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Wang Z, Duan H, Hao F, Hao P, Zhao W, Gao Y, Gu Y, Song J, Li X, Yang Z. Circuit reconstruction of newborn neurons after spinal cord injury in adult rats via an NT3-chitosan scaffold. Prog Neurobiol 2023; 220:102375. [PMID: 36410665 DOI: 10.1016/j.pneurobio.2022.102375] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 11/07/2022] [Accepted: 11/15/2022] [Indexed: 11/22/2022]
Abstract
An implanted neurotrophin-3 (NT3)-chitosan scaffold can recruit endogenous neural stem cells to migrate to a lesion region and differentiate into mature neurons after adult spinal cord injury (SCI). However, the identities of these newborn neurons and whether they can form functional synapses and circuits to promote recovery after paraplegia remain unknown. By using combined advanced technologies, we revealed here that the newborn neurons of several subtypes received synaptic input from the corticospinal tract (CST), rubrospinal tract (RST), and supraspinal tracts. They formed a functional neural circuit at the injured spinal region, further driving the local circuits beneath the lesion. Our results showed that the NT3-chitosan scaffold facilitated the maturation of spinal neurons and the reestablishment of the spinal neural circuit in the lesion region 12 weeks after SCI. Transsynaptic virus experiments revealed that these newborn spinal neurons received synaptic connections from the CST and RST and drove the neural circuit beneath the lesion via newly formed synapses. These re-established circuits successfully recovered the formation and function of the neuromuscular junction (NMJ) beneath the lesion spinal segments. These findings suggest that the NT3-chitosan scaffold promotes the formation of relay neural circuits to accommodate various types of brain descending inputs and facilitate functional recovery after paraplegia.
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Affiliation(s)
- Zijue Wang
- Department of Neurobiology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Hongmei Duan
- Department of Neurobiology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Fei Hao
- Beijing Key Laboratory for Biomaterials and Neural Regeneration, School of Engineering Medicine, Beihang University, Beijing 100191, China
| | - Peng Hao
- Department of Neurobiology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Wen Zhao
- Department of Neurobiology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Yudan Gao
- Department of Neurobiology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Yiming Gu
- Physical Education Department, Capital University of Economics and Business, Beijing 100070, China
| | - Jianren Song
- Translational Research Institute of Brain and Brain-Like Intelligence, Shanghai Fourth People's Hospital, School of Medicine, Tongji University, Shanghai 200434, China; Clinical Center for Brain and Spinal Cord Research, Tongji University, Shanghai 200092, China.
| | - Xiaoguang Li
- Department of Neurobiology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China; Department of Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China.
| | - Zhaoyang Yang
- Department of Neurobiology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China.
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2
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Dissanayake KN, Redman RR, Mackenzie H, Eddleston M, Ribchester RR. "Calcium bombs" as harbingers of synaptic pathology and their mitigation by magnesium at murine neuromuscular junctions. Front Mol Neurosci 2022; 15:937974. [PMID: 35959105 PMCID: PMC9361872 DOI: 10.3389/fnmol.2022.937974] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 07/04/2022] [Indexed: 12/24/2022] Open
Abstract
Excitotoxicity is thought to be an important factor in the onset and progression of amyotrophic lateral sclerosis (ALS). Evidence from human and animal studies also indicates that early signs of ALS include degeneration of motor nerve terminals at neuromuscular junctions (NMJs), before degeneration of motor neuron cell bodies. Here we used a model of excitotoxicity at NMJs in isolated mouse muscle, utilizing the organophosphorus (OP) compound omethoate, which inhibits acetylcholinesterase activity. Acute exposure to omethoate (100 μM) induced prolonged motor endplate contractures in response to brief tetanic nerve stimulation at 20-50 Hz. In some muscle fibers, Fluo-4 fluorescence showed association of these contractures with explosive increases in Ca2+ ("calcium bombs") localized to motor endplates. Calcium bombs were strongly and selectively mitigated by increasing Mg2+ concentration in the bathing medium from 1 to 5 mM. Overnight culture of nerve-muscle preparations from WldS mice in omethoate or other OP insecticide components and their metabolites (dimethoate, cyclohexanone, and cyclohexanol) induced degeneration of NMJs. This degeneration was also strongly mitigated by increasing [Mg2+] from 1 to 5 mM. Thus, equivalent increases in extracellular [Mg2+] mitigated both post-synaptic calcium bombs and degeneration of NMJs. The data support a link between Ca2+ and excitotoxicity at NMJs and suggest that elevating extracellular [Mg2+] could be an effective intervention in treatment of synaptic pathology induced by excitotoxic triggers.
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Affiliation(s)
- Kosala N. Dissanayake
- Euan MacDonald Centre for Motor Neurone Disease Research, The University of Edinburgh, Edinburgh, United Kingdom,Centre for Discovery Brain Sciences, The University of Edinburgh, Edinburgh, United Kingdom
| | - Robert R. Redman
- Euan MacDonald Centre for Motor Neurone Disease Research, The University of Edinburgh, Edinburgh, United Kingdom,Centre for Discovery Brain Sciences, The University of Edinburgh, Edinburgh, United Kingdom
| | - Harry Mackenzie
- Euan MacDonald Centre for Motor Neurone Disease Research, The University of Edinburgh, Edinburgh, United Kingdom,Centre for Discovery Brain Sciences, The University of Edinburgh, Edinburgh, United Kingdom
| | - Michael Eddleston
- Clinical Pharmacology, Toxicology and Therapeutics, Centre for Cardiovascular Science, Queen’s Medical Research Institute, The University of Edinburgh, Edinburgh, United Kingdom
| | - Richard R. Ribchester
- Euan MacDonald Centre for Motor Neurone Disease Research, The University of Edinburgh, Edinburgh, United Kingdom,Centre for Discovery Brain Sciences, The University of Edinburgh, Edinburgh, United Kingdom,*Correspondence: Richard R. Ribchester,
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3
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Patejdl R, Klawitter F, Walter U, Zanaty K, Schwandner F, Sellmann T, Porath K, Ehler J. A novel ex vivo model for critical illness neuromyopathy using freshly resected human colon smooth muscle. Sci Rep 2021; 11:24249. [PMID: 34930954 PMCID: PMC8688412 DOI: 10.1038/s41598-021-03711-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 12/02/2021] [Indexed: 01/15/2023] Open
Abstract
Patients suffering from critical illness are at risk to develop critical illness neuromyopathy (CINM). The underlying pathophysiology is complex and controversial. A central question is whether soluble serum factors are involved in the pathogenesis of CINM. In this study, smooth muscle preparations obtained from the colon of patients undergoing elective surgery were used to investigate the effects of serum from critically ill patients. At the time of blood draw, CINM was assessed by clinical rating and electrophysiology. Muscle strips were incubated with serum of healthy controls or patients in organ baths and isometric force was measured. Fifteen samples from healthy controls and 98 from patients were studied. Ratios of responses to electric field stimulation (EFS) before and after incubation were 118% for serum from controls and 51% and 62% with serum from critically ill patients obtained at day 3 and 10 of critical illness, respectively (p = 0.003, One-Way-ANOVA). Responses to carbachol and high-K+ were equal between these groups. Ratios of post/pre-EFS responses correlated with less severe CINM. These results support the existence of pathogenic, i.e. neurotoxic factors in the serum of critically ill patients. Using human colon smooth muscle as a bioassay may facilitate their future molecular identification.
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Affiliation(s)
- Robert Patejdl
- Oscar Langendorff Institute of Physiology, Rostock University Medical Center, Gertrudenstraße 9, 18057, Rostock, Germany.
| | - Felix Klawitter
- Department of Anesthesiology and Intensive Care Medicine, Rostock University Medical Center, Rostock, Germany
| | - Uwe Walter
- Department of Neurology, Rostock University Medical Center, Rostock, Germany
| | - Karim Zanaty
- Oscar Langendorff Institute of Physiology, Rostock University Medical Center, Gertrudenstraße 9, 18057, Rostock, Germany
| | - Frank Schwandner
- Department of General, Thoracic, Vascular and Transplantation Surgery, Rostock University Medical Center, Rostock, Germany
| | - Tina Sellmann
- Oscar Langendorff Institute of Physiology, Rostock University Medical Center, Gertrudenstraße 9, 18057, Rostock, Germany
| | - Katrin Porath
- Oscar Langendorff Institute of Physiology, Rostock University Medical Center, Gertrudenstraße 9, 18057, Rostock, Germany
| | - Johannes Ehler
- Department of Anesthesiology and Intensive Care Medicine, Rostock University Medical Center, Rostock, Germany
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4
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Roesl C, Evans ER, Dissanayake KN, Boczonadi V, Jones RA, Jordan GR, Ledahawsky L, Allen GCC, Scott M, Thomson A, Wishart TM, Hughes DI, Mead RJ, Shone CC, Slater CR, Gillingwater TH, Skehel PA, Ribchester RR. Confocal Endomicroscopy of Neuromuscular Junctions Stained with Physiologically Inert Protein Fragments of Tetanus Toxin. Biomolecules 2021; 11:1499. [PMID: 34680132 PMCID: PMC8534034 DOI: 10.3390/biom11101499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 10/07/2021] [Accepted: 10/08/2021] [Indexed: 01/09/2023] Open
Abstract
Live imaging of neuromuscular junctions (NMJs) in situ has been constrained by the suitability of ligands for inert vital staining of motor nerve terminals. Here, we constructed several truncated derivatives of the tetanus toxin C-fragment (TetC) fused with Emerald Fluorescent Protein (emGFP). Four constructs, namely full length emGFP-TetC (emGFP-865:TetC) or truncations comprising amino acids 1066-1315 (emGFP-1066:TetC), 1093-1315 (emGFP-1093:TetC) and 1109-1315 (emGFP-1109:TetC), produced selective, high-contrast staining of motor nerve terminals in rodent or human muscle explants. Isometric tension and intracellular recordings of endplate potentials from mouse muscles indicated that neither full-length nor truncated emGFP-TetC constructs significantly impaired NMJ function or transmission. Motor nerve terminals stained with emGFP-TetC constructs were readily visualised in situ or in isolated preparations using fibre-optic confocal endomicroscopy (CEM). emGFP-TetC derivatives and CEM also visualised regenerated NMJs. Dual-waveband CEM imaging of preparations co-stained with fluorescent emGFP-TetC constructs and Alexa647-α-bungarotoxin resolved innervated from denervated NMJs in axotomized WldS mouse muscle and degenerating NMJs in transgenic SOD1G93A mouse muscle. Our findings highlight the region of the TetC fragment required for selective binding and visualisation of motor nerve terminals and show that fluorescent derivatives of TetC are suitable for in situ morphological and physiological characterisation of healthy, injured and diseased NMJs.
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Affiliation(s)
- Cornelia Roesl
- Centre for Discovery Brain Sciences and the Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, George Square, Edinburgh EH8 9XD, UK; (C.R.); (K.N.D.); (R.A.J.); (G.R.J.); (L.L.); (G.C.C.A.); (M.S.); (A.T.); (T.H.G.)
| | - Elizabeth R. Evans
- Public Health England, National Infection Service, Porton Down, Salisbury SP4 0JG, UK; (E.R.E.); (C.C.S.)
| | - Kosala N. Dissanayake
- Centre for Discovery Brain Sciences and the Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, George Square, Edinburgh EH8 9XD, UK; (C.R.); (K.N.D.); (R.A.J.); (G.R.J.); (L.L.); (G.C.C.A.); (M.S.); (A.T.); (T.H.G.)
| | - Veronika Boczonadi
- Applied Neuromuscular Junction Facility, Bio-Imaging Unit, Biosciences Institute, University of Newcastle-upon-Tyne, Framlington Place, Newcastle-upon-Tyne NE2 4HH, UK; (V.B.); (C.R.S.)
| | - Ross A. Jones
- Centre for Discovery Brain Sciences and the Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, George Square, Edinburgh EH8 9XD, UK; (C.R.); (K.N.D.); (R.A.J.); (G.R.J.); (L.L.); (G.C.C.A.); (M.S.); (A.T.); (T.H.G.)
| | - Graeme R. Jordan
- Centre for Discovery Brain Sciences and the Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, George Square, Edinburgh EH8 9XD, UK; (C.R.); (K.N.D.); (R.A.J.); (G.R.J.); (L.L.); (G.C.C.A.); (M.S.); (A.T.); (T.H.G.)
| | - Leire Ledahawsky
- Centre for Discovery Brain Sciences and the Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, George Square, Edinburgh EH8 9XD, UK; (C.R.); (K.N.D.); (R.A.J.); (G.R.J.); (L.L.); (G.C.C.A.); (M.S.); (A.T.); (T.H.G.)
| | - Guy C. C. Allen
- Centre for Discovery Brain Sciences and the Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, George Square, Edinburgh EH8 9XD, UK; (C.R.); (K.N.D.); (R.A.J.); (G.R.J.); (L.L.); (G.C.C.A.); (M.S.); (A.T.); (T.H.G.)
| | - Molly Scott
- Centre for Discovery Brain Sciences and the Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, George Square, Edinburgh EH8 9XD, UK; (C.R.); (K.N.D.); (R.A.J.); (G.R.J.); (L.L.); (G.C.C.A.); (M.S.); (A.T.); (T.H.G.)
| | - Alanna Thomson
- Centre for Discovery Brain Sciences and the Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, George Square, Edinburgh EH8 9XD, UK; (C.R.); (K.N.D.); (R.A.J.); (G.R.J.); (L.L.); (G.C.C.A.); (M.S.); (A.T.); (T.H.G.)
| | - Thomas M. Wishart
- The Roslin Institute, Royal (Dick) School of Veterinary Studies, College of Medicine and Veterinary Medicine, University of Edinburgh, Easter Bush, Edinburgh EH25 9RG, UK;
| | - David I. Hughes
- Spinal Cord Research Group, Institute of Neuroscience and Psychology, University of Glasgow, Glasgow G12 8QQ, UK;
| | - Richard J. Mead
- Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Glossop Road, Sheffield S10 2HQ, UK;
| | - Clifford C. Shone
- Public Health England, National Infection Service, Porton Down, Salisbury SP4 0JG, UK; (E.R.E.); (C.C.S.)
| | - Clarke R. Slater
- Applied Neuromuscular Junction Facility, Bio-Imaging Unit, Biosciences Institute, University of Newcastle-upon-Tyne, Framlington Place, Newcastle-upon-Tyne NE2 4HH, UK; (V.B.); (C.R.S.)
| | - Thomas H. Gillingwater
- Centre for Discovery Brain Sciences and the Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, George Square, Edinburgh EH8 9XD, UK; (C.R.); (K.N.D.); (R.A.J.); (G.R.J.); (L.L.); (G.C.C.A.); (M.S.); (A.T.); (T.H.G.)
| | - Paul A. Skehel
- Centre for Discovery Brain Sciences and the Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, George Square, Edinburgh EH8 9XD, UK; (C.R.); (K.N.D.); (R.A.J.); (G.R.J.); (L.L.); (G.C.C.A.); (M.S.); (A.T.); (T.H.G.)
| | - Richard R. Ribchester
- Centre for Discovery Brain Sciences and the Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, George Square, Edinburgh EH8 9XD, UK; (C.R.); (K.N.D.); (R.A.J.); (G.R.J.); (L.L.); (G.C.C.A.); (M.S.); (A.T.); (T.H.G.)
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5
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Villarroel-Campos D, Schiavo G, Sleigh JN. Dissection, in vivo imaging and analysis of the mouse epitrochleoanconeus muscle. J Anat 2021; 241:1108-1119. [PMID: 34121181 PMCID: PMC9558155 DOI: 10.1111/joa.13478] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 05/07/2021] [Accepted: 05/18/2021] [Indexed: 12/25/2022] Open
Abstract
Analysis of rodent muscles affords an opportunity to glean key insights into neuromuscular development and the detrimental impact of disease‐causing genetic mutations. Muscles of the distal leg, for instance the gastrocnemius and tibialis anterior, are commonly used in such studies with mice and rats. However, thin and flat muscles, which can be dissected, processed and imaged without major disruption to muscle fibres and nerve‐muscle contacts, are more suitable for accurate and detailed analyses of the peripheral motor nervous system. One such wholemount muscle is the predominantly fast twitch epitrochleoanconeus (ETA), which is located in the upper forelimb, innervated by the radial nerve, and contains relatively large and uniformly flat neuromuscular junctions (NMJs). To facilitate incorporation of the ETA into the experimental toolkit of the neuromuscular disease field, here, we describe a simple method for its rapid isolation (<5 min), supported by high‐resolution videos and step‐by‐step images. Furthermore, we outline how the ETA can be imaged in live, anaesthetised mice, to enable examination of dynamic cellular processes occurring at the NMJ and within intramuscular axons, including transport of organelles, such as mitochondria and signalling endosomes. Finally, we present reference data on wild‐type ETA fibre‐type composition in young adult, male C57BL6/J mice. Comparative neuroanatomical studies of different muscles in rodent models of disease can generate critical insights into pathogenesis and pathology; dissection of the wholemount ETA provides the possibility to diversify the repertoire of muscles analysed for this endeavour.
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Affiliation(s)
- David Villarroel-Campos
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Giampietro Schiavo
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, UK.,UK Dementia Research Institute, University College London, London, UK
| | - James N Sleigh
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, UK.,UK Dementia Research Institute, University College London, London, UK
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6
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Plesia M, Stevens OA, Lloyd GR, Kendall CA, Coldicott I, Kennerley AJ, Miller G, Shaw PJ, Mead RJ, Day JCC, Alix JJP. In Vivo Fiber Optic Raman Spectroscopy of Muscle in Preclinical Models of Amyotrophic Lateral Sclerosis and Duchenne Muscular Dystrophy. ACS Chem Neurosci 2021; 12:1768-1776. [PMID: 33950665 PMCID: PMC8154326 DOI: 10.1021/acschemneuro.0c00794] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 04/30/2021] [Indexed: 12/13/2022] Open
Abstract
Neuromuscular diseases result in muscle weakness, disability, and, in many instances, death. Preclinical models form the bedrock of research into these disorders, and the development of in vivo and potentially translational biomarkers for the accurate identification of disease is crucial. Spontaneous Raman spectroscopy can provide a rapid, label-free, and highly specific molecular fingerprint of tissue, making it an attractive potential biomarker. In this study, we have developed and tested an in vivo intramuscular fiber optic Raman technique in two mouse models of devastating human neuromuscular diseases, amyotrophic lateral sclerosis, and Duchenne muscular dystrophy (SOD1G93A and mdx, respectively). The method identified diseased and healthy muscle with high classification accuracies (area under the receiver operating characteristic curves (AUROC): 0.76-0.92). In addition, changes in diseased muscle over time were also identified (AUROCs 0.89-0.97). Key spectral changes related to proteins and the loss of α-helix protein structure. Importantly, in vivo recording did not cause functional motor impairment and only a limited, resolving tissue injury was seen on high-resolution magnetic resonance imaging. Lastly, we demonstrate that ex vivo muscle from human patients with these conditions produced similar spectra to those observed in mice. We conclude that spontaneous Raman spectroscopy of muscle shows promise as a translational research tool.
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Affiliation(s)
- Maria Plesia
- Sheffield
Institute for Translational Neuroscience, University of Sheffield, Sheffield S10 2HQ, UK
| | - Oliver A. Stevens
- Interface
Analysis Centre, School of Physics, University
of Bristol, Bristol BS8 1TL, UK
| | - Gavin R. Lloyd
- Phenome
Centre Birmingham, University of Birmingham, Birmingham B15 2TT, UK
- Biophotonics
Research Unit, Gloucestershire Hospitals
NHS Foundation Trust, Gloucester GL1 3NN, UK
| | - Catherine A. Kendall
- Biophotonics
Research Unit, Gloucestershire Hospitals
NHS Foundation Trust, Gloucester GL1 3NN, UK
| | - Ian Coldicott
- Sheffield
Institute for Translational Neuroscience, University of Sheffield, Sheffield S10 2HQ, UK
| | | | - Gaynor Miller
- Department
of Oncology and Metabolism, University of
Sheffield, Sheffield S10 2RX, UK
| | - Pamela J. Shaw
- Sheffield
Institute for Translational Neuroscience, University of Sheffield, Sheffield S10 2HQ, UK
- Cross-Faculty
Neuroscience Institute, University of Sheffield, Sheffield S10 2HQ, UK
| | - Richard J. Mead
- Sheffield
Institute for Translational Neuroscience, University of Sheffield, Sheffield S10 2HQ, UK
- Cross-Faculty
Neuroscience Institute, University of Sheffield, Sheffield S10 2HQ, UK
| | - John C. C. Day
- Interface
Analysis Centre, School of Physics, University
of Bristol, Bristol BS8 1TL, UK
| | - James J. P. Alix
- Sheffield
Institute for Translational Neuroscience, University of Sheffield, Sheffield S10 2HQ, UK
- Cross-Faculty
Neuroscience Institute, University of Sheffield, Sheffield S10 2HQ, UK
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7
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Ribchester RR, Mehta AR. Neuromuscular junctions: mind meeting matter. Lancet Neurol 2021; 20:93. [PMID: 33484653 DOI: 10.1016/s1474-4422(20)30486-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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8
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Theme 8 Clinical imaging and electrophysiology. Amyotroph Lateral Scler Frontotemporal Degener 2018; 19:240-263. [DOI: 10.1080/21678421.2018.1510575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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9
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Sleigh JN, Vagnoni A, Twelvetrees AE, Schiavo G. Methodological advances in imaging intravital axonal transport. F1000Res 2017; 6:200. [PMID: 28344778 PMCID: PMC5333613 DOI: 10.12688/f1000research.10433.1] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/27/2017] [Indexed: 11/25/2022] Open
Abstract
Axonal transport is the active process whereby neurons transport cargoes such as organelles and proteins anterogradely from the cell body to the axon terminal and retrogradely in the opposite direction. Bi-directional transport in axons is absolutely essential for the functioning and survival of neurons and appears to be negatively impacted by both aging and diseases of the nervous system, such as Alzheimer’s disease and amyotrophic lateral sclerosis. The movement of individual cargoes along axons has been studied
in vitro in live neurons and tissue explants for a number of years; however, it is currently unclear as to whether these systems faithfully and consistently replicate the
in vivo situation. A number of intravital techniques originally developed for studying diverse biological events have recently been adapted to monitor axonal transport in real-time in a range of live organisms and are providing novel insight into this dynamic process. Here, we highlight these methodological advances in intravital imaging of axonal transport, outlining key strengths and limitations while discussing findings, possible improvements, and outstanding questions.
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Affiliation(s)
- James N Sleigh
- Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, London, UK
| | - Alessio Vagnoni
- Division of Cell Biology, MRC Laboratory of Molecular Biology, Cambridge, UK; Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Alison E Twelvetrees
- Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, London, UK
| | - Giampietro Schiavo
- Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, London, UK
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10
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Marateb HR, Farahi M, Rojas M, Mañanas MA, Farina D. Detection of Multiple Innervation Zones from Multi-Channel Surface EMG Recordings with Low Signal-to-Noise Ratio Using Graph-Cut Segmentation. PLoS One 2016; 11:e0167954. [PMID: 27978535 PMCID: PMC5158322 DOI: 10.1371/journal.pone.0167954] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 11/23/2016] [Indexed: 11/24/2022] Open
Abstract
Knowledge of the location of muscle Innervation Zones (IZs) is important in many applications, e.g. for minimizing the quantity of injected botulinum toxin for the treatment of spasticity or for deciding on the type of episiotomy during child delivery. Surface EMG (sEMG) can be noninvasively recorded to assess physiological and morphological characteristics of contracting muscles. However, it is not often possible to record signals of high quality. Moreover, muscles could have multiple IZs, which should all be identified. We designed a fully-automatic algorithm based on the enhanced image Graph-Cut segmentation and morphological image processing methods to identify up to five IZs in 60-ms intervals of very-low to moderate quality sEMG signal detected with multi-channel electrodes (20 bipolar channels with Inter Electrode Distance (IED) of 5 mm). An anisotropic multilayered cylinder model was used to simulate 750 sEMG signals with signal-to-noise ratio ranging from -5 to 15 dB (using Gaussian noise) and in each 60-ms signal frame, 1 to 5 IZs were included. The micro- and macro- averaged performance indices were then reported for the proposed IZ detection algorithm. In the micro-averaging procedure, the number of True Positives, False Positives and False Negatives in each frame were summed up to generate cumulative measures. In the macro-averaging, on the other hand, precision and recall were calculated for each frame and their averages are used to determine F1-score. Overall, the micro (macro)-averaged sensitivity, precision and F1-score of the algorithm for IZ channel identification were 82.7% (87.5%), 92.9% (94.0%) and 87.5% (90.6%), respectively. For the correctly identified IZ locations, the average bias error was of 0.02±0.10 IED ratio. Also, the average absolute conduction velocity estimation error was 0.41±0.40 m/s for such frames. The sensitivity analysis including increasing IED and reducing interpolation coefficient for time samples was performed. Meanwhile, the effect of adding power-line interference and using other image interpolation methods on the deterioration of the performance of the proposed algorithm was investigated. The average running time of the proposed algorithm on each 60-ms sEMG frame was 25.5±8.9 (s) on an Intel dual-core 1.83 GHz CPU with 2 GB of RAM. The proposed algorithm correctly and precisely identified multiple IZs in each signal epoch in a wide range of signal quality and is thus a promising new offline tool for electrophysiological studies.
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Affiliation(s)
- Hamid Reza Marateb
- The Biomedical Engineering Department, Engineering Faculty, the University of Isfahan, Isfahan, Iran
- Department of Automatic Control, Biomedical Engineering Research Center, Universitat Politècnica de Catalunya. BarcelonaTech (UPC), Barcelona, Spain
- * E-mail:
| | - Morteza Farahi
- The Biomedical Engineering Department, Engineering Faculty, the University of Isfahan, Isfahan, Iran
| | - Monica Rojas
- Department of Automatic Control, Biomedical Engineering Research Center, Universitat Politècnica de Catalunya. BarcelonaTech (UPC), Barcelona, Spain
- Department of Bioengineering, Universidad El Bosque, Bogotá, Colombia
| | - Miguel Angel Mañanas
- Department of Automatic Control, Biomedical Engineering Research Center, Universitat Politècnica de Catalunya. BarcelonaTech (UPC), Barcelona, Spain
| | - Dario Farina
- Department of NeuroRehabilitation Engineering, Bernstein Center for Computational Neuroscience, University Medical Center Göttingen, Georg-August University, Göttingen, Germany
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Brown R, Hynes-Allen A, Swan AJ, Dissanayake KN, Gillingwater TH, Ribchester RR. Activity-dependent degeneration of axotomized neuromuscular synapses in Wld S mice. Neuroscience 2015; 290:300-20. [PMID: 25617654 PMCID: PMC4362769 DOI: 10.1016/j.neuroscience.2015.01.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Revised: 01/10/2015] [Accepted: 01/12/2015] [Indexed: 12/12/2022]
Abstract
Use and disuse may influence synaptic maintenance but so far evidence for this has been indirect. We tested whether stimulation or disuse of neuromuscular junctions in adult WldS mice altered vulnerability to axotomy. Moderate activity optimized resistance to axotomy while disuse or stimulation increased the rate of synaptic degeneration.
Activity and disuse of synapses are thought to influence progression of several neurodegenerative diseases in which synaptic degeneration is an early sign. Here we tested whether stimulation or disuse renders neuromuscular synapses more or less vulnerable to degeneration, using axotomy as a robust trigger. We took advantage of the slow synaptic degeneration phenotype of axotomized neuromuscular junctions in flexor digitorum brevis (FDB) and deep lumbrical (DL) muscles of Wallerian degeneration-Slow (WldS) mutant mice. First, we maintained ex vivo FDB and DL nerve-muscle explants at 32 °C for up to 48 h. About 90% of fibers from WldS mice remained innervated, compared with about 36% in wild-type muscles at the 24-h checkpoint. Periodic high-frequency nerve stimulation (100 Hz: 1 s/100 s) reduced synaptic protection in WldS preparations by about 50%. This effect was abolished in reduced Ca2+ solutions. Next, we assayed FDB and DL innervation after 7 days of complete tetrodotoxin (TTX)-block of sciatic nerve conduction in vivo, followed by tibial nerve axotomy. Five days later, only about 9% of motor endplates remained innervated in the paralyzed muscles, compared with about 50% in 5 day-axotomized muscles from saline-control-treated WldS mice with no conditioning nerve block. Finally, we gave mice access to running wheels for up to 4 weeks prior to axotomy. Surprisingly, exercising WldS mice ad libitum for 4 weeks increased about twofold the amount of subsequent axotomy-induced synaptic degeneration. Together, the data suggest that vulnerability of mature neuromuscular synapses to axotomy, a potent neurodegenerative trigger, may be enhanced bimodally, either by disuse or by hyperactivity.
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Affiliation(s)
- R Brown
- Euan MacDonald Centre for Motor Neurone Disease Research, Hugh Robson Building, University of Edinburgh, George Square, Edinburgh EH8 9XD, UK
| | - A Hynes-Allen
- Euan MacDonald Centre for Motor Neurone Disease Research, Hugh Robson Building, University of Edinburgh, George Square, Edinburgh EH8 9XD, UK
| | - A J Swan
- Euan MacDonald Centre for Motor Neurone Disease Research, Hugh Robson Building, University of Edinburgh, George Square, Edinburgh EH8 9XD, UK
| | - K N Dissanayake
- Euan MacDonald Centre for Motor Neurone Disease Research, Hugh Robson Building, University of Edinburgh, George Square, Edinburgh EH8 9XD, UK
| | - T H Gillingwater
- Euan MacDonald Centre for Motor Neurone Disease Research, Hugh Robson Building, University of Edinburgh, George Square, Edinburgh EH8 9XD, UK
| | - R R Ribchester
- Euan MacDonald Centre for Motor Neurone Disease Research, Hugh Robson Building, University of Edinburgh, George Square, Edinburgh EH8 9XD, UK.
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