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Jeong JH, Seo CH, Lee DH. Electron Microscopic Study in the Rat Model of Electrically Injured Myelopathy: Preliminary Report. Korean J Neurotrauma 2023; 19:218-226. [PMID: 37431381 PMCID: PMC10329894 DOI: 10.13004/kjnt.2023.19.e15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 03/24/2023] [Accepted: 04/17/2023] [Indexed: 07/12/2023] Open
Abstract
Objective The patient with electrically injured myelopathy showed mild motor weakness without somatosensory pathway abnormalities. Few reports have been reported on the pathophysiological mechanisms of electrically injured myelopathy, and there is controversy about the exact pathological causes. This study aimed to investigate the ultrastructural changes in the electron microscopic findings of electrical spinal cord injury. Methods Nine rats were used in this study. We performed 7 electrical shocks (frequency, 120 Hz; pulse width, 0.9 ms; duration, 3 seconds; current, 99 mA) using an electroconvulsive therapy (ECT) apparatus (57800 ECT unit; UGO BASILE). We used one ear and one contralateral hind limb as entry and exit sites, respectively. We only enrolled rats with hind limb weakness and performed electron microscopy evaluations of the spinal cord on the first day and 4 weeks after injury. Results On the first day after injury, an electron microscopic examination showed a directly damaged area that appeared to be torn as physical damage, damaged myelin sheath, vacuolated axons in the myelin sheath, swollen Golgi apparatus, and injured mitochondria. Looking at changes in motor and sensory nerves, the sensory neurons showed recovered mitochondria and Golgi apparatus 4 weeks after injury; however, motor neurons still showed injured mitochondria, swollen Golgi apparatus, and endoplasmic reticulum. Conclusion This study showed that recovery from ultrastructural injury was more rapid in sensory neurons than in motor neurons.
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Affiliation(s)
- Je Hoon Jeong
- Department of Neurosurgery, Soonchunhyang University Bucheon Hospital, Bucheon, Korea
| | - Cheong Hoon Seo
- Department of Rehabilitation Medicine, Hangang Sacred Heart Hospital, College of Medicine, Hallym University, Seoul, Korea
| | - Dae Hoon Lee
- Korea Institute of Machinery and Materials, Daejeon, Korea
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Long-Term Effects of Neural Precursor Cell Transplantation on Secondary Injury Processes and Functional Recovery after Severe Cervical Contusion-Compression Spinal Cord Injury. Int J Mol Sci 2021; 22:ijms222313106. [PMID: 34884911 PMCID: PMC8658203 DOI: 10.3390/ijms222313106] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 11/29/2021] [Accepted: 12/02/2021] [Indexed: 01/21/2023] Open
Abstract
Cervical spinal cord injury (SCI) remains a devastating event without adequate treatment options despite decades of research. In this context, the usefulness of common preclinical SCI models has been criticized. We, therefore, aimed to use a clinically relevant animal model of severe cervical SCI to assess the long-term effects of neural precursor cell (NPC) transplantation on secondary injury processes and functional recovery. To this end, we performed a clip contusion-compression injury at the C6 level in 40 female Wistar rats and a sham surgery in 10 female Wistar rats. NPCs, isolated from the subventricular zone of green fluorescent protein (GFP) expressing transgenic rat embryos, were transplanted ten days after the injury. Functional recovery was assessed weekly, and FluoroGold (FG) retrograde fiber-labeling, as well as manganese-enhanced magnetic resonance imaging (MEMRI), were performed prior to the sacrifice of the animals eight weeks after SCI. After cryosectioning of the spinal cords, immunofluorescence staining was conducted. Results were compared between the treatment groups (NPC, Vehicle, Sham) and statistically analyzed (p < 0.05 was considered significant). Despite the severity of the injury, leading to substantial morbidity and mortality during the experiment, long-term survival of the engrafted NPCs with a predominant differentiation into oligodendrocytes could be observed after eight weeks. While myelination of the injured spinal cord was not significantly improved, NPC treated animals showed a significant increase of intact perilesional motor neurons and preserved spinal tracts compared to untreated Vehicle animals. These findings were associated with enhanced preservation of intact spinal cord tissue. However, reactive astrogliosis and inflammation where not significantly reduced by the NPC-treatment. While differences in the Basso–Beattie–Bresnahan (BBB) score and the Gridwalk test remained insignificant, animals in the NPC group performed significantly better in the more objective CatWalk XT gait analysis, suggesting some beneficial effects of the engrafted NPCs on the functional recovery after severe cervical SCI.
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Suto DJ, Nair G, Sudarshana DM, Steele SU, Dwyer J, Beck ES, Ohayon J, McFarland H, Koretsky AP, Cortese ICM, Reich DS. Manganese-Enhanced MRI in Patients with Multiple Sclerosis. AJNR Am J Neuroradiol 2020; 41:1569-1576. [PMID: 32763897 DOI: 10.3174/ajnr.a6665] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Accepted: 05/31/2020] [Indexed: 01/16/2023]
Abstract
BACKGROUND AND PURPOSE Cellular uptake of the manganese ion, when administered as a contrast agent for MR imaging, can noninvasively highlight cellular activity and disease processes in both animals and humans. The purpose of this study was to explore the enhancement profile of manganese in patients with multiple sclerosis. MATERIALS AND METHODS Mangafodipir is a manganese chelate that was clinically approved for MR imaging of liver lesions. We present a case series of 6 adults with multiple sclerosis who were scanned at baseline with gadolinium, then injected with mangafodipir, and followed at variable time points thereafter. RESULTS Fourteen new lesions formed during or shortly before the study, of which 10 demonstrated manganese enhancement of varying intensity, timing, and spatial pattern. One gadolinium-enhancing extra-axial mass, presumably a meningioma, also demonstrated enhancement with manganese. Most interesting, manganese enhancement was detected in lesions that formed in the days after mangafodipir injection, and this enhancement persisted for several weeks, consistent with contrast coming from intracellular uptake of manganese. Some lesions demonstrated a diffuse pattern of manganese enhancement in an area larger than that of both gadolinium enhancement and T2-FLAIR signal abnormality. CONCLUSIONS This work demonstrates the first use of a manganese-based contrast agent to enhance MS lesions on MR imaging. Multiple sclerosis lesions were enhanced with a temporal and spatial profile distinct from that of gadolinium. Further experiments are necessary to uncover the mechanism of manganese contrast enhancement as well as cell-specific uptake.
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Affiliation(s)
- D J Suto
- From the National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - G Nair
- From the National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - D M Sudarshana
- From the National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - S U Steele
- From the National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - J Dwyer
- From the National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - E S Beck
- From the National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - J Ohayon
- From the National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - H McFarland
- From the National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - A P Koretsky
- From the National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - I C M Cortese
- From the National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - D S Reich
- From the National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland.
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Krishnan V, Xu J, Mendoza AG, Koretsky A, Anderson SA, Pelled G. High-resolution MEMRI characterizes laminar specific ascending and descending spinal cord pathways in rats. J Neurosci Methods 2020; 340:108748. [PMID: 32335077 PMCID: PMC7281828 DOI: 10.1016/j.jneumeth.2020.108748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 04/19/2020] [Accepted: 04/19/2020] [Indexed: 11/17/2022]
Abstract
BACKGROUND The spinal cord is composed of nine distinct cellular laminae that currently can only be visualized by histological methods. Developing imaging methods that can visualize laminar architecture in-vivo is of significant interest. Manganese enhanced magnetic resonance imaging (MEMRI) yields valuable architectural and functional information about the brain and has great potential in characterizing neural pathways in the spinal cord. Here we apply MEMRI to visualize laminae architecture in the thoracic region of the spinal cord with ultra-high resolution. NEW METHOD Manganese chloride (MnCl2) was delivered systemically and imaging of the lumbar and thoracic spinal cord levels was acquired in high field, 11.7 T MRI scanner, 48 h following MnCl2 administration. RESULTS Here we demonstrate laminar specific signal enhancement in the spinal cord of rats administered with MnCl2 with 69 μm in-plane resolution. We also report reduced T1 values over time in MnCl2 groups across laminae IIX. COMPARISONS WITH EXISTING METHODS This is the first study to demonstrate that MEMRI is capable of identifying spinal laminae at a high resolution of 69 μm in a living animal. This would enable the visualization of architecture and function of distinct regions with improved resolution, in healthy and diseased animal models. CONCLUSIONS The regions with the largest T1 enhancements were observed to correspond to laminae that contain either high cell density or large motor neurons, making MEMRI an excellent tool for studying spinal cord architecture, physiology and function in different animal models.
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Affiliation(s)
- Vijai Krishnan
- Department of Biomedical Engineering, Michigan State University, East Lansing, MI, United States; The Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, United States
| | - Jiadi Xu
- Johns Hopkins Medicine Department of Radiology and Radiological Science, Baltimore, MD, United States
| | - Albert German Mendoza
- Johns Hopkins Medicine Department of Radiology and Radiological Science, Baltimore, MD, United States
| | - Alan Koretsky
- Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
| | - Stasia A Anderson
- National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, United States
| | - Galit Pelled
- Department of Biomedical Engineering, Michigan State University, East Lansing, MI, United States; The Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, United States; Department of Radiology, Michigan State University, East Lansing, MI, United States; Johns Hopkins Medicine Department of Radiology and Radiological Science, Baltimore, MD, United States.
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Yang J, Li Q. Manganese-Enhanced Magnetic Resonance Imaging: Application in Central Nervous System Diseases. Front Neurol 2020; 11:143. [PMID: 32161572 PMCID: PMC7052353 DOI: 10.3389/fneur.2020.00143] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 02/07/2020] [Indexed: 12/12/2022] Open
Abstract
Manganese-enhanced magnetic resonance imaging (MEMRI) relies on the strong paramagnetism of Mn2+. Mn2+ is a calcium ion analog and can enter excitable cells through voltage-gated calcium channels. Mn2+ can be transported along the axons of neurons via microtubule-based fast axonal transport. Based on these properties, MEMRI is used to describe neuroanatomical structures, monitor neural activity, and evaluate axonal transport rates. The application of MEMRI in preclinical animal models of central nervous system (CNS) diseases can provide more information for the study of disease mechanisms. In this article, we provide a brief review of MEMRI use in CNS diseases ranging from neurodegenerative diseases to brain injury and spinal cord injury.
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Affiliation(s)
- Jun Yang
- Department of Radiology, The Third Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital & Cancer Center, Kunming, China
| | - Qinqing Li
- Department of Radiology, The Third Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital & Cancer Center, Kunming, China
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Cha M, Lee K, Won JS, Lee BH. Manganese-enhanced magnetic resonance imaging of the spinal cord in rats with formalin-induced pain. Neurosci Res 2019; 149:14-21. [PMID: 30685495 DOI: 10.1016/j.neures.2019.01.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 01/02/2019] [Accepted: 01/21/2019] [Indexed: 11/29/2022]
Abstract
Manganese-enhanced magnetic resonance imaging (MEMRI) is based on neuronal activity-dependent manganese uptake, and provides information about nervous system function. However, systematic studies of pain processing using MEMRI are rare, and few investigations of pain using MEMRI have been performed in the spinal cord. Herein, we investigated the pain dependence of manganese ions administered in the rat spinal cord. MnCl2 was administered into the spinal cord via an intrathecal catheter before formalin injection into the right hind paw (50 μL of 5% formalin). The duration of flinching behavior was recorded and analyzed to measure formalin-induced pain. After the behavioral test, rats were sacrificed with an overdose of urethane (50 mg/kg), and spine samples were extracted and post-fixed in 4% paraformaldehyde solution. The samples were stored in 30% sucrose until molecular resonance (MR) scanning was performed. In axial Mn2+ enhancement images of the spinal cord, Mn2+ levels were found to be significantly elevated on the ipsilateral side of the spinal cord in formalin-injected rats. To confirm pain-dependent Mn enhancement in the spinal cord, c-Fos expression was analyzed, and was found to be increased in the formalin-injected rats. These results indicate that MEMRI is useful for functional analysis of the spinal cord under pain conditions. The gray matter appears to be the focus of intense paramagnetic signals. MEMRI may provide an effective technique for visualizing activity-dependent patterns in the spinal cord.
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Affiliation(s)
- Myeounghoon Cha
- Department of Physiology, Yonsei University College of Medicine, Seoul 03722, Republic of Korea
| | - Kyuhong Lee
- Inhalation Toxicology Research Center, Korea Institute of Toxicology, Jeonbuk 56212, Republic of Korea
| | - Jun Sik Won
- Department of Physiology, Yonsei University College of Medicine, Seoul 03722, Republic of Korea
| | - Bae Hwan Lee
- Department of Physiology, Yonsei University College of Medicine, Seoul 03722, Republic of Korea; Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul 03722, Republic of Korea.
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Martirosyan NL, Turner GH, Kaufman J, Patel AA, Belykh E, Kalani MYS, Theodore N, Preul MC. Manganese-enhanced MRI Offers Correlation with Severity of Spinal Cord Injury in Experimental Models. Open Neuroimag J 2016; 10:139-147. [PMID: 28144384 PMCID: PMC5226969 DOI: 10.2174/1874440001610010139] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Revised: 10/04/2016] [Accepted: 10/16/2016] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Spinal cord injuries (SCI) are clinically challenging, because neural regeneration after cord damage is unknown. In SCI animal models, regeneration is evaluated histologically, requiring animal sacrifice. Noninvasive techniques are needed to detect longitudinal SCI changes. OBJECTIVE To compare manganese-enhanced magnetic resonance imaging (MRI [MEMRI]) in hemisection and transection of SCI rat models with diffusion tensor imaging (DTI) and histology. METHODS Rats underwent T9 spinal cord transection (n=6), hemisection (n=6), or laminectomy without SCI (controls, n=6). One-half of each group received lateral ventricle MnCl2 injections 24 hours later. Conventional DTI or T1-weighted MRI was performed 84 hours post-surgery. MEMRI signal intensity ratio above and below the SCI level was calculated. Fractional anisotropy (FA) measurements were taken 1 cm rostral to the SCI. The percentage of FA change was calculated 10 mm rostral to the SCI epicenter, between FA at the dorsal column lesion normalized to a lateral area without FA change. Myelin load (percentage difference) among groups was analyzed by histology. RESULTS In transection and hemisection groups, mean MEMRI ratios were 0.62 and 0.87, respectively, versus 0.99 in controls (P<0.001 and P<0.001, respectively); mean FA decreases were 67.5% and 40.1%, respectively, compared with a 6.1% increase in controls (P=0.002 and P=0.019, respectively). Mean myelin load decreased by 38.8% (transection) and 51.8% (hemisection) compared to controls (99.1%) (P<0.001 and P<0.001, respectively). Pearson's correlation coefficients were -0.94 for MEMRI ratio and FA changes and 0.87 for MEMRI and myelin load. CONCLUSION MEMERI results correlated to SCI severity measured by FA and myelin load. MEMRI is a useful noninvasive tool to assess neuronal damage after SCI.
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Affiliation(s)
- Nikolay L Martirosyan
- Departments of Neurosurgery, Barrow Neurological Institute St. Joseph's Hospital and Medical Center Phoenix, Arizona,USA
| | - Gregory H Turner
- Center for Preclinical Imaging, Barrow Neurological Institute St. Joseph's Hospital and Medical Center Phoenix, Arizona, USA
| | - Jason Kaufman
- Department of Anatomy, Midwestern University Glendale, Arizona, USA
| | - Arpan A Patel
- Departments of Neurosurgery, Barrow Neurological Institute St. Joseph's Hospital and Medical Center Phoenix, Arizona,USA
| | - Evgenii Belykh
- Departments of Neurosurgery, Barrow Neurological Institute St. Joseph's Hospital and Medical Center Phoenix, Arizona,USA ; Irkutsk Scientific Center of Surgery and Traumatology, Irkutsk, Russia
| | - M Yashar S Kalani
- Departments of Neurosurgery, Barrow Neurological Institute St. Joseph's Hospital and Medical Center Phoenix, Arizona,USA
| | - Nicholas Theodore
- Departments of Neurosurgery, Barrow Neurological Institute St. Joseph's Hospital and Medical Center Phoenix, Arizona,USA
| | - Mark C Preul
- Departments of Neurosurgery, Barrow Neurological Institute St. Joseph's Hospital and Medical Center Phoenix, Arizona,USA
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Freitag MT, Márton G, Pajer K, Hartmann J, Walder N, Rossmann M, Parzer P, Redl H, Nógrádi A, Stieltjes B. Monitoring of Short-Term Erythropoietin Therapy in Rats with Acute Spinal Cord Injury Using Manganese-Enhanced Magnetic Resonance Imaging. J Neuroimaging 2014; 25:582-9. [DOI: 10.1111/jon.12202] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Revised: 07/29/2014] [Accepted: 09/13/2014] [Indexed: 11/28/2022] Open
Affiliation(s)
- Martin Thomas Freitag
- Quantitative Imaging-Based Disease Characterization; Department of Radiology; German Cancer Research Center; Heidelberg Germany
| | - Gábor Márton
- Laboratory of Neural Regeneration; Department of Anatomy; Histology, and Embryology; Faculty of Medicine; University of Szeged; Hungary
| | - Krisztián Pajer
- Laboratory of Neural Regeneration; Department of Anatomy; Histology, and Embryology; Faculty of Medicine; University of Szeged; Hungary
| | - Jens Hartmann
- Ludwig Boltzmann Institute for Experimental and Clinical Traumatology; Research Center of the AUVA; Vienna Austria
| | - Nadja Walder
- Ludwig Boltzmann Institute for Experimental and Clinical Traumatology; Research Center of the AUVA; Vienna Austria
| | - Markus Rossmann
- Ludwig Boltzmann Institute for Experimental and Clinical Traumatology; Research Center of the AUVA; Vienna Austria
| | - Peter Parzer
- Section Disorders of Personality Development; Department of Child and Adolescent Psychiatry; Center for Psychosocial Medicine; University of Heidelberg; Germany
| | - Heinz Redl
- Ludwig Boltzmann Institute for Experimental and Clinical Traumatology; Research Center of the AUVA; Vienna Austria
| | - Antal Nógrádi
- Laboratory of Neural Regeneration; Department of Anatomy; Histology, and Embryology; Faculty of Medicine; University of Szeged; Hungary
- Ludwig Boltzmann Institute for Experimental and Clinical Traumatology; Research Center of the AUVA; Vienna Austria
| | - Bram Stieltjes
- Quantitative Imaging-Based Disease Characterization; Department of Radiology; German Cancer Research Center; Heidelberg Germany
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Seo CH, Jeong JH, Lee DH, Kang TC, Jin ES, Lee DH, Jeon SR, Choi KH, Hwang HS. Radiological and pathological evaluation of the spinal cord in a rat model of electrical injury-induced myelopathy. Burns 2012; 38:1066-71. [PMID: 22683141 DOI: 10.1016/j.burns.2012.02.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Revised: 01/11/2012] [Accepted: 02/17/2012] [Indexed: 11/30/2022]
Abstract
BACKGROUND No study has reported an animal-based experimental model of electrical injury to the spinal cord. This paper presents the first systematic establishment of an animal model of electrical injury to the spinal cord with subsequent pathophysiologic analysis. METHOD The voltage required for the electrical shock was generated by an electroconvulsive therapy apparatus (57800 ECT unit; UGO BASILE, Italy). We used one side ear as the entry site and the contralateral hind limb as the exit site. Seven electrical shock (frequency, 120 Hz; pulse width, 0.9 ms; duration, 3 s; current, 99 mA) was applied to each rat and used rat showing hind limb weakness. Radiologic and histologic evaluations were performed at one day, one, two and four weeks after injury. RESULTS Twelve rats showed the hind limb weakness among the total 18 rats. Manganese-enhanced magnetic resonance imaging showed interruption of spinal cord enhancement in the thoracic area. Histological examination showed a greater decrease in the number of neurons in the ventral horn versus the dorsal horn. CONCLUSION This study demonstrates a novel design and analysis of an animal-based experimental model of spinal cord injury by electrical etiology. This model is useful for experimental studies of injuries to the spinal cord.
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Affiliation(s)
- Cheong Hoon Seo
- Department of Rehabilitation Medicine, College of Medicine, Hallym University, Republic of Korea
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Axonal regeneration effects of Wnt3a-secreting fibroblast transplantation in spinal cord-injured rats. Acta Neurochir (Wien) 2011; 153:1003-10. [PMID: 21249402 DOI: 10.1007/s00701-011-0945-1] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Accepted: 01/06/2011] [Indexed: 12/29/2022]
Abstract
BACKGROUND Axonal regeneration is a prerequisite for recovery from spinal cord injury. Here, we investigated whether Wnt3a-secreting fibroblasts exert a favorable effect on spinal cord regeneration in spinal cord-injured rats. METHODS Spinal cord injury (SCI) was induced in rats (n = 21) using an NYU impactor. One week after SCI, rats were assigned to a Wnt3a-secreting fibroblast transplantation group (Wnt group, n = 7), a L929 fibroblast transplantation group (vehicle group, n = 7), and contusion only group (sham group, n = 7). Motor function was tested weekly for 6 weeks. Manganese-enhanced magnetic resonance imaging (ME-MRI) was performed twice, once before cell transplantation and again 5 weeks after cell transplantation. After ME-MRI, expression of the axonal regeneration marker GAP-43 was assessed by immunohistochemistry (IHC). RESULTS In the Wnt group, the mean Basso-Beattie-Bresnahan score was higher than that of the vehicle and sham groups throughout the observation period. The Wnt group also exhibited stronger signal intensity on ME-MRI, and IHC revealed that GAP-43 was highly expressed in the injured spinal cord in the Wnt group. CONCLUSIONS These results strongly suggest that transplanted Wnt3a secreting fibroblasts promote axonal regeneration and functional improvement after SCI. Although further investigation will be necessary to clarify the intracellular mechanism by which Wnt signaling promotes axonal regeneration and functional improvement, this approach could be a highly promising therapeutic strategy for SCI.
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Abstract
Manganese-enhanced magnetic resonance imaging (MEMRI) relies on contrasts that are due to the shortening of the T (1) relaxation time of tissue water protons that become exposed to paramagnetic manganese ions. In experimental animals, the technique combines the high spatial resolution achievable by MRI with the biological information gathered by tissue-specific or functionally induced accumulations of manganese. After in vivo administration, manganese ions may enter cells via voltage-gated calcium channels. In the nervous system, manganese ions are actively transported along the axon. Based on these properties, MEMRI is increasingly used to delineate neuroanatomical structures, assess differences in functional brain activity, and unravel neuronal connectivities in both healthy animals and models of neurological disorders. Because of the cellular toxicity of manganese, a major challenge for a successful MEMRI study is to achieve the lowest possible dose for a particular biological question. Moreover, the interpretation of MEMRI findings requires a profound knowledge of the behavior of manganese in complex organ systems under physiological and pathological conditions. Starting with an overview of manganese pharmacokinetics and mechanisms of toxicity, this chapter covers experimental methods and protocols for applications in neuroscience.
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Affiliation(s)
- Susann Boretius
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, 37077 Göttingen, Germany.
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Afjehi-Sadat L, Brejnikow M, Kang SU, Vishwanath V, Walder N, Herkner K, Redl H, Lubec G. Differential protein levels and post-translational modifications in spinal cord injury of the rat. J Proteome Res 2010; 9:1591-7. [PMID: 20141154 DOI: 10.1021/pr901049a] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Although changes in protein expression in spinal cord injury (SCI) would be of pivotal interest, information so far is limited. It was therefore the aim of the study to determine protein levels and post-translational modifications in the early phase following SCI in the rat. SCI was induced in Sprague-Dawley rats and sham operated rats served as controls. A gel-based proteomic approach using two-dimensional gel electrophoresis followed by quantification with specific software and subsequent identification of differentially expressed proteins by nano-ESI-LC-MS/MS was applied. Proteins of several pathways and cascades were dysregulated in SCI: 14-3-3 epsilon protein, dynein light chain 1, and tubulin beta-5 chain showed higher levels in SCI, whereas adenylyl cyclase associated protein 1, dihydropyrimidinase-related protein 2, F-actin capping protein subunit beta, glyceraldehyde-3-phosphate dehydrogenase, stress-induced phosphoprotein 1 and transthyretin showed lower levels in the injured tissue. Post-translational modifications indicated free oxygen radical attack on proteins in SCI. The occurrence of stress is indicated by deranged stress-induced phosphoprotein 1 and signaling abnormalities are reflected by adenylyl cyclase-associated protein 1 and 14-3-3 epsilon protein. The findings propose the involvement of the corresponding cascades and challenge further work into aberrant signaling and oxidative stress in SCI, which may form the basis for experimental intervention for spinal cord trauma.
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Pitzer C, Klussmann S, Krüger C, Letellier E, Plaas C, Dittgen T, Kirsch F, Stieltjes B, Weber D, Laage R, Martin-Villalba A, Schneider A. The hematopoietic factor granulocyte-colony stimulating factor improves outcome in experimental spinal cord injury. J Neurochem 2010; 113:930-42. [PMID: 20202082 DOI: 10.1111/j.1471-4159.2010.06659.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Granulocyte-colony stimulating factor (G-CSF) is a potent hematopoietic factor that drives differentiation of neutrophilic granulocytes. We have recently shown that G-CSF also acts as a neuronal growth factor, protects neurons in vitro and in vivo, and has regenerative potential in various neurological disease models. Spinal cord injury (SCI) following trauma or secondary to skeletal instability is a terrible condition with no effective therapies available at present. In this study, we show that the G-CSF receptor is up-regulated upon experimental SCI and that G-CSF improves functional outcome in a partial dissection model of SCI. G-CSF significantly decreases apoptosis in an experimental partial spinal transsection model in the mouse and increases expression of the anti-apoptotic G-CSF target gene Bcl-X(L). In vitro, G-CSF enhances neurite outgrowth and branching capacity of hippocampal neurons. In vivo, G-CSF treatment results in improved functional connectivity of the injured spinal cord as measured by Mn(2+)-enhanced MRI. G-CSF also increased length of the dorsal corticospinal tract and density of serotonergic fibers cranial to the lesion center. Mice treated systemically with G-CSF as well as transgenic mice over-expressing G-CSF in the CNS exhibit a strong improvement in functional outcome as measured by the BBB score and gridwalk analysis. We show that G-CSF improves outcome after experimental SCI by counteracting apoptosis, and enhancing connectivity in the injured spinal cord. We conclude that G-CSF constitutes a promising and feasible new therapy option for SCI.
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Affiliation(s)
- Claudia Pitzer
- Sygnis Bioscience, Im Neuenheimer Feld, Heidelberg, Germany
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Martirosyan NL, Bennett KM, Theodore N, Preul MC. Manganese-Enhanced Magnetic Resonance Imaging in Experimental Spinal Cord Injury. Neurosurgery 2010; 66:131-6. [DOI: 10.1227/01.neu.0000361997.08116.96] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Nikolay L. Martirosyan
- Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona
| | - Kevin M. Bennett
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, Arizona
| | - Nicholas Theodore
- Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona
| | - Mark C. Preul
- Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona
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Cha MH, Lee C, Cho JH, Chung MA, Sohn JH, Cheong C, Lee HJ, Lee BH. Manganese-Enhanced Magnetic Resonance Imaging of the Spinal Cord in Rats. Exp Neurobiol 2009. [DOI: 10.5607/en.2009.18.1.57] [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
Affiliation(s)
- Myeoung Hoon Cha
- Department of Physiology and Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul 120-752, Korea
| | - Chulhyun Lee
- Korea Basic Science Institute, Daejeon 350-333, Korea
| | - Jee Hyun Cho
- Korea Basic Science Institute, Daejeon 350-333, Korea
| | - Myung-Ae Chung
- Electronics and Telecommunications Research Institute, Daejeon 305-350, Korea
| | - Jin-Hun Sohn
- Department of Psychology, Chungnam Nat'l University, Daejeon 305-764, Korea
| | | | - Hye-Jung Lee
- Acupuncture and Meridian Science Research Center, Kyung Hee University, Seoul 130-701, Korea
| | - Bae Hwan Lee
- Department of Physiology and Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul 120-752, Korea
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Current world literature. Curr Opin Neurol 2008; 21:615-24. [PMID: 18769258 DOI: 10.1097/wco.0b013e32830fb782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Abstract
The metal manganese is a potent magnetic resonance imaging (MRI) contrast agent that is essential in cell biology. Manganese-enhanced magnetic resonance imaging (MEMRI) is providing unique information in an ever-growing number of applications aimed at understanding the anatomy, the integration, and the function of neural circuits both in normal brain physiology as well as in translational models of brain disease. A major drawback to the use of manganese as a contrast agent, however, is its cellular toxicity. Therefore, paramount to the successful application of MEMRI is the ability to deliver Mn2+ to the site of interest using as low a dose as possible while preserving detectability by MRI. In the present work, the different approaches to MEMRI in translational neuroimaging are reviewed and challenges for future identified from a practical standpoint.
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Affiliation(s)
- Afonso C. Silva
- Cerebral Microcirculation Unit, Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA,To whom correspondence should be addressed: Cerebral Microcirculation Unit, Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 10 Center Drive MSC1065, Building 10, Room B1D106, Bethesda, MD 20892-1065; tel: 301-402-9703, fax: 301-480-2558, e-mail:
| | - Nicholas A. Bock
- Cerebral Microcirculation Unit, Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
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