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Zolkefley MKI, Firwana YMS, Hatta HZM, Rowbin C, Nassir CMNCM, Hanafi MH, Abdullah MS, Mustapha M. An overview of fractional anisotropy as a reliable quantitative measurement for the corticospinal tract (CST) integrity in correlation with a Fugl-Meyer assessment in stroke rehabilitation. J Phys Ther Sci 2021; 33:75-83. [PMID: 33519079 PMCID: PMC7829559 DOI: 10.1589/jpts.33.75] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Accepted: 10/25/2020] [Indexed: 11/24/2022] Open
Abstract
[Purpose] Understanding the essential mechanisms in post-stroke recovery not only
provides important basic insights into brain function and plasticity but can also guide
the development of new therapeutic approaches for stroke patients. This review aims to
give an overview of how various variables of Magnetic Resonance-Diffusion Tensor Imaging
(MR-DTI) metrics of fractional anisotropy (FA) can be used as a reliable quantitative
measurement and indicator of corticospinal tract (CST) changes, particularly in relation
to functional motor outcome correlation with a Fugl-Meyer assessment in stroke
rehabilitation. [Methods] PubMed electronic database was searched for the relevant
literature, using key words of diffusion tensor imaging (dti), corticospinal tract, and
stroke. [Results] We reviewed the role of FA in monitoring CST remodeling and its role of
predicting motor recovery after stroke. We also discussed the mechanism of CST remodeling
and its modulation from the value of FA and FMA-UE. [Conclusion] Heterogeneity of
post-stroke brain disorganization and motor impairment is a recognized challenge in the
development of accurate indicators of CST integrity. DTI-based FA measurements offer a
reliable and evidence-based indicator for CST integrity that would aid in predicting motor
recovery within the context of stroke rehabilitation.
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Affiliation(s)
- Mohd Khairul Izamil Zolkefley
- Department of Neurosciences, School of Medical Sciences, Universiti Sains Malaysia: 16150 Kubang Kerian, Kelantan, Malaysia
| | - Younis M S Firwana
- Department of Neurosciences, School of Medical Sciences, Universiti Sains Malaysia: 16150 Kubang Kerian, Kelantan, Malaysia
| | - Hasnettty Zuria Mohamed Hatta
- Department of Neurosciences, School of Medical Sciences, Universiti Sains Malaysia: 16150 Kubang Kerian, Kelantan, Malaysia.,Rehabilitation Unit, Hospital Universiti Sains Malaysia, Universiti Sains Malaysia, Malaysia
| | - Christina Rowbin
- Department of Neurosciences, School of Medical Sciences, Universiti Sains Malaysia: 16150 Kubang Kerian, Kelantan, Malaysia.,Rehabilitation Unit, Hospital Universiti Sains Malaysia, Universiti Sains Malaysia, Malaysia
| | | | - Muhammad Hafiz Hanafi
- Department of Neurosciences, School of Medical Sciences, Universiti Sains Malaysia: 16150 Kubang Kerian, Kelantan, Malaysia.,Rehabilitation Unit, Hospital Universiti Sains Malaysia, Universiti Sains Malaysia, Malaysia
| | - Mohd Shafie Abdullah
- Department of Radiology, School of Medical Sciences, Universiti Sains Malaysia, Malaysia
| | - Muzaimi Mustapha
- Department of Neurosciences, School of Medical Sciences, Universiti Sains Malaysia: 16150 Kubang Kerian, Kelantan, Malaysia
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2
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Giron A, Cox C, MacKay B. Techniques for Imaging Vascular Supply of Peripheral Nerves. J Brachial Plex Peripher Nerve Inj 2021; 16:e24-e30. [PMID: 34316297 PMCID: PMC8302262 DOI: 10.1055/s-0041-1731280] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 03/31/2021] [Indexed: 11/23/2022] Open
Abstract
Few studies have been developed to map the vascular structures feeding peripheral nerves, with the majority using cadaveric models and inadequate sample sizes. Preliminary evidence, while limited, indicates that the mapping of these vessels may allow or preclude certain procedures in nerve reconstruction due to the location of essential arterial inflow to the vasa nervorum. This review evaluates the evidence regarding historical, current, and emerging techniques for visualizing these vascular structures in vivo and considers their potential application in peripheral nerve vasculature.
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Affiliation(s)
- Alec Giron
- Department of Orthopaedic Surgery, Texas Tech University Health Sciences Center School of Medicine Lubbock, Texas Tech University Health Sciences Center School of Medicine, Lubbock, Texas, United Sates
| | - Cameron Cox
- Department of Orthopaedic Surgery, Texas Tech University Health Sciences Center, Lubbock, Texas, United States
| | - Brendan MacKay
- Department of Orthopaedic Surgery, Texas Tech Health Sciences Center, Lubbock, Texas, United Sates
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3
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Katoh H, Yokota K, Fehlings MG. Regeneration of Spinal Cord Connectivity Through Stem Cell Transplantation and Biomaterial Scaffolds. Front Cell Neurosci 2019; 13:248. [PMID: 31244609 PMCID: PMC6563678 DOI: 10.3389/fncel.2019.00248] [Citation(s) in RCA: 104] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 05/17/2019] [Indexed: 12/20/2022] Open
Abstract
Significant progress has been made in the treatment of spinal cord injury (SCI). Advances in post-trauma management and intensive rehabilitation have significantly improved the prognosis of SCI and converted what was once an “ailment not to be treated” into a survivable injury, but the cold hard fact is that we still do not have a validated method to improve the paralysis of SCI. The irreversible functional impairment of the injured spinal cord is caused by the disruption of neuronal transduction across the injury lesion, which is brought about by demyelination, axonal degeneration, and loss of synapses. Furthermore, refractory substrates generated in the injured spinal cord inhibit spontaneous recovery. The discovery of the regenerative capability of central nervous system neurons in the proper environment and the verification of neural stem cells in the spinal cord once incited hope that a cure for SCI was on the horizon. That hope was gradually replaced with mounting frustration when neuroprotective drugs, cell transplantation, and strategies to enhance remyelination, axonal regeneration, and neuronal plasticity demonstrated significant improvement in animal models of SCI but did not translate into a cure in human patients. However, recent advances in SCI research have greatly increased our understanding of the fundamental processes underlying SCI and fostered increasing optimism that these multiple treatment strategies are finally coming together to bring about a new era in which we will be able to propose encouraging therapies that will lead to appreciable improvements in SCI patients. In this review, we outline the pathophysiology of SCI that makes the spinal cord refractory to regeneration and discuss the research that has been done with cell replacement and biomaterial implantation strategies, both by itself and as a combined treatment. We will focus on the capacity of these strategies to facilitate the regeneration of neural connectivity necessary to achieve meaningful functional recovery after SCI.
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Affiliation(s)
- Hiroyuki Katoh
- Division of Genetics and Development, Krembil Research Institute, Toronto, ON, Canada.,Department of Orthopaedic Surgery - Surgical Sciences, School of Medicine, Tokai University, Tokyo, Japan
| | - Kazuya Yokota
- Division of Genetics and Development, Krembil Research Institute, Toronto, ON, Canada.,Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Michael G Fehlings
- Division of Genetics and Development, Krembil Research Institute, Toronto, ON, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, Canada.,Division of Neurosurgery, University of Toronto, Toronto, ON, Canada.,Spine Program, Toronto Western Hospital, University Health Network, Toronto, ON, Canada
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4
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Wanner R, Abaei A, Rasche V, Knöll B. Three-Dimensional In vivo Magnetic Resonance Imaging (MRI) of Mouse Facial Nerve Regeneration. Front Neurol 2019; 10:310. [PMID: 31001195 PMCID: PMC6454117 DOI: 10.3389/fneur.2019.00310] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 03/11/2019] [Indexed: 01/28/2023] Open
Abstract
MRI (magnetic resonance imaging) is an indispensable tool in the diagnosis of centrals nervous system (CNS) disorders such as spinal cord injury and multiple sclerosis (MS). In contrast, diagnosis of peripheral nerve injuries largely depends on clinical and electrophysiological parameters. Thus, currently MRI is not regularly used which in part is due to small nerve calibers and isointensity with surrounding tissue such as muscles. In this study we performed translational MRI research in mice to establish a novel MRI protocol visualizing intact and injured peripheral nerves in a non-invasive manner without contrast agents. With this protocol we were able to image even very small nerves and nerve branches such as the mouse facial nerve (diameter 100–300 μm) at highest spatial resolution. Analysis was performed in the same animal in a longitudinal study spanning 3 weeks after injury. Nerve injury caused hyperintense signal in T2-weighted images and an increase in nerve size of the proximal and distal nerve stumps were observed. Further hyperintense signal was observed in a bulb-like structure in the lesion site, which correlated histologically with the production of fibrotic tissue and immune cell infiltration. The longitudinal MR representation of the facial nerve lesions correlated well with physiological recovery of nerve function by quantifying whisker movement. In summary, we provide a novel protocol in rodents allowing for non-invasive, non-contrast agent enhanced, high-resolution MR imaging of small peripheral nerves longitudinally over several weeks. This protocol might further help to establish MRI as an important diagnostic and post-surgery follow-up tool to monitor peripheral nerve injuries in humans.
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Affiliation(s)
- Renate Wanner
- Institute of Physiological Chemistry, Ulm University, Ulm, Germany
| | - Alireza Abaei
- Core Facility Small Animal MRI, Medical Faculty, Ulm University, Ulm, Germany
| | - Volker Rasche
- Core Facility Small Animal MRI, Medical Faculty, Ulm University, Ulm, Germany.,Department of Internal Medicine II, University Hospital Ulm, Ulm, Germany
| | - Bernd Knöll
- Institute of Physiological Chemistry, Ulm University, Ulm, Germany
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5
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Bosma RL, Mojarad EA, Leung L, Pukall C, Staud R, Stroman PW. FMRI of spinal and supra-spinal correlates of temporal pain summation in fibromyalgia patients. Hum Brain Mapp 2016; 37:1349-60. [PMID: 26749315 DOI: 10.1002/hbm.23106] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 12/16/2015] [Accepted: 12/18/2015] [Indexed: 02/05/2023] Open
Abstract
Fibromyalgia syndrome (FM) is a debilitating chronic pain condition, which afflicts primarily females. Although the etiology of this illness is not completely understood, FM pain is thought to rely on enhanced pain sensitivity maintained by central mechanisms. One of these mechanisms is central pain amplification, which is characterized by altered temporal summation of second pain (TSSP). Here we use a TSSP paradigm and functional MRI (fMRI) of the spinal cord, brainstem, and brain to noninvasively examine the central nervous system contributions to TSSP in FM patients and normal controls (NC). Functional MRI of pain-free female adults (N = 15) and FM patients (N = 14) was conducted while brief, repetitive heat pain stimuli (0.33 Hz) were applied to the thenar eminence of the hand (C6 dermatome). The stimulus intensity was adjusted to each participant's heat pain sensitivity to achieve moderate pain. Data were analyzed by means of a General Linear Model and region-of-interest analyses. All participants demonstrated significant pain summation in the TSSP condition. FM subjects, however, required significantly lower stimulus intensities than NC to achieve similar TSSP. fMRI analyses of perceptually equal TSSP identified similar brain activity in NC and FM subjects; however, multiple areas in the brainstem (rostral ventromedial medulla and periaqueductal grey region) and spinal cord (dorsal horn) exhibited greater activity in NC subjects. Finally, increased after-sensations and enhanced dorsal horn activity was demonstrated in FM patients. In conclusion, the spinal and brainstem BOLD responses to TSSP are different between NC and FM patients, which may indicate alterations to descending pain control mechanisms suggesting contributions of these mechanisms to central sensitization and pain of FM patients.
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Affiliation(s)
- Rachael L Bosma
- Centre for Neuroscience Studies, Queen's University, Kingston, Ontario, Canada
| | - Elham Ameli Mojarad
- Centre for Neuroscience Studies, Queen's University, Kingston, Ontario, Canada
| | - Lawrence Leung
- Centre for Neuroscience Studies, Queen's University, Kingston, Ontario, Canada
| | - Caroline Pukall
- Department of Psychology, Queen's University, Kingston, Ontario, Canada
| | - Roland Staud
- Department of Medicine, University of Florida, Gainesville, Florida
| | - Patrick W Stroman
- Centre for Neuroscience Studies, Queen's University, Kingston, Ontario, Canada.,Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada.,Department of Physics, Queen's University, Kingston, Ontario, Canada
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6
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Krishna V, Andrews H, Varma A, Mintzer J, Kindy MS, Guest J. Spinal cord injury: how can we improve the classification and quantification of its severity and prognosis? J Neurotrauma 2014; 31:215-27. [PMID: 23895105 DOI: 10.1089/neu.2013.2982] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
The preservation of functional neural tissue after spinal cord injury (SCI) is the basis for spontaneous neurological recovery. Some injured patients in the acute phase have more potential for recovery than others. This fact is problematic for the construction of clinical trials because enrollment of subjects with variable recovery potential makes it difficult to detect effects, requires large sample sizes, and risks Type II errors. In addition, the current methods to assess injury and recovery are non-quantitative and not sensitive. It is likely that therapeutic combinations will be necessary to cause substantially improved function after SCI, thus we need highly sensitive techniques to evaluate changes in motor, sensory, autonomic and other functions. We review several emerging neurophysiological techniques with high sensitivity. Quantitative methods to evaluate residual tissue sparing after severe acute SCI have not entered widespread clinical use. This reduces the ability to correlate structural preservation with clinical outcome following SCI resulting in enrollment of subjects with varying patterns of tissue preservation and injury into clinical trials. We propose that the inclusion of additional measures of injury severity, pattern, and individual genetic characteristics may enable stratification in clinical trials to make the testing of therapeutic interventions more effective and efficient. New imaging techniques to assess tract injury and demyelination and methods to quantify tissue injury, inflammatory markers, and neuroglial biochemical changes may improve the evaluation of injury severity, and the correlation with neurological outcome, and measure the effects of treatment more robustly than is currently possible. The ability to test such a multimodality approach will require a high degree of collaboration between clinical and research centers and government research support. When the most informative of these assessments is determined, it may be possible to identify patients with substantial recovery potential, improve selection criteria and conduct more efficient clinical trials.
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Affiliation(s)
- Vibhor Krishna
- 1 Department of Neurosciences, Medical University of South Carolina , Charleston, South Carolina
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7
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Kalsi-Ryan S, Wilson J, Yang JM, Fehlings MG. Neurological Grading in Traumatic Spinal Cord Injury. World Neurosurg 2014; 82:509-18. [DOI: 10.1016/j.wneu.2013.01.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Revised: 10/10/2012] [Accepted: 01/03/2013] [Indexed: 01/25/2023]
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8
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Prognostic role of the number of involved extraspinal organs in patients with metastatic spinal cord compression. Clin Neurol Neurosurg 2014; 118:12-5. [DOI: 10.1016/j.clineuro.2013.12.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Accepted: 12/14/2013] [Indexed: 12/17/2022]
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9
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Abstract
The heterogeneity of traumatic spinal cord injury necessitates large clinical trials to differentiate natural improvements from enhanced recovery due to therapeutic intervention. Recent development of an imaging biomarker to visualize changes in the corticospinal motor system could offer the opportunity to directly visualize anatomical evidence of repair, regeneration and plasticity.
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10
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Cadotte DW, Cohen-Adad J, Fehlings MG. Visualizing Integrative Functioning in the Human Brainstem and Spinal Cord With Spinal Functional Magnetic Resonance Imaging. Neurosurgery 2013; 60 Suppl 1:102-9. [DOI: 10.1227/01.neu.0000430767.87725.95] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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11
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Cadotte DW, Fehlings MG. Will imaging biomarkers transform spinal cord injury trials? Lancet Neurol 2013; 12:843-844. [PMID: 23827393 DOI: 10.1016/s1474-4422(13)70157-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- David W Cadotte
- Krembil Neuroscience Centre, Spinal Program, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada M5T 2S8; Department of Surgery, Division of Neurosurgery, University of Toronto, Toronto, Ontario, Canada M5T 2S8
| | - Michael G Fehlings
- Krembil Neuroscience Centre, Spinal Program, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada M5T 2S8; Department of Surgery, Division of Neurosurgery, University of Toronto, Toronto, Ontario, Canada M5T 2S8.
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12
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Brennan FH, Cowin GJ, Kurniawan ND, Ruitenberg MJ. Longitudinal assessment of white matter pathology in the injured mouse spinal cord through ultra-high field (16.4 T) in vivo diffusion tensor imaging. Neuroimage 2013; 82:574-85. [PMID: 23770410 DOI: 10.1016/j.neuroimage.2013.06.019] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Revised: 05/16/2013] [Accepted: 06/03/2013] [Indexed: 01/04/2023] Open
Abstract
This study examined the sensitivity of ultra-high field (16.4 T) diffusion tensor imaging (DTI; 70 μm in-plane resolution, 1mm slice thickness) to evaluate the spatiotemporal development of severe mid-thoracic contusive spinal cord injury (SCI) in mice. In vivo imaging was performed prior to SCI, then again at 2h, 1 day, 3 days, 7 days, and 30 days post-SCI using a Bruker 16.4 T small animal nuclear magnetic resonance spectrometer. Cross-sectional spinal cord areas were measured in axial slices and various DTI parameters, i.e. fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (λ||) and radial diffusivity (λ⊥), were calculated for the total spared white matter (WM), ventral funiculi (VF), lateral funiculi (LF) and dorsal columns (DCs) and then correlated with histopathology. Cross-sectional area measurements revealed significant atrophy (32% reduction) of the injured spinal cord at the lesion epicentre in the chronic phase of injury. Analysis of diffusion tensor parameters further showed that tissue integrity was most severely affected in the DCs, i.e. the site of immediate impact, which demonstrated a rapid and permanent decrease in FA and λ||. In contrast, DTI parameters for the ventrolateral white matter changed more gradually with time, suggesting that these regions are undergoing more delayed degeneration in a manner that may be amenable to therapeutic intervention. Of all the DTI parameters, λ⊥ was most closely correlated to myelin content whereas changes in FA and λ|| appeared more indicative of axonal integrity, Wallerian degeneration and associated presence of macrophages. We conclude that longitudinal DTI at 16.4T provides a clinically relevant, objective measure for assessing white matter pathology following contusive SCI in mice that may aid the translation of putative neuroprotective strategies into the clinic.
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Affiliation(s)
- Faith H Brennan
- The University of Queensland, School of Biomedical Sciences, Brisbane, QLD 4072, Australia
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13
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Takahashi N, Sakurai T. Roles of glial cells in schizophrenia: possible targets for therapeutic approaches. Neurobiol Dis 2012; 53:49-60. [PMID: 23146995 DOI: 10.1016/j.nbd.2012.11.001] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2012] [Revised: 09/30/2012] [Accepted: 11/01/2012] [Indexed: 12/20/2022] Open
Abstract
Glial cells consisting of oligodendrocytes, astrocytes, microglia, and NG2 positive cells are major cell populations in the central nervous system, number-wise. They function as effectors and modulators of neurodevelopment through a wide variety of neuron-glial cell interactions in brain development and functions. Glial cells can be affected by both genetic and environmental factors, leading to their dysfunctions in supporting neuronal development and functions. These in turn can affect neuronal cells, causing alterations at the circuitry level that manifest as behavioral characteristics associated with schizophrenia in late teens-early twenties. Glial cells are also involved in neuroinflammatory processes, which sometimes have deleterious effects on the normal brain development. If the glial involvement plays significant roles in schizophrenia, the processes involving glial cells can become possible therapeutic targets for schizophrenia. A number of known antipsychotics are shown to have beneficial effects on glial cells, but other drugs targeting glial cell functions may also have therapeutic effects on schizophrenia. The latter can be taken into consideration for future drug development for schizophrenia.
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Affiliation(s)
- Nagahide Takahashi
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya, Japan
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