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Clawson WP, Levin M. Endless forms most beautiful 2.0: teleonomy and the bioengineering of chimaeric and synthetic organisms. Biol J Linn Soc Lond 2022. [DOI: 10.1093/biolinnean/blac073] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Abstract
The rich variety of biological forms and behaviours results from one evolutionary history on Earth, via frozen accidents and selection in specific environments. This ubiquitous baggage in natural, familiar model species obscures the plasticity and swarm intelligence of cellular collectives. Significant gaps exist in our understanding of the origin of anatomical novelty, of the relationship between genome and form, and of strategies for control of large-scale structure and function in regenerative medicine and bioengineering. Analysis of living forms that have never existed before is necessary to reveal deep design principles of life as it can be. We briefly review existing examples of chimaeras, cyborgs, hybrots and other beings along the spectrum containing evolved and designed systems. To drive experimental progress in multicellular synthetic morphology, we propose teleonomic (goal-seeking, problem-solving) behaviour in diverse problem spaces as a powerful invariant across possible beings regardless of composition or origin. Cybernetic perspectives on chimaeric morphogenesis erase artificial distinctions established by past limitations of technology and imagination. We suggest that a multi-scale competency architecture facilitates evolution of robust problem-solving, living machines. Creation and analysis of novel living forms will be an essential testbed for the emerging field of diverse intelligence, with numerous implications across regenerative medicine, robotics and ethics.
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Affiliation(s)
| | - Michael Levin
- Allen Discovery Center at Tufts University , Medford, MA , USA
- Wyss Institute for Biologically Inspired Engineering at Harvard University , Boston, MA , USA
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Doctor T, Witkowski O, Solomonova E, Duane B, Levin M. Biology, Buddhism, and AI: Care as the Driver of Intelligence. ENTROPY (BASEL, SWITZERLAND) 2022; 24:710. [PMID: 35626593 PMCID: PMC9140411 DOI: 10.3390/e24050710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 04/28/2022] [Accepted: 05/11/2022] [Indexed: 11/17/2022]
Abstract
Intelligence is a central feature of human beings' primary and interpersonal experience. Understanding how intelligence originated and scaled during evolution is a key challenge for modern biology. Some of the most important approaches to understanding intelligence are the ongoing efforts to build new intelligences in computer science (AI) and bioengineering. However, progress has been stymied by a lack of multidisciplinary consensus on what is central about intelligence regardless of the details of its material composition or origin (evolved vs. engineered). We show that Buddhist concepts offer a unique perspective and facilitate a consilience of biology, cognitive science, and computer science toward understanding intelligence in truly diverse embodiments. In coming decades, chimeric and bioengineering technologies will produce a wide variety of novel beings that look nothing like familiar natural life forms; how shall we gauge their moral responsibility and our own moral obligations toward them, without the familiar touchstones of standard evolved forms as comparison? Such decisions cannot be based on what the agent is made of or how much design vs. natural evolution was involved in their origin. We propose that the scope of our potential relationship with, and so also our moral duty toward, any being can be considered in the light of Care-a robust, practical, and dynamic lynchpin that formalizes the concepts of goal-directedness, stress, and the scaling of intelligence; it provides a rubric that, unlike other current concepts, is likely to not only survive but thrive in the coming advances of AI and bioengineering. We review relevant concepts in basal cognition and Buddhist thought, focusing on the size of an agent's goal space (its cognitive light cone) as an invariant that tightly links intelligence and compassion. Implications range across interpersonal psychology, regenerative medicine, and machine learning. The Bodhisattva's vow ("for the sake of all sentient life, I shall achieve awakening") is a practical design principle for advancing intelligence in our novel creations and in ourselves.
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Affiliation(s)
- Thomas Doctor
- Centre for Buddhist Studies, Rangjung Yeshe Institute, Kathmandu University, Kathmandu 44600, Nepal; (T.D.); (B.D.)
- Center for the Study of Apparent Selves, Rangjung Yeshe Institute, Kathmandu 44600, Nepal; (O.W.); (E.S.)
| | - Olaf Witkowski
- Center for the Study of Apparent Selves, Rangjung Yeshe Institute, Kathmandu 44600, Nepal; (O.W.); (E.S.)
- Cross Labs, Cross Compass Ltd., Kyoto 604-8206, Japan
- College of Arts and Sciences, University of Tokyo, Tokyo 113-8654, Japan
- Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo 145-0061, Japan
| | - Elizaveta Solomonova
- Center for the Study of Apparent Selves, Rangjung Yeshe Institute, Kathmandu 44600, Nepal; (O.W.); (E.S.)
- Neurophilosophy Lab, Department of Psychiatry, McGill University, Montreal, QC H3A 0G4, Canada
| | - Bill Duane
- Centre for Buddhist Studies, Rangjung Yeshe Institute, Kathmandu University, Kathmandu 44600, Nepal; (T.D.); (B.D.)
- Center for the Study of Apparent Selves, Rangjung Yeshe Institute, Kathmandu 44600, Nepal; (O.W.); (E.S.)
- Bill Duane and Associates LLC, San Francisco, CA 94117, USA
| | - Michael Levin
- Allen Discovery Center, Tufts University, Medford, MA 02155, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, USA
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Flores Á, López-Santos D, García-Alías G. When Spinal Neuromodulation Meets Sensorimotor Rehabilitation: Lessons Learned From Animal Models to Regain Manual Dexterity After a Spinal Cord Injury. FRONTIERS IN REHABILITATION SCIENCES 2021; 2:755963. [PMID: 36188826 PMCID: PMC9397786 DOI: 10.3389/fresc.2021.755963] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 11/16/2021] [Indexed: 12/22/2022]
Abstract
Electrical neuromodulation has strongly hit the foundations of spinal cord injury and repair. Clinical and experimental studies have demonstrated the ability to neuromodulate and engage spinal cord circuits to recover volitional motor functions lost after the injury. Although the science and technology behind electrical neuromodulation has attracted much of the attention, it cannot be obviated that electrical stimulation must be applied concomitantly to sensorimotor rehabilitation, and one would be very difficult to understand without the other, as both need to be finely tuned to efficiently execute movements. The present review explores the difficulties faced by experimental and clinical neuroscientists when attempting to neuromodulate and rehabilitate manual dexterity in spinal cord injured subjects. From a translational point of view, we will describe the major rehabilitation interventions employed in animal research to promote recovery of forelimb motor function. On the other hand, we will outline some of the state-of-the-art findings when applying electrical neuromodulation to the spinal cord in animal models and human patients, highlighting how evidences from lumbar stimulation are paving the path to cervical neuromodulation.
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Affiliation(s)
- África Flores
- Department of Cell Biology, Physiology and Immunology, Institute of Neuroscience, Universitat Autònoma de Barcelona and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Bellaterra, Spain
| | - Diego López-Santos
- Department of Cell Biology, Physiology and Immunology, Institute of Neuroscience, Universitat Autònoma de Barcelona and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Bellaterra, Spain
| | - Guillermo García-Alías
- Department of Cell Biology, Physiology and Immunology, Institute of Neuroscience, Universitat Autònoma de Barcelona and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Bellaterra, Spain
- Institut Guttmann de Neurorehabilitació, Badalona, Spain
- *Correspondence: Guillermo García-Alías
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Taylor C, McHugh C, Mockler D, Minogue C, Reilly RB, Fleming N. Transcutaneous spinal cord stimulation and motor responses in individuals with spinal cord injury: A methodological review. PLoS One 2021; 16:e0260166. [PMID: 34793572 PMCID: PMC8601579 DOI: 10.1371/journal.pone.0260166] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 11/03/2021] [Indexed: 11/18/2022] Open
Abstract
Background Transcutaneous spinal cord stimulation (tSCS) is a non-invasive modality in which electrodes can stimulate spinal circuitries and facilitate a motor response. This review aimed to evaluate the methodology of studies using tSCS to generate motor activity in persons with spinal cord injury (SCI) and to appraise the quality of included trials. Methods A systematic search for studies published until May 2021 was made of the following databases: EMBASE, Medline (Ovid) and Web of Science. Two reviewers independently screened the studies, extracted the data, and evaluated the quality of included trials. The electrical characteristics of stimulation were summarised to allow for comparison across studies. In addition, the surface electromyography (EMG) recording methods were evaluated. Results A total of 3753 articles were initially screened, of which 25 met the criteria for inclusion. Studies were divided into those using tSCS for neurophysiological investigations of reflex responses (n = 9) and therapeutic investigations of motor recovery (n = 16). The overall quality of evidence was deemed to be poor-to-fair (10.5 ± 4.9) based on the Downs and Black Quality Checklist criteria. The electrical characteristics were collated to establish the dosage range across stimulation trials. The methods employed by included studies relating to stimulation parameters and outcome measurement varied extensively, although some trends are beginning to appear in relation to electrode configuration and EMG outcomes. Conclusion This review outlines the parameters currently employed for tSCS of the cervicothoracic and thoracolumbar regions to produce motor responses. However, to establish standardised procedures for neurophysiological assessments and therapeutic investigations of tSCS, further high-quality investigations are required, ideally utilizing consistent electrophysiological recording methods, and reporting common characteristics of the electrical stimulation administered.
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Affiliation(s)
- Clare Taylor
- Department of Anatomy, School of Medicine, Trinity College, The University of Dublin, Dublin, Ireland
- * E-mail:
| | - Conor McHugh
- Department of Anatomy, School of Medicine, Trinity College, The University of Dublin, Dublin, Ireland
| | - David Mockler
- John Stearne Medical Library, Trinity Centre for Health Sciences, School of Medicine, St. James’s Hospital, Dublin, Ireland
| | - Conor Minogue
- Department of Anatomy, School of Medicine, Trinity College, The University of Dublin, Dublin, Ireland
| | - Richard B. Reilly
- Trinity Centre for Biomedical Engineering, Trinity College, The University of Dublin, Dublin, Ireland
- School of Engineering, Trinity College, The University of Dublin, Dublin, Ireland
- School of Medicine, Trinity College, The University of Dublin, Dublin, Ireland
| | - Neil Fleming
- Department of Anatomy, School of Medicine, Trinity College, The University of Dublin, Dublin, Ireland
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McHugh C, Taylor C, Mockler D, Fleming N. Epidural spinal cord stimulation for motor recovery in spinal cord injury: A systematic review. NeuroRehabilitation 2021; 49:1-22. [PMID: 33967072 DOI: 10.3233/nre-210093] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Epidural spinal cord stimulation (ESCS) emerged as a technology for eliciting motor function in the 1990's and was subsequently employed therapeutically in the population with spinal cord injury (SCI). Despite a considerable number of ESCS studies, a comprehensive systematic review of ESCS remains unpublished. OBJECTIVE The current review of the existing literature evaluated the efficacy of ESCS for improving motor function in individuals with SCI. METHODS A search for ESCS studies was performed using the following databases: Medline (Ovid), Web of Science and Embase. Furthermore, to maximize results, an inverse manual search of references cited by identified articles was also performed. Studies published between January 1995 and June 2020 were included. The search was constructed around the following key terms: Spinal cord stimulation, SCI and motor response generation. RESULTS A total of 3435 articles were initially screened, of which 18 met the inclusion criteria. The total sample comprised of 24 participants with SCI. All studies reported some measure of improvement in motor activity with ESCS, with 17 reporting altered EMG responses. Functional improvements were reported in stepping (n = 11) or muscle force (n = 4). Only 5 studies assessed ASIA scale pre- and post-intervention, documenting improved classification in 4 of 11 participants. Appraisal using the modified Downs and Black quality checklist determined that reviewed studies were of poor quality. Due to heterogeneity of outcome measures utilized in studies reviewed, a meta-analysis of data was not possible. CONCLUSION While the basic science is encouraging, the therapeutic efficacy of ESCS remains inconclusive.
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Affiliation(s)
- Conor McHugh
- Human Performance Laboratory, Department of Anatomy, School of Medicine, Trinity College Dublin, Dublin, Ireland
| | - Clare Taylor
- Human Performance Laboratory, Department of Anatomy, School of Medicine, Trinity College Dublin, Dublin, Ireland
| | - David Mockler
- John Stearne Medical Library, Trinity Centre for Health Sciences, School of Medicine, St. James's Hospital, Dublin, Ireland
| | - Neil Fleming
- Human Performance Laboratory, Department of Anatomy, School of Medicine, Trinity College Dublin, Dublin, Ireland
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Swimming Exercise Promotes Post-injury Axon Regeneration and Functional Restoration through AMPK. eNeuro 2021; 8:ENEURO.0414-20.2021. [PMID: 34031101 PMCID: PMC8211466 DOI: 10.1523/eneuro.0414-20.2021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 04/16/2021] [Accepted: 04/25/2021] [Indexed: 12/11/2022] Open
Abstract
Restoration of lost function following a nervous system injury is limited in adulthood as the regenerative capacity of nervous system declines with age. Pharmacological approaches have not been very successful in alleviating the consequences of nervous system injury. On the contrary, physical activity and rehabilitation interventions are often beneficial to improve the health conditions in the patients with neuronal injuries. Using touch neuron circuit of Caenorhabditis elegans, we investigated the role of physical exercise in the improvement of functional restoration after axotomy. We found that a swimming session of 90 min following the axotomy of posterior lateral microtubule (PLM) neuron can improve functional recovery in larval and adult stage animals. In older age, multiple exercise sessions were required to enhance the functional recovery. Genetic analysis of axon regeneration mutants showed that exercise-mediated enhancement of functional recovery depends on the ability of axon to regenerate. Exercise promotes early initiation of regrowth, self-fusion of proximal and distal ends, as well as postregrowth enhancement of function. We further found that the swimming exercise promotes axon regeneration through the activity of cellular energy sensor AAK-2/AMPK in both muscle and neuron. Our study established a paradigm where systemic effects of exercise on functional regeneration could be addressed at the single neuron level.
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Epidural Stimulation Combined with Triple Gene Therapy for Spinal Cord Injury Treatment. Int J Mol Sci 2020; 21:ijms21238896. [PMID: 33255323 PMCID: PMC7734573 DOI: 10.3390/ijms21238896] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 11/06/2020] [Accepted: 11/17/2020] [Indexed: 12/18/2022] Open
Abstract
The translation of new therapies for spinal cord injury to clinical trials can be facilitated with large animal models close in morpho-physiological scale to humans. Here, we report functional restoration and morphological reorganization after spinal contusion in pigs, following a combined treatment of locomotor training facilitated with epidural electrical stimulation (EES) and cell-mediated triple gene therapy with umbilical cord blood mononuclear cells overexpressing recombinant vascular endothelial growth factor, glial-derived neurotrophic factor, and neural cell adhesion molecule. Preliminary results obtained on a small sample of pigs 2 months after spinal contusion revealed the difference in post-traumatic spinal cord outcomes in control and treated animals. In treated pigs, motor performance was enabled by EES and the corresponding morpho-functional changes in hind limb skeletal muscles were accompanied by the reorganization of the glial cell, the reaction of stress cell, and synaptic proteins. Our data demonstrate effects of combined EES-facilitated motor training and cell-mediated triple gene therapy after spinal contusion in large animals, informing a background for further animal studies and clinical translation.
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Meyer C, Hofstoetter US, Hubli M, Hassani RH, Rinaldo C, Curt A, Bolliger M. Immediate Effects of Transcutaneous Spinal Cord Stimulation on Motor Function in Chronic, Sensorimotor Incomplete Spinal Cord Injury. J Clin Med 2020; 9:E3541. [PMID: 33147884 PMCID: PMC7694146 DOI: 10.3390/jcm9113541] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 10/22/2020] [Accepted: 10/30/2020] [Indexed: 12/15/2022] Open
Abstract
Deficient ankle control after incomplete spinal cord injury (iSCI) often accentuates walking impairments. Transcutaneous electrical spinal cord stimulation (tSCS) has been shown to augment locomotor activity after iSCI, presumably due to modulation of spinal excitability. However, the effects of possible excitability modulations induced by tSCS on ankle control have not yet been assessed. This study investigated the immediate (i.e., without training) effects during single-sessions of tonic tSCS on ankle control, spinal excitability, and locomotion in ten individuals with chronic, sensorimotor iSCI (American Spinal Injury Association Impairment Scale D). Participants performed rhythmic ankle movements (dorsi- and plantar flexion) at a given rate, and irregular ankle movements following a predetermined trajectory with and without tonic tSCS at 15 Hz, 30 Hz, and 50 Hz. In a subgroup of eight participants, the effects of tSCS on assisted over-ground walking were studied. Furthermore, the activity of a polysynaptic spinal reflex, associated with spinal locomotor networks, was investigated to study the effect of the stimulation on the dedicated spinal circuitry associated with locomotor function. Tonic tSCS at 30 Hz immediately improved maximum dorsiflexion by +4.6° ± 0.9° in the more affected lower limb during the rhythmic ankle movement task, resulting in an increase of +2.9° ± 0.9° in active range of motion. Coordination of ankle movements, assessed by the ability to perform rhythmic ankle movements at a given target rate and to perform irregular movements according to a trajectory, was unchanged during stimulation. tSCS at 30 Hz modulated spinal reflex activity, reflected by a significant suppression of pathological activity specific to SCI in the assessed polysynaptic spinal reflex. During walking, there was no statistical group effect of tSCS. In the subgroup of eight assessed participants, the three with the lowest as well as the one with the highest walking function scores showed positive stimulation effects, including increased maximum walking speed, or more continuous and faster stepping at a self-selected speed. Future studies need to investigate if multiple applications and individual optimization of the stimulation parameters can increase the effects of tSCS, and if the technique can improve the outcome of locomotor rehabilitation after iSCI.
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Affiliation(s)
- Christian Meyer
- Spinal Cord Injury Center, Balgrist University Hospital, Forchstrasse 340, 8008 Zurich, Switzerland; (C.M.); (M.H.); (R.H.H.); (C.R.); (A.C.); (M.B.)
| | - Ursula S. Hofstoetter
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, 1090 Vienna, Austria
| | - Michèle Hubli
- Spinal Cord Injury Center, Balgrist University Hospital, Forchstrasse 340, 8008 Zurich, Switzerland; (C.M.); (M.H.); (R.H.H.); (C.R.); (A.C.); (M.B.)
| | - Roushanak H. Hassani
- Spinal Cord Injury Center, Balgrist University Hospital, Forchstrasse 340, 8008 Zurich, Switzerland; (C.M.); (M.H.); (R.H.H.); (C.R.); (A.C.); (M.B.)
| | - Carmen Rinaldo
- Spinal Cord Injury Center, Balgrist University Hospital, Forchstrasse 340, 8008 Zurich, Switzerland; (C.M.); (M.H.); (R.H.H.); (C.R.); (A.C.); (M.B.)
| | - Armin Curt
- Spinal Cord Injury Center, Balgrist University Hospital, Forchstrasse 340, 8008 Zurich, Switzerland; (C.M.); (M.H.); (R.H.H.); (C.R.); (A.C.); (M.B.)
| | - Marc Bolliger
- Spinal Cord Injury Center, Balgrist University Hospital, Forchstrasse 340, 8008 Zurich, Switzerland; (C.M.); (M.H.); (R.H.H.); (C.R.); (A.C.); (M.B.)
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Cappellini G, Sylos-Labini F, Dewolf AH, Solopova IA, Morelli D, Lacquaniti F, Ivanenko Y. Maturation of the Locomotor Circuitry in Children With Cerebral Palsy. Front Bioeng Biotechnol 2020; 8:998. [PMID: 32974319 PMCID: PMC7462003 DOI: 10.3389/fbioe.2020.00998] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 07/30/2020] [Indexed: 12/26/2022] Open
Abstract
The first years of life represent an important phase of maturation of the central nervous system, processing of sensory information, posture control and acquisition of the locomotor function. Cerebral palsy (CP) is the most common group of motor disorders in childhood attributed to disturbances in the fetal or infant brain, frequently resulting in impaired gait. Here we will consider various findings about functional maturation of the locomotor output in early infancy, and how much the dysfunction of gait in children with CP can be related to spinal neuronal networks vs. supraspinal dysfunction. A better knowledge about pattern generation circuitries in infancy may improve our understanding of developmental motor disorders, highlighting the necessity for regulating the functional properties of abnormally developed neuronal locomotor networks as a target for early sensorimotor rehabilitation. Various clinical approaches and advances in biotechnology are also considered that might promote acquisition of the locomotor function in infants at risk for locomotor delays.
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Affiliation(s)
- Germana Cappellini
- Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, Rome, Italy.,Department of Pediatric Neurorehabilitation, IRCCS Santa Lucia Foundation, Rome, Italy
| | | | - Arthur H Dewolf
- Centre of Space Bio-medicine and Department of Systems Medicine, University of Rome "Tor Vergata", Rome, Italy
| | - Irina A Solopova
- Laboratory of Neurobiology of Motor Control, Institute for Information Transmission Problems, Moscow, Russia
| | - Daniela Morelli
- Department of Pediatric Neurorehabilitation, IRCCS Santa Lucia Foundation, Rome, Italy
| | - Francesco Lacquaniti
- Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, Rome, Italy.,Centre of Space Bio-medicine and Department of Systems Medicine, University of Rome "Tor Vergata", Rome, Italy
| | - Yury Ivanenko
- Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, Rome, Italy
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Valentinuzzi ME, Celani NML. Physical Rehabilitation: A Historical Look. IEEE Pulse 2020; 10:13-16. [PMID: 32011239 DOI: 10.1109/mpuls.2019.2958024] [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: 11/10/2022]
Abstract
Medicine aims toward restoring, maintaining, and improving human health, and engineering aims toward restoring, maintaining and improving human wellness. Both disciplines apply knowledge from science and technology at large to accomplish such objectives. Bioengineering, also called biomedical engineering, is defined as the application of engineering principles and techniques to problems in medicine and biology (always with restoration, maintenance, and improvement in mind), which now also includes veterinary medicine, and the environment in general.
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Capogrosso M, Gandar J, Greiner N, Moraud EM, Wenger N, Shkorbatova P, Musienko P, Minev I, Lacour S, Courtine G. Advantages of soft subdural implants for the delivery of electrochemical neuromodulation therapies to the spinal cord. J Neural Eng 2019; 15:026024. [PMID: 29339580 DOI: 10.1088/1741-2552/aaa87a] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
OBJECTIVE We recently developed soft neural interfaces enabling the delivery of electrical and chemical stimulation to the spinal cord. These stimulations restored locomotion in animal models of paralysis. Soft interfaces can be placed either below or above the dura mater. Theoretically, the subdural location combines many advantages, including increased selectivity of electrical stimulation, lower stimulation thresholds, and targeted chemical stimulation through local drug delivery. However, these advantages have not been documented, nor have their functional impact been studied in silico or in a relevant animal model of neurological disorders using a multimodal neural interface. APPROACH We characterized the recruitment properties of subdural interfaces using a realistic computational model of the rat spinal cord that included explicit representation of the spinal roots. We then validated and complemented computer simulations with electrophysiological experiments in rats. We additionally performed behavioral experiments in rats that received a lateral spinal cord hemisection and were implanted with a soft interface. MAIN RESULTS In silico and in vivo experiments showed that the subdural location decreased stimulation thresholds compared to the epidural location while retaining high specificity. This feature reduces power consumption and risks of long-term damage in the tissues, thus increasing the clinical safety profile of this approach. The hemisection induced a transient paralysis of the leg ipsilateral to the injury. During this period, the delivery of electrical stimulation restricted to the injured side combined with local chemical modulation enabled coordinated locomotor movements of the paralyzed leg without affecting the non-impaired leg in all tested rats. Electrode properties remained stable over time, while anatomical examinations revealed excellent bio-integration properties. SIGNIFICANCE Soft neural interfaces inserted subdurally provide the opportunity to deliver electrical and chemical neuromodulation therapies using a single, bio-compatible and mechanically compliant device that effectively alleviates locomotor deficits after spinal cord injury.
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Affiliation(s)
- Marco Capogrosso
- Center for Neuroprosthetics and Brain Mind Institute, School of Life Sciences, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland. Department of Medicine, Platform of Translational Neuroscience, University of Fribourg, Fribourg, Switzerland
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Shoji H, Ohashi M, Hirano T, Watanabe K, Endo N, Baba H, Kohno T. Mechanisms of noradrenergic modulation of synaptic transmission and neuronal excitability in ventral horn neurons of the rat spinal cord. Neuroscience 2019; 408:161-176. [PMID: 30986437 DOI: 10.1016/j.neuroscience.2019.03.026] [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] [Received: 07/16/2018] [Revised: 02/17/2019] [Accepted: 03/12/2019] [Indexed: 12/25/2022]
Abstract
Noradrenaline (NA) modulates the spinal motor networks for locomotion and facilitates neuroplasticity, possibly assisting neuronal network activation and neuroplasticity in the recovery phase of spinal cord injuries. However, neither the effects nor the mechanisms of NA on synaptic transmission and neuronal excitability in spinal ventral horn (VH) neurons are well characterized, especially in rats aged 7 postnatal days or older. To gain insight into NA regulation of VH neuronal activity, we used a whole-cell patch-clamp approach in late neonatal rats (postnatal day 7-15). In voltage-clamp recordings at -70 mV, NA increased the frequency and amplitude of excitatory postsynaptic currents via the activation of somatic α1- and β-adrenoceptors of presynaptic neurons. Moreover, NA induced an inward current through the activation of postsynapticα1- and β-adrenoceptors. At a holding potential of 0 mV, NA also increased frequency and amplitude of both GABAergic and glycinergic inhibitory postsynaptic currents via the activation of somatic adrenoceptors in presynaptic neurons. In current-clamp recordings, NA depolarized resting membrane potentials and increased the firing frequency of action potentials in VH neurons, indicating that it enhances the excitability of these neurons. Our findings provide new insights that establish NA-based pharmacological therapy as an effective method to activate neuronal networks of the spinal VH in the recovery phase of spinal cord injuries.
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Affiliation(s)
- Hirokazu Shoji
- Division of Orthopedic Surgery, Department of Regenerative and Transplant Medicine, Niigata University Graduate School of Medical and Dental Sciences, Asahimachidori 1-757, Chuo-ku, Niigata-city, 951-8510, Japan
| | - Masayuki Ohashi
- Division of Orthopedic Surgery, Department of Regenerative and Transplant Medicine, Niigata University Graduate School of Medical and Dental Sciences, Asahimachidori 1-757, Chuo-ku, Niigata-city, 951-8510, Japan
| | - Toru Hirano
- Division of Orthopedic Surgery, Department of Regenerative and Transplant Medicine, Niigata University Graduate School of Medical and Dental Sciences, Asahimachidori 1-757, Chuo-ku, Niigata-city, 951-8510, Japan
| | - Kei Watanabe
- Division of Orthopedic Surgery, Department of Regenerative and Transplant Medicine, Niigata University Graduate School of Medical and Dental Sciences, Asahimachidori 1-757, Chuo-ku, Niigata-city, 951-8510, Japan
| | - Naoto Endo
- Division of Orthopedic Surgery, Department of Regenerative and Transplant Medicine, Niigata University Graduate School of Medical and Dental Sciences, Asahimachidori 1-757, Chuo-ku, Niigata-city, 951-8510, Japan
| | - Hiroshi Baba
- Division of Anesthesiology, Niigata University Graduate School of Medical and Dental Sciences, Asahimachidori 1-757, Chuo-ku, Niigata-city, 951-8510, Japan
| | - Tatsuro Kohno
- Division of Anesthesiology, Niigata University Graduate School of Medical and Dental Sciences, Asahimachidori 1-757, Chuo-ku, Niigata-city, 951-8510, Japan; Department of Anesthesiology, Tohoku Medical and Pharmaceutical University, Fukumuro 1-12-1, Miyagino-ku, Sendai-city, 983-8512, Japan.
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Ganzer PD, Sharma G. Opportunities and challenges for developing closed-loop bioelectronic medicines. Neural Regen Res 2019; 14:46-50. [PMID: 30531069 PMCID: PMC6262994 DOI: 10.4103/1673-5374.243697] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The peripheral nervous system plays a major role in the maintenance of our physiology. Several peripheral nerves intimately regulate the state of the brain, spinal cord, and visceral systems. A new class of therapeutics, called bioelectronic medicines, are being developed to precisely regulate physiology and treat dysfunction using peripheral nerve stimulation. In this review, we first discuss new work using closed-loop bioelectronic medicine to treat upper limb paralysis. In contrast to open-loop bioelectronic medicines, closed-loop approaches trigger ‘on demand’ peripheral nerve stimulation due to a change in function (e.g., during an upper limb movement or a change in cardiopulmonary state). We also outline our perspective on timing rules for closed-loop bioelectronic stimulation, interface features for non-invasively stimulating peripheral nerves, and machine learning algorithms to recognize disease events for closed-loop stimulation control. Although there will be several challenges for this emerging field, we look forward to future bioelectronic medicines that can autonomously sense changes in the body, to provide closed-loop peripheral nerve stimulation and treat disease.
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Affiliation(s)
- Patrick D Ganzer
- Medical Devices and Neuromodulation, Battelle Memorial Institute, Columbus, OH, USA
| | - Gaurav Sharma
- Medical Devices and Neuromodulation, Battelle Memorial Institute, Columbus, OH, USA
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14
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Analysis of limb movement synchronization in primates locomotion. ANTHROPOLOGICAL REVIEW 2018. [DOI: 10.2478/anre-2018-0036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The authors present an original mathematical model based on features identified with discrete variables using vector and hierarchical cluster analysis in primates locomotion. Proposed model allows to formalize and analyze the synchronization variability of movements in given locomotion types of adaptation and specialization in monkeys, apes and humans. The material covers observations of 102 forms including 9 species of primates: the chimpanzee, bonobo, orangutan, gibbon, gelada, mandrill, brown capuchin and ring–tailed lemur. The studies included also the synchronization of locomotory movements in man. The sequences of moves of pectoral and pelvic limbs, right and left, were studied in four categories: walking, running, jumping and brachiation. The locomotion movements depend on the brain centers and allow to find phylogenetic relations between examined forms in the evolution process.
The knowledge of the pattern of movements is used in the treatment of paraplegia and paraparesis in humans.
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15
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Doyle C, Cristofaro V, Sullivan MP, Adam RM. Inosine - a Multifunctional Treatment for Complications of Neurologic Injury. Cell Physiol Biochem 2018; 49:2293-2303. [PMID: 30261493 DOI: 10.1159/000493831] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 09/18/2018] [Indexed: 01/31/2023] Open
Abstract
Spinal cord injury (SCI) caused by trauma or disease leads to motor and sensory abnormalities that depend on the level, severity and duration of the lesion. The most obvious consequence of SCI is paralysis affecting lower and upper limbs. SCI also leads to loss of bladder and bowel control, both of which have a deleterious, life-long impact on the social, psychological, functional, medical and economic well being of affected individuals. Currently, there is neither a cure for SCI nor is there adequate management of its consequences. Although medications provide symptomatic relief for the complications of SCI including muscle spasms, lower urinary tract dysfunction and hyperreflexic bowel, strategies for repair of spinal injuries and recovery of normal limb and organ function are still to be realized. In this review, we discuss experimental evidence supporting the use of the naturally occurring purine nucleoside inosine to improve the devastating sequelae of SCI. Evidence suggests inosine is a safe, novel agent with multifunctional properties that is effective in treating complications of SCI and other neuropathies.
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Affiliation(s)
- Claire Doyle
- Urological Diseases Research Center, Boston Children's Hospital, Boston, Massachusetts, USA.,Department of Surgery, Harvard Medical School, Boston, Massachusetts, USA
| | - Vivian Cristofaro
- Department of Surgery, Harvard Medical School, Boston, Massachusetts, USA.,Division of Urology, VA Boston Healthcare System, Boston, Massachusetts, USA.,Department of Surgery, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Maryrose P Sullivan
- Department of Surgery, Harvard Medical School, Boston, Massachusetts, USA.,Division of Urology, VA Boston Healthcare System, Boston, Massachusetts, USA.,Department of Surgery, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Rosalyn M Adam
- Urological Diseases Research Center, Boston Children's Hospital, Boston, Massachusetts, USA.,Department of Surgery, Harvard Medical School, Boston, Massachusetts, USA
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16
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Rath M, Vette AH, Ramasubramaniam S, Li K, Burdick J, Edgerton VR, Gerasimenko YP, Sayenko DG. Trunk Stability Enabled by Noninvasive Spinal Electrical Stimulation after Spinal Cord Injury. J Neurotrauma 2018; 35:2540-2553. [PMID: 29786465 DOI: 10.1089/neu.2017.5584] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Electrical neuromodulation of spinal networks improves the control of movement of the paralyzed limbs after spinal cord injury (SCI). However, the potential of noninvasive spinal stimulation to facilitate postural trunk control during sitting in humans with SCI has not been investigated. We hypothesized that transcutaneous electrical stimulation of the lumbosacral enlargement can improve trunk posture. Eight participants with non-progressive SCI at C3-T9, American Spinal Injury Association Impairment Scale (AIS) A or C, performed different motor tasks during sitting. Electromyography of the trunk muscles, three-dimensional kinematics, and force plate data were acquired. Spinal stimulation improved trunk control during sitting in all tested individuals. Stimulation resulted in elevated activity of the erector spinae, rectus abdominis, and external obliques, contributing to improved trunk control, more natural anterior pelvic tilt and lordotic curve, and greater multi-directional seated stability. During spinal stimulation, the center of pressure (COP) displacements decreased to 1.36 ± 0.98 mm compared with 4.74 ± 5.41 mm without stimulation (p = 0.0156) in quiet sitting, and the limits of stable displacement increased by 46.92 ± 35.66% (p = 0.0156), 36.92 ± 30.48% (p = 0.0156), 54.67 ± 77.99% (p = 0.0234), and 22.70 ± 26.09% (p = 0.0391) in the forward, backward, right, and left directions, respectively. During self-initiated perturbations, the correlation between anteroposterior arm velocity and the COP displacement decreased from r = 0.5821 (p = 0.0007) without to r = 0.5115 (p = 0.0039) with stimulation, indicating improved trunk stability. These data demonstrate that the spinal networks can be modulated transcutaneously with tonic electrical spinal stimulation to physiological states sufficient to generate a more stable, erect sitting posture after chronic paralysis.
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Affiliation(s)
- Mrinal Rath
- 1 Department of Biomedical Engineering, University of California , Los Angeles, California.,2 Department of Integrative Biology and Physiology, University of California , Los Angeles, California
| | - Albert H Vette
- 3 Department of Mechanical Engineering, University of Alberta , Donadeo Innovation Centre for Engineering, Edmonton, Alberta, Canada .,4 Glenrose Rehabilitation Hospital , Alberta Health Services, Edmonton, Alberta, Canada
| | | | - Kun Li
- 5 Division of Engineering and Applied Sciences, California Institute of Technology , Pasadena, California
| | - Joel Burdick
- 5 Division of Engineering and Applied Sciences, California Institute of Technology , Pasadena, California
| | - Victor R Edgerton
- 1 Department of Biomedical Engineering, University of California , Los Angeles, California.,2 Department of Integrative Biology and Physiology, University of California , Los Angeles, California.,6 Department of Neurobiology and Neurosurgery, University of California , Los Angeles, California.,7 Institut Guttmann, Hospital de Neurorehabilitació, Institut Universitari adscrit a la Universitat Autònoma de Barcelona , Barcelona, Badalona, Spain .,8 Centre for Neuroscience and Regenerative Medicine, Faculty of Science, University of Technology , Sydney, Australia
| | - Yury P Gerasimenko
- 2 Department of Integrative Biology and Physiology, University of California , Los Angeles, California.,9 Pavlov Institute of Physiology , St. Petersburg, Russia
| | - Dimitry G Sayenko
- 2 Department of Integrative Biology and Physiology, University of California , Los Angeles, California.,10 Department of Neurosurgery, Center for Neuroregeneration, Houston Methodist Research Institute , Houston, Texas
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17
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Interfacing with the nervous system: a review of current bioelectric technologies. Neurosurg Rev 2017; 42:227-241. [PMID: 29063229 DOI: 10.1007/s10143-017-0920-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 09/15/2017] [Accepted: 10/09/2017] [Indexed: 02/07/2023]
Abstract
The aim of this study is to discuss the state of the art with regard to established or promising bioelectric therapies meant to alter or control neurologic function. We present recent reports on bioelectric technologies that interface with the nervous system at three potential sites-(1) the end organ, (2) the peripheral nervous system, and (3) the central nervous system-while exploring practical and clinical considerations. A literature search was executed on PubMed, IEEE, and Web of Science databases. A review of the current literature was conducted to examine functional and histomorphological effects of neuroprosthetic interfaces with a focus on end-organ, peripheral, and central nervous system interfaces. Innovations in bioelectric technologies are providing increasing selectivity in stimulating distinct nerve fiber populations in order to activate discrete muscles. Significant advances in electrode array design focus on increasing selectivity, stability, and functionality of implantable neuroprosthetics. The application of neuroprosthetics to paretic nerves or even directly stimulating or recording from the central nervous system holds great potential in advancing the field of nerve and tissue bioelectric engineering and contributing to clinical care. Although current physiotherapeutic and surgical treatments seek to restore function, structure, or comfort, they bear significant limitations in enabling cosmetic or functional recovery. Instead, the introduction of bioelectric technology may play a role in the restoration of function in patients with neurologic deficits.
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18
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Anglister L, Cherniak M, Lev-Tov A. Ascending pathways that mediate cholinergic modulation of lumbar motor activity. J Neurochem 2017; 142 Suppl 2:82-89. [PMID: 28791705 DOI: 10.1111/jnc.14065] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 05/01/2017] [Accepted: 05/03/2017] [Indexed: 01/10/2023]
Abstract
Deciphering neuronal pathways that reactivate spinal central pattern generators (CPGs) and modulate the activity of spinal motoneurons in mammals in the absence of supraspinal control is important for understanding of neural control of movement and for developing novel therapeutic approaches to improve the mobility of spinal cord injury patients. Previously, we showed that the sacral and lumbar cholinergic system could potently modulate the locomotor CPGs in newborn rodents. Here, we review these and our more recent studies of sacral relay neurons with lumbar projections to the locomotor CPGs and to lumbar motoneurons and demonstrate that sacral and lumbar cholinergic components have the capacity to control the frequency of the locomotor CPGs and at the same time the motor output of the activated lumbar motoneurons during motor behavior. A model describing the suggested ascending sacro-lumbar connectivity involved in modulation of the locomotor rhythm by sacral cholinergic components is proposed and discussed. This is an article for the special issue XVth International Symposium on Cholinergic Mechanisms.
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Affiliation(s)
- Lili Anglister
- Department of Medical Neurobiology, IMRIC, the Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Meir Cherniak
- Department of Medical Neurobiology, IMRIC, the Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Aharon Lev-Tov
- Department of Medical Neurobiology, IMRIC, the Hebrew University-Hadassah Medical School, Jerusalem, Israel
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19
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Lemke KA, Aghayee A, Ashton RS. Deriving, regenerating, and engineering CNS tissues using human pluripotent stem cells. Curr Opin Biotechnol 2017; 47:36-42. [PMID: 28605638 DOI: 10.1016/j.copbio.2017.05.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 05/08/2017] [Indexed: 01/08/2023]
Abstract
Progress in deriving a spectrum of central nervous system cell phenotypes from human pluripotent stem cells has spurred significant advances in in vitro modeling and development of regenerative therapies for neurological disorders. While the clinical impact of these advances is still being evaluated, their integration with advanced tissue engineering methodologies and therapeutic approaches that induce neural circuit plasticity, respectively, remain underexplored frontiers.
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Affiliation(s)
- Kristen A Lemke
- Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI 53706, United States
| | - Alireza Aghayee
- Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI 53706, United States; Department of Material Science and Engineering, University of Wisconsin-Madison, Madison, WI 53715, United States
| | - Randolph S Ashton
- Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI 53706, United States; Department of Material Science and Engineering, University of Wisconsin-Madison, Madison, WI 53715, United States; Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI 53715, United States.
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20
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Chawla RS, Züchner M, Mastrangelopoulou M, Lambert FM, Glover JC, Boulland JL. Cellular reactions and compensatory tissue re-organization during spontaneous recovery after spinal cord injury in neonatal mice. Dev Neurobiol 2017; 77:928-946. [PMID: 28033684 DOI: 10.1002/dneu.22479] [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: 06/19/2016] [Revised: 11/08/2016] [Accepted: 12/06/2016] [Indexed: 01/23/2023]
Abstract
Following incomplete spinal cord injuries, neonatal mammals display a remarkable degree of behavioral recovery. Previously, we have demonstrated in neonatal mice a wholesale re-establishment and reorganization of synaptic connections from some descending axon tracts (Boulland et al.: PLoS One 8 (2013)). To assess the potential cellular mechanisms contributing to this recovery, we have here characterized a variety of cellular sequelae following thoracic compression injuries, focusing particularly on cell loss and proliferation, inflammation and reactive gliosis, and the dynamics of specific types of synaptic terminals. Early during the period of recovery, regressive events dominated. Tissue loss near the injury was severe, with about 80% loss of neurons and a similar loss of axons that later make up the white matter. There was no sign of neurogenesis, no substantial astroglial or microglial proliferation, no change in the ratio of M1 and M2 microglia and no appreciable generation of the terminal complement peptide C5a. One day after injury the number of synaptic terminals on lumbar motoneurons had dropped by a factor of 2, but normalized by 6 days. The ratio of VGLUT1/2+ to VGAT+ terminals remained similar in injured and uninjured spinal cords during this period. By 24 days after injury, when functional recovery is nearly complete, the density of 5-HT+ fibers below the injury site had increased by a factor of 2.5. Altogether this study shows that cellular reactions are diverse and dynamic. Pronounced recovery of both excitatory and inhibitory terminals and an increase in serotonergic innervation below the injury, coupled with a general lack of inflammation and reactive gliosis, are likely to contribute to the recovery. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 77: 928-946, 2017.
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Affiliation(s)
- Rishab S Chawla
- Laboratory of Neural Development and Optical Recording (NDEVOR), Division of Physiology, Department of Molecular Medicine, University of Oslo
| | - Mark Züchner
- Norwegian Center for Stem Cell Research, Oslo University Hospital.,Department of Neurosurgery, Oslo University Hospital
| | - Maria Mastrangelopoulou
- Laboratory of Neural Development and Optical Recording (NDEVOR), Division of Physiology, Department of Molecular Medicine, University of Oslo
| | - François M Lambert
- Laboratory of Neural Development and Optical Recording (NDEVOR), Division of Physiology, Department of Molecular Medicine, University of Oslo.,INCIA CNRS UMR 5287 Université de Bordeaux, Bordeaux, France
| | - Joel C Glover
- Laboratory of Neural Development and Optical Recording (NDEVOR), Division of Physiology, Department of Molecular Medicine, University of Oslo.,Norwegian Center for Stem Cell Research, Oslo University Hospital
| | - Jean-Luc Boulland
- Laboratory of Neural Development and Optical Recording (NDEVOR), Division of Physiology, Department of Molecular Medicine, University of Oslo.,Norwegian Center for Stem Cell Research, Oslo University Hospital
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21
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Huie JR, Morioka K, Haefeli J, Ferguson AR. What Is Being Trained? How Divergent Forms of Plasticity Compete To Shape Locomotor Recovery after Spinal Cord Injury. J Neurotrauma 2017; 34:1831-1840. [PMID: 27875927 DOI: 10.1089/neu.2016.4562] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Spinal cord injury (SCI) is a devastating syndrome that produces dysfunction in motor and sensory systems, manifesting as chronic paralysis, sensory changes, and pain disorders. The multi-faceted and heterogeneous nature of SCI has made effective rehabilitative strategies challenging. Work over the last 40 years has aimed to overcome these obstacles by harnessing the intrinsic plasticity of the spinal cord to improve functional locomotor recovery. Intensive training after SCI facilitates lower extremity function and has shown promise as a tool for retraining the spinal cord by engaging innate locomotor circuitry in the lumbar cord. As new training paradigms evolve, the importance of appropriate afferent input has emerged as a requirement for adaptive plasticity. The integration of kinematic, sensory, and loading force information must be closely monitored and carefully manipulated to optimize training outcomes. Inappropriate peripheral input may produce lasting maladaptive sensory and motor effects, such as central pain and spasticity. Thus, it is important to closely consider the type of afferent input the injured spinal cord receives. Here we review preclinical and clinical input parameters fostering adaptive plasticity, as well as those producing maladaptive plasticity that may undermine neurorehabilitative efforts. We differentiate between passive (hindlimb unloading [HU], limb immobilization) and active (peripheral nociception) forms of aberrant input. Furthermore, we discuss the timing of initiating exposure to afferent input after SCI for promoting functional locomotor recovery. We conclude by presenting a candidate rapid synaptic mechanism for maladaptive plasticity after SCI, offering a pharmacological target for restoring the capacity for adaptive spinal plasticity in real time.
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Affiliation(s)
- J Russell Huie
- 1 Department of Neurological Surgery, Brain and Spinal Injury Center, University of California , San Francisco, California
| | - Kazuhito Morioka
- 1 Department of Neurological Surgery, Brain and Spinal Injury Center, University of California , San Francisco, California
| | - Jenny Haefeli
- 1 Department of Neurological Surgery, Brain and Spinal Injury Center, University of California , San Francisco, California
| | - Adam R Ferguson
- 1 Department of Neurological Surgery, Brain and Spinal Injury Center, University of California , San Francisco, California.,2 San Francisco Veterans Affairs Medical Center , San Francisco, California
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22
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Krucoff MO, Rahimpour S, Slutzky MW, Edgerton VR, Turner DA. Enhancing Nervous System Recovery through Neurobiologics, Neural Interface Training, and Neurorehabilitation. Front Neurosci 2016; 10:584. [PMID: 28082858 PMCID: PMC5186786 DOI: 10.3389/fnins.2016.00584] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 12/06/2016] [Indexed: 12/21/2022] Open
Abstract
After an initial period of recovery, human neurological injury has long been thought to be static. In order to improve quality of life for those suffering from stroke, spinal cord injury, or traumatic brain injury, researchers have been working to restore the nervous system and reduce neurological deficits through a number of mechanisms. For example, neurobiologists have been identifying and manipulating components of the intra- and extracellular milieu to alter the regenerative potential of neurons, neuro-engineers have been producing brain-machine and neural interfaces that circumvent lesions to restore functionality, and neurorehabilitation experts have been developing new ways to revitalize the nervous system even in chronic disease. While each of these areas holds promise, their individual paths to clinical relevance remain difficult. Nonetheless, these methods are now able to synergistically enhance recovery of native motor function to levels which were previously believed to be impossible. Furthermore, such recovery can even persist after training, and for the first time there is evidence of functional axonal regrowth and rewiring in the central nervous system of animal models. To attain this type of regeneration, rehabilitation paradigms that pair cortically-based intent with activation of affected circuits and positive neurofeedback appear to be required-a phenomenon which raises new and far reaching questions about the underlying relationship between conscious action and neural repair. For this reason, we argue that multi-modal therapy will be necessary to facilitate a truly robust recovery, and that the success of investigational microscopic techniques may depend on their integration into macroscopic frameworks that include task-based neurorehabilitation. We further identify critical components of future neural repair strategies and explore the most updated knowledge, progress, and challenges in the fields of cellular neuronal repair, neural interfacing, and neurorehabilitation, all with the goal of better understanding neurological injury and how to improve recovery.
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Affiliation(s)
- Max O Krucoff
- Department of Neurosurgery, Duke University Medical Center Durham, NC, USA
| | - Shervin Rahimpour
- Department of Neurosurgery, Duke University Medical Center Durham, NC, USA
| | - Marc W Slutzky
- Department of Physiology, Feinberg School of Medicine, Northwestern UniversityChicago, IL, USA; Department of Neurology, Feinberg School of Medicine, Northwestern UniversityChicago, IL, USA
| | - V Reggie Edgerton
- Department of Integrative Biology and Physiology, University of California, Los Angeles Los Angeles, CA, USA
| | - Dennis A Turner
- Department of Neurosurgery, Duke University Medical CenterDurham, NC, USA; Department of Neurobiology, Duke University Medical CenterDurham, NC, USA; Research and Surgery Services, Durham Veterans Affairs Medical CenterDurham, NC, USA
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23
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Minassian K, Hofstoetter US. Spinal Cord Stimulation and Augmentative Control Strategies for Leg Movement after Spinal Paralysis in Humans. CNS Neurosci Ther 2016; 22:262-70. [PMID: 26890324 DOI: 10.1111/cns.12530] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 01/28/2016] [Accepted: 01/28/2016] [Indexed: 12/30/2022] Open
Abstract
Severe spinal cord injury is a devastating condition, tearing apart long white matter tracts and causing paralysis and disability of body functions below the lesion. But caudal to most injuries, the majority of neurons forming the distributed propriospinal system, the localized gray matter spinal interneuronal circuitry, and spinal motoneuron populations are spared. Epidural spinal cord stimulation can gain access to this neural circuitry. This review focuses on the capability of the human lumbar spinal cord to generate stereotyped motor output underlying standing and stepping, as well as full weight-bearing standing and rhythmic muscle activation during assisted treadmill stepping in paralyzed individuals in response to spinal cord stimulation. By enhancing the excitability state of the spinal circuitry, the stimulation can have an enabling effect upon otherwise "silent" translesional volitional motor control. Strategies for achieving functional movement in patients with severe injuries based on minimal translesional intentional control, task-specific proprioceptive feedback, and next-generation spinal cord stimulation systems will be reviewed. The role of spinal cord stimulation can go well beyond the immediate generation of motor output. With recently developed training paradigms, it can become a major rehabilitation approach in spinal cord injury for augmenting and steering trans- and sublesional plasticity for lasting therapeutic benefits.
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Affiliation(s)
- Karen Minassian
- Center for Medical Physics and Biomedical Engineering, Medical University Vienna, Vienna, Austria
| | - Ursula S Hofstoetter
- Center for Medical Physics and Biomedical Engineering, Medical University Vienna, Vienna, Austria
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