51
|
Atkinson DA, Mendez L, Goodrich N, Aslan SC, Ugiliweneza B, Behrman AL. Muscle Activation Patterns During Movement Attempts in Children With Acquired Spinal Cord Injury: Neurophysiological Assessment of Residual Motor Function Below the Level of Lesion. Front Neurol 2019; 10:1295. [PMID: 31920919 PMCID: PMC6933608 DOI: 10.3389/fneur.2019.01295] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 11/25/2019] [Indexed: 11/26/2022] Open
Abstract
Introduction: Characterization of residual neuromotor capacity after spinal cord injury (SCI) is challenging. The current gold standard for measurement of sensorimotor function after SCI, the International Society for Neurological Classification of Spinal Cord Injury (ISNCSCI) exam, seeks to determine isolated intentional muscle activation, however many individuals with SCI exhibit intentional movements and muscle activation patterns which are not confined to specific joint or muscle. Further, isolated muscle activation is a feature of the neuromuscular system that emerges during development, and thus may not be an appropriate measurement standard for children younger than 6. Methods: We utilized neurophysiological assessment methodology, long studied in adult SCI populations, to evaluate residual neuromotor capacity in 24 children with SCI, as well as 19 typically developing (TD) children. Surface electromyography (EMG) signals were recorded from 11 muscles bilaterally, representing spinal motor output from all regions (i.e., cervical, thoracic, and lumbosacral), during standardized movement attempts. EMG records were subjectively analyzed based on spatiotemporal muscle activation characteristics, while the voluntary response index (VRI) was utilized for objective analysis of unilateral leg movement tasks. Results: Evidence of intentional leg muscle activation below the level of lesion was found in 11/24 children with SCI, and was classified based on activation pattern. Trace activation, bilateral (generalized) activation, and unilateral or isolated activation occurred in 32, 49, and 8% of movement tasks, respectively. Similarly, VRI analyses objectively identified significant differences between TD and SCI children in both magnitude (p < 0.01) and similarity index (p < 0.05) for all unilateral leg movement tasks. Activation of the erector spinae muscles, recorded at the T10–T12 vertebral level, was observed in all children with SCI, regardless of injury level or severity. Conclusions: Residual descending influence on spinal motor circuits may be present after SCI in children. Assessment of multi-muscle activation patterns during intentional movement attempts can provide objective evidence of the presence and extent of such residual muscle activation, and may provide an indicator of motor recovery potential following injury. The presence of residual intentional muscle activation has important implications for rehabilitation following pediatric-onset SCI.
Collapse
Affiliation(s)
- Darryn A Atkinson
- Doctor of Physical Therapy Program, University of St. Augustine for Health Sciences, Austin, TX, United States
| | - Laura Mendez
- Kosair Charities Center for Pediatric NeuroRecovery, University of Louisville, Louisville, KY, United States.,Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, KY, United States
| | - Natalie Goodrich
- Kosair Charities Center for Pediatric NeuroRecovery, University of Louisville, Louisville, KY, United States.,Pediatric Neurorecovery Program, Frazier Rehab Institute, Louisville, KY, United States
| | - Sevda C Aslan
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, KY, United States.,Department of Neurological Surgery, University of Louisville, Louisville, KY, United States
| | - Beatrice Ugiliweneza
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, KY, United States.,Department of Neurological Surgery, University of Louisville, Louisville, KY, United States
| | - Andrea L Behrman
- Kosair Charities Center for Pediatric NeuroRecovery, University of Louisville, Louisville, KY, United States.,Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, KY, United States.,Department of Neurological Surgery, University of Louisville, Louisville, KY, United States
| |
Collapse
|
52
|
Han Q, Ordaz JD, Liu NK, Richardson Z, Wu W, Xia Y, Qu W, Wang Y, Dai H, Zhang YP, Shields CB, Smith GM, Xu XM. Descending motor circuitry required for NT-3 mediated locomotor recovery after spinal cord injury in mice. Nat Commun 2019; 10:5815. [PMID: 31862889 PMCID: PMC6925225 DOI: 10.1038/s41467-019-13854-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 11/29/2019] [Indexed: 01/22/2023] Open
Abstract
Locomotor function, mediated by lumbar neural circuitry, is modulated by descending spinal pathways. Spinal cord injury (SCI) interrupts descending projections and denervates lumbar motor neurons (MNs). We previously reported that retrogradely transported neurotrophin-3 (NT-3) to lumbar MNs attenuated SCI-induced lumbar MN dendritic atrophy and enabled functional recovery after a rostral thoracic contusion. Here we functionally dissected the role of descending neural pathways in response to NT-3-mediated recovery after a T9 contusive SCI in mice. We find that residual projections to lumbar MNs are required to produce leg movements after SCI. Next, we show that the spared descending propriospinal pathway, rather than other pathways (including the corticospinal, rubrospinal, serotonergic, and dopaminergic pathways), accounts for NT-3-enhanced recovery. Lastly, we show that NT-3 induced propriospino-MN circuit reorganization after the T9 contusion via promotion of dendritic regrowth rather than prevention of dendritic atrophy.
Collapse
Affiliation(s)
- Qi Han
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.,Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Josue D Ordaz
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.,Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Nai-Kui Liu
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.,Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Zoe Richardson
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.,Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Wei Wu
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.,Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Yongzhi Xia
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.,Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Wenrui Qu
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.,Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Ying Wang
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.,Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Heqiao Dai
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.,Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Yi Ping Zhang
- Norton Neuroscience Institute, Norton Healthcare, Louisville, KY, 40202, USA
| | - Christopher B Shields
- Norton Neuroscience Institute, Norton Healthcare, Louisville, KY, 40202, USA.,Department of Neurological Surgery, University of Louisville, Louisville, KY, 40292, USA
| | - George M Smith
- Department of Neuroscience, Shriners Hospitals Pediatric Research Center, Center for Neural Rehabilitation and Repair, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19122, USA
| | - Xiao-Ming Xu
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, 46202, USA. .,Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.
| |
Collapse
|
53
|
Laliberte AM, Goltash S, Lalonde NR, Bui TV. Propriospinal Neurons: Essential Elements of Locomotor Control in the Intact and Possibly the Injured Spinal Cord. Front Cell Neurosci 2019; 13:512. [PMID: 31798419 PMCID: PMC6874159 DOI: 10.3389/fncel.2019.00512] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 10/29/2019] [Indexed: 12/22/2022] Open
Abstract
Propriospinal interneurons (INs) communicate information over short and long distances within the spinal cord. They act to coordinate different parts of the body by linking motor circuits that control muscles across the forelimbs, trunk, and hindlimbs. Their role in coordinating locomotor circuits near and far may be invaluable to the recovery of locomotor function lost due to injury to the spinal cord where the flow of motor commands from the brain and brainstem to spinal motor circuits is disrupted. The formation and activation of circuits established by spared propriospinal INs may promote the re-emergence of locomotion. In light of progress made in animal models of spinal cord injury (SCI) and in human patients, we discuss the role of propriospinal INs in the intact spinal cord and describe recent studies investigating the assembly and/or activation of propriospinal circuits to promote recovery of locomotion following SCI.
Collapse
Affiliation(s)
- Alex M Laliberte
- Department of Biology, Faculty of Science, Brain and Mind Research Institute, University of Ottawa, Ottawa, ON, Canada
| | - Sara Goltash
- Department of Biology, Faculty of Science, Brain and Mind Research Institute, University of Ottawa, Ottawa, ON, Canada
| | - Nicolas R Lalonde
- Department of Biology, Faculty of Science, Brain and Mind Research Institute, University of Ottawa, Ottawa, ON, Canada
| | - Tuan Vu Bui
- Department of Biology, Faculty of Science, Brain and Mind Research Institute, University of Ottawa, Ottawa, ON, Canada
| |
Collapse
|
54
|
von Wild T, Brunelli GA, von Wild KR, Löhnhardt M, Catoi C, Catoi AF, Vester JC, Strilciuc S, Trillenberg P. Regeneration of Denervated Skeletal Muscles - Brunelli's CNS-PNS Paradigm. J Med Life 2019; 12:342-353. [PMID: 32025252 PMCID: PMC6993288 DOI: 10.25122/jml-2019-0063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 11/20/2019] [Indexed: 12/02/2022] Open
Abstract
The restoration of voluntary muscle activity in posttraumatic paraplegia in both animal experiments and other clinical applications requires reproducibility of a technically-demanding microsurgical procedure, limited by physicians' understanding of Brunelli's spinal cord grafting paradigm. The insufficient clinical investigation of the long-term benefits of the CNS-PNS graft application warrants additional inquiry. The objective of this study is to explore the potential benefits of the first replicated, graft-induced neuroregeneration of denervated skeletal muscle regarding long-term clinical outcomes and to investigate the effect of Cerebrolysin on neuromodulation. A randomized study evaluating 30 rats, approved by the National Animal Ethics Advisory Committee was performed. The medication was administered postoperatively. For 14 days, 12 rats received Cerebrolysin (serum), 11 received NaCl 0.9% (shams), and 7 were controls. For microsurgery, the lateral corticospinal tract T10 was grafted to the denervated internal obliquus abdominal muscle. On day 90, intraoperative proof of reinnervation was observed. On day 100, 15 rats were euthanized for fixation, organ removal, and extensive histology-morphology examination, and the Wei-Lachin statistical procedure was employed. After an open revision of 16 rats, 8 were CMAP positive. After intravenous Vecuronium application, two (Cerebrolysin, NaCl) out of two rats showed an incomplete compound muscle action potential (CMAP) loss due to glutamatergic and cholinergic co-transmission, while two others showed a complete loss of amplitude. Cerebrolysin medication initiated larger restored muscle fiber diameters and less scarring. FB+ neurons were not observed in the brain but were observed in the Rexed laminae. Brunelli's concept was successfully replicated, demonstrating the first graft induced existence of cholinergic and glutamatergic neurotransmission in denervated grafted muscles. Statistics of the histometric count of muscle fibers revealed larger fiber diameters after Cerebrolysin. Brunelli's CNS-PNS experimental concept is suitable to analyze graft-neuroplasticity focused on the voluntary restoration of denervated skeletal muscles in spinal cord injury. Neuroprotection by Cerebrolysin is demonstrated.
Collapse
Affiliation(s)
- Tobias von Wild
- Department of Plastic Reconstructive and Aesthetic Surgery, Hand Surgery, Praxisklinik in der Alster City, Hamburg, Germany
| | - Giorgio A. Brunelli
- School of Specialists in Orthopedics, Traumatology, Hand and Microsurgery, University of Brescia, Brescia, Italy
- Foundation Giorgio Brunelli for Research on Spinal Cord Lesions ONLUS, E.S.C.R.I., Brescia, Italy
| | - Klaus R.H. von Wild
- Department of Neurosurgery, Medical Faculty Westphalia Wilhelm’s University Münster, Münster, Germany
- International Neuroscience Institute, Hanover, Germany
| | - Marlene Löhnhardt
- Department of Plastic and Reconstructive Surgery, Hand Surgery, University Hospital, Hamburg, Germany
| | - Cornel Catoi
- Department of Pathology, University of Agricultural Science and Veterinary Medicine, Cluj-Napoca, Romania
| | - Adriana Florinela Catoi
- Department of Functional Biosciences, University of Medicine and Pharmacy “Iuliu Hatieganu”, Cluj-Napoca, Romania
| | - Johannes C. Vester
- Department of Biometry & Clinical Research, idv Data Analysis and Study Planning, Gauting, Germany
| | - Stefan Strilciuc
- Department of Neurology, University of Medicine and Pharmacy “Iuliu Hatieganu”, Cluj-Napoca; Romania
| | - Peter Trillenberg
- Department of Neurology, University Medical Center Schleswig-Holstein, Lübeck, Germany
| |
Collapse
|
55
|
Ohne H, Takahashi M, Satomi K, Hasegawa A, Takeuchi T, Sato S, Ichimura S. Mechanism of forelimb motor function restoration in rats with cervical spinal cord hemisection-neuroanatomical validation. IBRO Rep 2019; 7:10-25. [PMID: 31431931 PMCID: PMC6581651 DOI: 10.1016/j.ibror.2019.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 05/05/2019] [Indexed: 11/13/2022] Open
Abstract
Purpose The purpose of this study is neuroanatomical validation of forelimb motor function restoration in rats with cervical spinal cord injury. Materials and methods We used eight cervical hemisected rats and eight normal rats. We cut in half the C3/4 cervical spinal cord of 18-weeks-old normal rats. We used 24-weeks-old rats that had reached a nearly steady state of forelimb motor function after the hemisection (Hemisection group). Normal 24-week-old rats were used as Control group. To evaluate the corticospinal tracts, neuro-tracing by biotynirated dextran-amine (BDA) was used. BDA was injected into the damaged side of the cerebral primary motor cortex. In order to quantitatively analyze the specimen, we recorded a site where nerve fibers appear in each specimen in the image analysis (1) and defined the increase rate of immunostaining area using ImageJ in the image analysis (2). Based on the evaluation in the image analysis (1) and the image analysis (2), the Hemisection group and the Control group were compared. Results In the image analysis (1), a region with robust appearance of aberrant nerve fibers was observed in the cephalad side of the Hemisection site in Hemisection group than Control group. In the spinal cord caudal to the hemisection, such region was generally more in Hemisection group, however, disappeared or reduced appearance was observed in some regions. In the image analysis (2), no statistical significant difference was noted in each level. Conclusion There is a high probability that these aberrant nerve fibers beyond the midline could be involved in forelimb motor function restoration in rats with cervical cord hemisection.
Collapse
Affiliation(s)
- Hideaki Ohne
- Department of Orthopaedic Surgery, Kyorin University School of Medicine, 6-20-2 Shinkawa Mitaka, Tokyo, 181-8611, Japan
| | - Masahito Takahashi
- Department of Orthopaedic Surgery, Kyorin University School of Medicine, 6-20-2 Shinkawa Mitaka, Tokyo, 181-8611, Japan
| | - Kazuhiko Satomi
- Orthopaedic Surgery, Kugayama Hospital, 2-14-20 Kitakarasuyama Setagaya, Tokyo, 157-0061, Japan
| | - Atsushi Hasegawa
- Department of Orthopaedic Surgery, Kyorin University School of Medicine, 6-20-2 Shinkawa Mitaka, Tokyo, 181-8611, Japan
| | - Takumi Takeuchi
- Department of Orthopaedic Surgery, Kyorin University School of Medicine, 6-20-2 Shinkawa Mitaka, Tokyo, 181-8611, Japan
| | - Shunsuke Sato
- Department of Orthopaedic Surgery, Kyorin University School of Medicine, 6-20-2 Shinkawa Mitaka, Tokyo, 181-8611, Japan
| | - Shoichi Ichimura
- Department of Orthopaedic Surgery, Kyorin University School of Medicine, 6-20-2 Shinkawa Mitaka, Tokyo, 181-8611, Japan
| |
Collapse
|
56
|
Imbalanced Corticospinal and Reticulospinal Contributions to Spasticity in Humans with Spinal Cord Injury. J Neurosci 2019; 39:7872-7881. [PMID: 31413076 DOI: 10.1523/jneurosci.1106-19.2019] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 06/22/2019] [Accepted: 07/25/2019] [Indexed: 02/04/2023] Open
Abstract
Damage to the corticospinal and reticulospinal tract has been associated with spasticity in humans with upper motor neuron lesions. We hypothesized that these descending motor pathways distinctly contribute to the control of a spastic muscle in humans with incomplete spinal cord injury (SCI). To test this hypothesis, we examined motor-evoked potentials (MEPs) elicited by transcranial magnetic stimulation over the leg representation of the primary motor cortex, maximal voluntary contractions (MVCs), and the StartReact response (shortening in reaction time evoked by a startling stimulus) in the quadriceps femoris muscle in male and females with and without incomplete SCI. A total of 66.7% of the SCI participants showed symptoms of spasticity, whereas the other 33.3% showed no or low levels of spasticity. We found that participants with spasticity had smaller MEPs and MVCs and larger StartReact compared with participants with no or low spasticity and control subjects. These results were consistently present in spastic subjects but not in the other populations. Clinical scores of spasticity were negatively correlated with MEP-max and MVC values and positively correlated with shortening in reaction time. These findings provide evidence for lesser corticospinal and larger reticulospinal influences to spastic muscles in humans with SCI and suggest that these imbalanced contributions are important for motor recovery.SIGNIFICANCE STATEMENT Although spasticity is one of the most common symptoms manifested in humans with spinal cord injury (SCI) to date, its mechanisms of action remain poorly understood. We provide evidence, for the first time, of imbalanced contributions of the corticospinal and reticulospinal tract to control a spastic muscle in humans with chronic incomplete SCI. We found that participants with SCI with spasticity showed small corticospinal responses and maximal voluntary contractions and larger reticulospinal gain compared with participants with no or low spasticity and control subjects. These results were consistently present in spastic subjects but not in the other populations. We showed that imbalanced corticospinal and reticulospinal tract contributions are more pronounced in participants with chronic incomplete SCI with lesser recovery.
Collapse
|
57
|
Tsujioka H, Yamashita T. Comparison of gene expression profile of the spinal cord of sprouting-capable neonatal and sprouting-incapable adult mice. BMC Genomics 2019; 20:619. [PMID: 31362699 PMCID: PMC6668129 DOI: 10.1186/s12864-019-5974-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 07/15/2019] [Indexed: 12/11/2022] Open
Abstract
Background The regenerative ability of severed axons in the central nervous system is limited in mammals. However, after central nervous system injury, neural function is partially recovered by the formation of a compensatory neural circuit. In a mouse pyramidotomy model, axonal sprouting of the intact side of the corticospinal tract is observed in the spinal cord, and the axons make new synapses with the denervated side of propriospinal neurons. Moreover, this sprouting ability is enhanced in neonatal mice compared to that in adult mice. Myelin-associated molecules in the spinal cord or intrinsic factors in corticospinal neurons have been investigated in previous studies, but the factors that determine elevated sprouting ability in neonatal mice are not fully understood. Further, in the early phase after pyramidotomy, glial responses are observed in the spinal cord. To elucidate the basal difference in the spinal cord, we compared gene expression profiles of entire C4–7 cervical cord tissues between neonatal (injured at postnatal day 7) and adult (injured at 8 weeks of age) mice by RNA-sequencing. We also tried to identify discordant gene expression changes that might inhibit axonal sprouting in adult mice at the early phase (3 days) after pyramidotomy. Results A comparison of neonatal and adult sham groups revealed remarkable basal differences in the spinal cord, such as active neural circuit formation, cell proliferation, the development of myelination, and an immature immune system in neonatal mice compared to that observed in adult mice. Some inflammation-related genes were selectively expressed in adult mice after pyramidotomy, implying the possibility that these genes might be related to the low sprouting ability in adult mice. Conclusions This study provides useful information regarding the basal difference between neonatal and adult spinal cords and the possible differential response after pyramidotomy, both of which are necessary to understand why sprouting ability is increased in neonatal mice compared to that in adult mice. Electronic supplementary material The online version of this article (10.1186/s12864-019-5974-9) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Hiroshi Tsujioka
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, Osaka, Japan.,WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Toshihide Yamashita
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, Osaka, Japan. .,WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan. .,Graduate School of Frontier Bioscience, Osaka University, Osaka, Japan. .,Department of Neuro-Medical Science, Graduate School of Medicine, Osaka University, Osaka, Japan.
| |
Collapse
|
58
|
Burnside ER, De Winter F, Didangelos A, James ND, Andreica EC, Layard-Horsfall H, Muir EM, Verhaagen J, Bradbury EJ. Immune-evasive gene switch enables regulated delivery of chondroitinase after spinal cord injury. Brain 2019; 141:2362-2381. [PMID: 29912283 PMCID: PMC6061881 DOI: 10.1093/brain/awy158] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 04/22/2018] [Indexed: 12/12/2022] Open
Abstract
Chondroitinase ABC is a promising preclinical therapy that promotes functional neuroplasticity after CNS injury by degrading extracellular matrix inhibitors. Efficient delivery of chondroitinase ABC to the injured mammalian spinal cord can be achieved by viral vector transgene delivery. This approach dramatically modulates injury pathology and restores sensorimotor functions. However, clinical development of this therapy is limited by a lack of ability to exert control over chondroitinase gene expression. Prior experimental gene regulation platforms are likely to be incompatible with the non-resolving adaptive immune response known to occur following spinal cord injury. Therefore, here we apply a novel immune-evasive dual vector system, in which the chondroitinase gene is under a doxycycline inducible regulatory switch, utilizing a chimeric transactivator designed to evade T cell recognition. Using this novel vector system, we demonstrate tight temporal control of chondroitinase ABC gene expression, effectively removing treatment upon removal of doxycycline. This enables a comparison of short and long-term gene therapy paradigms in the treatment of clinically-relevant cervical level contusion injuries in adult rats. We reveal that transient treatment (2.5 weeks) is sufficient to promote improvement in sensory axon conduction and ladder walking performance. However, in tasks requiring skilled reaching and grasping, only long term treatment (8 weeks) leads to significantly improved function, with rats able to accurately grasp and retrieve sugar pellets. The late emergence of skilled hand function indicates enhanced neuroplasticity and connectivity and correlates with increased density of vGlut1+ innervation in spinal cord grey matter, particularly in lamina III–IV above and below the injury. Thus, our novel gene therapy system provides an experimental tool to study temporal effects of extracellular matrix digestion as well as an encouraging step towards generating a safer chondroitinase gene therapy strategy, longer term administration of which increases neuroplasticity and recovery of descending motor control. This preclinical study could have a significant impact for tetraplegic individuals, for whom recovery of hand function is an important determinant of independence, and supports the ongoing development of chondroitinase gene therapy towards clinical application for the treatment of spinal cord injury.
Collapse
Affiliation(s)
- Emily R Burnside
- King's College London, Regeneration Group, The Wolfson Centre for Age-Related Diseases, Institute of Psychiatry, Psychology and Neuroscience (IoPPN), Guy's Campus, London Bridge, London, SE1 1UL, UK
| | - Fred De Winter
- Netherlands Institute for Neuroscience, Laboratory for Neuroregeneration, 1105 BA Amsterdam, The Netherlands
| | - Athanasios Didangelos
- King's College London, Regeneration Group, The Wolfson Centre for Age-Related Diseases, Institute of Psychiatry, Psychology and Neuroscience (IoPPN), Guy's Campus, London Bridge, London, SE1 1UL, UK
| | - Nicholas D James
- King's College London, Regeneration Group, The Wolfson Centre for Age-Related Diseases, Institute of Psychiatry, Psychology and Neuroscience (IoPPN), Guy's Campus, London Bridge, London, SE1 1UL, UK
| | - Elena-Cristina Andreica
- King's College London, Regeneration Group, The Wolfson Centre for Age-Related Diseases, Institute of Psychiatry, Psychology and Neuroscience (IoPPN), Guy's Campus, London Bridge, London, SE1 1UL, UK
| | - Hugo Layard-Horsfall
- King's College London, Regeneration Group, The Wolfson Centre for Age-Related Diseases, Institute of Psychiatry, Psychology and Neuroscience (IoPPN), Guy's Campus, London Bridge, London, SE1 1UL, UK
| | - Elizabeth M Muir
- Department of Physiology, Development and Neuroscience, University of Cambridge, CB2 3EG, UK
| | - Joost Verhaagen
- Netherlands Institute for Neuroscience, Laboratory for Neuroregeneration, 1105 BA Amsterdam, The Netherlands
| | - Elizabeth J Bradbury
- King's College London, Regeneration Group, The Wolfson Centre for Age-Related Diseases, Institute of Psychiatry, Psychology and Neuroscience (IoPPN), Guy's Campus, London Bridge, London, SE1 1UL, UK
| |
Collapse
|
59
|
Katoh H, Yokota K, Fehlings MG. Regeneration of Spinal Cord Connectivity Through Stem Cell Transplantation and Biomaterial Scaffolds. Front Cell Neurosci 2019; 13:248. [PMID: 31244609 PMCID: PMC6563678 DOI: 10.3389/fncel.2019.00248] [Citation(s) in RCA: 104] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 05/17/2019] [Indexed: 12/20/2022] Open
Abstract
Significant progress has been made in the treatment of spinal cord injury (SCI). Advances in post-trauma management and intensive rehabilitation have significantly improved the prognosis of SCI and converted what was once an “ailment not to be treated” into a survivable injury, but the cold hard fact is that we still do not have a validated method to improve the paralysis of SCI. The irreversible functional impairment of the injured spinal cord is caused by the disruption of neuronal transduction across the injury lesion, which is brought about by demyelination, axonal degeneration, and loss of synapses. Furthermore, refractory substrates generated in the injured spinal cord inhibit spontaneous recovery. The discovery of the regenerative capability of central nervous system neurons in the proper environment and the verification of neural stem cells in the spinal cord once incited hope that a cure for SCI was on the horizon. That hope was gradually replaced with mounting frustration when neuroprotective drugs, cell transplantation, and strategies to enhance remyelination, axonal regeneration, and neuronal plasticity demonstrated significant improvement in animal models of SCI but did not translate into a cure in human patients. However, recent advances in SCI research have greatly increased our understanding of the fundamental processes underlying SCI and fostered increasing optimism that these multiple treatment strategies are finally coming together to bring about a new era in which we will be able to propose encouraging therapies that will lead to appreciable improvements in SCI patients. In this review, we outline the pathophysiology of SCI that makes the spinal cord refractory to regeneration and discuss the research that has been done with cell replacement and biomaterial implantation strategies, both by itself and as a combined treatment. We will focus on the capacity of these strategies to facilitate the regeneration of neural connectivity necessary to achieve meaningful functional recovery after SCI.
Collapse
Affiliation(s)
- Hiroyuki Katoh
- Division of Genetics and Development, Krembil Research Institute, Toronto, ON, Canada.,Department of Orthopaedic Surgery - Surgical Sciences, School of Medicine, Tokai University, Tokyo, Japan
| | - Kazuya Yokota
- Division of Genetics and Development, Krembil Research Institute, Toronto, ON, Canada.,Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Michael G Fehlings
- Division of Genetics and Development, Krembil Research Institute, Toronto, ON, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, Canada.,Division of Neurosurgery, University of Toronto, Toronto, ON, Canada.,Spine Program, Toronto Western Hospital, University Health Network, Toronto, ON, Canada
| |
Collapse
|
60
|
Hellenbrand DJ, Reichl KA, Travis BJ, Filipp ME, Khalil AS, Pulito DJ, Gavigan AV, Maginot ER, Arnold MT, Adler AG, Murphy WL, Hanna AS. Sustained interleukin-10 delivery reduces inflammation and improves motor function after spinal cord injury. J Neuroinflammation 2019; 16:93. [PMID: 31039819 PMCID: PMC6489327 DOI: 10.1186/s12974-019-1479-3] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 04/09/2019] [Indexed: 12/12/2022] Open
Abstract
Background The anti-inflammatory cytokine interleukin-10 (IL-10) has been explored previously as a treatment method for spinal cord injury (SCI) due to its ability to attenuate pro-inflammatory cytokines and reduce apoptosis. Primary limitations when using systemic injections of IL-10 are that it is rapidly cleared from the injury site and that it does not cross the blood–spinal cord barrier. Objective Here, mineral-coated microparticles (MCMs) were used to obtain a local sustained delivery of IL-10 directly into the injury site after SCI. Methods Female Sprague-Dawley rats were contused at T10 and treated with either an intraperitoneal injection of IL-10, an intramedullary injection of IL-10, or MCMs bound with IL-10 (MCMs+IL-10). After treatment, cytokine levels were measured in the spinal cord, functional testing and electrophysiology were performed, axon tracers were injected into the brainstem and motor cortex, macrophage levels were counted using flow cytometry and immunohistochemistry, and lesion size was measured. Results When treated with MCMs+IL-10, IL-10 was significantly elevated in the injury site and inflammatory cytokines were significantly suppressed, prompting significantly less cells expressing antigens characteristic of inflammatory macrophages and significantly more cells expressing antigens characteristic of earlier stage anti-inflammatory macrophages. Significantly more axons were preserved within the rubrospinal and reticulospinal tracts through the injury site when treated with MCMs+IL-10; however, there was no significant difference in corticospinal tract axons preserved, regardless of treatment group. The rats treated with MCMs+IL-10 were the only group with a significantly higher functional score compared to injured controls 28 days post-contusion. Conclusion These data demonstrate that MCMs can effectively deliver biologically active IL-10 for an extended period of time altering macrophage phenotype and aiding in functional recovery after SCI.
Collapse
Affiliation(s)
- Daniel J Hellenbrand
- Department of Neurological Surgery, University of Wisconsin, Madison, WI, 53792, USA.,Department of Biomedical Engineering, University of Wisconsin, Madison, WI, 53706, USA
| | - Kaitlyn A Reichl
- Department of Neurological Surgery, University of Wisconsin, Madison, WI, 53792, USA.,Department of Biomedical Engineering, University of Wisconsin, Madison, WI, 53706, USA
| | - Benjamin J Travis
- Department of Neurological Surgery, University of Wisconsin, Madison, WI, 53792, USA
| | - Mallory E Filipp
- Department of Neurological Surgery, University of Wisconsin, Madison, WI, 53792, USA
| | - Andrew S Khalil
- Department of Biomedical Engineering, University of Wisconsin, Madison, WI, 53706, USA
| | - Domenic J Pulito
- Department of Neurological Surgery, University of Wisconsin, Madison, WI, 53792, USA
| | - Ashley V Gavigan
- Department of Neurological Surgery, University of Wisconsin, Madison, WI, 53792, USA
| | - Elizabeth R Maginot
- Department of Neurological Surgery, University of Wisconsin, Madison, WI, 53792, USA
| | - Mitchell T Arnold
- Department of Neurological Surgery, University of Wisconsin, Madison, WI, 53792, USA
| | - Alexander G Adler
- Department of Neurological Surgery, University of Wisconsin, Madison, WI, 53792, USA
| | - William L Murphy
- Department of Biomedical Engineering, University of Wisconsin, Madison, WI, 53706, USA.,Department of Orthopedics and Rehabilitation, University of Wisconsin, Madison, WI, 53705, USA
| | - Amgad S Hanna
- Department of Neurological Surgery, University of Wisconsin, Madison, WI, 53792, USA.
| |
Collapse
|
61
|
Dickson RG, Lall VK, Ichiyama RM. Enhancing plasticity in spinal sensorimotor circuits following injuries to facilitate recovery of motor control. CURRENT OPINION IN PHYSIOLOGY 2019. [DOI: 10.1016/j.cophys.2019.02.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
|
62
|
Anti-Nogo-A Antibodies As a Potential Causal Therapy for Lower Urinary Tract Dysfunction after Spinal Cord Injury. J Neurosci 2019; 39:4066-4076. [PMID: 30902870 DOI: 10.1523/jneurosci.3155-18.2019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 02/06/2019] [Indexed: 01/23/2023] Open
Abstract
Loss of bladder control is common after spinal cord injury (SCI) and no causal therapies are available. Here we investigated whether function-blocking antibodies against the nerve-fiber growth inhibitory protein Nogo-A applied to rats with severe SCI could prevent development of neurogenic lower urinary tract dysfunction. Bladder function of rats with SCI was repeatedly assessed by urodynamic examination in fully awake animals. Four weeks after SCI, detrusor sphincter dyssynergia had developed in all untreated or control antibody-infused animals. In contrast, 2 weeks of intrathecal anti-Nogo-A antibody treatment led to significantly reduced aberrant maximum detrusor pressure during voiding and a reduction of the abnormal EMG high-frequency activity in the external urethral sphincter. Anatomically, we found higher densities of fibers originating from the pontine micturition center in the lumbosacral gray matter in the anti-Nogo-A antibody-treated animals, as well as a reduced number of inhibitory interneurons in lamina X. These results suggest that anti-Nogo-A therapy could also have positive effects on bladder function clinically.SIGNIFICANCE STATEMENT After spinal cord injury, loss of bladder control is common. Detrusor sphincter dyssynergia is a potentially life-threatening consequence. Currently, only symptomatic treatment options are available. First causal treatment options are urgently needed in humans. In this work, we show that function-blocking antibodies against the nerve-fiber growth inhibitory protein Nogo-A applied to rats with severe spinal cord injury could prevent development of neurogenic lower urinary tract dysfunction, in particular detrusor sphincter dyssynergia. Anti-Nogo-A therapy has entered phase II clinical trial in humans and might therefore soon be the first causal treatment option for neurogenic lower urinary tract dysfunction.
Collapse
|
63
|
Abstract
Reticulospinal (RS) neurons provide the spinal cord with the executive signals for a large repertoire of motor and autonomic functions, ensuring at the same time that these functions are adapted to the different behavioral contexts. This requires the coordinated action of many RS neurons. In this mini-review, we examine how the RS neurons that carry out specific functions distribute across the three parts of the brain stem. Extensive overlap between populations suggests a need to explore multi-functionality at the single cell-level. We next contrast functional diversity and homogeneity in transmitter phenotype. Then, we examine the molecular genetic mechanisms that specify brain stem development and likely contribute to RS neurons identities. We advocate that a better knowledge of the developmental lineage of the RS neurons and a better knowledge of RS neuron activity across multiple behaviors will help uncover the fundamental principles behind the diversity of RS systems in mammals.
Collapse
Affiliation(s)
| | - Andrea Giorgi
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia, USA
| |
Collapse
|
64
|
Choi H, Seo KC, Kim TU, Lee SJ, Hyun JK. Repetitive Transcranial Magnetic Stimulation Enhances Recovery in Central Cord Syndrome Patients. Ann Rehabil Med 2019; 43:62-73. [PMID: 30852872 PMCID: PMC6409668 DOI: 10.5535/arm.2019.43.1.62] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 10/05/2018] [Indexed: 12/17/2022] Open
Abstract
Objective To investigate the effect of repetitive transcranial magnetic stimulation (rTMS) on neurological and functional recovery in patients with central cord syndrome (CCS) involving the upper extremities between the treated and non-treated sides of the treated group and whether the outcomes are comparable to that of the untreated control group. Methods Nineteen CCS patients were treated with high-frequency (20 Hz) rTMS over the motor cortex for 5 days. The stimulation side was randomly selected, and all the subjects received conventional occupational therapy during the rTMS-treatment period. Twenty CCS patients who did not receive rTMS were considered as controls. Clinical assessments, including those by the International Standard for Neurological Classification of Spinal Cord Injury, the Jebsen-Taylor Hand Function Test, and the O'Connor Finger Dexterity Test were performed initially and followed up for 1 month after rTMS treatment or 5 weeks after initial assessments. Results The motor scores for upper extremities were increased and the number of improved cases was greater for the treated side in rTMS-treated patients than for the non-treated side in rTMS-treated patients or controls. The improved cases for writing time and score measured on the Jebsen-Taylor Hand Function Test were also significantly greater in number on the rTMS-treated side compared with the non-treated side and controls. There were no adverse effects during rTMS therapy or the follow-up period. Conclusion The results of the application of high-frequency rTMS treatment to CCS patients suggest that rTMS can enhance the motor recovery and functional fine motor task performance of the upper extremities in such individuals.
Collapse
Affiliation(s)
- Hana Choi
- Department of Rehabilitation Medicine, Dankook University College of Medicine, Cheonan, Korea
| | - Kyung Cheon Seo
- Department of Rehabilitation Medicine, Dankook University College of Medicine, Cheonan, Korea
| | - Tae Uk Kim
- Department of Rehabilitation Medicine, Dankook University College of Medicine, Cheonan, Korea
| | - Seong Jae Lee
- Department of Rehabilitation Medicine, Dankook University College of Medicine, Cheonan, Korea
| | - Jung Keun Hyun
- Department of Rehabilitation Medicine, Dankook University College of Medicine, Cheonan, Korea.,Department of Nanobiomedical Science and BK21 Plus NBM Global Research Center for Regenerative Medicine, Dankook University, Cheonan, Korea.,Institute of Tissue Regeneration Engineering (ITREN), Dankook University, Cheonan, Korea.,Wiregene Co. Ltd., Cheonan, Korea
| |
Collapse
|
65
|
Myelinated axons and functional blood vessels populate mechanically compliant rGO foams in chronic cervical hemisected rats. Biomaterials 2019; 192:461-474. [DOI: 10.1016/j.biomaterials.2018.11.024] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Revised: 11/06/2018] [Accepted: 11/13/2018] [Indexed: 11/18/2022]
|
66
|
Loy K, Bareyre FM. Rehabilitation following spinal cord injury: how animal models can help our understanding of exercise-induced neuroplasticity. Neural Regen Res 2019; 14:405-412. [PMID: 30539806 PMCID: PMC6334617 DOI: 10.4103/1673-5374.245951] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Spinal cord injury is a devastating condition that is followed by long and often unsuccessful recovery after trauma. The state of the art approach to manage paralysis and concomitant impairments is rehabilitation, which is the only strategy that has proven to be effective and beneficial for the patients over the last decades. How rehabilitation influences the remodeling of spinal axonal connections in patients is important to understand, in order to better target these changes and define the optimal timing and onset of training. While clinically the answers to these questions remain difficult to obtain, rodent models of rehabilitation like bicycling, treadmill training, swimming, enriched environments or wheel running that mimic clinical rehabilitation can be helpful to reveal the axonal changes underlying motor recovery. This review will focus on the different animal models of spinal cord injury rehabilitation and the underlying changes in neuronal networks that are improved by exercise and rehabilitation.
Collapse
Affiliation(s)
- Kristina Loy
- Institute of Clinical Neuroimmunology, Ludwig-Maximilians Universität München, Munich, Germany
| | - Florence M Bareyre
- Institute of Clinical Neuroimmunology, Ludwig-Maximilians Universität München; Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| |
Collapse
|
67
|
Yu P, Zhang W, Liu Y, Sheng C, So KF, Zhou L, Zhu H. The effects and potential mechanisms of locomotor training on improvements of functional recovery after spinal cord injury. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2019; 147:199-217. [DOI: 10.1016/bs.irn.2019.08.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
68
|
Abstract
Spinal cord injury is associated with chronic sensorimotor deficits due to the interruption of ascending and descending tracts between the brain and spinal cord. Functional recovery after anatomically complete spinal cord injury is limited due to the lack of long-distance axonal regeneration of severed fibers in the adult central nervous system. Most spinal cord injuries in humans, however, are anatomically incomplete. Although restorative treatment options for spinal cord injury remain currently limited, research from experimental models of spinal cord injury have revealed a tremendous capability for both spontaneous and treatment-induced plasticity of the corticospinal system that supports functional recovery. We review recent advances in the understanding of corticospinal circuit plasticity after spinal cord injury and concentrate mainly on the hindlimb motor cortex, its corticospinal projections, and the role of spinal mechanisms that support locomotor recovery. First, we discuss plasticity that occurs at the level of motor cortex and the reorganization of cortical movement representations. Next, we explore downstream plasticity in corticospinal projections. We then review the role of spinal mechanisms in locomotor recovery. We conclude with a perspective on harnessing neuroplasticity with therapeutic interventions to promote functional recovery.
Collapse
Affiliation(s)
- Andrew R Brown
- Département de Neurosciences, Faculté de Médecine, Université de Montréal; Hôpital du Sacré-Coeur de Montréal (CIUSS-NIM), Montréal, Québec, Canada
| | - Marina Martinez
- Département de Neurosciences, Faculté de Médecine, Université de Montréal; Hôpital du Sacré-Coeur de Montréal (CIUSS-NIM), Montréal; Groupe de Recherche sur le Système Nerveux Central, Université de Montréal, Montréal, Québec, Canada
| |
Collapse
|
69
|
Ipsilesional Motor Cortex Plasticity Participates in Spontaneous Hindlimb Recovery after Lateral Hemisection of the Thoracic Spinal Cord in the Rat. J Neurosci 2018; 38:9977-9988. [PMID: 30301755 DOI: 10.1523/jneurosci.1062-18.2018] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2018] [Revised: 08/20/2018] [Accepted: 09/29/2018] [Indexed: 01/08/2023] Open
Abstract
After an incomplete spinal cord injury (SCI) spontaneous motor recovery can occur in mammals, but the underlying neural substrates remain poorly understood. The motor cortex is crucial for skilled motor learning and the voluntary control of movement and is known to reorganize after cortical injury to promote recovery. Motor cortex plasticity has also been shown to parallel the recovery of forelimb function after cervical SCI, but whether cortical plasticity participates in hindlimb recovery after SCI remains unresolved. Using intracortical microstimulation (ICMS) mapping, behavioral and cortical inactivation techniques in the female Long-Evans rat, we evaluated the spontaneous cortical mechanisms of hindlimb motor recovery 1-5 weeks after lateral hemisection of the thoracic (T8) spinal cord that ablated the crossed corticospinal tract (CST) from the contralesional motor cortex while sparing the majority of the CST from the ipsilesional motor cortex. Hemisection initially impaired hindlimb motor function bilaterally but significant recovery occurred during the first 3 weeks. ICMS revealed time-dependent changes in motor cortex organization, characterized by a chronic abolishment of hindlimb motor representation in the contralesional motor cortex and the development of transient bilateral hindlimb representation in the ipsilesional motor cortex 3 weeks after hemisection, when significant behavioral recovery occurred. Consistently, reversible inactivation of the ipsilesional, but not the contralesional motor cortex, during skilled ladder walking 3 weeks after hemisection reinstated deficits in both hindlimbs. These findings indicate that the ipsilesional motor cortex transiently reorganizes after lateral hemisection of the thoracic spinal cord to support recovery of hindlimb motor function.SIGNIFICANCE STATEMENT Partial motor recovery can occur after an incomplete spinal cord injury and is hypothesized to result from the reorganization of spared descending motor pathways. The motor cortex is crucial for the control of voluntary movement and contains topographical movement representations (motor maps) that are highly plastic. We examined the organization of hindlimb motor maps bilaterally after a lateral hemisection of the spinal cord to show that while motor maps are abolished in the deefferented cortex, the spared ipsilesional cortex transiently reorganizes to gain a representation of the affected hindlimb after injury that relates to recovery. This finding demonstrates that plasticity in the ipsilesional motor cortex at early time points after spinal cord hemisection is initially important to support motor recovery.
Collapse
|
70
|
Fregosi M, Contestabile A, Badoud S, Borgognon S, Cottet J, Brunet JF, Bloch J, Schwab ME, Rouiller EM. Changes of motor corticobulbar projections following different lesion types affecting the central nervous system in adult macaque monkeys. Eur J Neurosci 2018; 48:2050-2070. [PMID: 30019432 PMCID: PMC6175012 DOI: 10.1111/ejn.14074] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 06/28/2018] [Accepted: 07/07/2018] [Indexed: 01/03/2023]
Abstract
Functional recovery from central nervous system injury is likely to be partly due to a rearrangement of neural circuits. In this context, the corticobulbar (corticoreticular) motor projections onto different nuclei of the ponto-medullary reticular formation (PMRF) were investigated in 13 adult macaque monkeys after either, primary motor cortex injury (MCI) in the hand area, or spinal cord injury (SCI) or Parkinson's disease-like lesions of the nigro-striatal dopaminergic system (PD). A subgroup of animals in both MCI and SCI groups was treated with neurite growth promoting anti-Nogo-A antibodies, whereas all PD animals were treated with autologous neural cell ecosystems (ANCE). The anterograde tracer BDA was injected either in the premotor cortex (PM) or in the primary motor cortex (M1) to label and quantify corticobulbar axonal boutons terminaux and en passant in PMRF. As compared to intact animals, after MCI the density of corticobulbar projections from PM was strongly reduced but maintained their laterality dominance (ipsilateral), both in the presence or absence of anti-Nogo-A antibody treatment. In contrast, the density of corticobulbar projections from M1 was increased following opposite hemi-section of the cervical cord (at C7 level) and anti-Nogo-A antibody treatment, with maintenance of contralateral laterality bias. In PD monkeys, the density of corticobulbar projections from PM was strongly reduced, as well as that from M1, but to a lesser extent. In conclusion, the densities of corticobulbar projections from PM or M1 were affected in a variable manner, depending on the type of lesion/pathology and the treatment aimed to enhance functional recovery.
Collapse
Affiliation(s)
- Michela Fregosi
- Faculty of Science and Medicine, Section of Medicine, Department of Neurosciences and Movement Sciences, University of Fribourg, Fribourg, Switzerland.,Fribourg Cognition Center, Fribourg, Switzerland.,Platform of Translational Neurosciences, Fribourg, Switzerland.,Swiss Primate Competence Center for Research (SPCCR), Fribourg, Switzerland
| | - Alessandro Contestabile
- Faculty of Science and Medicine, Section of Medicine, Department of Neurosciences and Movement Sciences, University of Fribourg, Fribourg, Switzerland.,Fribourg Cognition Center, Fribourg, Switzerland.,Platform of Translational Neurosciences, Fribourg, Switzerland.,Swiss Primate Competence Center for Research (SPCCR), Fribourg, Switzerland
| | - Simon Badoud
- Faculty of Science and Medicine, Section of Medicine, Department of Neurosciences and Movement Sciences, University of Fribourg, Fribourg, Switzerland.,Fribourg Cognition Center, Fribourg, Switzerland.,Platform of Translational Neurosciences, Fribourg, Switzerland.,Swiss Primate Competence Center for Research (SPCCR), Fribourg, Switzerland
| | - Simon Borgognon
- Faculty of Science and Medicine, Section of Medicine, Department of Neurosciences and Movement Sciences, University of Fribourg, Fribourg, Switzerland.,Fribourg Cognition Center, Fribourg, Switzerland.,Platform of Translational Neurosciences, Fribourg, Switzerland.,Swiss Primate Competence Center for Research (SPCCR), Fribourg, Switzerland
| | - Jérôme Cottet
- Faculty of Science and Medicine, Section of Medicine, Department of Neurosciences and Movement Sciences, University of Fribourg, Fribourg, Switzerland.,Fribourg Cognition Center, Fribourg, Switzerland.,Platform of Translational Neurosciences, Fribourg, Switzerland.,Swiss Primate Competence Center for Research (SPCCR), Fribourg, Switzerland
| | - Jean-François Brunet
- Cell production center (CPC), Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | - Jocelyne Bloch
- Department of Neurosurgery, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | - Martin E Schwab
- Brain Research Institute, University of Zürich, Zürich, Switzerland
| | - Eric M Rouiller
- Faculty of Science and Medicine, Section of Medicine, Department of Neurosciences and Movement Sciences, University of Fribourg, Fribourg, Switzerland.,Fribourg Cognition Center, Fribourg, Switzerland.,Platform of Translational Neurosciences, Fribourg, Switzerland.,Swiss Primate Competence Center for Research (SPCCR), Fribourg, Switzerland
| |
Collapse
|
71
|
Martinez SA, Nguyen ND, Bailey E, Doyle-Green D, Hauser HA, Handrakis JP, Knezevic S, Marett C, Weinman J, Romero AF, Santiago TM, Yang AH, Yung L, Asselin PK, Weir JP, Kornfeld SD, Bauman WA, Spungen AM, Harel NY. Multimodal cortical and subcortical exercise compared with treadmill training for spinal cord injury. PLoS One 2018; 13:e0202130. [PMID: 30092092 PMCID: PMC6084979 DOI: 10.1371/journal.pone.0202130] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 06/25/2018] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND AND PURPOSE Spared fibers after spinal cord injury (SCI) tend to consist predominantly of subcortical circuits that are not under volitional (cortical) control. We aim to improve function after SCI by using targeted physical exercises designed to simultaneously stimulate cortical and spared subcortical neural circuits. METHODS Participants with chronic motor-incomplete SCI enrolled in a single-center, prospective interventional crossover study. Participants underwent 48 sessions each of weight-supported robotic-assisted treadmill training and a novel combination of balance and fine hand exercises, in randomized order, with a 6-week washout period. Change post-intervention was measured for lower extremity motor score, soleus H-reflex facilitation; seated balance function; ambulation; spasticity; and pain. RESULTS Only 9 of 21 enrolled participants completed both interventions. Thirteen participants completed at least one intervention. Although there were no statistically significant differences, multimodal training tended to increase short-interval H-reflex facilitation, whereas treadmill training tended to improve dynamic seated balance. DISCUSSION The low number of participants who completed both phases of the crossover intervention limited the power of this study to detect significant effects. Other potential explanations for the lack of significant differences with multimodal training could include insufficient engagement of lower extremity motor cortex using skilled upper extremity exercises; and lack of skill transfer from upright postural stability during multimodal training to seated dynamic balance during testing. To our knowledge, this is the first published study to report seated posturography outcomes after rehabilitation interventions in individuals with SCI. CONCLUSION In participants with chronic incomplete SCI, a novel mix of multimodal exercises incorporating balance exercises with skilled upper extremity exercises showed no benefit compared to an active control program of body weight-supported treadmill training. To improve participant retention in long-term rehabilitation studies, subsequent trials would benefit from a parallel group rather than crossover study design.
Collapse
Affiliation(s)
| | - Nhuquynh D. Nguyen
- James J. Peters VA Medical Center, Bronx, New York, United States of America
| | - Eric Bailey
- James J. Peters VA Medical Center, Bronx, New York, United States of America
| | - Denis Doyle-Green
- James J. Peters VA Medical Center, Bronx, New York, United States of America
| | - Henry A. Hauser
- James J. Peters VA Medical Center, Bronx, New York, United States of America
| | - John P. Handrakis
- James J. Peters VA Medical Center, Bronx, New York, United States of America
- New York Institute of Technology, Old Westbury, New York, United States of America
| | - Steven Knezevic
- James J. Peters VA Medical Center, Bronx, New York, United States of America
| | - Casey Marett
- New York Institute of Technology, Old Westbury, New York, United States of America
| | - Jennifer Weinman
- New York Institute of Technology, Old Westbury, New York, United States of America
| | - Angelica F. Romero
- James J. Peters VA Medical Center, Bronx, New York, United States of America
| | - Tiffany M. Santiago
- James J. Peters VA Medical Center, Bronx, New York, United States of America
| | - Ajax H. Yang
- James J. Peters VA Medical Center, Bronx, New York, United States of America
- Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Lok Yung
- James J. Peters VA Medical Center, Bronx, New York, United States of America
| | - Pierre K. Asselin
- James J. Peters VA Medical Center, Bronx, New York, United States of America
| | - Joseph P. Weir
- University of Kansas, Lawrence, Kansas, United States of America
| | - Stephen D. Kornfeld
- James J. Peters VA Medical Center, Bronx, New York, United States of America
| | - William A. Bauman
- James J. Peters VA Medical Center, Bronx, New York, United States of America
- Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Ann M. Spungen
- James J. Peters VA Medical Center, Bronx, New York, United States of America
- Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Noam Y. Harel
- James J. Peters VA Medical Center, Bronx, New York, United States of America
- Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- * E-mail:
| |
Collapse
|
72
|
Wolpaw JR. The negotiated equilibrium model of spinal cord function. J Physiol 2018; 596:3469-3491. [PMID: 29663410 PMCID: PMC6092289 DOI: 10.1113/jp275532] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 04/05/2018] [Indexed: 12/25/2022] Open
Abstract
The belief that the spinal cord is hardwired is no longer tenable. Like the rest of the CNS, the spinal cord changes during growth and ageing, when new motor behaviours are acquired, and in response to trauma and disease. This paper describes a new model of spinal cord function that reconciles its recently appreciated plasticity with its long-recognized reliability as the final common pathway for behaviour. According to this model, the substrate of each motor behaviour comprises brain and spinal plasticity: the plasticity in the brain induces and maintains the plasticity in the spinal cord. Each time a behaviour occurs, the spinal cord provides the brain with performance information that guides changes in the substrate of the behaviour. All the behaviours in the repertoire undergo this process concurrently; each repeatedly induces plasticity to preserve its key features despite the plasticity induced by other behaviours. The aggregate process is a negotiation among the behaviours: they negotiate the properties of the spinal neurons and synapses that they all use. The ongoing negotiation maintains the spinal cord in an equilibrium - a negotiated equilibrium - that serves all the behaviours. This new model of spinal cord function is supported by laboratory and clinical data, makes predictions borne out by experiment, and underlies a new approach to restoring function to people with neuromuscular disorders. Further studies are needed to test its generality, to determine whether it may apply to other CNS areas such as the cerebral cortex, and to develop its therapeutic implications.
Collapse
Affiliation(s)
- Jonathan R. Wolpaw
- National Center for Adaptive Neurotechnologies, Wadsworth CenterNYS Department of HealthAlbanyNYUSA
- Department of NeurologyStratton VA Medical CenterAlbanyNYUSA
- Department of Biomedical SciencesSchool of Public HealthSUNY AlbanyNYUSA
- Department of Neurology, Neurological InstituteColumbia UniversityNew YorkNYUSA
| |
Collapse
|
73
|
Systemic epothilone D improves hindlimb function after spinal cord contusion injury in rats. Exp Neurol 2018; 306:250-259. [DOI: 10.1016/j.expneurol.2018.01.018] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 12/23/2017] [Accepted: 01/25/2018] [Indexed: 01/04/2023]
|
74
|
Sheikh IS, Keefe KM, Sterling NA, Junker IP, Eneanya CI, Liu Y, Tang XQ, Smith GM. Retrogradely Transportable Lentivirus Tracers for Mapping Spinal Cord Locomotor Circuits. Front Neural Circuits 2018; 12:60. [PMID: 30090059 PMCID: PMC6068242 DOI: 10.3389/fncir.2018.00060] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 07/03/2018] [Indexed: 12/11/2022] Open
Abstract
Retrograde tracing is a key facet of neuroanatomical studies involving long distance projection neurons. Previous groups have utilized a variety of tools ranging from classical chemical tracers to newer methods employing viruses for gene delivery. Here, we highlight the usage of a lentivirus that permits highly efficient retrograde transport (HiRet) from synaptic terminals within the cervical and lumbar enlargements of the spinal cord. By injecting HiRet, we can clearly identify supraspinal and propriospinal circuits innervating motor neuron pools relating to forelimb and hindlimb function. We observed robust labeling of propriospinal neurons, including high fidelity details of dendritic arbors and axon terminals seldom seen with chemical tracers. In addition, we examine changes in interneuronal circuits occurring after a thoracic contusion, highlighting populations that potentially contribute to spontaneous behavioral recovery in this lesion model. Our study demonstrates that the HiRet lentivirus is a unique tool for examining neuronal circuitry within the brain and spinal cord.
Collapse
Affiliation(s)
- Imran S Sheikh
- Department of Neuroscience, Shriners Hospitals Pediatric Research Center, Center for Neural Rehabilitation and Repair, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Kathleen M Keefe
- Department of Neuroscience, Shriners Hospitals Pediatric Research Center, Center for Neural Rehabilitation and Repair, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Noelle A Sterling
- Department of Neuroscience, Shriners Hospitals Pediatric Research Center, Center for Neural Rehabilitation and Repair, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Ian P Junker
- Department of Neuroscience, Shriners Hospitals Pediatric Research Center, Center for Neural Rehabilitation and Repair, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Chidubem I Eneanya
- Department of Neuroscience, Shriners Hospitals Pediatric Research Center, Center for Neural Rehabilitation and Repair, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Yingpeng Liu
- Department of Neuroscience, Shriners Hospitals Pediatric Research Center, Center for Neural Rehabilitation and Repair, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Xiao-Qing Tang
- Department of Neuroscience, Shriners Hospitals Pediatric Research Center, Center for Neural Rehabilitation and Repair, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - George M Smith
- Department of Neuroscience, Shriners Hospitals Pediatric Research Center, Center for Neural Rehabilitation and Repair, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| |
Collapse
|
75
|
Mohammed H, Hollis ER. Cortical Reorganization of Sensorimotor Systems and the Role of Intracortical Circuits After Spinal Cord Injury. Neurotherapeutics 2018; 15:588-603. [PMID: 29882081 PMCID: PMC6095783 DOI: 10.1007/s13311-018-0638-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022] Open
Abstract
The plasticity of sensorimotor systems in mammals underlies the capacity for motor learning as well as the ability to relearn following injury. Spinal cord injury, which both deprives afferent input and interrupts efferent output, results in a disruption of cortical somatotopy. While changes in corticospinal axons proximal to the lesion are proposed to support the reorganization of cortical motor maps after spinal cord injury, intracortical horizontal connections are also likely to be critical substrates for rehabilitation-mediated recovery. Intrinsic connections have been shown to dictate the reorganization of cortical maps that occurs in response to skilled motor learning as well as after peripheral injury. Cortical networks incorporate changes in motor and sensory circuits at subcortical or spinal levels to induce map remodeling in the neocortex. This review focuses on the reorganization of cortical networks observed after injury and posits a role of intracortical circuits in recovery.
Collapse
Affiliation(s)
- Hisham Mohammed
- Burke Neurological Institute, 785 Mamaroneck Avenue, White Plains, NY, 10605, USA
| | - Edmund R Hollis
- Burke Neurological Institute, 785 Mamaroneck Avenue, White Plains, NY, 10605, USA.
- Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA.
| |
Collapse
|
76
|
Faw TD, Lerch JK, Thaxton TT, Deibert RJ, Fisher LC, Basso DM. Unique Sensory and Motor Behavior in Thy1-GFP-M Mice before and after Spinal Cord Injury. J Neurotrauma 2018; 35:2167-2182. [PMID: 29385890 DOI: 10.1089/neu.2017.5395] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Sensorimotor recovery after spinal cord injury (SCI) is of utmost importance to injured individuals and will rely on improved understanding of SCI pathology and recovery. Novel transgenic mouse lines facilitate discovery, but must be understood to be effective. The purpose of this study was to characterize the sensory and motor behavior of a common transgenic mouse line (Thy1-GFP-M) before and after SCI. Thy1-GFP-M positive (TG+) mice and their transgene negative littermates (TG-) were acquired from two sources (in-house colony, n = 32, Jackson Laboratories, n = 4). C57BL/6J wild-type (WT) mice (Jackson Laboratories, n = 10) were strain controls. Moderate-severe T9 contusion (SCI) or transection (TX) occurred in TG+ (SCI, n = 25, TX, n = 5), TG- (SCI, n = 5), and WT (SCI, n = 10) mice. To determine responsiveness to rehabilitation, a cohort of TG+ mice with SCI (n = 4) had flat treadmill (TM) training 42-49 days post-injury (dpi). To characterize recovery, we performed Basso Mouse Scale, Grid Walk, von Frey Hair, and Plantar Heat Testing before and out to day 42 post-SCI. Open field locomotion was significantly better in the Thy1 SCI groups (TG+ and TG-) compared with WT by 7 dpi (p < 0.01) and was maintained through 42 dpi (p < 0.01). These unexpected locomotor gains were not apparent during grid walking, indicating severe impairment of precise motor control. Thy1 derived mice were hypersensitive to mechanical stimuli at baseline (p < 0.05). After SCI, mechanical hyposensitivity emerged in Thy1 derived groups (p < 0.001), while thermal hyperalgesia occurred in all groups (p < 0.001). Importantly, consistent findings across TG+ and TG- groups suggest that the effects are mediated by the genetic background rather than transgene manipulation itself. Surprisingly, TM training restored mechanical and thermal sensation to baseline levels in TG+ mice with SCI. This behavioral profile and responsiveness to chronic training will be important to consider when choosing models to study the mechanisms underlying sensorimotor recovery after SCI.
Collapse
Affiliation(s)
- Timothy D Faw
- 1 Neuroscience Graduate Program, The Ohio State University , Columbus, Ohio.,2 School of Health and Rehabilitation Sciences, The Ohio State University , Columbus, Ohio.,3 Center for Brain and Spinal Cord Repair, The Ohio State University , Columbus, Ohio
| | - Jessica K Lerch
- 3 Center for Brain and Spinal Cord Repair, The Ohio State University , Columbus, Ohio.,4 Department of Neuroscience, The Ohio State University , Columbus, Ohio
| | - Tyler T Thaxton
- 2 School of Health and Rehabilitation Sciences, The Ohio State University , Columbus, Ohio.,3 Center for Brain and Spinal Cord Repair, The Ohio State University , Columbus, Ohio
| | - Rochelle J Deibert
- 2 School of Health and Rehabilitation Sciences, The Ohio State University , Columbus, Ohio.,3 Center for Brain and Spinal Cord Repair, The Ohio State University , Columbus, Ohio
| | - Lesley C Fisher
- 2 School of Health and Rehabilitation Sciences, The Ohio State University , Columbus, Ohio.,3 Center for Brain and Spinal Cord Repair, The Ohio State University , Columbus, Ohio
| | - D Michele Basso
- 2 School of Health and Rehabilitation Sciences, The Ohio State University , Columbus, Ohio.,3 Center for Brain and Spinal Cord Repair, The Ohio State University , Columbus, Ohio
| |
Collapse
|
77
|
Classification of Neurons in the Primate Reticular Formation and Changes after Recovery from Pyramidal Tract Lesion. J Neurosci 2018; 38:6190-6206. [PMID: 29793974 PMCID: PMC6031583 DOI: 10.1523/jneurosci.3371-17.2018] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 04/06/2018] [Accepted: 04/12/2018] [Indexed: 12/27/2022] Open
Abstract
The reticular formation is important in primate motor control, both in health and during recovery after brain damage. Little is known about the different neurons present in the reticular nuclei. Here we recorded extracellular spikes from the reticular formation in five healthy female awake behaving monkeys (193 cells), and in two female monkeys 1 year after recovery from a unilateral pyramidal tract lesion (125 cells). Analysis of spike shape and four measures derived from the interspike interval distribution identified four clusters of neurons in control animals. Cluster 1 cells had a slow firing rate. Cluster 2 cells had narrow spikes and irregular firing, which often included high-frequency bursts. Cluster 3 cells were highly rhythmic and fast firing. Cluster 4 cells showed negative spikes. A separate population of 42 cells was antidromically identified as reticulospinal neurons in five anesthetized female monkeys. The distribution of spike width in these cells closely overlaid the distribution for cluster 2, leading us tentatively to suggest that cluster 2 included neurons with reticulospinal projections. In animals after corticospinal lesion, cells could be identified in all four clusters. The firing rate of cells in clusters 1 and 2 was increased in lesioned animals relative to control animals (by 52% and 60%, respectively); cells in cluster 2 were also more regular and more bursting in the lesioned animals. We suggest that changes in both membrane properties and local circuits within the reticular formation occur following lesioning, potentially increasing reticulospinal output to help compensate for lost corticospinal descending drive. SIGNIFICANCE STATEMENT This work is the first to subclassify neurons in the reticular formation, providing insights into the local circuitry of this important but little understood structure. The approach developed can be applied to any extracellular recording from this region, allowing future studies to place their data within our current framework of four neural types. Changes in reticular neurons may be important to subserve functional recovery after damage in human patients, such as after stroke or spinal cord injury.
Collapse
|
78
|
Neckel ND, Dai H, Rodriguez OC. Addition of forelimb training reduces gains from robotic gait training in a rat model of spinal cord injury. IEEE Int Conf Rehabil Robot 2018; 2017:346-351. [PMID: 28813843 DOI: 10.1109/icorr.2017.8009271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
To restore locomotor function following spinal cord injury the disrupted descending supraspinal drive needs to be re-connected to regions caudal to the injury. Robotic gait training aims to facilitate recovery by stimulating the proprioceptive networks of the legs in a coordinated walking pattern while the descending supraspinal connections are re-established. In incomplete injuries, it is believed that the interneuronal networks near the injury site form relay circuits to reroute the supraspinal signals through the spared tissue. Stimulating these neurons should lead to increased arborization, and more robust relay circuits. We set out to show that robotic gait training is more effective when it is paired with training that activates interneurons at the level of the injury. Following a C4/5 over-hemisection injury the addition of skilled forelimb training actually reduced the gains found with robotic gait training alone. Not just gains within the training device, but also in independent overground locomotion. MRI imaging shows that skilled forelimb training reduces cellular activity, and reduces the organization of the axonal tracks at the injury site. This may be evidence that spared interneurons have limited resources and/or ability in establishing relay circuits to route supraspinal drive around the injury site. Skilled forelimb training and robotic gait training may not be synergistic, but competitive rehabilitative tasks.
Collapse
|
79
|
Vitores AA, Sloley SS, Martinez C, Carballosa-Gautam MM, Hentall ID. Some Autonomic Deficits of Acute or Chronic Cervical Spinal Contusion Reversed by Interim Brainstem Stimulation. J Neurotrauma 2017; 35:560-572. [PMID: 29160143 DOI: 10.1089/neu.2017.5123] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Prolonged electrical stimulation of the hindbrain's nucleus raphe magnus (NRM) or of its major midbrain input region, the periaqueductal gray (PAG), was previously found in rats to promote recovery from sensory-motor and histological deficits of acute thoracic spinal cord injury (SCI). Here, some visceral deficits of acute and chronic midline cervical (C5) contusion are similarly examined. Cranially implanted wireless stimulators delivered intermittent 8 Hz, 30-70 μA cathodal pulse trains to a brainstem microelectrode. Injured controls were given inactive stimulators; rats without injuries or implants were also compared. Rectal distension or squeezing of the forepaws caused an exaggerated rise in mean arterial pressure in injured, untreated rats under anesthesia on post-injury week 6, probably reflecting autonomic dysreflexia (AD). These pressor responses became normal when 7 days of unilateral PAG stimulation was started on the injury day. Older untreated injuries (weeks 18-19) showed normal pressor responses, but unexpectedly had significant resting and nociceptive bradycardia, which was reversed by 3 weeks of PAG stimulation started on weeks 7 or 12. Subsequent chronic studies examined gastric emptying (GE), as indicated by intestinal transit of gavaged dye, and serum chemistry. GE and fasting serum insulin were reduced on injury weeks 14-15, and were both normalized by ∼5 weeks of PAG stimulation begun in weeks 7-8. Increases in calcitonin gene-related peptide, a prominent visceral afferent neurotransmitter, measured near untreated injuries (first thoracic segment) in superficial dorsal laminae were reversed by acutely or chronically initiated PAG stimulation. The NRM, given 2-3 weeks of stimulation beginning 2 days after SCI, prevented abnormalities in both pressor responses and GE on post-injury week 9, consistent with its relaying of repair commands from the PAG. The descending PAG-NRM axis thus exhibits broadly restorative influences on visceral as well as sensory-motor deficits, improving chronic as well as acute signs of injury.
Collapse
Affiliation(s)
- Alberto A Vitores
- Department of Neurological Surgery and The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine , Miami, Florida
| | - Stephanie S Sloley
- Department of Neurological Surgery and The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine , Miami, Florida
| | - Catalina Martinez
- Department of Neurological Surgery and The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine , Miami, Florida
| | - Melissa M Carballosa-Gautam
- Department of Neurological Surgery and The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine , Miami, Florida
| | - Ian D Hentall
- Department of Neurological Surgery and The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine , Miami, Florida
| |
Collapse
|
80
|
Kjell J, Olson L. Rat models of spinal cord injury: from pathology to potential therapies. Dis Model Mech 2017; 9:1125-1137. [PMID: 27736748 PMCID: PMC5087825 DOI: 10.1242/dmm.025833] [Citation(s) in RCA: 233] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
A long-standing goal of spinal cord injury research is to develop effective spinal cord repair strategies for the clinic. Rat models of spinal cord injury provide an important mammalian model in which to evaluate treatment strategies and to understand the pathological basis of spinal cord injuries. These models have facilitated the development of robust tests for assessing the recovery of locomotor and sensory functions. Rat models have also allowed us to understand how neuronal circuitry changes following spinal cord injury and how recovery could be promoted by enhancing spontaneous regenerative mechanisms and by counteracting intrinsic inhibitory factors. Rat studies have also revealed possible routes to rescuing circuitry and cells in the acute stage of injury. Spatiotemporal and functional studies in these models highlight the therapeutic potential of manipulating inflammation, scarring and myelination. In addition, potential replacement therapies for spinal cord injury, including grafts and bridges, stem primarily from rat studies. Here, we discuss advantages and disadvantages of rat experimental spinal cord injury models and summarize knowledge gained from these models. We also discuss how an emerging understanding of different forms of injury, their pathology and degree of recovery has inspired numerous treatment strategies, some of which have led to clinical trials. Summary: In this Review, we discuss the advantages and disadvantages of the rat for studies of experimental spinal cord injury and summarize the knowledge gained from such studies.
Collapse
Affiliation(s)
- Jacob Kjell
- Department of Physiological Genomics, Ludwig-Maximilians-Universität München, Munich 80336, Germany
| | - Lars Olson
- Department of Neuroscience, Karolinska Institutet, Stockholm 171 77, Sweden
| |
Collapse
|
81
|
Darlot F, Vinit S, Matarazzo V, Kastner A. Sustained cell body reactivity and loss of NeuN in a subset of axotomized bulbospinal neurons after a chronic high cervical spinal cord injury. Eur J Neurosci 2017; 46:2729-2745. [PMID: 28977718 DOI: 10.1111/ejn.13737] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 09/28/2017] [Accepted: 09/28/2017] [Indexed: 12/15/2022]
Abstract
Following central nervous system lesion, the ability of injured axons to regrowth may depend on the level and duration of the injured cell body response (CBR). Therefore, to investigate whether axotomized brainstem neurons maintain a durable growth-competent state after spinal cord injury, we studied the effect of a chronic C2 hemisection in rats on the expression of various CBR markers involved in axon regeneration, such as c-Jun, ATF-3, HSP27, NO synthase (NOS), and also of the neural mature phenotype marker NeuN, in the bulbospinal respiratory neurons as compared to the gigantocellularis nucleus. Both at 7 and 30 days post-lesion (DPL), c-Jun and HSP27 were present in, respectively, ~60 and ~20% of the axotomized respiratory neurons, whereas the apoptotic factor caspase 3 was not detected in these cells. NOS appeared belatedly, and it was detected in ~20% of the axotomized respiratory neurons at 30DPL. At 30DPL, these different CBR markers were strongly colocalized in a sub-population of axotomized respiratory neurons and also in a sub-population of injured neurons within the gigantocellularis nucleus. Such CBR was also accompanied by a sustained alteration of the neural mature phenotype, as indicated by a loss of NeuN immunoreactivity selectively in HSP27+ bulbospinal neurons at 7DPL and 30DPL. Altogether, this study shows that a subset of axotomized medullary respiratory neurons remains in a growth-competent state after a chronic injury, suggesting that they may play a preferential role in long-lasting respiratory neuroplasticity processes.
Collapse
Affiliation(s)
- Fannie Darlot
- Laboratoire de Physiologie et Physiopathologie du Système Nerveux Somatomoteur et Neurovégétatif (PPSN), Aix-Marseille Université, Ave Escadrille Normandie Niemen, 13013, Marseille, France
| | - Stéphane Vinit
- INSERM U1179, Université de Versailles Saint-Quentin-en-Yvelines, Montigny-le-Bretonneux, France
| | | | - Anne Kastner
- Laboratoire de Physiologie et Physiopathologie du Système Nerveux Somatomoteur et Neurovégétatif (PPSN), Aix-Marseille Université, Ave Escadrille Normandie Niemen, 13013, Marseille, France
| |
Collapse
|
82
|
Huang Z, Li R, Liu J, Huang Z, Hu Y, Wu X, Zhu Q. Longitudinal electrophysiological changes after cervical hemi-contusion spinal cord injury in rats. Neurosci Lett 2017; 664:116-122. [PMID: 29138091 DOI: 10.1016/j.neulet.2017.11.019] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 11/07/2017] [Accepted: 11/08/2017] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To evaluate the longitudinal somatosensory evoked potentials (SEPs) and motor evoked potentials (MEPs) characterization from acute to chronic injury following cervical hemi-contusion spinal cord injury (SCI) in rats, and correlate the MEPs & SEPs to the behavioral outcomes. METHODS Fifteen adult male Sprague-Dawley rats were subjected to the hemi-contusion spinal cord injury at C5. Forelimb MEPs & SEPs were applied to 5 animals before injury and 3h, 1d, 3d, 1w, 2w, 4w and 8w after injury respectively. Forelimb functional assessments, including Montoya staircase task and cylinder rearing test, were conducted on another 10 animals before injury and at 2w, 4w and 8w after injury respectively, as well as histological analysis of the cord at 8w after injury. A group correlation was performed between the MEPs & SEPs and behavioral outcomes. RESULTS The hemi-contusion injury resulted in unilateral tissue damage at the epicenter with loss of the ventral horns and lateral funiculus. Both ipsilateral and contralateral forelimb MEPs showed latency prolongation and amplitude reduction at 3h after injury. The MEPs amplitude increased with time after injury, but the ipsilateral amplitude was persistently lower than the contralateral amplitude. The ipsilateral MEPs latency increased with time after injury and was significantly longer than the contralateral MEPs latency. The ipsilateral SEPs amplitude dropped after injury and stayed at a lower level up to 8 weeks. There was no difference in the SEPs latency among time points and between sides. At 8 weeks after injury, the ipsilateral forelimb grasped 30% pellets while the contralateral forelimb close to 81%. An obvious decreased usage of the ipsilateral paw and increased usage of the contralateral paw were observed in rearing test after injury. The MEPs latency and amplitude correlated significantly with the forelimb motor function. CONCLUSION Cervical hemi-contusion SCI led to persistent changes in MEPs & SEPs of the ipsilateral forelimb, ipsilateral impairment in motor function and unilateral cord tissue damage. Reliable electrophysiology assessment was obtained in chronic phase due to unstable MEPs & SEPs of bilateral forelimb immediately after injury, which might reflect the underlying pathological processes. The present study further confirmed the link of the MEPs to the behavioral outcomes, supporting the longitudinal electrophysiology assessment for neurological impairment after SCI.
Collapse
Affiliation(s)
- Zucheng Huang
- Department of Spine Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Rong Li
- Department of Spine Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Junhao Liu
- Department of Spine Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Zhiping Huang
- Department of Spine Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Yong Hu
- Department of Orthopaedics and Traumatology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Xiaoliang Wu
- Department of Spine Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Qingan Zhu
- Department of Spine Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China.
| |
Collapse
|
83
|
Okabe N, Himi N, Maruyama-Nakamura E, Hayashi N, Narita K, Miyamoto O. Rehabilitative skilled forelimb training enhances axonal remodeling in the corticospinal pathway but not the brainstem-spinal pathways after photothrombotic stroke in the primary motor cortex. PLoS One 2017; 12:e0187413. [PMID: 29095902 PMCID: PMC5667818 DOI: 10.1371/journal.pone.0187413] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 10/19/2017] [Indexed: 12/17/2022] Open
Abstract
Task-specific rehabilitative training is commonly used for chronic stroke patients. Axonal remodeling is believed to be one mechanism underlying rehabilitation-induced functional recovery, and significant roles of the corticospinal pathway have previously been demonstrated. Brainstem-spinal pathways, as well as the corticospinal tract, have been suggested to contribute to skilled motor function and functional recovery after brain injury. However, whether axonal remodeling in the brainstem-spinal pathways is a critical component for rehabilitation-induced functional recovery is not known. In this study, rats were subjected to photothrombotic stroke in the caudal forelimb area of the primary motor cortex and received rehabilitative training with a skilled forelimb reaching task for 4 weeks. After completion of the rehabilitative training, the retrograde tracer Fast blue was injected into the contralesional lower cervical spinal cord. Fast blue-positive cells were counted in 32 brain areas located in the cerebral cortex, hypothalamus, midbrain, pons, and medulla oblongata. Rehabilitative training improved motor performance in the skilled forelimb reaching task but not in the cylinder test, ladder walk test, or staircase test, indicating that rehabilitative skilled forelimb training induced task-specific recovery. In the histological analysis, rehabilitative training significantly increased the number of Fast blue-positive neurons in the ipsilesional rostral forelimb area and secondary sensory cortex. However, rehabilitative training did not alter the number of Fast blue-positive neurons in any areas of the brainstem. These results indicate that rehabilitative skilled forelimb training enhances axonal remodeling selectively in the corticospinal pathway, which suggests a critical role of cortical plasticity, rather than brainstem plasticity, in task-specific recovery after subtotal motor cortex destruction.
Collapse
Affiliation(s)
- Naohiko Okabe
- Second Department of Physiology, Kawasaki Medical School, Matsushima, Kurashiki City, Okayama, Japan
- * E-mail:
| | - Naoyuki Himi
- Second Department of Physiology, Kawasaki Medical School, Matsushima, Kurashiki City, Okayama, Japan
| | - Emi Maruyama-Nakamura
- Second Department of Physiology, Kawasaki Medical School, Matsushima, Kurashiki City, Okayama, Japan
| | - Norito Hayashi
- Second Department of Physiology, Kawasaki Medical School, Matsushima, Kurashiki City, Okayama, Japan
| | - Kazuhiko Narita
- Second Department of Physiology, Kawasaki Medical School, Matsushima, Kurashiki City, Okayama, Japan
| | - Osamu Miyamoto
- Second Department of Physiology, Kawasaki Medical School, Matsushima, Kurashiki City, Okayama, Japan
| |
Collapse
|
84
|
Taccola G, Sayenko D, Gad P, Gerasimenko Y, Edgerton VR. And yet it moves: Recovery of volitional control after spinal cord injury. Prog Neurobiol 2017; 160:64-81. [PMID: 29102670 PMCID: PMC5773077 DOI: 10.1016/j.pneurobio.2017.10.004] [Citation(s) in RCA: 114] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 10/09/2017] [Accepted: 10/21/2017] [Indexed: 12/12/2022]
Abstract
Preclinical and clinical neurophysiological and neurorehabilitation research has generated rather surprising levels of recovery of volitional sensory-motor function in persons with chronic motor paralysis following a spinal cord injury. The key factor in this recovery is largely activity-dependent plasticity of spinal and supraspinal networks. This key factor can be triggered by neuromodulation of these networks with electrical and pharmacological interventions. This review addresses some of the systems-level physiological mechanisms that might explain the effects of electrical modulation and how repetitive training facilitates the recovery of volitional motor control. In particular, we substantiate the hypotheses that: (1) in the majority of spinal lesions, a critical number and type of neurons in the region of the injury survive, but cannot conduct action potentials, and thus are electrically non-responsive; (2) these neuronal networks within the lesioned area can be neuromodulated to a transformed state of electrical competency; (3) these two factors enable the potential for extensive activity-dependent reorganization of neuronal networks in the spinal cord and brain, and (4) propriospinal networks play a critical role in driving this activity-dependent reorganization after injury. Real-time proprioceptive input to spinal networks provides the template for reorganization of spinal networks that play a leading role in the level of coordination of motor pools required to perform a given functional task. Repetitive exposure of multi-segmental sensory-motor networks to the dynamics of task-specific sensory input as occurs with repetitive training can functionally reshape spinal and supraspinal connectivity thus re-enabling one to perform complex motor tasks, even years post injury.
Collapse
Affiliation(s)
- G Taccola
- Department of Integrative Biology and Physiology, University of California, Los Angeles, CA 90095 USA; Neuroscience Department, International School for Advanced Studies (SISSA), Bonomea 265, Trieste, Italy
| | - D Sayenko
- Department of Integrative Biology and Physiology, University of California, Los Angeles, CA 90095 USA
| | - P Gad
- Department of Integrative Biology and Physiology, University of California, Los Angeles, CA 90095 USA
| | - Y Gerasimenko
- Department of Integrative Biology and Physiology, University of California, Los Angeles, CA 90095 USA; Pavlov Institute of Physiology, St. Petersburg 199034, Russia
| | - V R Edgerton
- Department of Integrative Biology and Physiology, University of California, Los Angeles, CA 90095 USA; Department of Neurobiology, University of California, Los Angeles, CA 90095 USA; Department of Neurosurgery, University of California, Los Angeles, CA 90095 USA; Brain Research Institute, University of California, Los Angeles, CA 90095 USA; The Centre for Neuroscience and Regenerative Medicine, Faculty of Science, University of Technology Sydney, Ultimo, 2007 NSW, Australia; Institut Guttmann, Hospital de Neurorehabilitació, Institut Universitari adscrit a la Universitat Autònoma de Barcelona, Barcelona, 08916 Badalona, Spain.
| |
Collapse
|
85
|
Liu S, Sandner B, Schackel T, Nicholson L, Chtarto A, Tenenbaum L, Puttagunta R, Müller R, Weidner N, Blesch A. Regulated viral BDNF delivery in combination with Schwann cells promotes axonal regeneration through capillary alginate hydrogels after spinal cord injury. Acta Biomater 2017; 60:167-180. [PMID: 28735026 DOI: 10.1016/j.actbio.2017.07.024] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 07/05/2017] [Accepted: 07/18/2017] [Indexed: 12/24/2022]
Abstract
Grafting of cell-seeded alginate capillary hydrogels into a spinal cord lesion site provides an axonal bridge while physically directing regenerating axonal growth in a linear pattern. However, without an additional growth stimulus, bridging axons fail to extend into the distal host spinal cord. Here we examined whether a combinatory strategy would support regeneration of descending axons across a cervical (C5) lateral hemisection lesion in the rat spinal cord. Following spinal cord transections, Schwann cell (SC)-seeded alginate hydrogels were grafted to the lesion site and AAV5 expressing brain-derived neurotrophic factor (BDNF) under control of a tetracycline-regulated promoter was injected caudally. In addition, we examined whether SC injection into the caudal spinal parenchyma would further enhance regeneration of descending axons to re-enter the host spinal cord. Our data show that both serotonergic and descending axons traced by biotinylated dextran amine (BDA) extend throughout the scaffolds. The number of regenerating axons is significantly increased when caudal BDNF expression is activated and transient BDNF delivery is able to sustain axons after gene expression is switched off. Descending axons are confined to the caudal graft/host interface even with continuous BDNF expression for 8weeks. Only with a caudal injection of SCs, a pathway facilitating axonal regeneration through the host/graft interface is generated allowing axons to successfully re-enter the caudal spinal cord. STATEMENT OF SIGNIFICANCE Recovery from spinal cord injury is poor due to the limited regeneration observed in the adult mammalian central nervous system. Biomaterials, cell transplantation and growth factors that can guide axons across a lesion site, provide a cellular substrate, stimulate axon growth and have shown some promise in increasing the growth distance of regenerating axons. In the present study, we combined an alginate biomaterial with linear channels with transplantation of Schwann cells within and beyond the lesion site and injection of a regulatable vector for the transient expression of brain-derived neurotrophic factor (BDNF). Our data show that only with the full combination axons extend across the lesion site and that expression of BDNF beyond 4weeks does not further increase the number of regenerating axons.
Collapse
Affiliation(s)
- Shengwen Liu
- Spinal Cord Injury Center, Heidelberg University Hospital, Heidelberg, Germany; Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, PR China
| | - Beatrice Sandner
- Spinal Cord Injury Center, Heidelberg University Hospital, Heidelberg, Germany
| | - Thomas Schackel
- Spinal Cord Injury Center, Heidelberg University Hospital, Heidelberg, Germany
| | - LaShae Nicholson
- Spinal Cord Injury Center, Heidelberg University Hospital, Heidelberg, Germany
| | - Abdelwahed Chtarto
- Experimental Neurosurgery Laboratory and I.R.I.B.H.M., Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Liliane Tenenbaum
- Department of Clinical Neurosciences, University Hospital of Lausanne, Lausanne, Switzerland
| | - Radhika Puttagunta
- Spinal Cord Injury Center, Heidelberg University Hospital, Heidelberg, Germany
| | - Rainer Müller
- Department of Physical and Theoretical Chemistry, University of Regensburg, Regensburg, Germany
| | - Norbert Weidner
- Spinal Cord Injury Center, Heidelberg University Hospital, Heidelberg, Germany
| | - Armin Blesch
- Spinal Cord Injury Center, Heidelberg University Hospital, Heidelberg, Germany; Stark Neurosciences Research Institute, Indiana University School of Medicine, Dept. of Neurological Surgery and Goodman Campbell Brain and Spine, Indianapolis, USA.
| |
Collapse
|
86
|
Following Spinal Cord Injury Transected Reticulospinal Tract Axons Develop New Collateral Inputs to Spinal Interneurons in Parallel with Locomotor Recovery. Neural Plast 2017; 2017:1932875. [PMID: 29138697 PMCID: PMC5613456 DOI: 10.1155/2017/1932875] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 07/06/2017] [Accepted: 07/30/2017] [Indexed: 12/19/2022] Open
Abstract
The reticulospinal tract (RtST) descends from the reticular formation and terminates in the spinal cord. The RtST drives the initiation of locomotion and postural control. RtST axons form new contacts with propriospinal interneurons (PrINs) after incomplete spinal cord injury (SCI); however, it is unclear if injured or uninjured axons make these connections. We completely transected all traced RtST axons in rats using a staggered model, where a hemisection SCI at vertebra T10 is followed by a contralateral hemisection at vertebra T7. In one group of the animals, the T7 SCI was performed 2 weeks after the T10 SCI (delayed; dSTAG), and in another group, the T10 and T7 SCIs were concomitant (cSTAG). dSTAG animals had significantly more RtST-PrIN contacts in the grey matter compared to cSTAG animals (p < 0.05). These results were accompanied by enhanced locomotor recovery with dSTAG animals significantly outperforming cSTAG animals (BBB test; p < 0.05). This difference suggests that activity in neuronal networks below the first SCI may contribute to enhanced recovery, because dSTAG rats recovered locomotor ability before the second hemisection. In conclusion, our findings support the hypothesis that the injured RtST forms new connections and is a key player in the recovery of locomotion post-SCI.
Collapse
|
87
|
Reticulospinal Contributions to Gross Hand Function after Human Spinal Cord Injury. J Neurosci 2017; 37:9778-9784. [PMID: 28871033 DOI: 10.1523/jneurosci.3368-16.2017] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 08/10/2017] [Accepted: 08/16/2017] [Indexed: 11/21/2022] Open
Abstract
Multiple descending motor pathways likely contribute to the recovery of hand motor function following spinal cord injury (SCI). Reticulospinal neurons project to spinal motor neurons controlling hand muscles and extensively sprout into gray matter structures after SCI; therefore, it has been proposed that the reticulospinal tract is one of the descending motor pathways involved in recovery of hand function after injury. To test this hypothesis, we examined the StartReact response, an involuntary release of a planned movement via a startling stimulus that engages the reticulospinal tract, by measuring reaction times from electromyographic activity in an intrinsic finger muscle during three motor tasks requiring different degrees of hand dexterity: index finger abduction, a precision grip, and a power grip. Males and females with and without incomplete chronic cervical SCI were tested. We found that although SCI participants voluntarily responded to all tasks, reaction times were shorter during a startle cue while performing a power grip but not index finger abduction or precision grip. Control subjects had similarly shorter reaction times during a startle cue in all motor tasks. These results provide the first evidence for a contribution of the reticulospinal tract to hand control in humans with SCI during gross finger manipulations and suggest that this contribution is less pronounced during fine dexterous finger movements.SIGNIFICANCE STATEMENT It has been long proposed that brainstem pathways contribute to the recovery of hand function in humans with spinal cord injury (SCI). Here, we show that individuals with anatomically incomplete chronic cervical SCI responded to a startle stimulus, a test that engages the reticulospinal tract, while performing a power grip but not during index finger abduction or precision grip. Control subjects responded to a startle stimulus similarly across tasks. These observations suggest that reticulospinal outputs after SCI contribute to hand motor tasks involving gross finger movements. Interestingly, this contribution is less pronounced during fine dexterous finger movements.
Collapse
|
88
|
Wu D, Klaw MC, Connors T, Kholodilov N, Burke RE, Côté MP, Tom VJ. Combining Constitutively Active Rheb Expression and Chondroitinase Promotes Functional Axonal Regeneration after Cervical Spinal Cord Injury. Mol Ther 2017; 25:2715-2726. [PMID: 28967557 DOI: 10.1016/j.ymthe.2017.08.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 08/13/2017] [Accepted: 08/15/2017] [Indexed: 11/16/2022] Open
Abstract
After spinal cord injury (SCI), severed axons in the adult mammalian CNS are unable to mount a robust regenerative response. In addition, the glial scar at the lesion site further restricts the regenerative potential of axons. We hypothesized that a combinatorial approach coincidentally targeting these obstacles would promote axonal regeneration. We combined (1) transplantation of a growth-permissive peripheral nerve graft (PNG) into an incomplete, cervical lesion cavity; (2) transduction of neurons rostral to the SCI site to express constitutively active Rheb (caRheb; a Ras homolog enriched in brain), a GTPase that directly activates the growth-promoting pathway mammalian target of rapamycin (mTOR) via AAV-caRheb injection; and (3) digestion of growth-inhibitory chondroitin sulfate proteoglycans within the glial scar at the distal PNG interface using the bacterial enzyme chondroitinase ABC (ChABC). We found that expressing caRheb in neurons post-SCI results in modestly yet significantly more axons regenerating across a ChABC-treated distal graft interface into caudal spinal cord than either treatment alone. Excitingly, we found that caRheb+ChABC treatment significantly potentiates the formation of synapses in the host spinal cord and improves the animals' ability to use the affected forelimb. Thus, this combination strategy enhances functional axonal regeneration following a cervical SCI.
Collapse
Affiliation(s)
- Di Wu
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, USA
| | - Michelle C Klaw
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, USA
| | - Theresa Connors
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, USA
| | | | - Robert E Burke
- Department of Neurology, Columbia University, New York, NY, 10032 USA; Department of Pathology and Cell Biology, Columbia University, New York, NY 10032, USA
| | - Marie-Pascale Côté
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, USA
| | - Veronica J Tom
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, USA.
| |
Collapse
|
89
|
Manohar A, Foffani G, Ganzer PD, Bethea JR, Moxon KA. Cortex-dependent recovery of unassisted hindlimb locomotion after complete spinal cord injury in adult rats. eLife 2017; 6. [PMID: 28661400 PMCID: PMC5499944 DOI: 10.7554/elife.23532] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2016] [Accepted: 06/22/2017] [Indexed: 12/29/2022] Open
Abstract
After paralyzing spinal cord injury the adult nervous system has little ability to ‘heal’ spinal connections, and it is assumed to be unable to develop extra-spinal recovery strategies to bypass the lesion. We challenge this assumption, showing that completely spinalized adult rats can recover unassisted hindlimb weight support and locomotion without explicit spinal transmission of motor commands through the lesion. This is achieved with combinations of pharmacological and physical therapies that maximize cortical reorganization, inducing an expansion of trunk motor cortex and forepaw sensory cortex into the deafferented hindlimb cortex, associated with sprouting of corticospinal axons. Lesioning the reorganized cortex reverses the recovery. Adult rats can thus develop a novel cortical sensorimotor circuit that bypasses the lesion, probably through biomechanical coupling, to partly recover unassisted hindlimb locomotion after complete spinal cord injury. DOI:http://dx.doi.org/10.7554/eLife.23532.001
Collapse
Affiliation(s)
- Anitha Manohar
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, United States
| | - Guglielmo Foffani
- CINAC, Hospital Universitario HM Puerta del Sur, Universidad CEU-San Pablo, Madrid, Spain.,Hospital Nacional de Parapléjicos, Servicio de Salud de Castilla-La Mancha, Toledo, Spain
| | - Patrick D Ganzer
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, United States
| | - John R Bethea
- Department of Biology, Drexel University, Philadelphia, United States
| | - Karen A Moxon
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, United States.,Department of Biomedical Engineering, University of California, Davis, United States
| |
Collapse
|
90
|
Bravo-Esteban E, Taylor J, Aleixandre M, Simón-Martínez C, Torricelli D, Pons JL, Avila-Martín G, Galán-Arriero I, Gómez-Soriano J. Longitudinal estimation of intramuscular Tibialis Anterior coherence during subacute spinal cord injury: relationship with neurophysiological, functional and clinical outcome measures. J Neuroeng Rehabil 2017; 14:58. [PMID: 28619087 PMCID: PMC5472888 DOI: 10.1186/s12984-017-0271-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 06/05/2017] [Indexed: 12/11/2022] Open
Abstract
Background Estimation of surface intramuscular coherence has been used to indirectly assess pyramidal tract activity following spinal cord injury (SCI), especially within the 15-30 Hz bandwidth. However, change in higher frequency (>40 Hz) muscle coherence during SCI has not been characterised. Thus, the objective of this study was to identify change of high and low frequency intramuscular Tibialis Anterior (TA) coherence during incomplete subacute SCI. Methods Fifteen healthy subjects and 22 subjects with motor incomplete SCI (American Spinal Injury Association Impairment Scale, AIS, C or D grade) were recruited and tested during 4 sessions performed at 2-week intervals up to 8 months after SCI. Intramuscular TA coherence estimation was calculated within the 10–60 Hz bandwidth during controlled maximal isometric and isokinetic foot dorsiflexion. Maximal voluntary dorsiflexion torque, gait function measured with the WISCI II scale, and TA motor evoked potentials (MEP) were recorded. Results During subacute SCI, significant improvement in total lower limb manual muscle score, TA muscle strength and gait function were observed. No change in TA MEP amplitude was identified. Significant increase in TA coherence was detected in the 40–60 Hz, but not the 15–30 Hz bandwidth. The spasticity syndrome was associated with lower 15-30 Hz TA coherence during maximal isometric dorsiflexion and higher 10–60 Hz coherence during fast isokinetic movement (p < 0.05). Conclusions Longitudinal estimation of neurophysiological and clinical measures during subacute SCI suggest that estimation of TA muscle coherence during controlled movement provides indirect information regarding adaptive and maladaptive motor control mechanisms during neurorehabilitation.
Collapse
Affiliation(s)
- Elisabeth Bravo-Esteban
- Sensorimotor Function Group, Hospital Nacional de Parapléjicos, SESCAM, Toledo, Spain.,Neurorehabilitation Group, Instituto Cajal, CSIC, Madrid, Spain.,Toledo Physiotherapy Research Group (GIFTO), Nursing and Physiotherapy Faculty, Universidad de Castilla la Mancha, Toledo, Spain
| | - Julian Taylor
- Sensorimotor Function Group, Hospital Nacional de Parapléjicos, SESCAM, Toledo, Spain. .,Stoke Mandeville Spinal Research, National Spinal Injuries Centre, Buckinghamshire Healthcare Trust, NHS, Aylesbury, UK. .,Harris Manchester College, University of Oxford, Oxford, UK.
| | | | | | | | - Jose Luis Pons
- Neurorehabilitation Group, Instituto Cajal, CSIC, Madrid, Spain
| | - Gerardo Avila-Martín
- Sensorimotor Function Group, Hospital Nacional de Parapléjicos, SESCAM, Toledo, Spain
| | - Iriana Galán-Arriero
- Sensorimotor Function Group, Hospital Nacional de Parapléjicos, SESCAM, Toledo, Spain
| | - Julio Gómez-Soriano
- Sensorimotor Function Group, Hospital Nacional de Parapléjicos, SESCAM, Toledo, Spain.,Toledo Physiotherapy Research Group (GIFTO), Nursing and Physiotherapy Faculty, Universidad de Castilla la Mancha, Toledo, Spain
| |
Collapse
|
91
|
Huber E, Lachappelle P, Sutter R, Curt A, Freund P. Are midsagittal tissue bridges predictive of outcome after cervical spinal cord injury? Ann Neurol 2017; 81:740-748. [DOI: 10.1002/ana.24932] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 04/04/2017] [Accepted: 04/04/2017] [Indexed: 11/07/2022]
Affiliation(s)
- Eveline Huber
- Spinal Cord Injury Center; Balgrist University Hospital; Zurich Switzerland
| | | | - Reto Sutter
- Radiology; Balgrist University Hospital; Zurich Switzerland
| | - Armin Curt
- Spinal Cord Injury Center; Balgrist University Hospital; Zurich Switzerland
| | - Patrick Freund
- Spinal Cord Injury Center; Balgrist University Hospital; Zurich Switzerland
- Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology; University College London; London United Kingdom
- Department of Brain Repair and Rehabilitation, UCL Institute of Neurology; University College London; London United Kingdom
- Department of Neurophysics; Max Planck Institute for Human Cognitive and Brain Sciences; Leipzig Germany
| |
Collapse
|
92
|
Noga BR, Sanchez FJ, Villamil LM, O'Toole C, Kasicki S, Olszewski M, Cabaj AM, Majczyński H, Sławińska U, Jordan LM. LFP Oscillations in the Mesencephalic Locomotor Region during Voluntary Locomotion. Front Neural Circuits 2017; 11:34. [PMID: 28579945 PMCID: PMC5437718 DOI: 10.3389/fncir.2017.00034] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 04/28/2017] [Indexed: 11/28/2022] Open
Abstract
Oscillatory rhythms in local field potentials (LFPs) are thought to coherently bind cooperating neuronal ensembles to produce behaviors, including locomotion. LFPs recorded from sites that trigger locomotion have been used as a basis for identification of appropriate targets for deep brain stimulation (DBS) to enhance locomotor recovery in patients with gait disorders. Theta band activity (6–12 Hz) is associated with locomotor activity in locomotion-inducing sites in the hypothalamus and in the hippocampus, but the LFPs that occur in the functionally defined mesencephalic locomotor region (MLR) during locomotion have not been determined. Here we record the oscillatory activity during treadmill locomotion in MLR sites effective for inducing locomotion with electrical stimulation in rats. The results show the presence of oscillatory theta rhythms in the LFPs recorded from the most effective MLR stimulus sites (at threshold ≤60 μA). Theta activity increased at the onset of locomotion, and its power was correlated with the speed of locomotion. In animals with higher thresholds (>60 μA), the correlation between locomotor speed and theta LFP oscillations was less robust. Changes in the gamma band (previously recorded in vitro in the pedunculopontine nucleus (PPN), thought to be a part of the MLR) were relatively small. Controlled locomotion was best achieved at 10–20 Hz frequencies of MLR stimulation. Our results indicate that theta and not delta or gamma band oscillation is a suitable biomarker for identifying the functional MLR sites.
Collapse
Affiliation(s)
- Brian R Noga
- The Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami Miller School of MedicineMiami, FL, United States
| | - Francisco J Sanchez
- The Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami Miller School of MedicineMiami, FL, United States
| | - Luz M Villamil
- The Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami Miller School of MedicineMiami, FL, United States
| | - Christopher O'Toole
- The Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami Miller School of MedicineMiami, FL, United States
| | - Stefan Kasicki
- Department of Neurophysiology, Nencki Institute of Experimental BiologyWarsaw, Poland
| | - Maciej Olszewski
- Department of Neurophysiology, Nencki Institute of Experimental BiologyWarsaw, Poland
| | - Anna M Cabaj
- Department of Neurophysiology, Nencki Institute of Experimental BiologyWarsaw, Poland
| | - Henryk Majczyński
- Department of Neurophysiology, Nencki Institute of Experimental BiologyWarsaw, Poland
| | - Urszula Sławińska
- Department of Neurophysiology, Nencki Institute of Experimental BiologyWarsaw, Poland
| | - Larry M Jordan
- Department of Physiology, Spinal Cord Research Centre, University of ManitobaWinnipeg, MB, Canada
| |
Collapse
|
93
|
Killeen T, Easthope CS, Filli L, Linnebank M, Curt A, Bolliger M, Zörner B. Modulating Arm Swing Symmetry with Cognitive Load: A Window on Rhythmic Spinal Locomotor Networks in Humans? J Neurotrauma 2017; 34:1897-1902. [PMID: 27574966 DOI: 10.1089/neu.2016.4554] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Affiliation(s)
- Tim Killeen
- Spinal Cord Injury Center, University Hospital Balgrist, Zurich, Switzerland
| | | | - Linard Filli
- Department of Neurology, University Hospital Zurich, Zurich, Switzerland
| | - Michael Linnebank
- Department of Neurology, University Hospital Zurich, Zurich, Switzerland
- Department of Neurology, Helios-Klinik Hagen-Ambrock, Hagen, Germany
| | - Armin Curt
- Spinal Cord Injury Center, University Hospital Balgrist, Zurich, Switzerland
| | - Marc Bolliger
- Spinal Cord Injury Center, University Hospital Balgrist, Zurich, Switzerland
| | - Björn Zörner
- Spinal Cord Injury Center, University Hospital Balgrist, Zurich, Switzerland
| |
Collapse
|
94
|
Kardos J, Héja L, Jemnitz K, Kovács R, Palkovits M. The nature of early astroglial protection-Fast activation and signaling. Prog Neurobiol 2017; 153:86-99. [PMID: 28342942 DOI: 10.1016/j.pneurobio.2017.03.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 09/22/2016] [Accepted: 03/05/2017] [Indexed: 12/14/2022]
Abstract
Our present review is focusing on the uniqueness of balanced astroglial signaling. The balance of excitatory and inhibitory signaling within the CNS is mainly determined by sharp synaptic transients of excitatory glutamate (Glu) and inhibitory γ-aminobutyrate (GABA) acting on the sub-second timescale. Astroglia is involved in excitatory chemical transmission by taking up i) Glu through neurotransmitter-sodium transporters, ii) K+ released due to presynaptic action potential generation, and iii) water keeping osmotic pressure. Glu uptake-coupled Na+ influx may either ignite long-range astroglial Ca2+ transients or locally counteract over-excitation via astroglial GABA release and increased tonic inhibition. Imbalance of excitatory and inhibitory drives is associated with a number of disease conditions, including prevalent traumatic and ischaemic injuries or the emergence of epilepsy. Therefore, when addressing the potential of early therapeutic intervention, astroglial signaling functions combating progress of Glu excitotoxicity is of critical importance. We suggest, that excitotoxicity is linked primarily to over-excitation induced by the impairment of astroglial Glu uptake and/or GABA release. Within this framework, we discuss the acute alterations of Glu-cycling and metabolism and conjecture the therapeutic promise of regulation. We also confer the role played by key carrier proteins and enzymes as well as their interplay at the molecular, cellular, and organ levels. Moreover, based on our former studies, we offer potential prospect on the emerging theme of astroglial succinate sensing in course of Glu excitotoxicity.
Collapse
Affiliation(s)
- Julianna Kardos
- Functional Pharmacology Research Group, Institute of Organic Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Hungary.
| | - László Héja
- Functional Pharmacology Research Group, Institute of Organic Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Hungary
| | - Katalin Jemnitz
- Functional Pharmacology Research Group, Institute of Organic Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Hungary
| | - Richárd Kovács
- Institute of Neurophysiology, Charité - Universitätsmedizin, Berlin, Germany
| | - Miklós Palkovits
- Human Brain Tissue Bank and Laboratory, Semmelweis University, Budapest, Hungary
| |
Collapse
|
95
|
Flynn JR, Conn VL, Boyle KA, Hughes DI, Watanabe M, Velasquez T, Goulding MD, Callister RJ, Graham BA. Anatomical and Molecular Properties of Long Descending Propriospinal Neurons in Mice. Front Neuroanat 2017; 11:5. [PMID: 28220062 PMCID: PMC5292581 DOI: 10.3389/fnana.2017.00005] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 01/19/2017] [Indexed: 11/13/2022] Open
Abstract
Long descending propriospinal neurons (LDPNs) are interneurons that form direct connections between cervical and lumbar spinal circuits. LDPNs are involved in interlimb coordination and are important mediators of functional recovery after spinal cord injury (SCI). Much of what we know about LDPNs comes from a range of species, however, the increased use of transgenic mouse lines to better define neuronal populations calls for a more complete characterisation of LDPNs in mice. In this study, we examined the cell body location, inhibitory neurotransmitter phenotype, developmental provenance, morphology and synaptic inputs of mouse LDPNs throughout the cervical and upper thoracic spinal cord. LDPNs were retrogradely labelled from the lumbar spinal cord to map cell body locations throughout the cervical and upper thoracic segments. Ipsilateral LDPNs were distributed throughout the dorsal, intermediate and ventral grey matter as well as the lateral spinal nucleus and lateral cervical nucleus. In contrast, contralateral LDPNs were more densely concentrated in the ventromedial grey matter. Retrograde labelling in GlyT2GFP and GAD67GFP mice showed the majority of inhibitory LDPNs project either ipsilaterally or adjacent to the midline. Additionally, we used several transgenic mouse lines to define the developmental provenance of LDPNs and found that V2b positive neurons form a subset of ipsilaterally projecting LDPNs. Finally, a population of Neurobiotin (NB) labelled LDPNs were assessed in detail to examine morphology and plot the spatial distribution of contacts from a variety of neurochemically distinct axon terminals. These results provide important baseline data in mice for future work on their role in locomotion and recovery from SCI.
Collapse
Affiliation(s)
- Jamie R Flynn
- School of Biomedical Sciences and Pharmacy, University of NewcastleCallaghan, NSW, Australia; Hunter Medical Research InstituteNewcastle, NSW, Australia
| | - Victoria L Conn
- Institute of Neuroscience and Psychology, University of Glasgow Glasgow, UK
| | - Kieran A Boyle
- Institute of Neuroscience and Psychology, University of Glasgow Glasgow, UK
| | - David I Hughes
- Institute of Neuroscience and Psychology, University of Glasgow Glasgow, UK
| | - Masahiko Watanabe
- Department of Anatomy, Hokkaido University School of Medicine Sapporo, Japan
| | - Tomoko Velasquez
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies La Jolla, CA, USA
| | - Martyn D Goulding
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies La Jolla, CA, USA
| | - Robert J Callister
- School of Biomedical Sciences and Pharmacy, University of NewcastleCallaghan, NSW, Australia; Hunter Medical Research InstituteNewcastle, NSW, Australia
| | - Brett A Graham
- School of Biomedical Sciences and Pharmacy, University of NewcastleCallaghan, NSW, Australia; Hunter Medical Research InstituteNewcastle, NSW, Australia
| |
Collapse
|
96
|
Contribution of propriospinal neurons to recovery of hand dexterity after corticospinal tract lesions in monkeys. Proc Natl Acad Sci U S A 2017; 114:604-609. [PMID: 28049844 DOI: 10.1073/pnas.1610787114] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The direct cortico-motoneuronal connection is believed to be essential for the control of dexterous hand movements, such as precision grip in primates. It was reported, however, that even after lesion of the corticospinal tract (CST) at the C4-C5 segment, precision grip largely recovered within 1-3 mo, suggesting that the recovery depends on transmission through intercalated neurons rostral to the lesion, such as the propriospinal neurons (PNs) in the midcervical segments. To obtain direct evidence for the contribution of PNs to recovery after CST lesion, we applied a pathway-selective and reversible blocking method using double viral vectors to the PNs in six monkeys after CST lesions at C4-C5. In four monkeys that showed nearly full or partial recovery, transient blockade of PN transmission after recovery caused partial impairment of precision grip. In the other two monkeys, CST lesions were made under continuous blockade of PN transmission that outlasted the entire period of postoperative observation (3-4.5 mo). In these monkeys, precision grip recovery was not achieved. These results provide evidence for causal contribution of the PNs to recovery of hand dexterity after CST lesions; PN transmission is necessary for promoting the initial stage recovery; however, their contribution is only partial once the recovery is achieved.
Collapse
|
97
|
Benthall KN, Hough RA, McClellan AD. Descending propriospinal neurons mediate restoration of locomotor function following spinal cord injury. J Neurophysiol 2017; 117:215-229. [PMID: 27760818 PMCID: PMC5209543 DOI: 10.1152/jn.00544.2016] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 10/17/2016] [Indexed: 12/30/2022] Open
Abstract
Following spinal cord injury (SCI) in the lamprey, there is virtually complete recovery of locomotion within a few weeks, but interestingly, axonal regeneration of reticulospinal (RS) neurons is mostly limited to short distances caudal to the injury site. To explain this situation, we hypothesize that descending propriospinal (PS) neurons relay descending drive from RS neurons to indirectly activate spinal central pattern generators (CPGs). In the present study, the contributions of PS neurons to locomotor recovery were tested in the lamprey following SCI. First, long RS neuron projections were interrupted by staggered spinal hemitransections on the right side at 10% body length (BL; normalized from the tip of the oral hood) and on the left side at 30% BL. For acute recovery conditions (≤1 wk) and before axonal regeneration, swimming muscle burst activity was relatively normal, but with some deficits in coordination. Second, lampreys received two spaced complete spinal transections, one at 10% BL and one at 30% BL, to interrupt long-axon RS neuron projections. At short recovery times (3-5 wk), RS and PS neurons will have regenerated their axons for short distances and potentially established a polysynaptic descending command pathway. At these short recovery times, swimming muscle burst activity had only minor coordination deficits. A computer model that incorporated either of the two spinal lesions could mimic many aspects of the experimental data. In conclusion, descending PS neurons are a viable mechanism for indirect activation of spinal locomotor CPGs, although there can be coordination deficits of locomotor activity. NEW & NOTEWORTHY In the lamprey following spinal lesion-mediated interruption of long axonal projections of reticulospinal (RS) neurons, sensory stimulation still elicited relatively normal locomotor muscle burst activity, but with some coordination deficits. Computer models incorporating the spinal lesions could mimic many aspects of the experimental results. Thus, after disruption of long-axon projections from RS neurons in the lamprey, descending propriospinal (PS) neurons appear to be a viable compensatory mechanism for indirect activation of spinal locomotor networks.
Collapse
Affiliation(s)
- Katelyn N Benthall
- Division of Biological Sciences, University of Missouri, Columbia, Missouri; and
| | - Ryan A Hough
- Division of Biological Sciences, University of Missouri, Columbia, Missouri; and
| | - Andrew D McClellan
- Division of Biological Sciences, University of Missouri, Columbia, Missouri; and
- Interdisciplinary Neuroscience Program, University of Missouri, Columbia, Missouri
| |
Collapse
|
98
|
Fernández-López B, Barreiro-Iglesias A, Rodicio MC. Anatomical recovery of the spinal glutamatergic system following a complete spinal cord injury in lampreys. Sci Rep 2016; 6:37786. [PMID: 27886236 PMCID: PMC5122902 DOI: 10.1038/srep37786] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 11/02/2016] [Indexed: 12/14/2022] Open
Abstract
Lampreys recover locomotion following a spinal cord injury (SCI). Glutamate is necessary to initiate and control locomotion and recent data suggest a crucial role for intraspinal neurons in functional recovery following SCI. We aimed to determine whether, in lampreys, axotomized spinal glutamatergic neurons, which lose glutamate immunoreactivity immediately after SCI, recover it later on and to study the long-term evolution and anatomical recovery of the spinal glutamatergic system after SCI. We used glutamate immunoreactivity to study changes in the glutamatergic system, tract-tracing to label axotomized neurons and TUNEL labelling to study cell death. Transections of the cord were made at the level of the fifth gill. TUNEL experiments indicated that cell death is a minor contributor to the initial loss of glutamate immunoreactivity. At least some of the axotomized neurons lose glutamate immunoreactivity, survive and recover glutamate immunoreactivity 1 week post-lesion (wpl). We observed a progressive increase in the number of glutamatergic neurons/processes until an almost complete anatomical recovery at 10 wpl. Among all the glutamatergic populations, the population of cerebrospinal fluid-contacting cells is the only one that never recovers. Our results indicate that full recovery of the glutamatergic system is not necessary for the restoration of function in lampreys.
Collapse
Affiliation(s)
- Blanca Fernández-López
- Department of Functional Biology, CIBUS, Faculty of Biology, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain
| | - Antón Barreiro-Iglesias
- Department of Functional Biology, CIBUS, Faculty of Biology, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain
| | - María Celina Rodicio
- Department of Functional Biology, CIBUS, Faculty of Biology, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain
| |
Collapse
|
99
|
Côté MP, Murray M, Lemay MA. Rehabilitation Strategies after Spinal Cord Injury: Inquiry into the Mechanisms of Success and Failure. J Neurotrauma 2016; 34:1841-1857. [PMID: 27762657 DOI: 10.1089/neu.2016.4577] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Body-weight supported locomotor training (BWST) promotes recovery of load-bearing stepping in lower mammals, but its efficacy in individuals with a spinal cord injury (SCI) is limited and highly dependent on injury severity. While animal models with complete spinal transections recover stepping with step-training, motor complete SCI individuals do not, despite similarly intensive training. In this review, we examine the significant differences between humans and animal models that may explain this discrepancy in the results obtained with BWST. We also summarize the known effects of SCI and locomotor training on the muscular, motoneuronal, interneuronal, and supraspinal systems in human and non-human models of SCI and address the potential causes for failure to translate to the clinic. The evidence points to a deficiency in neuronal activation as the mechanism of failure, rather than muscular insufficiency. While motoneuronal and interneuronal systems cannot be directly probed in humans, the changes brought upon by step-training in SCI animal models suggest a beneficial re-organization of the systems' responsiveness to descending and afferent feedback that support locomotor recovery. The literature on partial lesions in humans and animal models clearly demonstrate a greater dependency on supraspinal input to the lumbar cord in humans than in non-human mammals for locomotion. Recent results with epidural stimulation that activates the lumbar interneuronal networks and/or increases the overall excitability of the locomotor centers suggest that these centers are much more dependent on the supraspinal tonic drive in humans. Sensory feedback shapes the locomotor output in animal models but does not appear to be sufficient to drive it in humans.
Collapse
Affiliation(s)
- Marie-Pascale Côté
- 1 Department of Neurobiology and Anatomy, Drexel University College of Medicine , Philadelphia, Pennsylvania
| | - Marion Murray
- 1 Department of Neurobiology and Anatomy, Drexel University College of Medicine , Philadelphia, Pennsylvania
| | - Michel A Lemay
- 2 Department of Bioengineering, Temple University , Philadelphia, Pennsylvania
| |
Collapse
|
100
|
Neuroprotective and Neurorestorative Processes after Spinal Cord Injury: The Case of the Bulbospinal Respiratory Neurons. Neural Plast 2016; 2016:7692602. [PMID: 27563469 PMCID: PMC4987469 DOI: 10.1155/2016/7692602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 06/29/2016] [Indexed: 11/18/2022] Open
Abstract
High cervical spinal cord injuries interrupt the bulbospinal respiratory pathways projecting to the cervical phrenic motoneurons resulting in important respiratory defects. In the case of a lateralized injury that maintains the respiratory drive on the opposite side, a partial recovery of the ipsilateral respiratory function occurs spontaneously over time, as observed in animal models. The rodent respiratory system is therefore a relevant model to investigate the neuroplastic and neuroprotective mechanisms that will trigger such phrenic motoneurons reactivation by supraspinal pathways. Since part of this recovery is dependent on the damaged side of the spinal cord, the present review highlights our current understanding of the anatomical neuroplasticity processes that are developed by the surviving damaged bulbospinal neurons, notably axonal sprouting and rerouting. Such anatomical neuroplasticity relies also on coordinated molecular mechanisms at the level of the axotomized bulbospinal neurons that will promote both neuroprotection and axon growth.
Collapse
|