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Malloy DC, Côté MP. Multi-session transcutaneous spinal cord stimulation prevents chloride homeostasis imbalance and the development of hyperreflexia after spinal cord injury in rat. Exp Neurol 2024; 376:114754. [PMID: 38493983 DOI: 10.1016/j.expneurol.2024.114754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 02/28/2024] [Accepted: 03/11/2024] [Indexed: 03/19/2024]
Abstract
Spasticity is a complex and multidimensional disorder that impacts nearly 75% of individuals with spinal cord injury (SCI) and currently lacks adequate treatment options. This sensorimotor condition is burdensome as hyperexcitability of reflex pathways result in exacerbated reflex responses, co-contractions of antagonistic muscles, and involuntary movements. Transcutaneous spinal cord stimulation (tSCS) has become a popular tool in the human SCI research field. The likeliness for this intervention to be successful as a noninvasive anti-spastic therapy after SCI is suggested by a mild and transitory improvement in spastic symptoms following a single stimulation session, but it remains to be determined if repeated tSCS over the course of weeks can produce more profound effects. Despite its popularity, the neuroplasticity induced by tSCS also remains widely unexplored, particularly due to the lack of suitable animal models to investigate this intervention. Thus, the basis of this work was to use tSCS over multiple sessions (multi-session tSCS) in a rat model to target spasticity after SCI and identify the long-term physiological improvements and anatomical neuroplasticity occurring in the spinal cord. Here, we show that multi-session tSCS in rats with an incomplete (severe T9 contusion) SCI (1) decreases hyperreflexia, (2) increases the low frequency-dependent modulation of the H-reflex, (3) prevents potassium-chloride cotransporter isoform 2 (KCC2) membrane downregulation in lumbar motoneurons, and (4) generally augments motor output, i.e., EMG amplitude in response to single pulses of tSCS, particularly in extensor muscles. Together, this work displays that multi-session tSCS can target and diminish spasticity after SCI as an alternative to pharmacological interventions and begins to highlight the underlying neuroplasticity contributing to its success in improving functional recovery.
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Affiliation(s)
- Dillon C Malloy
- Marion Murray Spinal Cord Research Center, Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, United States of America.
| | - Marie-Pascale Côté
- Marion Murray Spinal Cord Research Center, Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, United States of America.
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2
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Audet J, Lecomte CG, Harnie J, Yassine S, Al Arab R, Soucy F, Morency C, Mari S, Jéhannin P, Merlet AN, Frigon A. Simultaneous control of forward and backward locomotion by spinal sensorimotor circuits. J Physiol 2024; 602:183-204. [PMID: 38016922 DOI: 10.1113/jp285473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2023] [Accepted: 11/01/2023] [Indexed: 11/30/2023] Open
Abstract
Mammals walk in different directions, such as forward and backward. In human infants/adults and decerebrate cats, one leg can walk forward and the other backward simultaneously on a split-belt treadmill, termed hybrid or bidirectional locomotion. The purpose of the present study was to determine if spinal sensorimotor circuits generate hybrid locomotion and if so, how the limbs remain coordinated. We tested hybrid locomotion in 11 intact cats and in five following complete spinal thoracic transection (spinal cats) at three treadmill speeds with the hindlimbs moving forward, backward or bidirectionally. All intact cats generated hybrid locomotion with the forelimbs on a stationary platform. Four of five spinal cats generated hybrid locomotion, also with the forelimbs on a stationary platform, but required perineal stimulation. During hybrid locomotion, intact and spinal cats positioned their forward and backward moving hindlimbs caudal and rostral to the hip, respectively. The hindlimbs maintained consistent left-right out-of-phase alternation in the different stepping directions. Our results suggest that spinal locomotor networks generate hybrid locomotion by following certain rules at phase transitions. We also found that stance duration determined cycle duration in the different locomotor directions/conditions, consistent with a common rhythm-generating mechanism for different locomotor directions. Our findings provide additional insight on how left-right spinal networks and sensory feedback from the limbs interact to coordinate the hindlimbs and provide stability during locomotion in different directions. KEY POINTS: Terrestrial mammals can walk forward and backward, which is controlled in part by spinal sensorimotor circuits. Humans and cats also perform bidirectional or hybrid locomotion on a split-belt treadmill with one leg going forward and the other going backward. We show that cats with a spinal transection can perform hybrid locomotion and maintain left-right out-of-phase coordination, indicating that spinal sensorimotor circuits can perform simultaneous forward and backward locomotion. We also show that the regulation of cycle duration and phase duration is conserved across stepping direction, consistent with a common rhythm-generating mechanism for different stepping directions. The results help us better understand how spinal networks controlling the left and right legs enable locomotion in different directions.
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Affiliation(s)
- Johannie Audet
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du Centre Hospitalier de l'Université de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Charly G Lecomte
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du Centre Hospitalier de l'Université de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Jonathan Harnie
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du Centre Hospitalier de l'Université de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Sirine Yassine
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du Centre Hospitalier de l'Université de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Rasha Al Arab
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du Centre Hospitalier de l'Université de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Félix Soucy
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du Centre Hospitalier de l'Université de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Caroline Morency
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du Centre Hospitalier de l'Université de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Stephen Mari
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du Centre Hospitalier de l'Université de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Pierre Jéhannin
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du Centre Hospitalier de l'Université de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Angèle N Merlet
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du Centre Hospitalier de l'Université de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Alain Frigon
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du Centre Hospitalier de l'Université de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
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3
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Pechstein AE, Gollie JM, Keyser RE, Guccione AA. Walking Endurance and Oxygen Uptake On-Kinetics in Individuals With Parkinson Disease Following Overground Locomotor Training. J Neurol Phys Ther 2023; 47:99-111. [PMID: 36538418 DOI: 10.1097/npt.0000000000000423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND AND PURPOSE Poor walking endurance in Parkinson disease (PD) may be attributable to both bioenergetic and biomechanical factors, but locomotor training methods addressing both these factors simultaneously are understudied. Our objective was to examine the effects of overground locomotor training (OLT) on walking endurance in individuals with mild-to-moderate PD, and to further explore potential cardiorespiratory contributions. METHODS A single-arm, longitudinal design was used to examine the effects of 24 biweekly sessions of OLT in people with mild-to-moderate PD (n = 12). Walking endurance was measured as total distance walked during a 10-minute walk test (10minWT). Oxygen uptake (V˙ o2 ) on-kinetic profiles were determined using a monoexponential function. Perceived fatigability was assessed following the 10minWT using a self-report scale. Magnitude of change in primary outcomes was assessed using Cohen's d and adjusted for sample size (Cohen's d(unbiased) ). RESULTS Participants executed 3036 (297) steps and maintained 65.5% (8%) age-predicted heart rate maximum in a typical session lasting 56.9 (2.5) minutes. Medium effects in total distance walked-885.9 (157.2) versus 969.5 (140.9); Cohen's d(unbiased) = 0.54-and phase II time constant of the V˙ o2 on-kinetic profile-33.7 (12.3) versus 25.9 (15.3); Cohen's d(unbiased) = 0.54-were observed alongside trivial effects for perceived fatigability-4.7 (1.4) versus 4.8 (1.5); Cohen's d(unbiased) = 0.11-following OLT. DISCUSSION AND CONCLUSIONS These preliminary findings may demonstrate the potential for moderate-intensity OLT to improve walking endurance and enhance cardiorespiratory adjustments to walking activity in adults with mild-to-moderate PD.Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content 1, http://links.lww.com/JNPT/A407 ).
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Affiliation(s)
- Andrew E Pechstein
- Department of Rehabilitation Science, George Mason University, Fairfax, Virginia (A.E.P., J.M.G., R.E.K., A.A.G.); Department of Physical Therapy, University of Delaware, Newark (A.E.P.); and Research Service, Veterans Affairs Medical Center, Washington, District of Columbia (J.M.G.)
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Edgerton VR, Gad P. Spinal automaticity of movement control and its role in recovering function after spinal injury. Expert Rev Neurother 2022; 22:655-667. [PMID: 36043398 DOI: 10.1080/14737175.2022.2115359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION The significance of the spinal circuitry in controlling postural and locomotor functions largely re-emerged in the mid-1970s under the leadership of Sten Grillner, demonstrating key phenomena of "central pattern generation" and "fictive locomotion" with an evolutionary perspective. These concepts raised the question of how much function can be recovered after paralysis, given the intrinsic automaticity of spinal networks in injured and uninjured states in adults. AREAS COVERED This review explores biological mechanisms governing spinal control of movements such as posture and locomotion. We focus on concepts that have evolved from experiments performed over the past decade. Rather than a comprehensive review of the vast literature on the neural control of posture and locomotion, we focus on the various mechanisms underlying functional automaticity, and their clinical relevance. EXPERT OPINION We propose that multiple combinations of sensory mechanoreceptors linked to proprioception generate an infinite number of different sensory ensembles, having species-specific meaning and extensive influence in controlling posture and locomotion. These sensory ensembles are translated as a probabilistic phenomenon into highly specific but indeterminate actions. Therefore, we opine that spinal translation of these ensembles in real-time plays a central role in the automaticity of motor control in individuals with and without severe neuromotor dysfunction.
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Affiliation(s)
- V Reggie Edgerton
- 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.,Institut Guttmann. Hospital de Neurorehabilitació, Institut Universitari adscrit a la Universitat Autònoma de Barcelona, Barcelona, 08916 Badalona, Spain
| | - Parag Gad
- Department of Neurobiology, University of California, Los Angeles, CA 90095 USA
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5
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Stochastic spinal neuromodulation tunes the intrinsic logic of spinal neural networks. Exp Neurol 2022; 355:114138. [DOI: 10.1016/j.expneurol.2022.114138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 05/30/2022] [Accepted: 06/01/2022] [Indexed: 11/22/2022]
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6
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Musienko PE, Lyalka VF, Gorskii OV, Zelenin PV, Deliagina TG. Activity of Spinal Interneurons during Forward and Backward Locomotion. J Neurosci 2022; 42:3570-3586. [PMID: 35296546 PMCID: PMC9053856 DOI: 10.1523/jneurosci.1884-21.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 02/21/2022] [Accepted: 03/13/2022] [Indexed: 11/21/2022] Open
Abstract
Higher vertebrates are capable not only of forward but also backward and sideways locomotion. Also, single steps in different directions are generated for postural corrections. While the networks responsible for the control of forward walking (FW) have been studied in considerable detail, the networks controlling steps in other directions are mostly unknown. Here, to characterize the operation of the spinal locomotor network during FW and backward walking (BW), we recorded the activity of individual spinal interneurons from L4 to L6 during both FW and BW evoked by epidural stimulation (ES) of the spinal cord at L5-L6 in decerebrate cats of either sex. Three groups of neurons were revealed. Group 1 (45%) had a similar phase of modulation during both FW and BW. Group 2 (27%) changed the phase of modulation in the locomotor cycle depending on the direction of locomotion. Group 3 neurons were modulated during FW only (Group 3a, 21%) or during BW only (Group 3b, 7%). We suggest that Group 1 neurons belong to the network generating the vertical component of steps (the limb elevation and lowering) because it should operate similarly during locomotion in any direction, while Groups 2 and 3 neurons belong to the networks controlling the direction of stepping. Results of this study provide new insights into the organization of the spinal locomotor circuits, advance our understanding of ES therapeutic effects, and can potentially be used for the development of novel strategies for recuperation of impaired balance control, which requires the generation of corrective steps in different directions.SIGNIFICANCE STATEMENT Animals and humans can perform locomotion in different directions in relation to the body axis (forward, backward, sideways). While the networks that control forward walking have been studied in considerable detail, the networks controlling steps in other directions are unknown. Here, by recording the activity of the same spinal neurons during forward and backward walking, we revealed three groups of neurons forming, respectively, the network operating similarly during stepping in different directions, the network changing its operation with a change in the direction of stepping, and the network operating only during locomotion in a specific direction. These networks presumably control different aspects of the step. The obtained results provide new insights into the organization of the spinal locomotor networks.
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Affiliation(s)
- Pavel E Musienko
- Laboratory of Neuroprosthetics, Institute of Translational Biomedicine, St. Petersburg State University, St. Petersburg 199034, Russia
- Laboratory of Motor and Visceral Functions Neuromodulation, Pavlov Institute of Physiology, St. Petersburg 199034, Russia
- Sirius National Technical University, Sochi 354340, Russia
| | - Vladimir F Lyalka
- Department of Neuroscience, Karolinska Institute, SE-17177 Stockholm, Sweden
| | - Oleg V Gorskii
- Laboratory of Neuroprosthetics, Institute of Translational Biomedicine, St. Petersburg State University, St. Petersburg 199034, Russia
- Laboratory of Motor and Visceral Functions Neuromodulation, Pavlov Institute of Physiology, St. Petersburg 199034, Russia
| | - Pavel V Zelenin
- Department of Neuroscience, Karolinska Institute, SE-17177 Stockholm, Sweden
| | - Tatiana G Deliagina
- Department of Neuroscience, Karolinska Institute, SE-17177 Stockholm, Sweden
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7
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Merkulyeva N, Lyakhovetskii V, Gorskii O, Musienko P. Differences in backward and forward treadmill locomotion in decerebrated cats. J Exp Biol 2022; 225:275350. [PMID: 35438747 PMCID: PMC9163443 DOI: 10.1242/jeb.244210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 04/12/2022] [Indexed: 11/20/2022]
Abstract
Locomotion in different directions is vital for animal life and requires fine-adjusted neural activity of spinal networks. To compare the levels of recruitability of the locomotor circuitry responsible for forward and backward stepping, several electromyographic and kinematic characteristics of the two locomotor modes were analysed in decerebrated cats. Electrical epidural spinal cord stimulation was used to evoke forward and backward locomotion on a treadmill belt. The functional state of the bilateral spinal networks was tuned by symmetrical and asymmetrical epidural stimulation. A significant deficit in the backward but not forward stepping was observed when laterally shifted epidural stimulation was used but was not observed with central stimulation: only half of the cats were able to perform bilateral stepping, but all the cats performed forward stepping. This difference was in accordance with the features of stepping during central epidural stimulation. Both the recruitability and stability of the EMG signals as well as inter-limb coordination during backward stepping were significantly decreased compared to those during forward stepping. The possible underlying neural mechanisms of the obtained functional differences of backward and forward locomotion (spinal network organisation, commissural communication, and supraspinal influence) are discussed.
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Affiliation(s)
| | | | - Oleg Gorskii
- Pavlov Institute of Physiology, 199034 St. Petersburg, Russia.,Institute of Translational Biomedicine, St. Petersburg State University, 199034 St. Petersburg, Russia
| | - Pavel Musienko
- Pavlov Institute of Physiology, 199034 St. Petersburg, Russia.,Institute of Translational Biomedicine, St. Petersburg State University, 199034 St. Petersburg, Russia
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8
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Sato Y, Kondo T, Uchida A, Sato K, Yoshino-Saito K, Nakamura M, Okano H, Ushiba J. Preserved Intersegmental Coordination During Locomotion after Cervical Spinal Cord Injury in Common Marmosets. Behav Brain Res 2022; 425:113816. [DOI: 10.1016/j.bbr.2022.113816] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Revised: 02/21/2022] [Accepted: 02/22/2022] [Indexed: 11/27/2022]
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9
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Ahmed U, Karimi H, Amir S, Ahmed A. Effects of intensive multiplanar trunk training coupled with dual-task exercises on balance, mobility, and fall risk in patients with stroke: a randomized controlled trial. J Int Med Res 2021; 49:3000605211059413. [PMID: 34812070 PMCID: PMC8647262 DOI: 10.1177/03000605211059413] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
OBJECTIVE We determined whether an exercise regime comprising high-intensity training, multiplanar trunk movements, and dual-task practice could improve trunk control, balance, functional mobility, and reduce fall risk in patients with hemiplegic stroke. METHODS In this randomized controlled trial, 74 patients (mean age 61.71 years) were randomly assigned to the experimental and comparison groups. Primary outcome was trunk impairment scale (TIS) scores. Secondary outcomes were scores on the Berg balance scale, 10-meter walk test, Timed-up-and-go test, timed-Up-Go-cognitive, and Stroke Impact Scale-16 to measure between-group changes from baseline. We used linear mixed modeling to identify changes over time within and between groups on each scale and whether changes persisted at 6- and 12-month follow-ups. RESULTS We observed significantly increased mean TIS scores from baseline to 3 months post-treatment (7.74); the increased scores were maintained at 6- and 12-month follow-ups (8.60 and 8.43, respectively). In the experimental group, all secondary outcomes showed significant and clinically meaningful results. Fall risk between groups was significantly reduced at 6 and 12 months. CONCLUSIONS Intensive multiplanar trunk movements coupled with dual-task practice promoted trunk control, balance, and functional recovery in patients with stroke, reduced fall risk, and improved independent mobility.Trial registration: #IRCT20200127046275N1.
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Affiliation(s)
- Umair Ahmed
- University Institute of Physical Therapy, University of Lahore, Lahore, Pakistan
| | - Hossein Karimi
- University Institute of Physical Therapy, University of Lahore, Lahore, Pakistan.,Istanbul Gelisim University, Istanbul, Turkey
| | - Syed Amir
- Istanbul Gelisim University, Istanbul, Turkey
| | - Ashfaq Ahmed
- University Institute of Physical Therapy, University of Lahore, Lahore, Pakistan.,Allied Health Sciences, The University of Lahore, Lahore, Pakistan
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10
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Siddiqui AM, Islam R, Cuellar CA, Silvernail JL, Knudsen B, Curley DE, Strickland T, Manske E, Suwan PT, Latypov T, Akhmetov N, Zhang S, Summer P, Nesbitt JJ, Chen BK, Grahn PJ, Madigan NN, Yaszemski MJ, Windebank AJ, Lavrov IA. Newly regenerated axons via scaffolds promote sub-lesional reorganization and motor recovery with epidural electrical stimulation. NPJ Regen Med 2021; 6:66. [PMID: 34671050 PMCID: PMC8528837 DOI: 10.1038/s41536-021-00176-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 08/31/2021] [Indexed: 01/10/2023] Open
Abstract
Here, we report the effect of newly regenerated axons via scaffolds on reorganization of spinal circuitry and restoration of motor functions with epidural electrical stimulation (EES). Motor recovery was evaluated for 7 weeks after spinal transection and following implantation with scaffolds seeded with neurotrophin producing Schwann cell and with rapamycin microspheres. Combined treatment with scaffolds and EES-enabled stepping led to functional improvement compared to groups with scaffold or EES, although, the number of axons across scaffolds was not different between groups. Re-transection through the scaffold at week 6 reduced EES-enabled stepping, still demonstrating better performance compared to the other groups. Greater synaptic reorganization in the presence of regenerated axons was found in group with combined therapy. These findings suggest that newly regenerated axons through cell-containing scaffolds with EES-enabled motor training reorganize the sub-lesional circuitry improving motor recovery, demonstrating that neuroregenerative and neuromodulatory therapies cumulatively enhancing motor function after complete SCI.
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Affiliation(s)
- Ahad M. Siddiqui
- grid.66875.3a0000 0004 0459 167XDepartment of Neurology, Mayo Clinic, Rochester, MN USA
| | - Riazul Islam
- grid.66875.3a0000 0004 0459 167XDepartment of Neurology, Mayo Clinic, Rochester, MN USA
| | - Carlos A. Cuellar
- grid.440977.90000 0004 0483 7094School of Sport Sciences, Universidad Anáhuac México, Campus Norte, Huixquilucan, State of Mexico Mexico
| | - Jodi L. Silvernail
- grid.66875.3a0000 0004 0459 167XDepartment of Neurology, Mayo Clinic, Rochester, MN USA
| | - Bruce Knudsen
- grid.66875.3a0000 0004 0459 167XDepartment of Neurologic Surgery, Mayo Clinic, Rochester, MN USA
| | - Dallece E. Curley
- grid.66875.3a0000 0004 0459 167XDepartment of Neurology, Mayo Clinic, Rochester, MN USA ,grid.40263.330000 0004 1936 9094Department of Neuroscience, Brown University, Providence, Rhode Island USA
| | - Tammy Strickland
- grid.9344.a0000 0004 0488 240XNational University of Ireland Gallway, Gallway, Ireland
| | - Emilee Manske
- grid.66875.3a0000 0004 0459 167XDepartment of Neurology, Mayo Clinic, Rochester, MN USA ,grid.421979.00000 0001 2158 754XDepartment of Neuroscience, Scripps College, Claremont, CA USA
| | | | - Timur Latypov
- grid.231844.80000 0004 0474 0428Division of Brain, Imaging, and Behaviour – Systems Neuroscience, Krembil Research Institute, Toronto Western Hospital, University Health Network, Toronto, ON Canada ,grid.17063.330000 0001 2157 2938Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, ON Canada
| | - Nafis Akhmetov
- grid.77268.3c0000 0004 0543 9688Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | - Shuya Zhang
- grid.66875.3a0000 0004 0459 167XDepartment of Neurology, Mayo Clinic, Rochester, MN USA
| | - Priska Summer
- Paracelsus Medical Private University, Salzburg, Austria
| | - Jarred J. Nesbitt
- grid.66875.3a0000 0004 0459 167XDepartment of Neurology, Mayo Clinic, Rochester, MN USA
| | - Bingkun K. Chen
- grid.66875.3a0000 0004 0459 167XDepartment of Neurology, Mayo Clinic, Rochester, MN USA
| | - Peter J. Grahn
- grid.66875.3a0000 0004 0459 167XDepartment of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, MN USA
| | - Nicolas N. Madigan
- grid.66875.3a0000 0004 0459 167XDepartment of Neurology, Mayo Clinic, Rochester, MN USA
| | - Michael J. Yaszemski
- grid.66875.3a0000 0004 0459 167XDepartment of Orthopedic Surgery, Mayo Clinic, Rochester, MN USA
| | - Anthony J. Windebank
- grid.66875.3a0000 0004 0459 167XDepartment of Neurology, Mayo Clinic, Rochester, MN USA
| | - Igor A. Lavrov
- grid.66875.3a0000 0004 0459 167XDepartment of Neurology, Mayo Clinic, Rochester, MN USA ,grid.77268.3c0000 0004 0543 9688Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia ,grid.66875.3a0000 0004 0459 167XDepartment of Biomedical Engineering, Mayo Clinic, Rochester, MN USA
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Edgerton VR, Hastings S, Gad PN. Engaging Spinal Networks to Mitigate Supraspinal Dysfunction After CP. Front Neurosci 2021; 15:643463. [PMID: 33912005 PMCID: PMC8072045 DOI: 10.3389/fnins.2021.643463] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 03/22/2021] [Indexed: 12/13/2022] Open
Abstract
Although children with cerebral palsy seem to have the neural networks necessary to generate most movements, they are markedly dysfunctional, largely attributable to abnormal patterns of muscle activation, often characterized as spasticity, largely reflecting a functionally abnormal spinal-supraspinal connectivity. While it is generally assumed that the etiologies of the disruptive functions associated with cerebral palsy can be attributed primarily to supraspinal networks, we propose that the more normal connectivity that persists between peripheral proprioception-cutaneous input to the spinal networks can be used to guide the reorganization of a more normal spinal-supraspinal connectivity. The level of plasticity necessary to achieve the required reorganization within and among different neural networks can be achieved with a combination of spinal neuromodulation and specific activity-dependent mechanisms. By engaging these two concepts, we hypothesize that bidirectional reorganization of proprioception-spinal cord-brain connectivity to higher levels of functionality can be achieved without invasive surgery.
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Affiliation(s)
- V Reggie Edgerton
- Department of Neurobiology, University of California, Los Angeles, Los Angeles, CA, United States.,Department of Neurosurgery, University of California, Los Angeles, Los Angeles, CA, United States.,Brain Research Institute, University of California, Los Angeles, Los Angeles, CA, United States.,Institut Guttmann, Hospital de Neurorehabilitació, Institut Universitari Adscrit a la Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Susan Hastings
- SH Pediatric Physical Therapy, San Jose, CA, United States
| | - Parag N Gad
- Department of Neurobiology, University of California, Los Angeles, Los Angeles, CA, United States.,Rancho Research Institute, Downey, CA, United States.,SpineX, Inc., Los Angeles, CA, United States
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12
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Machine learning classifies predictive kinematic features in a mouse model of neurodegeneration. Sci Rep 2021; 11:3950. [PMID: 33597593 PMCID: PMC7889656 DOI: 10.1038/s41598-021-82694-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Accepted: 01/21/2021] [Indexed: 01/31/2023] Open
Abstract
Motor deficits are observed in Alzheimer's disease (AD) prior to the appearance of cognitive symptoms. To investigate the role of amyloid proteins in gait disturbances, we characterized locomotion in APP-overexpressing transgenic J20 mice. We used three-dimensional motion capture to characterize quadrupedal locomotion on a treadmill in J20 and wild-type mice. Sixteen J20 mice and fifteen wild-type mice were studied at two ages (4- and 13-month). A random forest (RF) classification algorithm discriminated between the genotypes within each age group using a leave-one-out cross-validation. The balanced accuracy of the RF classification was 92.3 ± 5.2% and 93.3 ± 4.5% as well as False Negative Rate (FNR) of 0.0 ± 0.0% and 0.0 ± 0.0% for the 4-month and 13-month groups, respectively. Feature ranking algorithms identified kinematic features that when considered simultaneously, achieved high genotype classification accuracy. The identified features demonstrated an age-specific kinematic profile of the impact of APP-overexpression. Trunk tilt and unstable hip movement patterns were important in classifying the 4-month J20 mice, whereas patterns of shoulder and iliac crest movement were critical for classifying 13-month J20 mice. Examining multiple kinematic features of gait simultaneously could also be developed to classify motor disorders in humans.
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Pham BN, Luo J, Anand H, Kola O, Salcedo P, Nguyen C, Gaunt S, Zhong H, Garfinkel A, Tillakaratne N, Edgerton VR. Redundancy and multifunctionality among spinal locomotor networks. J Neurophysiol 2020; 124:1469-1479. [PMID: 32966757 DOI: 10.1152/jn.00338.2020] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
c-Fos is used to identify system-wide neural activation with cellular resolution in vivo. However, c-Fos can only capture neural activation of one event. Targeted recombination in active populations (TRAP) allows the capture of two different c-Fos activation patterns in the same animal. So far, TRAP has only been used to examine brain circuits. This study uses TRAP to investigate spinal circuit activation during resting and stepping, giving novel insights of network activation during these events. The level of colabeled (c-Fos+ and TRAP+) neurons observed after performing two bouts of stepping suggests that there is a probabilistic-like phenomenon that can recruit many combinations of neural populations (synapses) when repetitively generating many step cycles. Between two 30-min bouts of stepping, each consisting of thousands of steps, only ∼20% of the neurons activated from the first bout of stepping were also activated by the second bout. We also show colabeling of interneurons that have been active during stepping and resting. The use of the FosTRAP methodology in the spinal cord provides a new tool to compare the engagement of different populations of spinal interneurons in vivo under different motor tasks or under different conditions.NEW & NOTEWORTHY The results are consistent with there being an extensive amount of redundancy among spinal locomotor circuits. Using the newly developed FosTRAP mouse model, only ∼20% of neurons that were active (labeled by Fos-linked tdTomato expression) during a first bout of 30-min stepping were also labeled for c-Fos during a second bout of stepping. This finding suggests variability of neural networks that enables selection of many combinations of neurons (synapses) when generating each step cycle.
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Affiliation(s)
- Bau N Pham
- Department of Bioengineering, University of California, Los Angeles, California
| | - Jiangyuan Luo
- Department of Neuroscience, University of California, Los Angeles, California
| | - Harnadar Anand
- Institute for Society and Genetics, University of California, Los Angeles, California
| | - Olivia Kola
- Department of Neuroscience, University of California, Los Angeles, California
| | - Pia Salcedo
- Department of Psychobiology, University of California, Los Angeles, California
| | - Connie Nguyen
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California
| | - Sarah Gaunt
- Department of Molecular Cellular and Developmental Biology, University of California, Los Angeles, California
| | - Hui Zhong
- Department of Integrative Biology and Physiology, University of California, Los Angeles, California
| | - Alan Garfinkel
- Department of Integrative Biology and Physiology, University of California, Los Angeles, California
| | - Niranjala Tillakaratne
- Department of Integrative Biology and Physiology, University of California, Los Angeles, California.,Brain Research Institute, University of California, Los Angeles, California
| | - V Reggie Edgerton
- Department of Integrative Biology and Physiology, University of California, Los Angeles, California.,Brain Research Institute, University of California, Los Angeles, California.,Department of Neurobiology, University of California, Los Angeles, California.,Department of Neurosurgery, University of California, Los Angeles, California.,Institut Guttmann, Hospital de Neurorehabilitació, Universitat Autònoma de Barcelona, Badalona, Spain.,Centre for Neuroscience and Regenerative Medicine, Faculty of Science, University of Technology Sydney, Ultimo, Australia
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14
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Jack AS, Hurd C, Martin J, Fouad K. Electrical Stimulation as a Tool to Promote Plasticity of the Injured Spinal Cord. J Neurotrauma 2020; 37:1933-1953. [PMID: 32438858 DOI: 10.1089/neu.2020.7033] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Unlike their peripheral nervous system counterparts, the capacity of central nervous system neurons and axons for regeneration after injury is minimal. Although a myriad of therapies (and different combinations thereof) to help promote repair and recovery after spinal cord injury (SCI) have been trialed, few have progressed from bench-top to bedside. One of the few such therapies that has been successfully translated from basic science to clinical applications is electrical stimulation (ES). Although the use and study of ES in peripheral nerve growth dates back nearly a century, only recently has it started to be used in a clinical setting. Since those initial experiments and seminal publications, the application of ES to restore function and promote healing have greatly expanded. In this review, we discuss the progression and use of ES over time as it pertains to promoting axonal outgrowth and functional recovery post-SCI. In doing so, we consider four major uses for the study of ES based on the proposed or documented underlying mechanism: (1) using ES to introduce an electric field at the site of injury to promote axonal outgrowth and plasticity; (2) using spinal cord ES to activate or to increase the excitability of neuronal networks below the injury; (3) using motor cortex ES to promote corticospinal tract axonal outgrowth and plasticity; and (4) leveraging the timing of paired stimuli to produce plasticity. Finally, the use of ES in its current state in the context of human SCI studies is discussed, in addition to ongoing research and current knowledge gaps, to highlight the direction of future studies for this therapeutic modality.
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Affiliation(s)
- Andrew S Jack
- Department of Neurological Surgery, University of California San Francisco (UCSF), San Francisco, California, USA
| | - Caitlin Hurd
- Department of Physical Therapy, Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - John Martin
- Department of Molecular, Cellular, and Biomedical Sciences, City University of New York School of Medicine, and City University of New York Graduate Center, New York, New York, USA
| | - Karim Fouad
- Department of Physical Therapy, Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Alberta, Canada.,Neuroscience and Mental Health Institute, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
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15
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Panchal NK, Sabina EP. A serine/threonine protein PIM kinase as a biomarker of cancer and a target for anti-tumor therapy. Life Sci 2020; 255:117866. [PMID: 32479955 DOI: 10.1016/j.lfs.2020.117866] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 05/26/2020] [Accepted: 05/27/2020] [Indexed: 01/04/2023]
Abstract
The PIM Kinases belong to the family of a proto-oncogene that essentially phosphorylates the serine/threonine residues of the target proteins. They are primarily categorized into three types PIM-1, PIM-2, PIM-3 which plays an indispensable regulatory role in signal transduction cascades, by promoting cell survival, proliferation, and drug resistance. These kinases are overexpressed in several solid as well as hematopoietic tumors which supports in vitro and in vivo malignant cell growth along with survival by regulating cell cycle and inhibiting apoptosis. They lack regulatory domain which makes them constitutively active once transcribed. PIM kinases usually appear to be important downstream effectors of oncoproteins which overexpresses and helps in mediating drug resistance to available agents, such as rapamycin. Structural studies of PIM kinases revealed that they have unique hinge regions where two Proline resides and makes ATP binding unique, by offering a target for an increasing number of potent PIM kinase inhibitors. Preclinical studies of those inhibitory compounds in various cancers indicate that these novel agents show promising activity and some of them currently being under examination. In this review, we have outlined PIM kinases molecular mechanism and signaling pathways along with matriculation in various cancer and list of inhibitors often used.
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Affiliation(s)
- Nagesh Kishan Panchal
- Department of Biomedical Sciences, School of Biosciences and Technology, Vellore Institute of Technology, Vellore, India
| | - E P Sabina
- Department of Biomedical Sciences, School of Biosciences and Technology, Vellore Institute of Technology, Vellore, India.
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16
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Doperalski AE, Montgomery LR, Mondello SE, Howland DR. Anatomical Plasticity of Rostrally Terminating Axons as a Possible Bridging Substrate across a Spinal Injury. J Neurotrauma 2020; 37:877-888. [PMID: 31774025 DOI: 10.1089/neu.2018.6193] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Transfer of information across a spinal lesion is required for many aspects of recovery across diverse motor systems. Our understanding of axonal plasticity and which subpopulations of neurons may contribute to bridging substrates following injury, however, remains relatively incomplete. Most recently, attention has been directed to propriospinal neurons (PSNs), with research suggesting that they are capable of bridging a spinal lesion in rodents. In the current study, subpopulations of both long (C5) and short (T6, T8) PSNs-as well as a supraspinal system, the rubrospinal tract (RST)-were assessed following low thoracic (T9) hemisection in the cat using the retrograde tracer Fluoro-Gold. Acutely, within 2 weeks post-hemisection, the numbers of short and long PSNs, as well as contralateral RST neurons, with axons crossing the lesion were significantly decreased relative to uninjured controls. This decrease persisted bilaterally and was permanent in the long PSNs and the contralateral red nucleus (RN). However, by 16 weeks post-hemisection, the numbers of ipsilesional and contralesional short PSNs bridging the lesion were significantly increased. Further, the number of contralesional contributing short PSNs was significantly greater in injured animals than in uninjured animals. A significant increase over uninjured numbers also was seen in the ipsilateral (non-axotomized) RN. These findings suggest that a novel substrate of undamaged axons, which normally terminates rostral to the lesion, grows past a thoracic lesion after injury. This rostral population represents a major component of the bridging substrate seen and may represent an important anatomical target for evolving rehabilitation approaches as a substrate capable of contributing to functional recovery.
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Affiliation(s)
- Adele E Doperalski
- Department of Biology, American University, Washington DC.,Department of Neuroscience, University of Florida, Gainesville, Florida.,Malcom Randall VA Medical Center, Gainesville, Florida
| | - Lynnette R Montgomery
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky.,Department of Neurological Surgery, University of Louisville, Louisville, Kentucky.,Robley Rex VA Medical Center, Louisville, Kentucky
| | - Sarah E Mondello
- Department of Neuroscience, University of Florida, Gainesville, Florida.,Malcom Randall VA Medical Center, Gainesville, Florida.,Department of Rehabilitation Medicine, University of Washington, Seattle, Washington
| | - Dena R Howland
- Department of Neuroscience, University of Florida, Gainesville, Florida.,Malcom Randall VA Medical Center, Gainesville, Florida.,Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky.,Department of Neurological Surgery, University of Louisville, Louisville, Kentucky.,Robley Rex VA Medical Center, Louisville, Kentucky
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17
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Goel SA, Varghese V, Demir T. Animal models of spinal injury for studying back pain and SCI. J Clin Orthop Trauma 2020; 11:816-821. [PMID: 32904094 PMCID: PMC7452356 DOI: 10.1016/j.jcot.2020.07.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 06/30/2020] [Accepted: 07/05/2020] [Indexed: 11/20/2022] Open
Abstract
INTRODUCTION Back pain is a common ailment affecting individuals around the globe. Animal models to understand the back pain mechanism, treatment modalities, and spinal cord injury are widely researched topics worldwide. Despite the presence of several animal models on disc degeneration and Spinal Cord Injury, there is a lack of a comprehensive review. MATERIAL AND METHOD A methodological narrative literature review was carried out for the study. A total of 1273 publications were found, out of which 763 were related to spine surgery in animals. The literature with full-text availability was selected for the review. Scale for the Assessment of Narrative Review Articles (SANRA) guidelines was used to assess the studies. Only English language publications were included which were listed on PubMed. A total of 113 studies were shortlisted (1976-2019) after internal validation scoring. RESULT The animal models for spine surgery ranged from rodents to primates. These are used to study the mechanisms of back pain as well as spinal cord injuries. The models could either be created surgically or through various means like use of electric cautery, chemicals or trauma. Genetic spine models have also been documented in which the injuries are created by genetic alterations and knock outs. Though the dorsal approach is the most common, the literature also mentions the anterior and lateral approach for spine surgery animal experiments. CONCLUSION There are no single perfect animal models to represent and study human models. The selection is based on the application and the methodology. Careful selection is needed to give optimum and appropriate results.
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Affiliation(s)
- Shakti A. Goel
- Indian Spinal Injuries Centre, Vasant Kunj, New Delhi, 110070, India
- Corresponding author.
| | - Vicky Varghese
- TOBB Economics, and Technology University Mechanical Engineering Department.Ankara, Turkey
| | - Tyfik Demir
- Department of Neurosurgery, Medical College of Wisconsin, WI, USA
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18
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Islam R, Cuellar CA, Felmlee B, Riccelli T, Silvernail J, Boschen SL, Grahn P, Lavrov I. Multifactorial motor behavior assessment for real-time evaluation of emerging therapeutics to treat neurologic impairments. Sci Rep 2019; 9:16503. [PMID: 31712725 PMCID: PMC6848091 DOI: 10.1038/s41598-019-52806-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 10/15/2019] [Indexed: 12/31/2022] Open
Abstract
Integrating multiple assessment parameters of motor behavior is critical for understanding neural activity dynamics during motor control in both intact and dysfunctional nervous systems. Here, we described a novel approach (termed Multifactorial Behavioral Assessment (MfBA)) to integrate, in real-time, electrophysiological and biomechanical properties of rodent spinal sensorimotor network activity with behavioral aspects of motor task performance. Specifically, the MfBA simultaneously records limb kinematics, multi-directional forces and electrophysiological metrics, such as high-fidelity chronic intramuscular electromyography synchronized in time to spinal stimulation in order to characterize spinal cord functional motor evoked potentials (fMEPs). Additionally, we designed the MfBA to incorporate a body weight support system to allow bipedal and quadrupedal stepping on a treadmill and in an open field environment to assess function in rodent models of neurologic disorders that impact motor activity. This novel approach was validated using, a neurologically intact cohort, a cohort with unilateral Parkinsonian motor deficits due to midbrain lesioning, and a cohort with complete hind limb paralysis due to T8 spinal cord transection. In the SCI cohort, lumbosacral epidural electrical stimulation (EES) was applied, with and without administration of the serotonergic agonist Quipazine, to enable hind limb motor functions following paralysis. The results presented herein demonstrate the MfBA is capable of integrating multiple metrics of motor activity in order to characterize relationships between EES inputs that modulate mono- and polysynaptic outputs from spinal circuitry which in turn, can be used to elucidate underlying electrophysiologic mechanisms of motor behavior. These results also demonstrate that proposed MfBA is an effective tool to integrate biomechanical and electrophysiology metrics, synchronized to therapeutic inputs such as EES or pharmacology, during body weight supported treadmill or open field motor activities, to target a high range of variations in motor behavior as a result of neurological deficit at the different levels of CNS.
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Affiliation(s)
- Riazul Islam
- Department of Neurology, Mayo Clinic, Rochester, MN, USA
| | - Carlos A Cuellar
- Centro de Investigación en Ciencias de la Salud (CICSA), Universidad Anáhuac México, Campus Norte, Huixquilucan, State of Mexico, Mexico
| | - Ben Felmlee
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, USA
| | | | | | | | - Peter Grahn
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, USA
- Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, MN, USA
| | - Igor Lavrov
- Department of Neurology, Mayo Clinic, Rochester, MN, USA.
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, USA.
- Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia.
- Department of Biomedical Engineering, Mayo Clinic, Rochester, MN, USA.
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19
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Vemula MG, Deliagina TG, Zelenin PV. Kinematics of forward and backward locomotion performed in different environmental conditions. J Neurophysiol 2019; 122:2142-2155. [PMID: 31596639 DOI: 10.1152/jn.00239.2019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Mice are frequently used in analyses of the locomotor system. Although forward locomotion (FWL) in intact mice has been studied previously, backward locomotion (BWL) in mice has never been analyzed. The aim of the present study was to compare kinematics of FWL and BWL performed in different environmental conditions (i.e., in a tunnel, on a treadmill, and on an air-ball). In all setups, the average speed and step amplitude during BWL were significantly reduced compared with FWL. The cycle duration varied greatly during both FWL and BWL. The average swing duration during BWL was twice shorter than during FWL on each setup. Mice exhibited different interlimb coordinations (trot and walk with lateral or diagonal sequence) during BWL but only one gait (walk with lateral sequence) during FWL. Location of the rostro-caudal paw trajectory in relation to the hip projection to the surface (HP) depended on hip height. With low hip height, the trajectory was displaced either rostrally (anterior steps) or caudally (posterior steps) to HP. With high hip height, HP was near the middle of the trajectory (middle steps). During FWL, all three forms of steps were observed in the tunnel and predominantly anterior and posterior steps on the treadmill and air-ball, respectively. During BWL, only anterior steps were observed. Intralimb coordination depended on the form of stepping. Limb joints were coordinated to keep the hip at approximately constant height during stance and to have the smallest functional limb length during swing when the limb passed under the hip.NEW & NOTEWORTHY Mice are extensively used for the analysis of the locomotor system. This study is the first examination of the kinematics of forward and backward locomotor movements in different environmental conditions in mice. Obtained results represent a benchmark for studies based on manipulations of activity of specific populations of neurons to reveal their roles in control of specific aspects of locomotion.
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Affiliation(s)
| | | | - Pavel V Zelenin
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
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20
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Richards TM, Sharma P, Kuang A, Whitty D, Ahmed Z, Shah PK. Novel Speed-Controlled Automated Ladder Walking Device Reveals Walking Speed as a Critical Determinant of Skilled Locomotion after a Spinal Cord Injury in Adult Rats. J Neurotrauma 2019; 36:2698-2721. [DOI: 10.1089/neu.2018.6152] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Affiliation(s)
- Tiffany M. Richards
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, New York
| | - Pawan Sharma
- Department of Physical Therapy, Stony Brook University, Stony Brook, New York
| | - Aaron Kuang
- Department of Physical Therapy, Stony Brook University, Stony Brook, New York
| | - Douglas Whitty
- Department of Physical Therapy, Stony Brook University, Stony Brook, New York
| | - Zaghloul Ahmed
- Department of Physical Therapy, Center for Developmental Neuroscience, The College of Staten Island, Staten Island, New York
- Graduate Center, City University of New York, New York, New York
| | - Prithvi K. Shah
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, New York
- Department of Physical Therapy, Stony Brook University, Stony Brook, New York
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21
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High-Intensity Variable Stepping Training in Patients With Motor Incomplete Spinal Cord Injury: A Case Series. J Neurol Phys Ther 2019; 42:94-101. [PMID: 29547484 DOI: 10.1097/npt.0000000000000217] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND AND PURPOSE Previous data suggest that large amounts of high-intensity stepping training in variable contexts (tasks and environments) may improve locomotor function, aerobic capacity, and treadmill gait kinematics in individuals poststroke. Whether similar training strategies are tolerated and efficacious for patients with other acute-onset neurological diagnoses, such as motor incomplete spinal cord injury (iSCI), is unknown. Individuals with iSCI potentially have greater bilateral impairments. This case series evaluated the feasibility and preliminary short- and long-term efficacy of high-intensity variable stepping practice in ambulatory participants for more than 1 year post-iSCI. CASE SERIES DESCRIPTION Four participants with iSCI (neurological levels C5-T3) completed up to 40 one-hour sessions over 3 to 4 months. Stepping training in variable contexts was performed at up to 85% maximum predicted heart rate, with feasibility measures of patient tolerance, total steps/session, and intensity of training. Clinical measures of locomotor function, balance, peak metabolic capacity, and gait kinematics during graded treadmill assessments were performed at baseline and posttraining, with more than 1-year follow-up. OUTCOMES Participants completed 24 to 40 sessions over 8 to 15 weeks, averaging 2222 ± 653 steps per session, with primary adverse events of fatigue and muscle soreness. Modest improvements in locomotor capacity where observed at posttraining, with variable changes in lower extremity kinematics during treadmill walking. DISCUSSION High-intensity, variable stepping training was feasible and tolerated by participants with iSCI although only modest gains in gait function or quality were observed. The utility of this intervention in patients with more profound impairments may be limited.Video Abstract available for more insights from the authors (see Video, Supplemental Digital Content 1, http://links.lww.com/JNPT/A200).
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22
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Becker M, Parker D. Time course of functional changes in locomotor and sensory systems after spinal cord lesions in lamprey. J Neurophysiol 2019; 121:2323-2335. [DOI: 10.1152/jn.00120.2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Changes in motor and sensory properties occur either side of spinal cord lesion sites from lower vertebrates to humans. We have previously examined these changes in the lamprey, a model system for studying recovery after spinal cord injury. These analyses were performed 8–12 wk after complete spinal cord lesions, a time when most animals have recovered good locomotor function. However, anatomical analyses have been performed at earlier and later times than this. Because there have been no functional studies at these times, in this study we have examined changes between 2 and 24+ wk after lesioning. Functional changes developed at different times in different regions of the spinal cord. Spinal cord excitability was significantly reduced above and below the lesion site less than 6 wk after lesioning but showed variable region-specific changes at later times. Excitatory synaptic inputs to motor neurons were increased above the lesion site during the recovery phase (2–8 wk after lesioning) but only increased below the lesion site once recovery had occurred (8 wk and later). These synaptic effects were associated with lesion-induced changes in connectivity between premotor excitatory interneurons. Sensory inputs were potentiated at 8 wk and later after lesioning but were markedly reduced at earlier times. There are thus time- and region-specific changes in motor and sensory properties above and below the lesion site. Although animals typically recover good locomotor function by 8 wk, there were further changes at 24+ wk. With the assumption that these changes can help to compensate for the reduced descending input to the spinal cord, effects at later times may reflect ongoing modifications as regeneration continues. NEW & NOTEWORTHY The lamprey is a model system for studying functional recovery and regeneration after spinal cord injury. We show that changes in spinal cord excitability and sensory inputs develop at different times above and below the lesion site during recovery. These changes may occur in response to the lesion-induced removal of descending inputs and may subsequently help to compensate for the reduction of the descending drive to allow locomotor recovery. Changes also continue once animals have recovered locomotor function, potentially reflecting adaptations to further regeneration at later recovery times.
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Affiliation(s)
- Matthew Becker
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - David Parker
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
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23
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Motor primitives are determined in early development and are then robustly conserved into adulthood. Proc Natl Acad Sci U S A 2019; 116:12025-12034. [PMID: 31138689 DOI: 10.1073/pnas.1821455116] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Motor patterns in legged vertebrates show modularity in both young and adult animals, comprising motor synergies or primitives. Are such spinal modules observed in young mammals conserved into adulthood or altered? Conceivably, early circuit modules alter radically through experience and descending pathways' activity. We analyze lumbar motor patterns of intact adult rats and the same rats after spinal transection and compare these with adult rats spinal transected 5 days postnatally, before most motor experience, using only rats that never developed hind limb weight bearing. We use independent component analysis (ICA) to extract synergies from electromyography (EMG). ICA information-based methods identify both weakly active and strongly active synergies. We compare all spatial synergies and their activation/drive strengths as proxies of spinal modules and their underlying circuits. Remarkably, we find that spatial primitives/synergies of adult injured and neonatal injured rats differed insignificantly, despite different developmental histories. However, intact rats possess some synergies that differ significantly, although modestly, in spatial structure. Rats injured as adults were more similar in modularity to rats that had neonatal spinal transection than to themselves before injury. We surmise that spinal circuit modules for spatial synergy patterns may be determined early, before postnatal day 5 (P5), and remain largely unaltered by subsequent development or weight-bearing experience. An alternative explanation but equally important is that, after complete spinal transection, both neonatal and mature adult spinal cords rapidly converge to common synergy sets. This fundamental or convergent synergy circuitry, fully determined by P5, is revealed after spinal cord transection.
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24
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Spinal Cord Epidural Stimulation for Lower Limb Motor Function Recovery in Individuals with Motor Complete Spinal Cord Injury. Phys Med Rehabil Clin N Am 2019; 30:337-354. [DOI: 10.1016/j.pmr.2018.12.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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25
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Gerasimenko Y, Preston C, Zhong H, Roy RR, Edgerton VR, Shah PK. Rostral lumbar segments are the key controllers of hindlimb locomotor rhythmicity in the adult spinal rat. J Neurophysiol 2019; 122:585-600. [PMID: 30943092 DOI: 10.1152/jn.00810.2018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The precise location and functional organization of the spinal neuronal locomotor-related networks in adult mammals remain unclear. Our recent neurophysiological findings provided empirical evidence that the rostral lumbar spinal cord segments play a critical role in the initiation and generation of the rhythmic activation patterns necessary for hindlimb locomotion in adult spinal rats. Since added epidural stimulation at the S1 segments significantly enhanced the motor output generated by L2 stimulation, these data also suggested that the sacral spinal cord provides a strong facilitory influence in rhythm initiation and generation. However, whether L2 will initiate hindlimb locomotion in the absence of S1 segments, and whether S1 segments can facilitate locomotion in the absence of L2 segments remain unknown. Herein, adult rats received complete spinal cord transections at T8 and then at either L2 or S1. Rats with spinal cord transections at T8 and S1 remained capable of generating coordinated hindlimb locomotion when receiving epidural stimulation at L2 and when ensembles of locomotor related loadbearing input were present. In contrast, minimal locomotion was observed when S1 stimulation was delivered after spinal cord transections at T8 and L2. Results were similar when the nonspecific serotonergic agonists were administered. These results demonstrate in adult rats that rostral lumbar segments are essential for the regulation of hindlimb locomotor rhythmicity. In addition, the more caudal spinal networks alone cannot control locomotion in the absence of the rostral segments around L2 even when loadbearing rhythmic proprioceptive afferent input is imposed.NEW & NOTEWORTHY The exact location of the spinal neuronal locomotor-related networks in adult mammals remains unknown. The present data demonstrate that when the rostral lumbar spinal segments (~L2) are completely eliminated in thoracic spinal adult rats, hindlimb stepping is not possible with neurochemical modulation of the lumbosacral cord. In contrast, eliminating the sacral cord retains stepping ability. These observations highlight the importance of rostral lumbar segments in generating effective mammalian locomotion.
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Affiliation(s)
- Yury Gerasimenko
- Pavlov Institute of Physiology, Russian Academy of Sciences, St. Petersburg, Russia.,Department of Integrative Biology and Physiology, University of California, Los Angeles, California
| | - Chet Preston
- Department of Physical Therapy, School of Health Technology and Management, Stony Brook University, Stony Brook, New York
| | - Hui Zhong
- Department of Integrative Biology and Physiology, University of California, Los Angeles, California
| | - Roland R Roy
- Department of Integrative Biology and Physiology, University of California, Los Angeles, California
| | - V Reggie Edgerton
- Department of Integrative Biology and Physiology, University of California, Los Angeles, California.,Department of Neurobiology, David Geffen School of Medicine at University of California, Los Angeles, California.,Department of Neurosurgery, David Geffen School of Medicine at University of California, Los Angeles, California.,Brain Research Institute, University of California, Los Angeles, California.,Institute Guttmann. Hospital de Neurorehabilitació, Institut Universitari Adscrit a la Universitat Autònoma de Barcelona, Badalona, Spain.,Centre for Neuroscience and Regenerative Medicine, Faculty of Science, University of Technology Sydney, Ultimo, New South Wales, Australia.,Department of Neurology, David Geffen School of Medicine at University of California, Los Angeles, California
| | - Prithvi K Shah
- Department of Physical Therapy, School of Health Technology and Management, Stony Brook University, Stony Brook, New York.,Department of Neurobiology, Stony Brook University, Stony Brook, New York
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26
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Ahmed RU, Alam M, Zheng YP. Experimental spinal cord injury and behavioral tests in laboratory rats. Heliyon 2019; 5:e01324. [PMID: 30906898 PMCID: PMC6411514 DOI: 10.1016/j.heliyon.2019.e01324] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 11/01/2018] [Accepted: 03/04/2019] [Indexed: 12/15/2022] Open
Abstract
Traumatic spinal cord injury (SCI) results in some serious neurophysiological consequences that alter healthy body functions and devastate the quality of living of individuals. To find a cure for SCI, researchers around the world are working on different neurorepair and neurorehabilitation modalities. To test a new treatment for SCI as well as to understand the mechanism of recovery, animal models are being widely used. Among them, SCI rat models are arguably the most prominent. Furthermore, it is important to select a suitable behavioral test to evaluate both the motor and sensory recovery following any therapeutic intervention. In this paper, we review the rat models of spinal injury and commonly used behavioral tests to serve as a useful guideline for neuroscientists in the field of SCI research.
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Affiliation(s)
- Rakib Uddin Ahmed
- Department of Biomedical Engineering, The Hong Kong Polytechnic University, Hong Kong
| | - Monzurul Alam
- Department of Biomedical Engineering, The Hong Kong Polytechnic University, Hong Kong
| | - Yong-Ping Zheng
- Department of Biomedical Engineering, The Hong Kong Polytechnic University, Hong Kong
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Calvert JS, Grahn PJ, Zhao KD, Lee KH. Emergence of Epidural Electrical Stimulation to Facilitate Sensorimotor Network Functionality After Spinal Cord Injury. Neuromodulation 2019; 22:244-252. [PMID: 30840354 DOI: 10.1111/ner.12938] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 01/15/2019] [Accepted: 01/19/2019] [Indexed: 02/06/2023]
Abstract
BACKGROUND Traumatic spinal cord injury (SCI) disrupts signaling pathways between the brain and spinal networks below the level of injury. In cases of severe SCI, permanent loss of sensorimotor and autonomic function can occur. The standard of care for severe SCI uses compensation strategies to maximize independence during activities of daily living while living with chronic SCI-related dysfunctions. Over the past several years, the research field of spinal neuromodulation has generated promising results that hold potential to enable recovery of functions via epidural electrical stimulation (EES). METHODS This review provides a historical account of the translational research efforts that led to the emergence of EES of the spinal cord to enable intentional control of motor functions that were lost after SCI. We also highlight the major limitations associated with EES after SCI and propose future directions of spinal neuromodulation research. RESULTS Multiple, independent studies have demonstrated return of motor function via EES in individuals with chronic SCI. These enabled motor functions include intentional, controlled movement of previously paralyzed extremities, independent standing and stepping, and increased grip strength. In addition, improvements in cardiovascular health, respiratory function, body composition, and urologic function have been reported. CONCLUSIONS EES holds promise to enable functions thought to be permanently lost due to SCI. However, EES is currently restricted to scientific investigation in humans with SCI and requires further validation of factors such as safety and efficacy before clinical translation.
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Affiliation(s)
| | - Peter J Grahn
- Department of Neurologic Surgery, Rochester, MN, USA.,Department of Physical Medicine and Rehabilitation, Rehabilitation Medicine Research Center, Rochester, MN, USA
| | - Kristin D Zhao
- Department of Physical Medicine and Rehabilitation, Rehabilitation Medicine Research Center, Rochester, MN, USA.,Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
| | - Kendall H Lee
- Department of Neurologic Surgery, Rochester, MN, USA.,Department of Physical Medicine and Rehabilitation, Rehabilitation Medicine Research Center, Rochester, MN, USA.,Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
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Deliagina TG, Musienko PE, Zelenin PV. Nervous mechanisms of locomotion in different directions. CURRENT OPINION IN PHYSIOLOGY 2018; 8:7-13. [PMID: 31468024 DOI: 10.1016/j.cophys.2018.11.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Locomotion, that is active propulsive movement of the body in space, is a vital motor function. Intensive studies of the main, for the majority of living beings, form of locomotion, forward locomotion, have revealed essential features of the organization and operation of underlying neural mechanisms. However, animals and humans are capable to locomote not only forward but also in other directions in relation to the body axis, e.g. backward, sideways, etc. Single steps in different directions are also used for postural corrections during locomotion and during standing. Recent studies of mechanisms underlying control of locomotion in different directions have greatly expanded our knowledge about locomotor system and can contribute to improvement of rehabilitation strategies aimed at restoration of locomotion and balance control in patients. This review outlines recent advances in the studies of locomotion in different directions in lower and higher vertebrates, with special attention given to the neuronal locomotor mechanisms.
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Affiliation(s)
- Tatiana G Deliagina
- Department of Neuroscience, Karolinska Institute, SE-17177, Stockholm, Sweden
| | - Pavel E Musienko
- Institute of Translational Biomedicine, St. Petersburg State University, 199034 St. Petersburg, Russia
- Pavlov Institute of Physiology, 199034 St. Petersburg, Russia
- Russian Research Center of Radiology and Surgical Technologies, Ministry of Healthcare of the RF, 197758 St. Petersburg, Russia
| | - Pavel V Zelenin
- Department of Neuroscience, Karolinska Institute, SE-17177, Stockholm, Sweden
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29
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Gradual increase of perturbation load induces a longer retention of locomotor adaptation in children with cerebral palsy. Hum Mov Sci 2018; 63:20-33. [PMID: 30481722 DOI: 10.1016/j.humov.2018.11.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 11/15/2018] [Accepted: 11/20/2018] [Indexed: 11/22/2022]
Abstract
The goal of this study is to determine whether the size and the variability of error have an impact on the retention of locomotor adaptation in children with cerebral palsy (CP). Eleven children with CP, aged 7-16 years old, were recruited to participate in this study. Three types of force perturbations (i.e., abrupt, gradual and noisy loads) were applied to the right leg above the ankle starting from late stance to mid-swing in three test sessions while the subject walked on a treadmill. Spatial-temporal gait parameters were recorded using a custom designed 3D position sensor during treadmill walking. We observed that children with CP adapted to the resistance force perturbation and showed an aftereffect consisting of increased step length after load release. Further, we observed a longer retention of the aftereffect for the condition with a gradual load than that with an abrupt load. Results from this study suggested that the size of error might have an impact on the retention of motor adaptation in children with CP with a longer retention of motor adaptation for the condition with a small size of error than that with a large error. In addition, enhanced variability of error seems facilitate motor learning during treadmill training. Results from this study may be used for the development of force perturbation based training paradigms for improving walking function in children with CP.
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30
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Spiess MR, Steenbrink F, Esquenazi A. Getting the Best Out of Advanced Rehabilitation Technology for the Lower Limbs: Minding Motor Learning Principles. PM R 2018; 10:S165-S173. [PMID: 30269803 DOI: 10.1016/j.pmrj.2018.06.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 06/04/2018] [Accepted: 06/09/2018] [Indexed: 01/12/2023]
Abstract
Advanced technology, including gait-training devices, is increasingly being integrated into neurorehabilitation. However, to use gait-training devices to their optimal potential, it is important that they are applied in accordance with motor learning and locomotor training principles. In this article, we outline the most important principles and explain how advanced gait-training devices are best used to improve therapy outcome.
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31
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Neuromodulation of lumbosacral spinal networks enables independent stepping after complete paraplegia. Nat Med 2018; 24:1677-1682. [DOI: 10.1038/s41591-018-0175-7] [Citation(s) in RCA: 274] [Impact Index Per Article: 45.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 08/03/2018] [Indexed: 11/08/2022]
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32
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Rascoe A, Sharma P, Shah PK. Development of an Activity-Dependent Epidural Stimulation System in Freely Moving Spinal Cord Injured Rats: A Proof of Concept Study. Front Neurosci 2018; 12:472. [PMID: 30083089 PMCID: PMC6064745 DOI: 10.3389/fnins.2018.00472] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2017] [Accepted: 06/21/2018] [Indexed: 11/13/2022] Open
Abstract
Purpose: Extensive pre-clinical and clinical experimentation has yielded data on the robustness and versatility of epidural stimulation (ES) strategies to activate spinal neural circuitry to produce functional benefits. Increasing studies are now reporting that closed-loop electrical stimulation delivery methods significantly enhance the neuromodulation effects of stimulation, to in turn, improve physiological outcomes of the intervention. No studies have yet explored the feasibility and usage of closed-loop systems to neuromodulate the cervical spinal cord using ES. Methods: We developed an activity-dependent system that utilizes electromyography (EMG) activity to trigger epidural stimulation (tES) of the cervical spinal cord in awake, freely moving rats. Experiments were performed on rats that were implanted with chronic forelimb EMG and cervical epidural implants, with (n = 7) and without (n = 2) a complete C4 spinal hemisection. Results: Our results show that the EMG triggered activity-dependent system can be reliably applied and reproduced for: (i) stimulating multiple rats simultaneously throughout the night during free home-cage activity and (ii) use as a mobile system for testing and training during various short-term behavioral testing conditions. The system was able to consistently generate stimulation pulse trains in response to attempted EMG activity that crossed a user-defined threshold in all rats for all experiments, including the overnight experiments that lasts for 7 h/session for 6 days/week through the 3-month period. Conclusion: The developed closed-loop system can be considered to represent a class of bidirectional neural prostheses via a circuit that enables two-way interactions between neural activity (real-time processing of EMG activity) and external devices (such as a stimulator). It can operate autonomously for extended periods of time in unrestrained rats, allowing its use as a long-term therapeutic tool. It can also enable us to study the long-term physiological effects of incorporating electrical stimulation techniques into the nervous system. The system can also be experimented for connecting several neural systems into a Brainet by combining neural signals from multiple rats dynamically and in real-time so as to enhance motor performance. Studies are ongoing in our laboratory to test the usefulness of this system in the recovery of hand function after cervical spinal cord injuries.
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Affiliation(s)
- Avi Rascoe
- Division of Rehabilitation Sciences, Department of Physical Therapy, School of Health Technology and Management, Stony Brook University, Stony Brook, NY, United States.,Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY, United States
| | - Pawan Sharma
- Division of Rehabilitation Sciences, Department of Physical Therapy, School of Health Technology and Management, Stony Brook University, Stony Brook, NY, United States
| | - Prithvi K Shah
- Division of Rehabilitation Sciences, Department of Physical Therapy, School of Health Technology and Management, Stony Brook University, Stony Brook, NY, United States.,Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY, United States
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33
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Zhao BL, Li WT, Zhou XH, Wu SQ, Cao HS, Bao ZR, An LB. Effective robotic assistive pattern of treadmill training for spinal cord injury in a rat model. Exp Ther Med 2018; 15:3283-3294. [PMID: 29545846 PMCID: PMC5840943 DOI: 10.3892/etm.2018.5822] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 01/24/2018] [Indexed: 01/18/2023] Open
Abstract
The purpose of the present study was to establish an effective robotic assistive stepping pattern of body-weight-supported treadmill training based on a rat spinal cord injury (SCI) model and assess the effect by comparing this with another frequently used assistive stepping pattern. The recorded stepping patterns of both hind limbs of trained intact rats were edited to establish a 30-sec playback normal rat stepping pattern (NRSP). Step features (step length, step height, step number and swing duration), BBB scores, latencies, and amplitudes of the transcranial electrical motor-evoked potentials (tceMEPs) and neurofilament 200 (NF200) expression in the spinal cord lesion area during and after 3 weeks of body-weight-supported treadmill training (BWSTT) were compared in rats with spinal contusion receiving NRSP assistance (NRSPA) and those that received manual assistance (MA). Hind limb stepping performance among rats receiving NRSPA during BWSTT was greater than that among rats receiving MA in terms of longer step length, taller step height, and longer swing duration. Furthermore a higher BBB score was also indicated. The rats in the NRSPA group achieved superior results in the tceMEPs assessment and greater NF200 expression in the spinal cord lesion area compared with the rats in the MA group. These findings suggest NRSPA was an effective assistive pattern of treadmill training compared with MA based on the rat SCI model and this approach could be used as a new platform for animal experiments for better understanding the mechanisms of SCI rehabilitation.
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Affiliation(s)
- Bo-Lun Zhao
- Department of Clinical Nursing, School of Nursing, Jilin University, Changchun, Jilin 130021, P.R. China
| | - Wen-Tao Li
- Department of Clinical Nursing, School of Nursing, Dalian University, Dalian, Liaoning 116622, P.R. China
| | - Xiao-Hua Zhou
- Department of Clinical Nursing, School of Nursing, Dalian University, Dalian, Liaoning 116622, P.R. China
| | - Su-Qian Wu
- Department of Clinical Nursing, School of Nursing, Dalian University, Dalian, Liaoning 116622, P.R. China
| | - Hong-Shi Cao
- Department of Clinical Nursing, School of Nursing, Jilin University, Changchun, Jilin 130021, P.R. China
| | - Zhu-Ren Bao
- Department of Clinical Nursing, School of Nursing, Dalian University, Dalian, Liaoning 116622, P.R. China
| | - Li-Bin An
- Department of Clinical Nursing, School of Nursing, Jilin University, Changchun, Jilin 130021, P.R. China
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34
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Influence of skill and exercise training parameters on locomotor recovery during stroke rehabilitation. Curr Opin Neurol 2018; 29:677-683. [PMID: 27748688 DOI: 10.1097/wco.0000000000000397] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
PURPOSE OF REVIEW Research findings from the fields of motor learning and exercise physiology suggest specific training parameters that can be manipulated during physical rehabilitation profoundly influence skilled task performance. This review details the rationale for some of these training variables and their application in selected intervention studies focused on improving walking function in patients poststroke. RECENT FINDINGS Basic and applied studies have shown that the amount, intensity, and variability of specific task practice applied during rehabilitation interventions can affect recovery of walking poststroke. Many studies detailing the effects of conventional, therapist, and mechanically assisted interventions may incorporate some of these training parameters but minimize others, and their relative contributions may influence walking outcomes. Specific patient factors, such as the stroke acuity and degree of impairments, appear to influence the relative contributions of these training variables, and different patient subgroups may benefit from greater emphasis on specific parameters. SUMMARY The present findings suggest these training parameters should be considered when evaluating or implementing physical interventions directed toward improving locomotor function poststroke. More work is needed to understand their optimal combinations to maximize walking outcomes in patients with different levels of impairment poststroke.
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35
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Rose DK, DeMark L, Fox EJ, Clark DJ, Wludyka P. A Backward Walking Training Program to Improve Balance and Mobility in Acute Stroke: A Pilot Randomized Controlled Trial. J Neurol Phys Ther 2018; 42:12-21. [PMID: 29232308 DOI: 10.1097/npt.0000000000000210] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND AND PURPOSE Strategies to address gait and balance deficits early poststroke are minimal. The postural and motor control requirements of Backward Walking Training (BWT) may provide benefits to improve balance and walking speed in this population. This pilot study (1) determined the feasibility of administering BWT during inpatient rehabilitation and (2) compared the effectiveness of BWT to Standing Balance Training (SBT) on walking speed, balance, and balance-related efficacy in acute stroke. METHODS Eighteen individuals 1-week poststroke were randomized to eight, 30-minute sessions of BWT or SBT in addition to scheduled therapy. Five-Meter Walk Test, 3-Meter Backward Walk Test, Activities-Specific Balance Confidence Scale, Berg Balance Scale, Sensory Organization Test, and Function Independence Measure-Mobility were assessed pre- and postintervention and at 3 months poststroke. RESULTS Forward gait speed change (BWT: 0.75 m/s; SBT: 0.41 m/s), assessed by the 5-Meter Walk Test, and backward gait speed change (BWT: 0.53 m/s; SBT: 0.23 m/s), assessed by the 3-Meter Backward Walk Test, preintervention to 1-month retention were greater for BWT than for SBT (P < 0.05). Group difference effect size from preintervention to 1-month retention was large for Activities-Specific Balance Confidence Scale, moderate for Berg Balance Scale and Function Independence Measure-Mobility, and small for Sensory Organization Test. DISCUSSION AND CONCLUSIONS Individuals 1-week poststroke tolerated 30 min/d of additional therapy. At 1-month postintervention, BWT resulted in greater improvements in both forward and backward walking speed than SBT. Backward walking training is a feasible important addition to acute stroke rehabilitation. Future areas of inquiry should examine BWT as a preventative modality for future fall incidence.Video Abstract available for more insights from the authors (see Video, Supplemental Digital Content 1, http://links.lww.com/JNPT/A193).
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Affiliation(s)
- Dorian K Rose
- Department of Physical Therapy, University of Florida, Gainesville (D.K.R., E.J.F.); Malcom Randall VA Medical Center, Gainesville, Florida (D.K.R., D.J.C.); Brooks Rehabilitation, Jacksonville, Florida (D.K.R., L.D., E.J.F.); Department of Aging, University of Florida, Gainesville (D.J.C.); and University of North Florida, Jacksonville (P.W.)
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36
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Parker D. The Lesioned Spinal Cord Is a "New" Spinal Cord: Evidence from Functional Changes after Spinal Injury in Lamprey. Front Neural Circuits 2017; 11:84. [PMID: 29163065 PMCID: PMC5681538 DOI: 10.3389/fncir.2017.00084] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 10/16/2017] [Indexed: 01/13/2023] Open
Abstract
Finding a treatment for spinal cord injury (SCI) focuses on reconnecting the spinal cord by promoting regeneration across the lesion site. However, while regeneration is necessary for recovery, on its own it may not be sufficient. This presumably reflects the requirement for regenerated inputs to interact appropriately with the spinal cord, making sub-lesion network properties an additional influence on recovery. This review summarizes work we have done in the lamprey, a model system for SCI research. We have compared locomotor behavior (swimming) and the properties of descending inputs, locomotor networks, and sensory inputs in unlesioned animals and animals that have received complete spinal cord lesions. In the majority (∼90%) of animals swimming parameters after lesioning recovered to match those in unlesioned animals. Synaptic inputs from individual regenerated axons also matched the properties in unlesioned animals, although this was associated with changes in release parameters. This suggests against any compensation at these synapses for the reduced descending drive that will occur given that regeneration is always incomplete. Compensation instead seems to occur through diverse changes in cellular and synaptic properties in locomotor networks and proprioceptive systems below, but also above, the lesion site. Recovery of locomotor performance is thus not simply the reconnection of the two sides of the spinal cord, but reflects a distributed and varied range of spinal cord changes. While locomotor network changes are insufficient on their own for recovery, they may facilitate locomotor outputs by compensating for the reduction in descending drive. Potentiated sensory feedback may in turn be a necessary adaptation that monitors and adjusts the output from the “new” locomotor network. Rather than a single aspect, changes in different components of the motor system and their interactions may be needed after SCI. If these are general features, and where comparisons with mammalian systems can be made effects seem to be conserved, improving functional recovery in higher vertebrates will require interventions that generate the optimal spinal cord conditions conducive to recovery. The analyses needed to identify these conditions are difficult in the mammalian spinal cord, but lower vertebrate systems should help to identify the principles of the optimal spinal cord response to injury.
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Affiliation(s)
- David Parker
- Department of Physiology, Neuroscience and Development, University of Cambridge, Cambridge, United Kingdom
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37
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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.
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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.
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38
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Leech KA, Kim HE, Hornby TG. Strategies to augment volitional and reflex function may improve locomotor capacity following incomplete spinal cord injury. J Neurophysiol 2017; 119:894-903. [PMID: 29093168 DOI: 10.1152/jn.00051.2017] [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] [Indexed: 01/06/2023] Open
Abstract
Many studies highlight the remarkable plasticity demonstrated by spinal circuits following an incomplete spinal cord injury (SCI). Such plasticity can contribute to improvements in volitional motor recovery, such as walking function, although similar mechanisms underlying this recovery may also contribute to the manifestation of exaggerated responses to afferent input, or spastic behaviors. Rehabilitation interventions directed toward augmenting spinal excitability have shown some initial success in improving locomotor function. However, the potential effects of these strategies on involuntary motor behaviors may be of concern. In this article, we provide a brief review of the mechanisms underlying recovery of volitional function and exaggerated reflexes, and the potential overlap between these changes. We then highlight findings from studies that explore changes in spinal excitability during volitional movement in controlled conditions, as well as altered kinematic and behavioral performance during functional tasks. The initial focus will be directed toward recovery of reflex and volitional behaviors following incomplete SCI, followed by recent work elucidating neurophysiological mechanisms underlying patterns of static and dynamic muscle activation following chronic incomplete SCI during primarily single-joint movements. We will then transition to studies of locomotor function and the role of altered spinal integration following incomplete SCI, including enhanced excitability of specific spinal circuits with physical and pharmacological interventions that can modulate locomotor output. The effects of previous and newly developed strategies will need to focus on changes in both volitional function and involuntary spastic reflexes for the successful translation of effective therapies to the clinical setting.
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Affiliation(s)
- Kristan A Leech
- Department of Neuroscience, Johns Hopkins University , Baltimore, Maryland
| | - Hyosub E Kim
- Department of Psychology, University of California at Berkeley , Berkeley, California
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Teaching Adult Rats Spinalized as Neonates to Walk Using Trunk Robotic Rehabilitation: Elements of Success, Failure, and Dependence. J Neurosci 2017; 36:8341-55. [PMID: 27511008 DOI: 10.1523/jneurosci.2435-14.2016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Accepted: 06/10/2016] [Indexed: 01/22/2023] Open
Abstract
UNLABELLED Robot therapy promotes functional recovery after spinal cord injury (SCI) in animal and clinical studies. Trunk actions are important in adult rats spinalized as neonates (NTX rats) that walk autonomously. Quadrupedal robot rehabilitation was tested using an implanted orthosis at the pelvis. Trunk cortical reorganization follows such rehabilitation. Here, we test the functional outcomes of such training. Robot impedance control at the pelvis allowed hindlimb, trunk, and forelimb mechanical interactions. Rats gradually increased weight support. Rats showed significant improvement in hindlimb stepping ability, quadrupedal weight support, and all measures examined. Function in NTX rats both before and after training showed bimodal distributions, with "poor" and "high weight support" groupings. A total of 35% of rats initially classified as "poor" were able to increase their weight-supported step measures to a level considered "high weight support" after robot training, thus moving between weight support groups. Recovered function in these rats persisted on treadmill with the robot both actuated and nonactuated, but returned to pretraining levels if they were completely disconnected from the robot. Locomotor recovery in robot rehabilitation of NTX rats thus likely included context dependence and/or incorporation of models of robot mechanics that became essential parts of their learned strategy. Such learned dependence is likely a hurdle to autonomy to be overcome for many robot locomotor therapies. Notwithstanding these limitations, trunk-based quadrupedal robot rehabilitation helped the rats to visit mechanical states they would never have achieved alone, to learn novel coordinations, and to achieve major improvements in locomotor function. SIGNIFICANCE STATEMENT Neonatal spinal transected rats without any weight support can be taught weight support as adults by using robot rehabilitation at trunk. No adult control rats with neonatal spinal transections spontaneously achieve similar changes. The robot rehabilitation system can be inactivated and the skills that were learned persist. Responding rats cannot be detached from the robot altogether, a dependence develops in the skill learned. From data and analysis here, the likelihood of such rats to respond to the robot therapy can also now be predicted. These results are all novel. Understanding trunk roles in voluntary and spinal reflex integration after spinal cord injury and in recovery of function are broadly significant for basic and clinical understanding of motor function.
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Lewis MJ, Howard JF, Olby NJ. The Relationship between Trans-Lesional Conduction, Motor Neuron Pool Excitability, and Motor Function in Dogs with Incomplete Recovery from Severe Spinal Cord Injury. J Neurotrauma 2017; 34:2994-3002. [PMID: 28462632 DOI: 10.1089/neu.2017.5012] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Spontaneous, acute, complete thoracolumbar spinal cord injury (TL-SCI) in dogs frequently results in permanent deficits modeling chronic paralysis in people. Recovery of walking without recovery of sensation has been interpreted in dogs as reflexive spinal walking. To evaluate this assumption, this study characterized the electrophysiological status of motor and sensory long tracts and local reflex circuitry in dogs with absent recovery of sensation after acute TL-SCI and correlated findings to gait scores. Twenty dogs with permanent deficits after acute, clinically complete TL-SCI and 6 normal dogs were prospectively enrolled. Transcranial magnetic motor evoked potentials (MEPs), somatosensory evoked potentials (SSEPs), H-reflex, and F-waves were evaluated. Gait was quantified using an ordinal, open field scale (OFS) and treadmill-based stepping and coordination scores (SS, RI). MEP latency and H-reflex variables were compared between cases and controls. Associations between presence of MEPs, SSEPs, F-waves or H-reflex variables, and gait scores were determined. Pelvic limb MEPs were detected in 4 cases; no case had trans-lesional sensory conduction. Latency was longer and conduction velocity slower in cases than controls (pa = 0.0064, 0.0023, respectively). Three of 4 cases with pelvic limb MEPs were ambulatory, and gait scores (OFS, SS, RI) were each associated with presence of trans-lesional conduction (pa = 0.006, 0.006, 0.003, respectively). H threshold in cases (mean, 3.2mA ±2.5) was lower than controls (mean, 7.9mA ±3.1; pa = 0.011) and was inversely associated with treadmill-based scores, SS, and RI (pa = 0.042, 0.043, respectively). The association between pelvic limb MEPs and gait scores supports the importance of descending influence on regaining walking after severe TL-SCI in dogs rather than just activation of spinal walking. The inverse association between H-reflex threshold and gait scores implies that increases in motor neuron pool excitability might also contribute to motor recovery.
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Affiliation(s)
- Melissa J Lewis
- 1 Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University , Raleigh, North Carolina.,2 Comparative Medicine Institute, North Carolina State University , Raleigh, North Carolina
| | - James F Howard
- 3 Department of Neurology, School of Medicine, University of North Carolina , Chapel Hill, North Carolina
| | - Natasha J Olby
- 1 Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University , Raleigh, North Carolina.,2 Comparative Medicine Institute, North Carolina State University , Raleigh, North Carolina
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Gad P, Gerasimenko Y, Zdunowski S, Turner A, Sayenko D, Lu DC, Edgerton VR. Weight Bearing Over-ground Stepping in an Exoskeleton with Non-invasive Spinal Cord Neuromodulation after Motor Complete Paraplegia. Front Neurosci 2017. [PMID: 28642680 PMCID: PMC5462970 DOI: 10.3389/fnins.2017.00333] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
We asked whether coordinated voluntary movement of the lower limbs could be regained in an individual having been completely paralyzed (>4 year) and completely absent of vision (>15 year) using two novel strategies-transcutaneous electrical spinal cord stimulation at selected sites over the spine as well as pharmacological neuromodulation by buspirone. We also asked whether these neuromodulatory strategies could facilitate stepping assisted by an exoskeleton (EKSO, EKSO Bionics, CA) that is designed so that the subject can voluntarily complement the work being performed by the exoskeleton. We found that spinal cord stimulation and drug enhanced the level of effort that the subject could generate while stepping in the exoskeleton. In addition, stimulation improved the coordination patterns of the lower limb muscles resulting in a more continuous, smooth stepping motion in the exoskeleton along with changes in autonomic functions including cardiovascular and thermoregulation. Based on these data from this case study it appears that there is considerable potential for positive synergistic effects after complete paralysis by combining the over-ground step training in an exoskeleton, combined with transcutaneous electrical spinal cord stimulation either without or with pharmacological modulation.
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Affiliation(s)
- Parag Gad
- Department of Integrative Biology and Physiology, University of California, Los AngelesLos Angeles, CA, United States
| | - Yury Gerasimenko
- Department of Integrative Biology and Physiology, University of California, Los AngelesLos Angeles, CA, United States.,Pavlov Institute of PhysiologySt. Petersburg, Russia
| | - Sharon Zdunowski
- Department of Integrative Biology and Physiology, University of California, Los AngelesLos Angeles, CA, United States
| | - Amanda Turner
- Department of Integrative Biology and Physiology, University of California, Los AngelesLos Angeles, CA, United States
| | - Dimitry Sayenko
- Department of Integrative Biology and Physiology, University of California, Los AngelesLos Angeles, CA, United States
| | - Daniel C Lu
- Department of Neurosurgery, University of California, Los AngelesLos Angeles, CA, United States.,Brain Research Institute, University of California, Los AngelesLos Angeles, CA, United States
| | - V Reggie Edgerton
- Department of Integrative Biology and Physiology, University of California, Los AngelesLos Angeles, CA, United States.,Department of Neurosurgery, University of California, Los AngelesLos Angeles, CA, United States.,Brain Research Institute, University of California, Los AngelesLos Angeles, CA, United States.,Department of Neurobiology, University of California, Los AngelesLos Angeles, CA, United States.,Institut Guttmann, Hospital de Neurorehabilitació, Institut Universitari adscrit a la Universitat Autònoma de BarcelonaBarcelona, Spain
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Shah PK, Lavrov I. Spinal Epidural Stimulation Strategies: Clinical Implications of Locomotor Studies in Spinal Rats. Neuroscientist 2017; 23:664-680. [PMID: 28345483 DOI: 10.1177/1073858417699554] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Significant advancements in spinal epidural stimulation (ES) strategies to enable volitional motor control in persons with a complete spinal cord injury (SCI) have generated much excitement in the field of neurorehabilitation. Still, an obvious gap lies in the ability of ES to effectively generate a robust locomotor stepping response after a complete SCI in rodents, but not in humans. In order to reveal potential discrepancies between rodent and human studies that account for this void, in this review, we summarize the findings of studies that have utilized ES strategies to enable successful hindlimb stepping in spinal rats. Recent clinical and preclinical evidence indicates that motor training with ES plays a crucial role in tuning spinal neural circuitry to generate meaningful motor output. Concurrently administered pharmacology can also facilitate the circuitry to provide near optimal motor performance in SCI rats. However, as of today, the evidence for pharmacological agents to enhance motor function in persons with complete SCI is insignificant. These and other recent findings discussed in this review provide insight into addressing the translational gap, guide the design of relevant preclinical experiments, and facilitate development of new approaches for motor recovery in patients with complete SCIs.
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Affiliation(s)
- Prithvi K Shah
- 1 Division of Rehabilitation Sciences, School of Health Technology and Management, Stony Brook University, Stony Brook, NY, USA.,2 Department of Neurobiology, Stony Brook University, Stony Brook, NY, USA
| | - Igor Lavrov
- 3 Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, USA.,4 Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA.,5 Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
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Animal models of spinal cord injury: a systematic review. Spinal Cord 2017; 55:714-721. [PMID: 28117332 DOI: 10.1038/sc.2016.187] [Citation(s) in RCA: 146] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Revised: 11/08/2016] [Accepted: 11/27/2016] [Indexed: 02/06/2023]
Abstract
STUDY DESIGN PRISMA-guided systematic review. OBJECTIVES To provide a comprehensive framework of the current animal models for investigating spinal cord injury (SCI) and categorize them based on the aims, patterns and levels of injury, and outcome measurements as well as animal species. SETTING Sina Trauma and Surgery Research Center, Tehran University of Medical Sciences, Tehran, Iran. METHODS An electronic search of the Medline database for literature describing animal models of SCI was performed on 1 January 2016 using the following keywords: 'spinal cord injuries' and 'animal models'. The search retrieved 2870 articles. Reviews and non-original articles were excluded. Data extraction was independently performed by two reviewers. RESULTS Among the 2209 included studies, testing the effects of drug's or growth factor's interventions was the most common aim (36.6%) followed by surveying pathophysiologic changes (30.2%). The most common spinal region involved was thoracic (81%). Contusion was the most common pattern of injury (41%) followed by transection (32.5%) and compression (19.4%). The most common species involved in animal models of SCI was the rat (72.4%). Two or more types of outcome assessments were used in the majority of the studies, and the most common assessment method was biological plus behavioral (50.8%). CONCLUSIONS Prior to choosing an animal model, the objectives of the proposed study must precisely be defined. Contusion and compression models better simulate the biomechanics and neuropathology of human injury, whereas transection models are valuable to study anatomic regeneration. Rodents are the most common and probably best-suited species for preliminary SCI studies.
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Gollie JM, Guccione AA. Overground Locomotor Training in Spinal Cord Injury: A Performance-Based Framework. Top Spinal Cord Inj Rehabil 2017; 23:226-233. [PMID: 29339898 PMCID: PMC5562030 DOI: 10.1310/sci2303-226] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Background: Locomotor training (LT) is the most commonly used treatment to improve walking performance following spinal cord injury (SCI). The advancement of LT treatments requires the addition of integrative models accounting for the numerous systems responsible for the recovery of walking function following SCI. Objective: This perspective monograph aims to (a) describe a performance-based framework for overground LT (OLT), (b) describe principles of adaptation and motor learning used to inform OLT program design, and (c) present an example OLT program based on the proposed framework. Methods: Individuals with chronic motor-incomplete SCI (7 male, 1 female) classified according to the American Spinal Injury Association Impairment Scale (AIS) as C and D were included. OLT included two 90-minute sessions performed over 12 weeks for a total of 24 sessions. Outcomes measures included overground walking speed, walking economy, pulmonary oxygen uptake, and muscle oxygen extraction measured via near-infrared spectroscopy. Results: Preliminary findings demonstrate the potential of OLT, as describe here, to increase overground walking speed, improve walking economy, accelerate processes associated with oxygen delivery and utilization at the rest-to-work transition, and lower oxygen extraction requirements of skeletal muscle during walking in individuals with chronic motor-incomplete SCI. Conclusion: The proposed framework offers a valuable template for LT program design in both clinical and research settings. Further research is necessary to better understand the effects of OLT and how principles of specificity, progressive overload, and variation within the performance-based framework can be manipulated to maximize function, health, and quality of life in SCI.
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Affiliation(s)
- Jared M. Gollie
- Department of Rehabilitation Science, George Mason University College of Health and Human Services, Fairfax, Virginia
| | - Andrew A. Guccione
- Department of Rehabilitation Science, George Mason University College of Health and Human Services, Fairfax, Virginia
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Correction: Multi-site spinal stimulation strategies to enhance locomotion after paralysis. Neural Regen Res 2017; 12:161-162. [PMID: 28250764 PMCID: PMC5319224 DOI: 10.4103/1673-5374.199010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Gerasimenko Y, Sayenko D, Gad P, Liu CT, Tillakaratne NJK, Roy RR, Kozlovskaya I, Edgerton VR. Feed-Forwardness of Spinal Networks in Posture and Locomotion. Neuroscientist 2016; 23:441-453. [PMID: 28403746 DOI: 10.1177/1073858416683681] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
We present a new perspective on the concept of feed-forward compared to feedback mechanisms for motor control. We propose that conceptually all sensory information in real time provided to the brain and spinal cord can be viewed as a feed-forward phenomenon. We also propose that the spinal cord continually adapts to a broad array of ongoing sensory information that is used to adjust the probability of making timely and predictable decisions of selected networks that will execute a given response. One interpretation of the term feedback historically entails responses with short delays. We propose that feed-forward mechanisms, however, range in timeframes of milliseconds to an evolutionary perspective, that is, "evolutionary learning." Continuously adapting events enable a high level of automaticity within the sensorimotor networks that mediate "planned" motor tasks. We emphasize that either a very small or a very large proportion of motor responses can be under some level of conscious vs automatic control. Furthermore, we make a case that a major component of automaticity of the neural control of movement in vertebrates is located within spinal cord networks. Even without brain input, the spinal cord routinely uses feed-forward processing of sensory information, particularly proprioceptive and cutaneous, to continuously make fundamental decisions that define motor responses. In effect, these spinal networks may be largely responsible for executing coordinated sensorimotor tasks, even those under normal "conscious" control.
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Affiliation(s)
- Yury Gerasimenko
- 1 Department of Integrative Biology and Physiology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA.,2 Pavlov Institute of Physiology, St. Petersburg, Russia.,3 Russian Federation State Scientific Center, Institute for Bio-Medical Problems, Russian Academy of Sciences, Moscow, Russia.,4 Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | - Dimitry Sayenko
- 1 Department of Integrative Biology and Physiology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Parag Gad
- 1 Department of Integrative Biology and Physiology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Chao-Tuan Liu
- 1 Department of Integrative Biology and Physiology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Niranjala J K Tillakaratne
- 1 Department of Integrative Biology and Physiology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA.,5 Brain Research Institute, University of California, Los Angeles, CA, USA
| | - Roland R Roy
- 1 Department of Integrative Biology and Physiology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA.,5 Brain Research Institute, University of California, Los Angeles, CA, USA
| | | | - V Reggie Edgerton
- 1 Department of Integrative Biology and Physiology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA.,5 Brain Research Institute, University of California, Los Angeles, CA, USA.,6 Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA.,7 Department of Neurosurgery, David Geffen School of Medicine, University of California, Los Angeles, CA, USA.,8 Institute Guttmann. Hospital de Neurorehabilitació, Institut Universitari adscrit a la Universitat Autònoma de Barcelona, Badalona, Spain
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Effects of Overground Locomotor Training on Walking Performance in Chronic Cervical Motor Incomplete Spinal Cord Injury: A Pilot Study. Arch Phys Med Rehabil 2016; 98:1119-1125. [PMID: 27965006 DOI: 10.1016/j.apmr.2016.10.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 10/21/2016] [Accepted: 10/29/2016] [Indexed: 12/23/2022]
Abstract
OBJECTIVE To determine the effects of a novel overground locomotor training program on walking performance in people with chronic cervical motor incomplete spinal cord injury (iSCI). DESIGN Before-after pilot study. SETTING Human performance research laboratory. PARTICIPANTS Adults (N=6, age >18y) with chronic cervical iSCI with American Spinal Injury Association Impairment Scale grades C and D. INTERVENTIONS Overground locomotor training included two 90-minute sessions per week for 12 to 15 weeks. Training sessions alternated between uniplanar and multiplanar stepping patterns. Each session was comprised of 5 segments: joint mobility, volitional muscle activation, task isolation, task integration, and activity rehearsal. MAIN OUTCOME MEASURES Overground walking speed, oxygen consumption (V˙o2), and carbon dioxide production (V˙co2). RESULTS Overground locomotor training increased overground walking speed (.36±.20 vs .51±.24 m/s, P<.001, d=.68). Significant decreases in V˙o2 (6.6±1.3 vs 5.7±1.4mL·kg·min, P=.038, d=.67) and V˙co2 (753.1±125.5 vs 670.7±120.3mL/min, P=.036, d=.67) during self-selected constant work rate treadmill walking were also noted after training. CONCLUSIONS The overground locomotor training program used in this pilot study is feasible and improved both overground walking speed and walking economy in a small sample of people with chronic cervical iSCI. Future studies are necessary to establish the efficacy of this overground locomotor training program and to differentiate among potential mechanisms contributing to enhanced walking performance in people with iSCI after overground locomotor training.
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Effects of Locomotor Exercise Intensity on Gait Performance in Individuals With Incomplete Spinal Cord Injury. Phys Ther 2016; 96:1919-1929. [PMID: 27313241 PMCID: PMC5131185 DOI: 10.2522/ptj.20150646] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 06/12/2016] [Indexed: 01/25/2023]
Abstract
BACKGROUND High-intensity stepping practice may be a critical component to improve gait following motor incomplete spinal cord injury (iSCI). However, such practice is discouraged by traditional theories of rehabilitation that suggest high-intensity locomotor exercise degrades gait performance. Accordingly, such training is thought to reinforce abnormal movement patterns, although evidence to support this notion is limited. OBJECTIVE The purposes of this study were: (1) to evaluate the effects of short-term manipulations in locomotor intensity on gait performance in people with iSCI and (2) to evaluate potential detrimental effects of high-intensity locomotor training on walking performance. DESIGN A single-day, repeated-measures, pretraining-posttraining study design was used. METHODS Nineteen individuals with chronic iSCI performed a graded-intensity locomotor exercise task with simultaneous collection of lower extremity kinematic and electromyographic data. Measures of interest were compared across intensity levels of 33%, 67%, and 100% of peak gait speed. A subset of 9 individuals participated in 12 weeks of high-intensity locomotor training. Similar measurements were collected and compared between pretraining and posttraining evaluations. RESULTS The results indicate that short-term increases in intensity led to significant improvements in muscle activity, spatiotemporal metrics, and joint excursions, with selected improvements in measures of locomotor coordination. High-intensity locomotor training led to significant increases in peak gait speed (0.64-0.80 m/s), and spatiotemporal and kinematic metrics indicate a trend for improved coordination. LIMITATIONS Measures of gait performance were assessed during treadmill ambulation and not compared with a control group. Generalizability of these results to overground ambulation is unknown. CONCLUSIONS High-intensity locomotor exercise and training does not degrade, but rather improves, locomotor function and quality in individuals with iSCI, which contrasts with traditional theories of motor dysfunction following neurologic injury.
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Stepping in Place While Voluntarily Turning Around Produces a Long-Lasting Posteffect Consisting in Inadvertent Turning While Stepping Eyes Closed. Neural Plast 2016; 2016:7123609. [PMID: 27635264 PMCID: PMC5011410 DOI: 10.1155/2016/7123609] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 06/20/2016] [Accepted: 07/03/2016] [Indexed: 11/17/2022] Open
Abstract
Training subjects to step in place on a rotating platform while maintaining a fixed body orientation in space produces a posteffect consisting in inadvertent turning around while stepping in place eyes closed (podokinetic after-rotation, PKAR). We tested the hypothesis that voluntary turning around while stepping in place also produces a posteffect similar to PKAR. Sixteen subjects performed 12 min of voluntary turning while stepping around their vertical axis eyes closed and 12 min of stepping in place eyes open on the center of a platform rotating at 60°/s (pretests). Then, subjects continued stepping in place eyes closed for at least 10 min (posteffect). We recorded the positions of markers fixed to head, shoulder, and feet. The posteffect of voluntary turning shared all features of PKAR. Time decay of angular velocity, stepping cadence, head acceleration, and ratio of angular velocity after to angular velocity before were similar between both protocols. Both postrotations took place inadvertently. The posteffects are possibly dependent on the repeated voluntary contraction of leg and foot intrarotating pelvic muscles that rotate the trunk over the stance foot, a synergy common to both protocols. We propose that stepping in place and voluntary turning can be a scheme ancillary to the rotating platform for training body segment coordination in patients with impairment of turning synergies of various origin.
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Neuromodulation of the neural circuits controlling the lower urinary tract. Exp Neurol 2016; 285:182-189. [PMID: 27381425 DOI: 10.1016/j.expneurol.2016.06.034] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2016] [Revised: 06/30/2016] [Accepted: 06/30/2016] [Indexed: 01/01/2023]
Abstract
The inability to control timely bladder emptying is one of the most serious challenges among the many functional deficits that occur after a spinal cord injury. We previously demonstrated that electrodes placed epidurally on the dorsum of the spinal cord can be used in animals and humans to recover postural and locomotor function after complete paralysis and can be used to enable voiding in spinal rats. In the present study, we examined the neuromodulation of lower urinary tract function associated with acute epidural spinal cord stimulation, locomotion, and peripheral nerve stimulation in adult rats. Herein we demonstrate that electrically evoked potentials in the hindlimb muscles and external urethral sphincter are modulated uniquely when the rat is stepping bipedally and not voiding, immediately pre-voiding, or when voiding. We also show that spinal cord stimulation can effectively neuromodulate the lower urinary tract via frequency-dependent stimulation patterns and that neural peripheral nerve stimulation can activate the external urethral sphincter both directly and via relays in the spinal cord. The data demonstrate that the sensorimotor networks controlling bladder and locomotion are highly integrated neurophysiologically and behaviorally and demonstrate how these two functions are modulated by sensory input from the tibial and pudental nerves. A more detailed understanding of the high level of interaction between these networks could lead to the integration of multiple neurophysiological strategies to improve bladder function. These data suggest that the development of strategies to improve bladder function should simultaneously engage these highly integrated networks in an activity-dependent manner.
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