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Chung B, Zia M, Thomas KA, Michaels JA, Jacob A, Pack A, Williams MJ, Nagapudi K, Teng LH, Arrambide E, Ouellette L, Oey N, Gibbs R, Anschutz P, Lu J, Wu Y, Kashefi M, Oya T, Kersten R, Mosberger AC, O'Connell S, Wang R, Marques H, Mendes AR, Lenschow C, Kondakath G, Kim JJ, Olson W, Quinn KN, Perkins P, Gatto G, Thanawalla A, Coltman S, Kim T, Smith T, Binder-Markey B, Zaback M, Thompson CK, Giszter S, Person A, Goulding M, Azim E, Thakor N, O'Connor D, Trimmer B, Lima SQ, Carey MR, Pandarinath C, Costa RM, Pruszynski JA, Bakir M, Sober SJ. Myomatrix arrays for high-definition muscle recording. eLife 2023; 12:RP88551. [PMID: 38113081 PMCID: PMC10730117 DOI: 10.7554/elife.88551] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2023] Open
Abstract
Neurons coordinate their activity to produce an astonishing variety of motor behaviors. Our present understanding of motor control has grown rapidly thanks to new methods for recording and analyzing populations of many individual neurons over time. In contrast, current methods for recording the nervous system's actual motor output - the activation of muscle fibers by motor neurons - typically cannot detect the individual electrical events produced by muscle fibers during natural behaviors and scale poorly across species and muscle groups. Here we present a novel class of electrode devices ('Myomatrix arrays') that record muscle activity at unprecedented resolution across muscles and behaviors. High-density, flexible electrode arrays allow for stable recordings from the muscle fibers activated by a single motor neuron, called a 'motor unit,' during natural behaviors in many species, including mice, rats, primates, songbirds, frogs, and insects. This technology therefore allows the nervous system's motor output to be monitored in unprecedented detail during complex behaviors across species and muscle morphologies. We anticipate that this technology will allow rapid advances in understanding the neural control of behavior and identifying pathologies of the motor system.
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Affiliation(s)
- Bryce Chung
- Department of Biology, Emory UniversityAtlantaUnited States
| | - Muneeb Zia
- School of Electrical and Computer Engineering, Georgia Institute of TechnologyAtlantaUnited States
| | - Kyle A Thomas
- Graduate Program in Biomedical Engineering at Emory University and Georgia TechAtlantaUnited States
| | | | - Amanda Jacob
- Department of Biology, Emory UniversityAtlantaUnited States
| | - Andrea Pack
- Neuroscience Graduate Program, Emory UniversityAtlantaUnited States
| | - Matthew J Williams
- Graduate Program in Biomedical Engineering at Emory University and Georgia TechAtlantaUnited States
| | | | - Lay Heng Teng
- Department of Biology, Emory UniversityAtlantaUnited States
| | | | | | - Nicole Oey
- Department of Biology, Emory UniversityAtlantaUnited States
| | - Rhuna Gibbs
- Department of Biology, Emory UniversityAtlantaUnited States
| | - Philip Anschutz
- Graduate Program in BioEngineering, Georgia TechAtlantaUnited States
| | - Jiaao Lu
- Graduate Program in Electrical and Computer Engineering, Georgia TechAtlantaUnited States
| | - Yu Wu
- School of Electrical and Computer Engineering, Georgia Institute of TechnologyAtlantaUnited States
| | - Mehrdad Kashefi
- Department of Physiology and Pharmacology, Western UniversityLondonCanada
| | - Tomomichi Oya
- Department of Physiology and Pharmacology, Western UniversityLondonCanada
| | - Rhonda Kersten
- Department of Physiology and Pharmacology, Western UniversityLondonCanada
| | - Alice C Mosberger
- Zuckerman Mind Brain Behavior Institute at Columbia UniversityNew YorkUnited States
| | - Sean O'Connell
- Graduate Program in Biomedical Engineering at Emory University and Georgia TechAtlantaUnited States
| | - Runming Wang
- Department of Biomedical Engineering at Emory University and Georgia TechAtlantaUnited States
| | - Hugo Marques
- Champalimaud Neuroscience Programme, Champalimaud FoundationLisbonPortugal
| | - Ana Rita Mendes
- Champalimaud Neuroscience Programme, Champalimaud FoundationLisbonPortugal
| | - Constanze Lenschow
- Champalimaud Neuroscience Programme, Champalimaud FoundationLisbonPortugal
| | | | - Jeong Jun Kim
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins School of MedicineBaltimoreUnited States
| | - William Olson
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins School of MedicineBaltimoreUnited States
| | - Kiara N Quinn
- Departments of Biomedical Engineering and Neurology, Johns Hopkins School of MedicineBaltimoreUnited States
| | - Pierce Perkins
- Departments of Biomedical Engineering and Neurology, Johns Hopkins School of MedicineBaltimoreUnited States
| | - Graziana Gatto
- Salk Institute for Biological StudiesLa JollaUnited States
| | | | - Susan Coltman
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Taegyo Kim
- Department of Neurobiology & Anatomy, Drexel University, College of MedicinePhiladelphiaUnited States
| | - Trevor Smith
- Department of Neurobiology & Anatomy, Drexel University, College of MedicinePhiladelphiaUnited States
| | - Ben Binder-Markey
- Department of Physical Therapy and Rehabilitation Sciences, Drexel University College of Nursing and Health ProfessionsPhiladelphiaUnited States
| | - Martin Zaback
- Department of Health and Rehabilitation Sciences, Temple UniversityPhiladelphiaUnited States
| | - Christopher K Thompson
- Department of Health and Rehabilitation Sciences, Temple UniversityPhiladelphiaUnited States
| | - Simon Giszter
- Department of Neurobiology & Anatomy, Drexel University, College of MedicinePhiladelphiaUnited States
| | - Abigail Person
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical CampusAuroraUnited States
- Allen InstituteSeattleUnited States
| | | | - Eiman Azim
- Salk Institute for Biological StudiesLa JollaUnited States
| | - Nitish Thakor
- Departments of Biomedical Engineering and Neurology, Johns Hopkins School of MedicineBaltimoreUnited States
| | - Daniel O'Connor
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins School of MedicineBaltimoreUnited States
| | - Barry Trimmer
- Department of Biology, Tufts UniversityMedfordUnited States
| | - Susana Q Lima
- Champalimaud Neuroscience Programme, Champalimaud FoundationLisbonPortugal
| | - Megan R Carey
- Champalimaud Neuroscience Programme, Champalimaud FoundationLisbonPortugal
| | - Chethan Pandarinath
- Department of Biomedical Engineering at Emory University and Georgia TechAtlantaUnited States
| | - Rui M Costa
- Zuckerman Mind Brain Behavior Institute at Columbia UniversityNew YorkUnited States
| | | | - Muhannad Bakir
- School of Electrical and Computer Engineering, Georgia Institute of TechnologyAtlantaUnited States
| | - Samuel J Sober
- Department of Biology, Emory UniversityAtlantaUnited States
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Chung B, Zia M, Thomas KA, Michaels JA, Jacob A, Pack A, Williams MJ, Nagapudi K, Teng LH, Arrambide E, Ouellette L, Oey N, Gibbs R, Anschutz P, Lu J, Wu Y, Kashefi M, Oya T, Kersten R, Mosberger AC, O'Connell S, Wang R, Marques H, Mendes AR, Lenschow C, Kondakath G, Kim JJ, Olson W, Quinn KN, Perkins P, Gatto G, Thanawalla A, Coltman S, Kim T, Smith T, Binder-Markey B, Zaback M, Thompson CK, Giszter S, Person A, Goulding M, Azim E, Thakor N, O'Connor D, Trimmer B, Lima SQ, Carey MR, Pandarinath C, Costa RM, Pruszynski JA, Bakir M, Sober SJ. Myomatrix arrays for high-definition muscle recording. bioRxiv 2023:2023.02.21.529200. [PMID: 36865176 PMCID: PMC9980060 DOI: 10.1101/2023.02.21.529200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Neurons coordinate their activity to produce an astonishing variety of motor behaviors. Our present understanding of motor control has grown rapidly thanks to new methods for recording and analyzing populations of many individual neurons over time. In contrast, current methods for recording the nervous system's actual motor output - the activation of muscle fibers by motor neurons - typically cannot detect the individual electrical events produced by muscle fibers during natural behaviors and scale poorly across species and muscle groups. Here we present a novel class of electrode devices ("Myomatrix arrays") that record muscle activity at unprecedented resolution across muscles and behaviors. High-density, flexible electrode arrays allow for stable recordings from the muscle fibers activated by a single motor neuron, called a "motor unit", during natural behaviors in many species, including mice, rats, primates, songbirds, frogs, and insects. This technology therefore allows the nervous system's motor output to be monitored in unprecedented detail during complex behaviors across species and muscle morphologies. We anticipate that this technology will allow rapid advances in understanding the neural control of behavior and in identifying pathologies of the motor system.
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Affiliation(s)
- Bryce Chung
- Department of Biology, Emory University (Atlanta, GA, USA)
| | - Muneeb Zia
- School of Electrical and Computer Engineering, Georgia Institute of Technology (Atlanta, GA, USA)
| | - Kyle A Thomas
- Graduate Program in Biomedical Engineering at Emory University and Georgia Tech (Atlanta, GA, USA)
| | - Jonathan A Michaels
- Department of Physiology and Pharmacology, Western University (London, ON, Canada)
| | - Amanda Jacob
- Department of Biology, Emory University (Atlanta, GA, USA)
| | - Andrea Pack
- Neuroscience Graduate Program, Emory University (Atlanta, GA, USA)
| | - Matthew J Williams
- Graduate Program in Biomedical Engineering at Emory University and Georgia Tech (Atlanta, GA, USA)
| | | | - Lay Heng Teng
- Department of Biology, Emory University (Atlanta, GA, USA)
| | | | | | - Nicole Oey
- Department of Biology, Emory University (Atlanta, GA, USA)
| | - Rhuna Gibbs
- Department of Biology, Emory University (Atlanta, GA, USA)
| | - Philip Anschutz
- Graduate Program in BioEngineering, Georgia Tech (Atlanta, GA, USA)
| | - Jiaao Lu
- Graduate Program in Electrical and Computer Engineering, Georgia Tech (Atlanta, GA, USA)
| | - Yu Wu
- School of Electrical and Computer Engineering, Georgia Institute of Technology (Atlanta, GA, USA)
| | - Mehrdad Kashefi
- Department of Physiology and Pharmacology, Western University (London, ON, Canada)
| | - Tomomichi Oya
- Department of Physiology and Pharmacology, Western University (London, ON, Canada)
| | - Rhonda Kersten
- Department of Physiology and Pharmacology, Western University (London, ON, Canada)
| | - Alice C Mosberger
- Zuckerman Mind Brain Behavior Institute at Columbia University (New York, NY, USA)
| | - Sean O'Connell
- Graduate Program in Biomedical Engineering at Emory University and Georgia Tech (Atlanta, GA, USA)
| | - Runming Wang
- Department of Biomedical Engineering at Emory University and Georgia Tech (Atlanta, GA, USA)
| | - Hugo Marques
- Champalimaud Neuroscience Programme, Champalimaud Foundation (Lisbon, Portugal)
| | - Ana Rita Mendes
- Champalimaud Neuroscience Programme, Champalimaud Foundation (Lisbon, Portugal)
| | - Constanze Lenschow
- Champalimaud Neuroscience Programme, Champalimaud Foundation (Lisbon, Portugal)
- current address: Institute of Biology, Otto-von-Guericke University, (Magdeburg, Germany)
| | | | - Jeong Jun Kim
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins School of Medicine (Baltimore, MD, USA)
| | - William Olson
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins School of Medicine (Baltimore, MD, USA)
| | - Kiara N Quinn
- Departments of Biomedical Engineering and Neurology, Johns Hopkins School of Medicine (Baltimore, MD, USA)
| | - Pierce Perkins
- Departments of Biomedical Engineering and Neurology, Johns Hopkins School of Medicine (Baltimore, MD, USA)
| | - Graziana Gatto
- Salk Institute for Biological Studies (La Jolla, CA, USA)
- current address: Department of Neurology, University Hospital of Cologne (Cologne, Germany)
| | | | - Susan Coltman
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus (Aurora, CO, USA)
| | - Taegyo Kim
- Department of Neurobiology & Anatomy, Drexel University, College of Medicine (Philadelphia, PA, USA)
| | - Trevor Smith
- Department of Neurobiology & Anatomy, Drexel University, College of Medicine (Philadelphia, PA, USA)
| | - Ben Binder-Markey
- Department of Physical Therapy and Rehabilitation Sciences, Drexel University College of Nursing and Health Professions (Philadelphia, PA)
| | - Martin Zaback
- Department of Health and Rehabilitation Sciences, Temple University (Philadelphia, PA, USA)
| | - Christopher K Thompson
- Department of Health and Rehabilitation Sciences, Temple University (Philadelphia, PA, USA)
| | - Simon Giszter
- Department of Neurobiology & Anatomy, Drexel University, College of Medicine (Philadelphia, PA, USA)
| | - Abigail Person
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus (Aurora, CO, USA)
| | | | - Eiman Azim
- Salk Institute for Biological Studies (La Jolla, CA, USA)
| | - Nitish Thakor
- Departments of Biomedical Engineering and Neurology, Johns Hopkins School of Medicine (Baltimore, MD, USA)
| | - Daniel O'Connor
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins School of Medicine (Baltimore, MD, USA)
| | - Barry Trimmer
- Department of Biology, Tufts University (Medford, MA, USA)
| | - Susana Q Lima
- Champalimaud Neuroscience Programme, Champalimaud Foundation (Lisbon, Portugal)
| | - Megan R Carey
- Champalimaud Neuroscience Programme, Champalimaud Foundation (Lisbon, Portugal)
| | - Chethan Pandarinath
- Department of Biomedical Engineering at Emory University and Georgia Tech (Atlanta, GA, USA)
| | - Rui M Costa
- Zuckerman Mind Brain Behavior Institute at Columbia University (New York, NY, USA)
- Allen Institute (Seattle, WA, USA)
| | - J Andrew Pruszynski
- Department of Physiology and Pharmacology, Western University (London, ON, Canada)
| | - Muhannad Bakir
- School of Electrical and Computer Engineering, Georgia Institute of Technology (Atlanta, GA, USA)
| | - Samuel J Sober
- Department of Biology, Emory University (Atlanta, GA, USA)
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Hormigo KM, Zholudeva LV, Spruance VM, Marchenko V, Cote MP, Vinit S, Giszter S, Bezdudnaya T, Lane MA. Enhancing neural activity to drive respiratory plasticity following cervical spinal cord injury. Exp Neurol 2017; 287:276-287. [PMID: 27582085 PMCID: PMC5121051 DOI: 10.1016/j.expneurol.2016.08.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 07/20/2016] [Accepted: 08/26/2016] [Indexed: 02/07/2023]
Abstract
Cervical spinal cord injury (SCI) results in permanent life-altering sensorimotor deficits, among which impaired breathing is one of the most devastating and life-threatening. While clinical and experimental research has revealed that some spontaneous respiratory improvement (functional plasticity) can occur post-SCI, the extent of the recovery is limited and significant deficits persist. Thus, increasing effort is being made to develop therapies that harness and enhance this neuroplastic potential to optimize long-term recovery of breathing in injured individuals. One strategy with demonstrated therapeutic potential is the use of treatments that increase neural and muscular activity (e.g. locomotor training, neural and muscular stimulation) and promote plasticity. With a focus on respiratory function post-SCI, this review will discuss advances in the use of neural interfacing strategies and activity-based treatments, and highlights some recent results from our own research.
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Affiliation(s)
- Kristiina M Hormigo
- Spinal Cord Research Center, Department of Neurobiology and Anatomy, College of Medicine, Drexel University, 2900 W Queen Lane, Philadelphia, PA, USA
| | - Lyandysha V Zholudeva
- Spinal Cord Research Center, Department of Neurobiology and Anatomy, College of Medicine, Drexel University, 2900 W Queen Lane, Philadelphia, PA, USA
| | - Victoria M Spruance
- Spinal Cord Research Center, Department of Neurobiology and Anatomy, College of Medicine, Drexel University, 2900 W Queen Lane, Philadelphia, PA, USA
| | - Vitaliy Marchenko
- Spinal Cord Research Center, Department of Neurobiology and Anatomy, College of Medicine, Drexel University, 2900 W Queen Lane, Philadelphia, PA, USA
| | - Marie-Pascale Cote
- Spinal Cord Research Center, Department of Neurobiology and Anatomy, College of Medicine, Drexel University, 2900 W Queen Lane, Philadelphia, PA, USA
| | - Stephane Vinit
- Université de Versailles Saint-Quentin-en-Yvelines, INSERM U1179 End:icap, UFR des Sciences de la Santé - Simone Veil, Montigny-le-Bretonneux, France
| | - Simon Giszter
- Spinal Cord Research Center, Department of Neurobiology and Anatomy, College of Medicine, Drexel University, 2900 W Queen Lane, Philadelphia, PA, USA
| | - Tatiana Bezdudnaya
- Spinal Cord Research Center, Department of Neurobiology and Anatomy, College of Medicine, Drexel University, 2900 W Queen Lane, Philadelphia, PA, USA
| | - Michael A Lane
- Spinal Cord Research Center, Department of Neurobiology and Anatomy, College of Medicine, Drexel University, 2900 W Queen Lane, Philadelphia, PA, USA.
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Giszter S, Davies MR, Ramakrishnan A, Udoekwere UI, Kargo WJ. Trunk sensorimotor cortex is essential for autonomous weight-supported locomotion in adult rats spinalized as P1/P2 neonates. J Neurophysiol 2008; 100:839-51. [PMID: 18509082 DOI: 10.1152/jn.00866.2007] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Unlike adult spinalized rats, approximately 20% of rats spinalized as postnatal day 1 or 2 (P1/P2) neonates achieve autonomous hindlimb weight support. Cortical representations of mid/low trunk occur only in such rats with high weight support. However, the importance of hindlimb/trunk motor cortex in function of spinalized rats remains unclear. We tested the importance of trunk sensorimotor cortex in their locomotion using lesions guided by cortical microstimulation in P1/P2 weight-supporting neonatal spinalized rats and controls. In four intact control rats, lesions of hindlimb/trunk cortex caused no treadmill deficits. All spinalized rats lesioned in trunk cortex (n = 16: 4 transplant, 6 transect, 6 transect + fibrin glue) lost an average of about 40% of their weight support. Intact trunk cortex was essential to their level of function. Lesion of trunk cortex substantially increased roll of the hindquarters, which correlated to diminished weight support, but other kinematic stepping parameters showed little change. Embryonic day 14 (E14) transplants support development of the trunk motor representations in their normal location. We tested the role of novel relay circuits arising from the grafts in such cortical representations in E14 transplants using the rats that received (noncellular) fibrin glue grafting at P1/P2 (8 allografts and 32 xenografts). Fibrin-repaired rats with autonomous weight support also had trunk cortical representations similar to those of E14 transplant rats. Thus acellular repair and intrinsic plasticity were sufficient to support the observed features. Our data show that effective cortical mechanisms for trunk control are essential for autonomous weight support in P1/P2 spinalized rats and these can be achieved by intrinsic plasticity.
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Affiliation(s)
- Simon Giszter
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA 19129, USA.
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Giszter S, Patil V, Hart C. Primitives, premotor drives, and pattern generation: a combined computational and neuroethological perspective. Progress in Brain Research 2007; 165:323-46. [DOI: 10.1016/s0079-6123(06)65020-6] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Abstract
In this review we consider recovery of function after spinal cord injury, and, in particular, recovery improved following intraspinal cellular transplants. Some recovery occurs spontaneously and this can be especially dramatic in neonates, supporting the notion that developing and adult spinal cord respond differently to injury. Recovery can be improved in both neonates and adults by appropriate cellular transplants into the injury site. We describe several functional tests used in animals with spinal lesions and transplants. We compare the effects of transplants of fetal tissue and genetically modified fibroblasts into neonatal and adult injury sites on recovery of motor and sensorimotor function. Fetal tissue transplants support greater recovery and elicit more regeneration in neonates than in adults. Transplants of fibroblasts modified to produce neurotrophic factors however support both recovery and axonal growth even in adults. The contribution of the transplant to recovery is shown by the loss of function that follows a second lesion just rostral to the original lesion/transplant site. The effect of the re-lesion indicates that the recovery is mediated by the presence of the transplant but the way in which transplants act to promote recovery may include a number of mechanisms, including regeneration and sprouting, neuroprotection, and modifications of organization of spared CNS structures.
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Affiliation(s)
- Marion Murray
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129, USA.
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Rybak IA, Moxon KA, Giszter S, Chapin JK. Computational modeling of integration of voluntary/behavioral and automatic mechanisms for breathing control. Adv Exp Med Biol 2002; 499:425-30. [PMID: 11729919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Affiliation(s)
- I A Rybak
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA 19104, USA
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Kim D, Adipudi V, Shibayama M, Giszter S, Tessler A, Murray M, Simansky KJ. Direct agonists for serotonin receptors enhance locomotor function in rats that received neural transplants after neonatal spinal transection. J Neurosci 1999; 19:6213-24. [PMID: 10407057 PMCID: PMC6783084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023] Open
Abstract
We analyzed whether acute treatment with serotonergic agonists would improve motor function in rats with transected spinal cords (spinal rats) and in rats that received transplants of fetal spinal cord into the transection site (transplant rats). Neonates received midthoracic spinal transections within 48 hr of birth; transplant rats received fetal (embryonic day 14) spinal cord grafts at the time of transection. At 3 weeks, rats began 1-2 months of training in treadmill locomotion. Rats in the transplant group developed better weight-supported stepping than spinal rats. Systemic administration of two directly acting agonists for serotonergic 5-HT(2) receptor subtypes, quipazine and (+/-)-1-[2, 5]-dimethoxy-4-iodophenyl-2-aminopropane), further increased weight-supported stepping in transplant rats. The improvement was dose-dependent and greatest in rats with poor to moderate baseline weight support. In contrast, indirectly acting serotonergic agonists, which block reuptake of 5-HT (sertraline) or release 5-HT and block its reuptake (D-fenfluramine), failed to enhance motor function. Neither direct nor indirect agonists significantly improved locomotion in spinal rats as a group, despite equivalent upregulation of 5-HT(2) receptors in the lumbar ventral horn of lesioned rats with and without transplants. The distribution of immunoreactive serotonergic fibers within and caudal to the transplant did not appear to correspond to restoration of motor function. Our results confirm our previous demonstration that transplants improve motor performance in spinal rats. Additional stimulation with agonists at subtypes of 5-HT receptors produces a beneficial interaction with transplants that further improves motor competence.
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Affiliation(s)
- D Kim
- Department of Neurobiology and Anatomy, MCP Hahnemann University, Philadelphia, Pennsylvania 19129, USA
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Giszter S, Graziani V, Kargo W, Hockensmith G, Davies MR, Smeraski CS, Murray M. Pattern generators and cortical maps in locomotion of spinal injured rats. Ann N Y Acad Sci 1998; 860:554-5. [PMID: 9928361 DOI: 10.1111/j.1749-6632.1998.tb09102.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- S Giszter
- Department of Neurobiology and Anatomy, Medical College of Pensylvannia/Hahnemann Medical School, Allegheny University of the Health Sciences, Philadelphia 19129, USA.
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Miya D, Giszter S, Mori F, Adipudi V, Tessler A, Murray M. Fetal transplants alter the development of function after spinal cord transection in newborn rats. J Neurosci 1997; 17:4856-72. [PMID: 9169544 PMCID: PMC6573335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Pieces of fetal spinal tissue were transplanted into the site of complete midthoracic spinal transections in neonatal rat pups (transplant rats). The development of locomotion in these animals was compared with that of unoperated control rats and rats that received spinal transections alone (spinal rats). Reflex, treadmill and overground locomotion, staircase descent, and horizontal ladder crossing for a water reward were tested in control, spinal, and transplant rats from 3 weeks to adulthood. All tests were readily performed by control animals. Most spinal rats were unable to make many linked weight-supported steps on these tasks. Transplant rats were variable in their locomotor capabilities, but a subset of rats were able to demonstrate coordinated and adaptable locomotion on these tasks. Some transplant rats performed better on more challenging tasks, suggesting that motor strategies for these tasks used different information, perhaps from descending systems. Transplanted tissue survived, and in most cases there was immunocytochemical staining of serotonergic fibers passing into and caudal to the transplant, supporting the conclusion that descending systems grew through the transplanted tissue. Integration with the host tissue was often poor, suggesting that nonspecific or trophic effects of the transplant might also contribute to the development of locomotor function. Therefore several mechanisms may contribute to the repair of injured spinal cord provided by transplants that permit the development of useful locomotion.
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Affiliation(s)
- D Miya
- Department of Neurobiology and Anatomy, Allegheny University of the Health Sciences, Philadelphia, Pennsylvania 19129, USA
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Abstract
To execute voluntary movements, the central nervous system must transform the neural representation of the direction, amplitude, and velocity of the limb, represented by the activity of cortical and subcortical neurons, into signals that activate the muscles that move the limb. This task is equivalent to solving an "ill-posed" computational problem because the number of degrees of freedom of the musculoskeletal apparatus is much larger than that specified in the plan of action. Some of the mechanisms and circuitry underlying the transformation of motor plans into motor commands are described. A central feature of this transformation is a coarse map of limb postures in the premotor areas of the spinal cord. Vectorial combination of motor outputs among different areas of the spinal map may produce a large repertoire of motor behaviors.
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Affiliation(s)
- E Bizzi
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge 02139
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