and manipulating their activity. Furthermore, recombinant viral tools have been utilized to promote the intrinsic regenerative capacities of PSNs, towards manipulating the 'hostile' microenvironment for improving functional regeneration of PSNs. Here we summarize the latest development in this fast-moving field and provide a perspective for using this technology to dissect PSN physiological role in contributing to recovery of function after SCI.
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Affiliation(s)
- Lingxiao Deng
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202, United States; Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN 46202, United States
| | - Baylen Ravenscraft
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202, United States
| | - Xiao-Ming Xu
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202, United States; Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN 46202, United States.
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Shepard CT, Pocratsky AM, Brown BL, Van Rijswijck MA, Zalla RM, Burke DA, Morehouse JR, Riegler AS, Whittemore SR, Magnuson DSK. Silencing long ascending propriospinal neurons after spinal cord injury improves hindlimb stepping in the adult rat. eLife 2021; 10:e70058. [PMID: 34854375 PMCID: PMC8639151 DOI: 10.7554/elife.70058] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 11/23/2021] [Indexed: 12/11/2022] Open
Abstract
Long ascending propriospinal neurons (LAPNs) are a subpopulation of spinal cord interneurons that directly connect the lumbar and cervical enlargements. Previously we showed, in uninjured animals, that conditionally silencing LAPNs disrupted left-right coordination of the hindlimbs and forelimbs in a context-dependent manner, demonstrating that LAPNs secure alternation of the fore- and hindlimb pairs during overground stepping. Given the ventrolateral location of LAPN axons in the spinal cord white matter, many likely remain intact following incomplete, contusive, thoracic spinal cord injury (SCI), suggesting a potential role in the recovery of stepping. Thus, we hypothesized that silencing LAPNs after SCI would disrupt recovered locomotion. Instead, we found that silencing spared LAPNs post-SCI improved locomotor function, including paw placement order and timing, and a decrease in the number of dorsal steps. Silencing also restored left-right hindlimb coordination and normalized spatiotemporal features of gait such as stance and swing time. However, hindlimb-forelimb coordination was not restored. These data indicate that the temporal information carried between the spinal enlargements by the spared LAPNs post-SCI is detrimental to recovered hindlimb locomotor function. These findings are an illustration of a post-SCI neuroanatomical-functional paradox and have implications for the development of neuronal- and axonal-protective therapeutic strategies and the clinical study/implementation of neuromodulation strategies.
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Affiliation(s)
- Courtney T Shepard
- Interdisciplinary Program in Translational Neuroscience, School of Interdisciplinary and Graduate Studies, University of LouisvilleLouisvilleUnited States
- Department of Anatomical Sciences and Neurobiology, University of Louisville, LouisvilleLouisvilleUnited States
- Kentucky Spinal Cord Injury Research Center, University of LouisvilleLouisvilleUnited States
| | - Amanda M Pocratsky
- Department of Anatomical Sciences and Neurobiology, University of Louisville, LouisvilleLouisvilleUnited States
- Kentucky Spinal Cord Injury Research Center, University of LouisvilleLouisvilleUnited States
| | - Brandon L Brown
- Interdisciplinary Program in Translational Neuroscience, School of Interdisciplinary and Graduate Studies, University of LouisvilleLouisvilleUnited States
- Department of Anatomical Sciences and Neurobiology, University of Louisville, LouisvilleLouisvilleUnited States
- Kentucky Spinal Cord Injury Research Center, University of LouisvilleLouisvilleUnited States
| | - Morgan A Van Rijswijck
- Kentucky Spinal Cord Injury Research Center, University of LouisvilleLouisvilleUnited States
- Speed School of Engineering, University of LouisvilleLouisvilleUnited States
| | - Rachel M Zalla
- Kentucky Spinal Cord Injury Research Center, University of LouisvilleLouisvilleUnited States
- Speed School of Engineering, University of LouisvilleLouisvilleUnited States
| | - Darlene A Burke
- Kentucky Spinal Cord Injury Research Center, University of LouisvilleLouisvilleUnited States
- Department of Neurological Surgery, University of LouisvilleLouisvilleUnited States
| | - Johnny R Morehouse
- Kentucky Spinal Cord Injury Research Center, University of LouisvilleLouisvilleUnited States
- Department of Neurological Surgery, University of LouisvilleLouisvilleUnited States
| | - Amberley S Riegler
- Kentucky Spinal Cord Injury Research Center, University of LouisvilleLouisvilleUnited States
- Department of Neurological Surgery, University of LouisvilleLouisvilleUnited States
| | - Scott R Whittemore
- Interdisciplinary Program in Translational Neuroscience, School of Interdisciplinary and Graduate Studies, University of LouisvilleLouisvilleUnited States
- Department of Anatomical Sciences and Neurobiology, University of Louisville, LouisvilleLouisvilleUnited States
- Kentucky Spinal Cord Injury Research Center, University of LouisvilleLouisvilleUnited States
- Department of Neurological Surgery, University of LouisvilleLouisvilleUnited States
| | - David SK Magnuson
- Interdisciplinary Program in Translational Neuroscience, School of Interdisciplinary and Graduate Studies, University of LouisvilleLouisvilleUnited States
- Department of Anatomical Sciences and Neurobiology, University of Louisville, LouisvilleLouisvilleUnited States
- Kentucky Spinal Cord Injury Research Center, University of LouisvilleLouisvilleUnited States
- Speed School of Engineering, University of LouisvilleLouisvilleUnited States
- Department of Neurological Surgery, University of LouisvilleLouisvilleUnited States
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30
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Zhang L, Wang L, Xia H, Tan Y, Li C, Fang C. Connectomic mapping of brain-spinal cord neural networks: future directions in assessing spinal cord injury at rest. Neurosci Res 2021; 176:9-17. [PMID: 34699861 DOI: 10.1016/j.neures.2021.10.008] [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: 05/12/2021] [Revised: 10/20/2021] [Accepted: 10/20/2021] [Indexed: 12/01/2022]
Abstract
Following spinal cord injury (SCI), the central nervous system undergoes significant reconstruction. The dynamic change in the interaction of the brain-spinal cord axis as well as in structure-function relations plays a vital role in the determination of neurological functions, which might have important clinical implications for the treatment and its efficacy evaluation of patients with SCI. Brain connectomes based on neuroimaging data is a relatively new field of research that maps the brain's large-scale structural and functional networks at rest. Importantly, increasing evidence shows that such resting-state signals can also be seen in the spinal cord. In the present review, we focus on the reconstruction of multi-level neural circuits after SCI. We also describe how the connectome concept could further our understanding of neuroplasticity after SCI. We propose that mapping the cortical-subcortical-spinal cord networks can provide novel insights into the pathologies of SCI.
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Affiliation(s)
- Lijian Zhang
- Postdoctoral Research Station of Neurosurgery, Affiliated Hospital of Hebei University, Hebei University, China; Department of Neurosurgery, Affiliated Hospital of Hebei University, Hebei University, China; Key Laboratory of Precise Diagnosis and Treatment of Glioma in Hebei Province, Affiliated Hospital of Hebei University, Hebei University, China
| | - Luxuan Wang
- Department of Neurology, Affiliated Hospital of Hebei University, Hebei University, China
| | - Hechun Xia
- Department of Neurosurgery, General Hospital of Ningxia Medical University, Ningxia Medical University, China
| | - Yanli Tan
- Key Laboratory of Precise Diagnosis and Treatment of Glioma in Hebei Province, Affiliated Hospital of Hebei University, Hebei University, China; Department of Pathology, Affiliated Hospital of Hebei University, Hebei University, China.
| | - Chunhui Li
- Department of Neurosurgery, Affiliated Hospital of Hebei University, Hebei University, China.
| | - Chuan Fang
- Postdoctoral Research Station of Neurosurgery, Affiliated Hospital of Hebei University, Hebei University, China; Department of Neurosurgery, Affiliated Hospital of Hebei University, Hebei University, China; Key Laboratory of Precise Diagnosis and Treatment of Glioma in Hebei Province, Affiliated Hospital of Hebei University, Hebei University, China.
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31
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Stieglitz LH, Hofer AS, Bolliger M, Oertel MF, Filli L, Willi R, Cathomen A, Meyer C, Schubert M, Hubli M, Kessler TM, Baumann CR, Imbach L, Krüsi I, Prusse A, Schwab ME, Regli L, Curt A. Deep brain stimulation for locomotion in incomplete human spinal cord injury (DBS-SCI): protocol of a prospective one-armed multi-centre study. BMJ Open 2021; 11:e047670. [PMID: 34593490 PMCID: PMC8487195 DOI: 10.1136/bmjopen-2020-047670] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 09/09/2021] [Indexed: 01/11/2023] Open
Abstract
INTRODUCTION Spinal cord injury (SCI) is a devastating condition with immediate impact on the individual's health and quality of life. Major functional recovery reaches a plateau 3-4 months after injury despite intensive rehabilitative training. To enhance training efficacy and improve long-term outcomes, the combination of rehabilitation with electrical modulation of the spinal cord and brain has recently aroused scientific interest with encouraging results. The mesencephalic locomotor region (MLR), an evolutionarily conserved brainstem locomotor command and control centre, is considered a promising target for deep brain stimulation (DBS) in patients with SCI. Experiments showed that MLR-DBS can induce locomotion in rats with spinal white matter destructions of >85%. METHODS AND ANALYSIS In this prospective one-armed multi-centre study, we investigate the safety, feasibility, and therapeutic efficacy of MLR-DBS to enable and enhance locomotor training in severely affected, subchronic and chronic American Spinal Injury Association Impairment Scale C patients in order to improve functional recovery. Patients undergo an intensive training programme with MLR-DBS while being regularly followed up until 6 months post-implantation. The acquired data of each timepoint are compared with baseline while the primary endpoint is performance in the 6-minute walking test. The clinical trial protocol was written in accordance with the Standard Protocol Items: Recommendations for Interventional Trials checklist. ETHICS AND DISSEMINATION This first in-man study investigates the therapeutic potential of MLR-DBS in SCI patients. One patient has already been implanted with electrodes and underwent MLR stimulation during locomotion. Based on the preliminary results which promise safety and feasibility, recruitment of further patients is currently ongoing. Ethical approval has been obtained from the Ethical Committee of the Canton of Zurich (case number BASEC 2016-01104) and Swissmedic (10000316). Results will be published in peer-reviewed journals and presented at conferences. TRIAL REGISTRATION NUMBER NCT03053791.
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Affiliation(s)
| | - Anna-Sophie Hofer
- Department of Neurosurgery, University Hospital Zurich, Zurich, Switzerland
- Institute for Regenerative Medicine, University of Zurich, Schlieren, Switzerland
| | - Marc Bolliger
- Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
| | - Markus F Oertel
- Department of Neurosurgery, University Hospital Zurich, Zurich, Switzerland
| | - Linard Filli
- Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
| | - Romina Willi
- Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
| | - Adrian Cathomen
- Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
| | - Christian Meyer
- Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
| | - Martin Schubert
- Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
| | - Michèle Hubli
- Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
| | - Thomas M Kessler
- Department of Neuro-Urology, Balgrist University Hospital, Zurich, Switzerland
| | | | - Lukas Imbach
- Department of Neurology, University Hospital Zurich, Zurich, Switzerland
| | - Iris Krüsi
- Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
| | - Andrea Prusse
- Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
| | - Martin E Schwab
- Institute for Regenerative Medicine, University of Zurich, Schlieren, Switzerland
| | - Luca Regli
- Department of Neurosurgery, University Hospital Zurich, Zurich, Switzerland
| | - Armin Curt
- Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
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Walker JR, Detloff MR. Plasticity in Cervical Motor Circuits following Spinal Cord Injury and Rehabilitation. BIOLOGY 2021; 10:biology10100976. [PMID: 34681075 PMCID: PMC8533179 DOI: 10.3390/biology10100976] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 09/17/2021] [Accepted: 09/22/2021] [Indexed: 11/16/2022]
Abstract
Simple Summary Spinal cord injury results in a decreased quality of life and impacts hundreds of thousands of people in the US alone. This review discusses the underlying cellular mechanisms of injury and the concurrent therapeutic hurdles that impede recovery. It then describes the phenomena of neural plasticity—the nervous system’s ability to change. The primary focus of the review is on the impact of cervical spinal cord injury on control of the upper limbs. The neural plasticity that occurs without intervention is discussed, which shows new connections growing around the injury site and the involvement of compensatory movements. Rehabilitation-driven neural plasticity is shown to have the ability to guide connections to create more normal functions. Various novel stimulation and recording technologies are outlined for their role in further improving rehabilitative outcomes and gains in independence. Finally, the importance of sensory input, an often-overlooked aspect of motor control, is shown in driving neural plasticity. Overall, this review seeks to delineate the historical and contemporary research into neural plasticity following injury and rehabilitation to guide future studies. Abstract Neuroplasticity is a robust mechanism by which the central nervous system attempts to adapt to a structural or chemical disruption of functional connections between neurons. Mechanical damage from spinal cord injury potentiates via neuroinflammation and can cause aberrant changes in neural circuitry known as maladaptive plasticity. Together, these alterations greatly diminish function and quality of life. This review discusses contemporary efforts to harness neuroplasticity through rehabilitation and neuromodulation to restore function with a focus on motor recovery following cervical spinal cord injury. Background information on the general mechanisms of plasticity and long-term potentiation of the nervous system, most well studied in the learning and memory fields, will be reviewed. Spontaneous plasticity of the nervous system, both maladaptive and during natural recovery following spinal cord injury is outlined to provide a baseline from which rehabilitation builds. Previous research has focused on the impact of descending motor commands in driving spinal plasticity. However, this review focuses on the influence of physical therapy and primary afferent input and interneuron modulation in driving plasticity within the spinal cord. Finally, future directions into previously untargeted primary afferent populations are presented.
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Martins Â, Gouveia D, Cardoso A, Carvalho C, Silva C, Coelho T, Gamboa Ó, Ferreira A. Functional Neurorehabilitation in Dogs with an Incomplete Recovery 3 Months following Intervertebral Disc Surgery: A Case Series. Animals (Basel) 2021; 11:ani11082442. [PMID: 34438900 PMCID: PMC8388785 DOI: 10.3390/ani11082442] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Revised: 08/13/2021] [Accepted: 08/15/2021] [Indexed: 12/27/2022] Open
Abstract
Simple Summary A non-invasive neurorehabilitation multimodal protocol (NRMP) may be applicable to chronic T3-L3 dogs 3 months after undergoing surgery for acute Intervertebral Disc Disease (IVDD) Hansen type I; this protocol has been shown to be safe, feasible, and potentially effective at improving ambulation in both open field score (OFS) 0 and OFS 1 dogs. The specific sample population criteria limit the number of dogs included, mainly due to owners withdrawing over time. Thus, the present case series study aimed to demonstrate that an NRMP could contribute to a functional treatment possibly based on synaptic and anatomic reorganization of the spinal cord. Abstract This case series study aimed to evaluate the safety, feasibility, and positive outcome of the neurorehabilitation multimodal protocol (NRMP) in 16 chronic post-surgical IVDD Hansen type I dogs, with OFS 0/DPP− (n = 9) and OFS 1/DPP+ (n = 7). All were enrolled in the NRMP for a maximum of 90 days and were clinically discharged after achieving ambulation. The NRMP was based on locomotor training, functional electrical stimulation, transcutaneous electrical spinal cord stimulation, and 4-aminopyridine (4-AP) pharmacological management. In the Deep Pain Perception (DPP)+ dogs, 100% recovered ambulation within a mean period of 47 days, reaching OFS ≥11, which suggests that a longer period of time is needed for recovery. At follow-up, all dogs presented a positive evolution with voluntary micturition. Of the DPP− dogs admitted, all achieved a flexion/extension locomotor pattern within 30 days, and after starting the 4-AP, two dogs were discharged at outcome day 45, with 78% obtaining Spinal Reflex Locomotion (SRL) and automatic micturition within a mean period of 62 days. At follow-up, all dogs maintained their neurological status. After the NRMP, ambulatory status was achieved in 88% (14/16) of dogs, without concurrent events. Thus, an NRMP may be an important therapeutic option to reduce the need for euthanasia in the clinical setting.
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Affiliation(s)
- Ângela Martins
- Faculty of Veterinary Medicine, Lusófona University, Campo Grande, 1300-477 Lisboa, Portugal
- Animal Rehabilitation Center, Arrábida Veterinary Hospital, Azeitão, 2925-583 Setúbal, Portugal; (D.G.); (A.C.); (C.C.); (C.S.); (T.C.)
- CIISA—Centro Interdisciplinar-Investigação em Saúde Animal, Faculdade de Medicina Veterinária, Av. Universidade Técnica de Lisboa, 1300-477 Lisboa, Portugal;
- Superior School of Health, Protection and Animal Welfare, Polytechnic Institute of Lusophony, Campo Grande, 1300-477 Lisboa, Portugal
- Correspondence:
| | - Débora Gouveia
- Animal Rehabilitation Center, Arrábida Veterinary Hospital, Azeitão, 2925-583 Setúbal, Portugal; (D.G.); (A.C.); (C.C.); (C.S.); (T.C.)
- Superior School of Health, Protection and Animal Welfare, Polytechnic Institute of Lusophony, Campo Grande, 1300-477 Lisboa, Portugal
| | - Ana Cardoso
- Animal Rehabilitation Center, Arrábida Veterinary Hospital, Azeitão, 2925-583 Setúbal, Portugal; (D.G.); (A.C.); (C.C.); (C.S.); (T.C.)
| | - Carla Carvalho
- Animal Rehabilitation Center, Arrábida Veterinary Hospital, Azeitão, 2925-583 Setúbal, Portugal; (D.G.); (A.C.); (C.C.); (C.S.); (T.C.)
| | - Cátia Silva
- Animal Rehabilitation Center, Arrábida Veterinary Hospital, Azeitão, 2925-583 Setúbal, Portugal; (D.G.); (A.C.); (C.C.); (C.S.); (T.C.)
| | - Tiago Coelho
- Animal Rehabilitation Center, Arrábida Veterinary Hospital, Azeitão, 2925-583 Setúbal, Portugal; (D.G.); (A.C.); (C.C.); (C.S.); (T.C.)
| | - Óscar Gamboa
- Faculty of Veterinary Medicine, University of Lisbon, 1300-477 Lisboa, Portugal;
| | - António Ferreira
- CIISA—Centro Interdisciplinar-Investigação em Saúde Animal, Faculdade de Medicina Veterinária, Av. Universidade Técnica de Lisboa, 1300-477 Lisboa, Portugal;
- Faculty of Veterinary Medicine, University of Lisbon, 1300-477 Lisboa, Portugal;
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Neckel ND, Dai H, Hanckel J, Lee Y, Albanese C, Rodriguez O. Skilled reach training enhances robotic gait training to restore overground locomotion following spinal cord injury in rats. Behav Brain Res 2021; 414:113490. [PMID: 34358574 DOI: 10.1016/j.bbr.2021.113490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Revised: 07/23/2021] [Accepted: 07/25/2021] [Indexed: 10/20/2022]
Abstract
Rehabilitative training has been shown to improve motor function following spinal cord injury (SCI). Unfortunately, these gains are primarily task specific; where reach training only improves reaching, step training only improves stepping and stand training only improves standing. More troublesome is the tendency that the improvement in a trained task often comes at the expense of an untrained task. However, the task specificity of training does not preclude the benefits of combined rehabilitative training. Here we show that robot assisted gait training alone can partially reduce the deficits in unassisted overground locomotion following a C4/5 overhemisection injury in rats. When robot-assisted gait training is done in conjunction with skilled forelimb training, we observe a much greater level of recovery of unassisted overground locomotion. In order to provide reach training that would not interfere with our robotic gait training schedule, we prompted rats to increase the use of their forelimbs by replacing the standard overhead feeder with a custom made, deep welled hopper that dispensed nutritionally equivalent small milled pellets. We speculate that the increase in recovery from combined training is due to a more robust interneuronal relay network around the injury site. in vivo manganese-enhanced magnetic resonance imaging of the spinal cord indicated that there was no increase in the cellular activity, however ex vivo diffusion tensor imaging (DTI) suggested an increase in collateralization around the injury site in rats that received both reach training and robot assisted gait training.
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Affiliation(s)
- Nathan D Neckel
- Department of Neuroscience, Georgetown University, United States; Department of Rehabilitation Medicine, Georgetown University, United States.
| | - Haining Dai
- Department of Neuroscience, Georgetown University, United States
| | - John Hanckel
- Department of Neuroscience, Georgetown University, United States
| | - Yichien Lee
- Department of Oncology, Georgetown University, United States; Center for Translational Imaging, Georgetown University, United States
| | - Christopher Albanese
- Department of Oncology, Georgetown University, United States; Center for Translational Imaging, Georgetown University, United States
| | - Olga Rodriguez
- Department of Oncology, Georgetown University, United States; Center for Translational Imaging, Georgetown University, United States
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Corticospinal Motor Circuit Plasticity After Spinal Cord Injury: Harnessing Neuroplasticity to Improve Functional Outcomes. Mol Neurobiol 2021; 58:5494-5516. [PMID: 34341881 DOI: 10.1007/s12035-021-02484-w] [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: 01/13/2021] [Accepted: 07/07/2021] [Indexed: 10/20/2022]
Abstract
Spinal cord injury (SCI) is a devastating condition that affects approximately 294,000 people in the USA and several millions worldwide. The corticospinal motor circuitry plays a major role in controlling skilled movements and in planning and coordinating movements in mammals and can be damaged by SCI. While axonal regeneration of injured fibers over long distances is scarce in the adult CNS, substantial spontaneous neural reorganization and plasticity in the spared corticospinal motor circuitry has been shown in experimental SCI models, associated with functional recovery. Beneficially harnessing this neuroplasticity of the corticospinal motor circuitry represents a highly promising therapeutic approach for improving locomotor outcomes after SCI. Several different strategies have been used to date for this purpose including neuromodulation (spinal cord/brain stimulation strategies and brain-machine interfaces), rehabilitative training (targeting activity-dependent plasticity), stem cells and biological scaffolds, neuroregenerative/neuroprotective pharmacotherapies, and light-based therapies like photodynamic therapy (PDT) and photobiomodulation (PMBT). This review provides an overview of the spontaneous reorganization and neuroplasticity in the corticospinal motor circuitry after SCI and summarizes the various therapeutic approaches used to beneficially harness this neuroplasticity for functional recovery after SCI in preclinical animal model and clinical human patients' studies.
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Guérout N. Plasticity of the Injured Spinal Cord. Cells 2021; 10:cells10081886. [PMID: 34440655 PMCID: PMC8395000 DOI: 10.3390/cells10081886] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 07/21/2021] [Accepted: 07/23/2021] [Indexed: 12/11/2022] Open
Abstract
Complete spinal cord injury (SCI) leads to permanent motor, sensitive and sensory deficits. In humans, there is currently no therapy to promote recovery and the only available treatments include surgical intervention to prevent further damage and symptomatic relief of pain and infections in the acute and chronic phases, respectively. Basically, the spinal cord is classically viewed as a nonregenerative tissue with limited plasticity. Thereby the establishment of the “glial” scar which appears within the SCI is mainly described as a hermetic barrier for axon regeneration. However, recent discoveries have shed new light on the intrinsic functional plasticity and endogenous recovery potential of the spinal cord. In this review, we will address the different aspects that the spinal cord plasticity can take on. Indeed, different experimental paradigms have demonstrated that axonal regrowth can occur even after complete SCI. Moreover, recent articles have demonstrated too that the “glial” scar is in fact composed of several cellular populations and that each of them exerts specific roles after SCI. These recent discoveries underline the underestimation of the plasticity of the spinal cord at cellular and molecular levels. Finally, we will address the modulation of this endogenous spinal cord plasticity and the perspectives of future therapeutic opportunities which can be offered by modulating the injured spinal cord microenvironment.
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Affiliation(s)
- Nicolas Guérout
- EA3830 GRHV, Institute for Research and Innovation in Biomedicine (IRIB), Normandie Université, UNIROUEN, 76000 Rouen, France
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37
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Brown AR, Martinez M. Chronic inactivation of the contralesional hindlimb motor cortex after thoracic spinal cord hemisection impedes locomotor recovery in the rat. Exp Neurol 2021; 343:113775. [PMID: 34081986 DOI: 10.1016/j.expneurol.2021.113775] [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: 03/08/2021] [Revised: 05/13/2021] [Accepted: 05/27/2021] [Indexed: 10/21/2022]
Abstract
After incomplete spinal cord injury (SCI), cortical plasticity is involved in hindlimb locomotor recovery. Nevertheless, whether cortical activity is required for motor map plasticity and recovery remains unresolved. Here, we combined a unilateral thoracic spinal cord injury (SCI) with a cortical inactivation protocol that uncovered a functional role of contralesional cortical activity in hindlimb recovery and ipsilesional map plasticity. In adult rats, left hindlimb paralysis was induced by sectioning half of the spinal cord at the thoracic level (hemisection) and we used a continuous infusion of muscimol (GABAA agonist, 10 mM, 0.11 µl/h) delivered via implanted osmotic pump (n = 9) to chronically inactivate the contralesional hindlimb motor cortex. Hemisected rats with saline infusion served as a SCI control group (n = 8), and intact rats with muscimol infusion served as an inactivation control group (n = 6). Locomotion was assessed in an open field, on a horizontal ladder, and on a treadmill prior to and for three weeks after hemisection. Cortical inactivation after hemisection significantly impeded hindlimb locomotor recovery in all tasks and specifically disrupted the ability of rats to generate proper flexion of the affected hindlimb during stepping compared to SCI controls, with no significant effect of inactivation in intact rats. Chronic and acute (n = 4) cortical inactivation after hemisection also significantly reduced the representation of the affected hindlimb in the ipsilesional motor cortex derived with intracortical microsimulation (ICMS). Our results provide evidence that residual activity in the contralesional hindlimb motor cortex after thoracic hemisection contributes to spontaneous locomotor recovery and map plasticity.
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Affiliation(s)
- Andrew R Brown
- Département de Neurosciences Groupe de recherche sur le système nerveux central (GRSNC) and Centre Interdisciplinaire de Recherche sur le Cerveau au service de l'Apprentissage (CIRCA), Université de Montréal, Québec, Canada; CIUSSS du Nord-de-l'Île-de-Montréal, Québec, Canada
| | - Marina Martinez
- Département de Neurosciences Groupe de recherche sur le système nerveux central (GRSNC) and Centre Interdisciplinaire de Recherche sur le Cerveau au service de l'Apprentissage (CIRCA), Université de Montréal, Québec, Canada; CIUSSS du Nord-de-l'Île-de-Montréal, Québec, Canada.
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Bilchak JN, Caron G, Côté MP. Exercise-Induced Plasticity in Signaling Pathways Involved in Motor Recovery after Spinal Cord Injury. Int J Mol Sci 2021; 22:ijms22094858. [PMID: 34064332 PMCID: PMC8124911 DOI: 10.3390/ijms22094858] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 04/28/2021] [Accepted: 04/29/2021] [Indexed: 02/06/2023] Open
Abstract
Spinal cord injury (SCI) leads to numerous chronic and debilitating functional deficits that greatly affect quality of life. While many pharmacological interventions have been explored, the current unsurpassed therapy for most SCI sequalae is exercise. Exercise has an expansive influence on peripheral health and function, and by activating the relevant neural pathways, exercise also ameliorates numerous disorders of the central nervous system (CNS). While the exact mechanisms by which this occurs are still being delineated, major strides have been made in the past decade to understand the molecular underpinnings of this essential treatment. Exercise rapidly and prominently affects dendritic sprouting, synaptic connections, neurotransmitter production and regulation, and ionic homeostasis, with recent literature implicating an exercise-induced increase in neurotrophins as the cornerstone that binds many of these effects together. The field encompasses vast complexity, and as the data accumulate, disentangling these molecular pathways and how they interact will facilitate the optimization of intervention strategies and improve quality of life for individuals affected by SCI. This review describes the known molecular effects of exercise and how they alter the CNS to pacify the injury environment, increase neuronal survival and regeneration, restore normal neural excitability, create new functional circuits, and ultimately improve motor function following SCI.
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Prager J, Ito D, Carwardine DR, Jiju P, Chari DM, Granger N, Wong LF. Delivery of chondroitinase by canine mucosal olfactory ensheathing cells alongside rehabilitation enhances recovery after spinal cord injury. Exp Neurol 2021; 340:113660. [PMID: 33647272 DOI: 10.1016/j.expneurol.2021.113660] [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: 12/14/2020] [Revised: 02/21/2021] [Accepted: 02/24/2021] [Indexed: 01/11/2023]
Abstract
Spinal cord injury (SCI) can cause chronic paralysis and incontinence and remains a major worldwide healthcare burden, with no regenerative treatment clinically available. Intraspinal transplantation of olfactory ensheathing cells (OECs) and injection of chondroitinase ABC (chABC) are both promising therapies but limited and unpredictable responses are seen, particularly in canine clinical trials. Sustained delivery of chABC presents a challenge due to its thermal instability; we hypothesised that transplantation of canine olfactory mucosal OECs genetically modified ex vivo by lentiviral transduction to express chABC (cOEC-chABC) would provide novel delivery of chABC and synergistic therapy. Rats were randomly divided into cOEC-chABC, cOEC, or vehicle transplanted groups and received transplant immediately after dorsal column crush corticospinal tract (CST) injury. Rehabilitation for forepaw reaching and blinded behavioural testing was conducted for 8 weeks. We show that cOEC-chABC transplanted animals recover greater forepaw reaching accuracy on Whishaw testing and more normal gait than cOEC transplanted or vehicle control rats. Increased CST axon sprouting cranial to the injury and serotonergic fibres caudal to the injury suggest a mechanism for recovery. We therefore demonstrate that cOECs can deliver sufficient chABC to drive modest functional improvement, and that this genetically engineered cellular and molecular approach is a feasible combination therapy for SCI.
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Affiliation(s)
- Jon Prager
- Bristol Veterinary School, University of Bristol, Bristol, UK; The Royal Veterinary College, University of London, Hatfield, UK
| | - Daisuke Ito
- Bristol Medical School, University of Bristol, Bristol, UK; School of Veterinary Medicine, Nihon University, Japan
| | | | - Prince Jiju
- Bristol Medical School, University of Bristol, Bristol, UK
| | - Divya M Chari
- Neural Tissue Engineering, Keele School of Medicine, Keele University, Keele, UK
| | - Nicolas Granger
- The Royal Veterinary College, University of London, Hatfield, UK
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40
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Santi S, Corridori I, Pugno NM, Motta A, Migliaresi C. Injectable Scaffold-Systems for the Regeneration of Spinal Cord: Advances of the Past Decade. ACS Biomater Sci Eng 2021; 7:983-999. [PMID: 33523634 DOI: 10.1021/acsbiomaterials.0c01779] [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] [Indexed: 12/29/2022]
Abstract
Nowadays, whenever is possible and as an alternative to open spine surgery, minimally invasive procedures are preferred to treat spinal cord injuries (SCI), with percutaneous injections or small incisions, that are faster, less traumatic, and require less recovery time. Injectable repair systems are based on materials that can be injected in the lesion site, can eventually be loaded with drugs or even cells, and act as scaffolds for the lesion repair. The review analyzes papers written from 2010 onward on injectable materials/systems used/proposed for the regenerative and combinatorial therapies of SCI and discusses the in vivo models that have been used to validate them.
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Affiliation(s)
- Sofia Santi
- BIOTech Research Center and European Institute of Excellence on Tissue Engineering and Regenerative Medicine, University of Trento, Via delle Regole 101, 38123 Trento, Italy.,Department of Industrial Engineering, University of Trento, Via Sommarive 9, 38123 Trento, Italy
| | - Ilaria Corridori
- Laboratory of Bio-inspired, Bionic, Nano, Meta Materials & Mechanics, Department of Civil, Environmental and Mechanical Engineering, University of Trento, Via Mesiano 77, 38123 Trento, Italy
| | - Nicola M Pugno
- Laboratory of Bio-inspired, Bionic, Nano, Meta Materials & Mechanics, Department of Civil, Environmental and Mechanical Engineering, University of Trento, Via Mesiano 77, 38123 Trento, Italy.,School of Engineering and Material Science, Queen Mary University of London, Mile End Road, E1 4NS London, United Kingdom
| | - Antonella Motta
- BIOTech Research Center and European Institute of Excellence on Tissue Engineering and Regenerative Medicine, University of Trento, Via delle Regole 101, 38123 Trento, Italy.,Department of Industrial Engineering, University of Trento, Via Sommarive 9, 38123 Trento, Italy
| | - Claudio Migliaresi
- BIOTech Research Center and European Institute of Excellence on Tissue Engineering and Regenerative Medicine, University of Trento, Via delle Regole 101, 38123 Trento, Italy.,Department of Industrial Engineering, University of Trento, Via Sommarive 9, 38123 Trento, Italy
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41
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Jones I, Novikova LN, Wiberg M, Carlsson L, Novikov LN. Human Embryonic Stem Cell-derived Neural Crest Cells Promote Sprouting and Motor Recovery Following Spinal Cord Injury in Adult Rats. Cell Transplant 2021; 30:963689720988245. [PMID: 33522309 PMCID: PMC7863557 DOI: 10.1177/0963689720988245] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Spinal cord injury results in irreversible tissue damage and permanent sensorimotor impairment. The development of novel therapeutic strategies that improve the life quality of affected individuals is therefore of paramount importance. Cell transplantation is a promising approach for spinal cord injury treatment and the present study assesses the efficacy of human embryonic stem cell–derived neural crest cells as preclinical cell-based therapy candidates. The differentiated neural crest cells exhibited characteristic molecular signatures and produced a range of biologically active trophic factors that stimulated in vitro neurite outgrowth of rat primary dorsal root ganglia neurons. Transplantation of the neural crest cells into both acute and chronic rat cervical spinal cord injury models promoted remodeling of descending raphespinal projections and contributed to the partial recovery of forelimb motor function. The results achieved in this proof-of-concept study demonstrates that human embryonic stem cell–derived neural crest cells warrant further investigation as cell-based therapy candidates for the treatment of spinal cord injury.
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Affiliation(s)
- Iwan Jones
- 59588Umeå Center for Molecular Medicine, Umeå University, Umeå, Sweden.,Department of Integrative Medical Biology, Umeå University, Umeå, Sweden
| | | | - Mikael Wiberg
- Department of Integrative Medical Biology, Umeå University, Umeå, Sweden.,Department of Surgical and Perioperative Science, Section of Hand and Plastic Surgery, Umeå University, Umeå, Sweden
| | - Leif Carlsson
- 59588Umeå Center for Molecular Medicine, Umeå University, Umeå, Sweden
| | - Lev N Novikov
- Department of Integrative Medical Biology, Umeå University, Umeå, Sweden
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42
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Fouad K, Popovich PG, Kopp MA, Schwab JM. The neuroanatomical-functional paradox in spinal cord injury. Nat Rev Neurol 2021; 17:53-62. [PMID: 33311711 PMCID: PMC9012488 DOI: 10.1038/s41582-020-00436-x] [Citation(s) in RCA: 73] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/11/2020] [Indexed: 12/13/2022]
Abstract
Although lesion size is widely considered to be the most reliable predictor of outcome after CNS injury, lesions of comparable size can produce vastly different magnitudes of functional impairment and subsequent recovery. This neuroanatomical-functional paradox is likely to contribute to the many failed attempts to independently replicate findings from animal models of neurotrauma. In humans, the analogous clinical-radiological paradox could explain why individuals with similar injuries can respond differently to rehabilitation. We describe the neuroanatomical-functional paradox in the context of traumatic spinal cord injury (SCI) and discuss the underlying mechanisms of the paradox, including the concepts of lesion-affected and recovery-related networks. We also consider the various secondary complications that further limit the accuracy of outcome prediction in SCI and provide suggestions for how to increase the predictive, translational value of preclinical SCI models.
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Affiliation(s)
- Karim Fouad
- Department of Physical Therapy, Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, AB, Canada
- Institute for Neuroscience and Mental Health, University of Alberta, Edmonton, AB, Canada
| | - Phillip G Popovich
- Belford Center for Spinal Cord Injury, The Ohio State University, Wexner Medical Center, Columbus, OH, USA
- Center for Brain and Spinal Cord Repair, The Ohio State University, Wexner Medical Center, Columbus, OH, USA
- Department of Neuroscience, The Ohio State University, Wexner Medical Center, Columbus, OH, USA
- The Neurological Institute, The Ohio State University, Wexner Medical Center, Columbus, OH, USA
| | - Marcel A Kopp
- Clinical & Experimental Spinal Cord Injury Research, Department of Neurology with Experimental Neurology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
- Berlin Institute of Health (QUEST-Center for Transforming Biomedical Research), Berlin, Germany
| | - Jan M Schwab
- Belford Center for Spinal Cord Injury, The Ohio State University, Wexner Medical Center, Columbus, OH, USA.
- Center for Brain and Spinal Cord Repair, The Ohio State University, Wexner Medical Center, Columbus, OH, USA.
- Department of Neuroscience, The Ohio State University, Wexner Medical Center, Columbus, OH, USA.
- The Neurological Institute, The Ohio State University, Wexner Medical Center, Columbus, OH, USA.
- Clinical & Experimental Spinal Cord Injury Research, Department of Neurology with Experimental Neurology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany.
- Spinal Cord Injury Medicine (Neuroplegiology), Department of Neurology, The Ohio State University, Wexner Medical Center, Columbus, OH, USA.
- Department of Physical Medicine and Rehabilitation, The Ohio State University, Wexner Medical Center, Columbus, OH, USA.
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43
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Li R, Huang ZC, Cui HY, Huang ZP, Liu JH, Zhu QA, Hu Y. Utility of somatosensory and motor-evoked potentials in reflecting gross and fine motor functions after unilateral cervical spinal cord contusion injury. Neural Regen Res 2021; 16:1323-1330. [PMID: 33318412 PMCID: PMC8284273 DOI: 10.4103/1673-5374.301486] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Fine motor skills are thought to rely on the integrity of ascending sensory pathways in the spinal dorsal column as well as descending motor pathways that have a neocortical origin. However, the neurophysiological processes underlying communication between the somatosensory and motor pathways that regulate fine motor skills during spontaneous recovery after spinal cord contusion injury remain unclear. Here, we established a rat model of cervical hemicontusive injury using C5 laminectomy followed by contusional displacement of 1.2 mm (mild injury) or 2.0 mm (severe injury) to the C5 spinal cord. Electrophysiological recordings were performed on the brachial muscles up to 12 weeks after injury to investigate the mechanisms by which spinal cord pathways participate in motor function. After spinal cord contusion injury, the amplitudes of somatosensory and motor-evoked potentials were reduced, and the latencies were increased. The forelimb open field locomotion test, grooming test, rearing test and Montoya staircase test revealed improvement in functions. With increasing time after injury, the amplitudes of somatosensory and motor-evoked potentials in rats with mild spinal cord injury increased gradually, and the latencies gradually shortened. In comparison, the recovery times of somatosensory and motor-evoked potential amplitudes and latencies were longer, and the recovery of motor function was delayed in rats with severe spinal cord injury. Correlation analysis revealed that somatosensory-evoked potential and motor-evoked potential parameters were correlated with gross and fine motor function in rats with mild spinal cord contusion injury. In contrast, only somatosensory-evoked potential amplitude was correlated with fine motor skills in rats with severe spinal cord injury. Our results show that changes in both somatosensory and motor-evoked potentials can reflect the changes in gross and fine motor functions after mild spinal cord contusion injury, and that the change in somatosensory-evoked potential amplitude can also reflect the change in fine motor function after severe spinal cord contusion injury. This study was approved by the Animal Ethics Committee of Nanfang Hospital, Southern Medical University, China (approval No. NFYY-2017-67) on June 11, 2017.
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Affiliation(s)
- Rong Li
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin; Department of Orthopedics and Traumatology, The Hong Kong University Shenzhen Hospital, Shenzhen, Guangdong Province, China
| | - Zu-Cheng Huang
- Department of Spine Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Hong-Yan Cui
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China
| | - Zhi-Ping Huang
- Department of Spine Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Jun-Hao Liu
- Department of Spine Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Qing-An Zhu
- Department of Spine Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Yong Hu
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin; Department of Orthopedics and Traumatology, The University of Hong Kong, Hong Kong Special Administrative Region; Department of Orthopedics and Traumatology, The Hong Kong University Shenzhen Hospital, Shenzhen, Guangdong Province, China
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44
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Engmann AK, Bizzozzero F, Schneider MP, Pfyffer D, Imobersteg S, Schneider R, Hofer AS, Wieckhorst M, Schwab ME. The Gigantocellular Reticular Nucleus Plays a Significant Role in Locomotor Recovery after Incomplete Spinal Cord Injury. J Neurosci 2020; 40:8292-8305. [PMID: 32978289 PMCID: PMC7577599 DOI: 10.1523/jneurosci.0474-20.2020] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 09/14/2020] [Accepted: 09/18/2020] [Indexed: 11/21/2022] Open
Abstract
Traditionally, the brainstem has been seen as hardwired and poorly capable of plastic adaptations following spinal cord injury (SCI). Data acquired over the past decades, however, suggest differently: following SCI in various animal models (lamprey, chick, rodents, nonhuman primates), different forms of spontaneous anatomic plasticity of reticulospinal projections, many of them originating from the gigantocellular reticular nucleus (NRG), have been observed. In line with these anatomic observations, animals and humans with incomplete SCI often show various degrees of spontaneous motor recovery of hindlimb/leg function. Here, we investigated the functional relevance of two different modes of reticulospinal fiber growth after cervical hemisection, local rewiring of axotomized projections at the lesion site versus compensatory outgrowth of spared axons, using projection-specific, adeno-associated virus-mediated chemogenetic neuronal silencing. Detailed assessment of joint movements and limb kinetics during overground locomotion in female adult rats showed that locally rewired as well as compensatory NRG fibers were responsible for different aspects of recovered forelimb and hindlimb functions (i.e., stability, strength, coordination, speed, or timing). During walking and swimming, both locally rewired as well as compensatory NRG plasticity were crucial for recovered function, while the contribution of locally rewired NRG plasticity to wading performance was limited. Our data demonstrate comprehensively that locally rewired as well as compensatory plasticity of reticulospinal axons functionally contribute to the observed spontaneous improvement of stepping performance after incomplete SCI and are at least partially causative to the observed recovery of function, which can also be observed in human patients with spinal hemisection lesions.SIGNIFICANCE STATEMENT Following unilateral hemisection of the spinal cord, reticulospinal projections are destroyed on the injured side, resulting in impaired locomotion. Over time, a high degree of recovery can be observed in lesioned animals, like in human hemicord patients. In the rat, recovery is accompanied by pronounced spontaneous plasticity of axotomized and spared reticulospinal axons. We demonstrate the causative relevance of locally rewired as well as compensatory reticulospinal plasticity for the recovery of locomotor functions following spinal hemisection, using chemogenetic tools to selectively silence newly formed connections in behaviorally recovered animals. Moving from a correlative to a causative understanding of the role of neuroanatomical plasticity for functional recovery is fundamental for successful translation of treatment approaches from experimental studies to the clinics.
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Affiliation(s)
- Anne K Engmann
- Department of Health Sciences and Technology, ETH Zurich, Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
| | - Flavio Bizzozzero
- Department of Health Sciences and Technology, ETH Zurich, Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
| | - Marc P Schneider
- Department of Health Sciences and Technology, ETH Zurich, Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
| | - Dario Pfyffer
- Department of Health Sciences and Technology, ETH Zurich, Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
| | - Stefan Imobersteg
- Department of Health Sciences and Technology, ETH Zurich, Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
| | - Regula Schneider
- Department of Health Sciences and Technology, ETH Zurich, Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
| | - Anna-Sophie Hofer
- Department of Health Sciences and Technology, ETH Zurich, Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
| | - Martin Wieckhorst
- Department of Health Sciences and Technology, ETH Zurich, Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
| | - Martin E Schwab
- Department of Health Sciences and Technology, ETH Zurich, Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
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45
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Behroozi Z, Ramezani F, Janzadeh A, Rahimi B, Nasirinezhad F. Platelet-rich plasma in umbilical cord blood reduces neuropathic pain in spinal cord injury by altering the expression of ATP receptors. Physiol Behav 2020; 228:113186. [PMID: 32980385 DOI: 10.1016/j.physbeh.2020.113186] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 09/21/2020] [Accepted: 09/22/2020] [Indexed: 12/27/2022]
Abstract
BACKGROUND Neuropathic pain following injury or dysfunction of the peripheral or CNS is one of the most important medical challenges to treat. Humane platelet-rich plasma (HPRP), which is a rich source of growth factors, may be able to treat and reduce pain caused by spinal cord injury (SCI). In this study, the effect of HPRP on neuropathic pain caused by SCI was investigated. METHODS Sixty adult male Wistar rats were randomly divided into 6 groups: control, sham, SCI, vehicle (SCI+platelet-poor plasma), SCI+ PRP2day (injection 48 hrs after SCI) and SCI+PRP14day (injection 14 days after SCI). SCI was induced at the T12-T13 level. Behavioral tests were conducted weekly after injury for six weeks. Allodynia and hyperalgesia were assessed using acetone drops, plantar test and von Frey filament. Cavity size and the number of fibroblasts were determined by H&E stain, and the expression of mTOR, p-mTOR, P2×3R and P2Y4R were determined using the western blot technique. Data were analyzed using PRISM & SPSS software. RESULTS PRP injection showed a higher pain threshold in mechanical allodynia (p<0.0001), cold allodynia (p<0.0001) and thermal hyperalgesia (p<0.0001) than those in the spinal. Animals treated with PRP also reduced cavity size, fibroblast number, p-mTOR/mTOR ratio, and P2×3R expression, and increased P2Y4R expression. The difference between the two groups was not statistically significant. CONCLUSIONS The results showed that PRP reduced SCI-induced allodynia and hyperalgesia by regulating ATP signaling. Using HPRP can open a new window in the treatment of pain caused by damage to the nervous system.
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Affiliation(s)
- Zahra Behroozi
- Student research committee, Iran University of Medical Sciences, Tehran, Iran; Department of Physiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Fatemeh Ramezani
- Physiology Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Atousa Janzadeh
- Radiation Biology Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Behnaz Rahimi
- Department of Physiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Farinaz Nasirinezhad
- Department of Physiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran; Physiology Research Center, Iran University of Medical Sciences, Tehran, Iran
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46
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Distinct Corticospinal and Reticulospinal Contributions to Voluntary Control of Elbow Flexor and Extensor Muscles in Humans with Tetraplegia. J Neurosci 2020; 40:8831-8841. [PMID: 32883710 DOI: 10.1523/jneurosci.1107-20.2020] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 08/20/2020] [Accepted: 08/27/2020] [Indexed: 12/14/2022] Open
Abstract
Humans with cervical spinal cord injury (SCI) often recover voluntary control of elbow flexors and, to a much lesser extent, elbow extensor muscles. The neural mechanisms underlying this asymmetrical recovery remain unknown. Anatomical and physiological evidence in animals and humans indicates that corticospinal and reticulospinal pathways differentially control elbow flexor and extensor motoneurons; therefore, it is possible that reorganization in these pathways contributes to the asymmetrical recovery of elbow muscles after SCI. To test this hypothesis, we examined motor-evoked potentials (MEPs) elicited by transcranial magnetic stimulation over the arm representation of the primary motor cortex, maximal voluntary contractions, the StartReact response (a shortening in reaction time evoked by a startling stimulus), and the effect of an acoustic startle cue on MEPs elicited by cervicomedullary stimulation (CMEPs) on biceps and triceps brachii in males and females with and without chronic cervical incomplete SCI. We found that SCI participants showed similar MEPs and maximal voluntary contractions in biceps but smaller responses in triceps compared with controls, suggesting reduced corticospinal inputs to elbow extensors. The StartReact and CMEP facilitation was larger in biceps but similar to controls in triceps, suggesting enhanced reticulospinal inputs to elbow flexors. These findings support the hypothesis that the recovery of biceps after cervical SCI results, at least in part, from increased reticulospinal inputs and that the lack of these extra inputs combined with the loss of corticospinal drive contribute to the pronounced weakness found in triceps.SIGNIFICANCE STATEMENT Although a number of individuals with cervical incomplete spinal cord injury show limited functional recovery of elbow extensors compared with elbow flexor muscles, to date, the neural mechanisms underlying this asymmetrical recovery remain unknown. Here, we provide for the first time evidence for increased reticulospinal inputs to biceps but not triceps brachii and loss of corticospinal drive to triceps brachii in humans with tetraplegia. We propose that this reorganization in descending control contributes to the asymmetrical recovery between elbow flexor and extensor muscles after cervical spinal cord injury.
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47
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Eisdorfer JT, Smit RD, Keefe KM, Lemay MA, Smith GM, Spence AJ. Epidural Electrical Stimulation: A Review of Plasticity Mechanisms That Are Hypothesized to Underlie Enhanced Recovery From Spinal Cord Injury With Stimulation. Front Mol Neurosci 2020; 13:163. [PMID: 33013317 PMCID: PMC7497436 DOI: 10.3389/fnmol.2020.00163] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 08/07/2020] [Indexed: 12/17/2022] Open
Abstract
Spinal cord injury (SCI) often results in life-long sensorimotor impairment. Spontaneous recovery from SCI is limited, as supraspinal fibers cannot spontaneously regenerate to form functional networks below the level of injury. Despite this, animal models and humans exhibit many motor behaviors indicative of recovery when electrical stimulation is applied epidurally to the dorsal aspect of the lumbar spinal cord. In 1976, epidural stimulation was introduced to alleviate spasticity in Multiple Sclerosis. Since then, epidural electrical stimulation (EES) has been demonstrated to improve voluntary mobility across the knee and/or ankle in several SCI patients, highlighting its utility in enhancing motor activation. The mechanisms that EES induces to drive these improvements in sensorimotor function remain largely unknown. In this review, we discuss several sensorimotor plasticity mechanisms that we hypothesize may enable epidural stimulation to promote recovery, including changes in local lumbar circuitry, propriospinal interneurons, and the internal model. Finally, we discuss genetic tools for afferent modulation as an emerging method to facilitate the search for the mechanisms of action.
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Affiliation(s)
- Jaclyn T Eisdorfer
- Department of Bioengineering, College of Engineering, Temple University, Philadelphia, PA, United States
| | - Rupert D Smit
- Department of Neuroscience, Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Kathleen M Keefe
- Department of Bioengineering, College of Engineering, Temple University, Philadelphia, PA, United States
| | - Michel A Lemay
- Department of Bioengineering, College of Engineering, Temple University, Philadelphia, PA, United States
| | - George M Smith
- Department of Neuroscience, Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Andrew J Spence
- Department of Bioengineering, College of Engineering, Temple University, Philadelphia, PA, United States
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Zheng Y, Mao YR, Yuan TF, Xu DS, Cheng LM. Multimodal treatment for spinal cord injury: a sword of neuroregeneration upon neuromodulation. Neural Regen Res 2020; 15:1437-1450. [PMID: 31997803 PMCID: PMC7059565 DOI: 10.4103/1673-5374.274332] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 04/28/2019] [Accepted: 07/08/2019] [Indexed: 12/25/2022] Open
Abstract
Spinal cord injury is linked to the interruption of neural pathways, which results in irreversible neural dysfunction. Neural repair and neuroregeneration are critical goals and issues for rehabilitation in spinal cord injury, which require neural stem cell repair and multimodal neuromodulation techniques involving personalized rehabilitation strategies. Besides the involvement of endogenous stem cells in neurogenesis and neural repair, exogenous neural stem cell transplantation is an emerging effective method for repairing and replacing damaged tissues in central nervous system diseases. However, to ensure that endogenous or exogenous neural stem cells truly participate in neural repair following spinal cord injury, appropriate interventional measures (e.g., neuromodulation) should be adopted. Neuromodulation techniques, such as noninvasive magnetic stimulation and electrical stimulation, have been safely applied in many neuropsychiatric diseases. There is increasing evidence to suggest that neuromagnetic/electrical modulation promotes neuroregeneration and neural repair by affecting signaling in the nervous system; namely, by exciting, inhibiting, or regulating neuronal and neural network activities to improve motor function and motor learning following spinal cord injury. Several studies have indicated that fine motor skill rehabilitation training makes use of residual nerve fibers for collateral growth, encourages the formation of new synaptic connections to promote neural plasticity, and improves motor function recovery in patients with spinal cord injury. With the development of biomaterial technology and biomechanical engineering, several emerging treatments have been developed, such as robots, brain-computer interfaces, and nanomaterials. These treatments have the potential to help millions of patients suffering from motor dysfunction caused by spinal cord injury. However, large-scale clinical trials need to be conducted to validate their efficacy. This review evaluated the efficacy of neural stem cells and magnetic or electrical stimulation combined with rehabilitation training and intelligent therapies for spinal cord injury according to existing evidence, to build up a multimodal treatment strategy of spinal cord injury to enhance nerve repair and regeneration.
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Affiliation(s)
- Ya Zheng
- Rehabilitation Section, Spine Surgery Division of Department of Orthopedics, Tongji Hospital Affiliated to Tongji University School of Medicine, Shanghai, China
| | - Ye-Ran Mao
- Rehabilitation Section, Spine Surgery Division of Department of Orthopedics, Tongji Hospital Affiliated to Tongji University School of Medicine, Shanghai, China
| | - Ti-Fei Yuan
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
| | - Dong-Sheng Xu
- Rehabilitation Section, Spine Surgery Division of Department of Orthopedics, Tongji Hospital Affiliated to Tongji University School of Medicine, Shanghai, China
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education of the People's Republic of China, Tongji University, Shanghai, China
| | - Li-Ming Cheng
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education of the People's Republic of China, Tongji University, Shanghai, China
- Spine Surgery Division of Department of Orthopedics, Tongji Hospital Affiliated to Tongji University School of Medicine, Shanghai, China
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49
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Meehan CF, Ford TW, Kirkwood PA. Plasticity of thoracic interneurones rostral to a lateral spinal cord lesion. Exp Neurol 2020; 331:113361. [PMID: 32464119 DOI: 10.1016/j.expneurol.2020.113361] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Revised: 05/03/2020] [Accepted: 05/17/2020] [Indexed: 01/14/2023]
Abstract
The morphology and projections of ventral horn interneurones in the segment above an ipsilateral thoracic lateral spinal cord lesion were studied in the cat by intracellular injections of Neurobiotin at 6 to 18 weeks post-lesion and compared with previously published control data from uninjured spinal cords. The cell axons ascended, descended or both, mostly contralaterally and mostly spared by the lesion. Unusual morphological dendritic features were seen in the lesion group, mostly growth-related, including complex dendritic appendages, twisted or multiple-branched terminal dendrites, commissural dendrites, apparently swollen proximal dendrites and rostrocaudal asymmetries. Significant quantitative differences included more dendritic spines in the lesion group (3.4×) and smaller soma areas in the lesion group (with similar numbers of primary dendrites and rostrocaudal dendritic spans). Immunoreactivity to microtubule associated protein 2a/b was detected in the proximal, but not distal, dendrites of cells in the lesion group, corresponding to an overall decrease in immunoreactivity in the ventral horns on the lesion side compared to the other. For axon collaterals, significant increases for the lesion group were seen in the number of collaterals in the first 4 mm of axon and in the area of ventral/intermediate horn occupied by terminals, including increased innervation of some regions, among which were the intermediolateral columns. This dendritic and axonal plasticity makes the interneuones candidates for a role in detour circuits but also for a maladaptive role in autonomic hyperreflexia.
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Affiliation(s)
- Claire Francesca Meehan
- Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK.
| | - Timothy W Ford
- Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Peter A Kirkwood
- Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
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Doperalski AE, Montgomery LR, Mondello SE, Howland DR. Anatomical Plasticity of Rostrally Terminating Axons as a Possible Bridging Substrate across a Spinal Injury. J Neurotrauma 2020; 37:877-888. [PMID: 31774025 DOI: 10.1089/neu.2018.6193] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Transfer of information across a spinal lesion is required for many aspects of recovery across diverse motor systems. Our understanding of axonal plasticity and which subpopulations of neurons may contribute to bridging substrates following injury, however, remains relatively incomplete. Most recently, attention has been directed to propriospinal neurons (PSNs), with research suggesting that they are capable of bridging a spinal lesion in rodents. In the current study, subpopulations of both long (C5) and short (T6, T8) PSNs-as well as a supraspinal system, the rubrospinal tract (RST)-were assessed following low thoracic (T9) hemisection in the cat using the retrograde tracer Fluoro-Gold. Acutely, within 2 weeks post-hemisection, the numbers of short and long PSNs, as well as contralateral RST neurons, with axons crossing the lesion were significantly decreased relative to uninjured controls. This decrease persisted bilaterally and was permanent in the long PSNs and the contralateral red nucleus (RN). However, by 16 weeks post-hemisection, the numbers of ipsilesional and contralesional short PSNs bridging the lesion were significantly increased. Further, the number of contralesional contributing short PSNs was significantly greater in injured animals than in uninjured animals. A significant increase over uninjured numbers also was seen in the ipsilateral (non-axotomized) RN. These findings suggest that a novel substrate of undamaged axons, which normally terminates rostral to the lesion, grows past a thoracic lesion after injury. This rostral population represents a major component of the bridging substrate seen and may represent an important anatomical target for evolving rehabilitation approaches as a substrate capable of contributing to functional recovery.
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Affiliation(s)
- Adele E Doperalski
- Department of Biology, American University, Washington DC.,Department of Neuroscience, University of Florida, Gainesville, Florida.,Malcom Randall VA Medical Center, Gainesville, Florida
| | - Lynnette R Montgomery
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky.,Department of Neurological Surgery, University of Louisville, Louisville, Kentucky.,Robley Rex VA Medical Center, Louisville, Kentucky
| | - Sarah E Mondello
- Department of Neuroscience, University of Florida, Gainesville, Florida.,Malcom Randall VA Medical Center, Gainesville, Florida.,Department of Rehabilitation Medicine, University of Washington, Seattle, Washington
| | - Dena R Howland
- Department of Neuroscience, University of Florida, Gainesville, Florida.,Malcom Randall VA Medical Center, Gainesville, Florida.,Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky.,Department of Neurological Surgery, University of Louisville, Louisville, Kentucky.,Robley Rex VA Medical Center, Louisville, Kentucky
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