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Latifi S, Carmichael ST. The emergence of multiscale connectomics-based approaches in stroke recovery. Trends Neurosci 2024; 47:303-318. [PMID: 38402008 DOI: 10.1016/j.tins.2024.01.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 12/31/2023] [Accepted: 01/21/2024] [Indexed: 02/26/2024]
Abstract
Stroke is a leading cause of adult disability. Understanding stroke damage and recovery requires deciphering changes in complex brain networks across different spatiotemporal scales. While recent developments in brain readout technologies and progress in complex network modeling have revolutionized current understanding of the effects of stroke on brain networks at a macroscale, reorganization of smaller scale brain networks remains incompletely understood. In this review, we use a conceptual framework of graph theory to define brain networks from nano- to macroscales. Highlighting stroke-related brain connectivity studies at multiple scales, we argue that multiscale connectomics-based approaches may provide new routes to better evaluate brain structural and functional remapping after stroke and during recovery.
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Affiliation(s)
- Shahrzad Latifi
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA; Department of Neuroscience, Rockefeller Neuroscience Institute, West Virginia University, Morgantown, WV 26506, USA
| | - S Thomas Carmichael
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA.
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2
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Koukalova L, Chmelova M, Amlerova Z, Vargova L. Out of the core: the impact of focal ischemia in regions beyond the penumbra. Front Cell Neurosci 2024; 18:1336886. [PMID: 38504666 PMCID: PMC10948541 DOI: 10.3389/fncel.2024.1336886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Accepted: 02/08/2024] [Indexed: 03/21/2024] Open
Abstract
The changes in the necrotic core and the penumbra following induction of focal ischemia have been the focus of attention for some time. However, evidence shows, that ischemic injury is not confined to the primarily affected structures and may influence the remote areas as well. Yet many studies fail to probe into the structures beyond the penumbra, and possibly do not even find any significant results due to their short-term design, as secondary damage occurs later. This slower reaction can be perceived as a therapeutic opportunity, in contrast to the ischemic core defined as irreversibly damaged tissue, where the window for salvation is comparatively short. The pathologies in remote structures occur relatively frequently and are clearly linked to the post-stroke neurological outcome. In order to develop efficient therapies, a deeper understanding of what exactly happens in the exo-focal regions is necessary. The mechanisms of glia contribution to the ischemic damage in core/penumbra are relatively well described and include impaired ion homeostasis, excessive cell swelling, glutamate excitotoxic mechanism, release of pro-inflammatory cytokines and phagocytosis or damage propagation via astrocytic syncytia. However, little is known about glia involvement in post-ischemic processes in remote areas. In this literature review, we discuss the definitions of the terms "ischemic core", "penumbra" and "remote areas." Furthermore, we present evidence showing the array of structural and functional changes in the more remote regions from the primary site of focal ischemia, with a special focus on glia and the extracellular matrix. The collected information is compared with the processes commonly occurring in the ischemic core or in the penumbra. Moreover, the possible causes of this phenomenon and the approaches for investigation are described, and finally, we evaluate the efficacy of therapies, which have been studied for their anti-ischemic effect in remote areas in recent years.
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Affiliation(s)
- Ludmila Koukalova
- Department of Neuroscience, Second Faculty of Medicine, Charles University, Prague, Czechia
| | - Martina Chmelova
- Department of Neuroscience, Second Faculty of Medicine, Charles University, Prague, Czechia
- Department of Cellular Neurophysiology, Institute of Experimental Medicine of the Czech Academy of Sciences, Prague, Czechia
| | - Zuzana Amlerova
- Department of Neuroscience, Second Faculty of Medicine, Charles University, Prague, Czechia
| | - Lydia Vargova
- Department of Neuroscience, Second Faculty of Medicine, Charles University, Prague, Czechia
- Department of Cellular Neurophysiology, Institute of Experimental Medicine of the Czech Academy of Sciences, Prague, Czechia
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Weber RZ, Bernardoni D, Rentsch NH, Buil BA, Halliday S, Augath MA, Razansky D, Tackenberg C, Rust R. A toolkit for stroke infarct volume estimation in rodents. Neuroimage 2024; 287:120518. [PMID: 38219841 DOI: 10.1016/j.neuroimage.2024.120518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 01/09/2024] [Accepted: 01/11/2024] [Indexed: 01/16/2024] Open
Abstract
Stroke volume is a key determinant of infarct severity and an important metric for evaluating treatments. However, accurate estimation of stroke volume can be challenging, due to the often confined 2-dimensional nature of available data. Here, we introduce a comprehensive semi-automated toolkit to reliably estimate stroke volumes based on (1) whole brains ex-vivo magnetic resonance imaging (MRI) and (2) brain sections that underwent immunofluorescence staining. We located and quantified infarct areas from MRI three days (acute) and 28 days (chronic) after photothrombotic stroke induction in whole mouse brains. MRI results were compared with measures obtained from immunofluorescent histologic sections of the same brains. We found that infarct volume determined by post-mortem MRI was highly correlated with a deviation of only 6.6 % (acute) and 4.9 % (chronic) to the measurements as determined in the histological brain sections indicating that both methods are capable of accurately assessing brain tissue damage (Pearson r > 0.9, p < 0.001). The Dice similarity coefficient (DC) showed a high degree of coherence (DC > 0.8) between MRI-delineated regions of interest (ROIs) and ROIs obtained from histologic sections at four to six pre-defined landmarks, with histology-based delineation demonstrating higher inter-operator similarity compared to MR images. We further investigated stroke-related scarring and post-ischemic angiogenesis in cortical peri‑infarct regions and described a negative correlation between GFAP+fluorescence intensity and MRI-obtained lesion size.
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Affiliation(s)
- Rebecca Z Weber
- Institute for Regenerative Medicine, University of Zurich, Schlieren 8952, Switzerland; Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Davide Bernardoni
- Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland
| | - Nora H Rentsch
- Institute for Regenerative Medicine, University of Zurich, Schlieren 8952, Switzerland; Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Beatriz Achón Buil
- Institute for Regenerative Medicine, University of Zurich, Schlieren 8952, Switzerland; Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Stefanie Halliday
- Institute for Regenerative Medicine, University of Zurich, Schlieren 8952, Switzerland
| | - Mark-Aurel Augath
- Institute for Biomedical Engineering and Institute of Pharmacology and Toxicology, Faculty of Medicine, University of Zurich, Zurich 8052, Switzerland; Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, ETH Zurich, Zurich 8093, Switzerland
| | - Daniel Razansky
- Institute for Biomedical Engineering and Institute of Pharmacology and Toxicology, Faculty of Medicine, University of Zurich, Zurich 8052, Switzerland; Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, ETH Zurich, Zurich 8093, Switzerland
| | - Christian Tackenberg
- Institute for Regenerative Medicine, University of Zurich, Schlieren 8952, Switzerland; Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Ruslan Rust
- Institute for Regenerative Medicine, University of Zurich, Schlieren 8952, Switzerland; Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland; Department of Physiology and Neuroscience, University of Southern California, Los Angeles, CA 90089, United States; Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, 1501 San Pablo St., Los Angeles, CA 900893, United States.
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Götz J, Wieters F, Fritz VJ, Käsgen O, Kalantari A, Fink GR, Aswendt M. Temporal and Spatial Gene Expression Profile of Stroke Recovery Genes in Mice. Genes (Basel) 2023; 14:454. [PMID: 36833381 PMCID: PMC9956317 DOI: 10.3390/genes14020454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 02/06/2023] [Accepted: 02/07/2023] [Indexed: 02/12/2023] Open
Abstract
Stroke patients show some degree of spontaneous functional recovery, but this is not sufficient to prevent long-term disability. One promising approach is to characterize the dynamics of stroke recovery genes in the lesion and distant areas. We induced sensorimotor cortex lesions in adult C57BL/6J mice using photothrombosis and performed qPCR on selected brain areas at 14, 28, and 56 days post-stroke (P14-56). Based on the grid walk and rotating beam test, the mice were classified into two groups. The expression of cAMP pathway genes Adora2a, Pde10a, and Drd2, was higher in poor- compared to well-recovered mice in contralesional primary motor cortex (cl-MOp) at P14&56 and cl-thalamus (cl-TH), but lower in cl-striatum (cl-Str) at P14 and cl-primary somatosensory cortex (cl-SSp) at P28. Plasticity and axonal sprouting genes, Lingo1 and BDNF, were decreased in cl-MOp at P14 and cl-Str at P28 and increased in cl-SSp at P28 and cl-Str at P14, respectively. In the cl-TH, Lingo1 was increased, and BDNF decreased at P14. Atrx, also involved in axonal sprouting, was only increased in poor-recovered mice in cl-MOp at P28. The results underline the gene expression dynamics and spatial variability and challenge existing theories of restricted neural plasticity.
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Affiliation(s)
- Jan Götz
- Faculty of Medicine, University of Cologne, 50923 Cologne, Germany
- Department of Neurology, University Hospital Cologne, 50931 Cologne, Germany
| | - Frederique Wieters
- Faculty of Medicine, University of Cologne, 50923 Cologne, Germany
- Department of Neurology, University Hospital Cologne, 50931 Cologne, Germany
| | - Veronika J. Fritz
- Faculty of Medicine, University of Cologne, 50923 Cologne, Germany
- Department of Neurology, University Hospital Cologne, 50931 Cologne, Germany
| | - Olivia Käsgen
- Faculty of Medicine, University of Cologne, 50923 Cologne, Germany
- Department of Neurology, University Hospital Cologne, 50931 Cologne, Germany
| | - Aref Kalantari
- Faculty of Medicine, University of Cologne, 50923 Cologne, Germany
- Department of Neurology, University Hospital Cologne, 50931 Cologne, Germany
| | - Gereon R. Fink
- Faculty of Medicine, University of Cologne, 50923 Cologne, Germany
- Department of Neurology, University Hospital Cologne, 50931 Cologne, Germany
- Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Research Centre Juelich, 52425 Juelich, Germany
| | - Markus Aswendt
- Faculty of Medicine, University of Cologne, 50923 Cologne, Germany
- Department of Neurology, University Hospital Cologne, 50931 Cologne, Germany
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Weber RZ, Mulders G, Perron P, Tackenberg C, Rust R. Molecular and anatomical roadmap of stroke pathology in immunodeficient mice. Front Immunol 2022; 13:1080482. [PMID: 36569903 PMCID: PMC9785704 DOI: 10.3389/fimmu.2022.1080482] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 11/22/2022] [Indexed: 12/13/2022] Open
Abstract
Background Stroke remains a leading cause of disability and death worldwide. It has become apparent that inflammation and immune mediators have a pre-dominant role in initial tissue damage and long-term recovery. Still, different immunosuppressed mouse models are necessary in stroke research e.g., to evaluate therapies using human cell grafts. Despite mounting evidence delineating the importance of inflammation in the stroke pathology, it is poorly described to what extent immune deficiency influences overall stroke outcome. Methods Here, we assessed the stroke pathology of popular genetic immunodeficient mouse models, i.e., NOD scid gamma (NSG) and recombination activating gene 2 (Rag2-/-) mice as well as pharmacologically immunosuppressed mice and compared them to immune competent, wildtype (WT) C57BL/6J mice three weeks after injury. We performed histology, gene expression, blood serum and behavioural analysis to identify the impact of immunosuppression on stroke progression. Results We detected changes in microglia activation/macrophage infiltration, scar-forming and vascular repair in immune-suppressed mice three weeks after injury. Transcriptomic analysis of stroked tissue revealed the strongest deviation from WT was observed in NSG mice affecting immunological and angiogenic pathways. Pharmacological immunosuppression resulted in the least variation in gene expression compared with the WT. These anatomical and genetic changes did not affect functional recovery in a time course of three weeks. To determine whether timing of immunosuppression is critical, we compared mice with acute and delayed pharmacological immunosuppression after stroke. Mice with delayed immunosuppression (7d) showed increased inflammatory and scarring responses compared to animals acutely treated with tacrolimus, thus more closely resembling WT pathology. Transplantation of human cells in the brains of immunosuppressed mice led to prolonged cell survival in all immunosuppressed mouse models, which was most consistent in NSG and Rag2-/- mice. Conclusions We detected distinct anatomical and molecular changes in the stroke pathology between individual immunosuppressed mouse models that should be considered when selecting an appropriate mouse model for stroke research.
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Affiliation(s)
- Rebecca Z. Weber
- Institute for Regenerative Medicine, University of Zurich, Schlieren, Switzerland,Neuroscience Center Zurich, University of Zurich and Eidgenössische Technische Hochschule (ETH) Zurich, Zurich, Switzerland
| | - Geertje Mulders
- Department of Health Sciences and Technology, Eidgenössische Technische Hochschule (ETH) Zurich, Zurich, Switzerland
| | - Patrick Perron
- Institute for Regenerative Medicine, University of Zurich, Schlieren, Switzerland
| | - Christian Tackenberg
- Institute for Regenerative Medicine, University of Zurich, Schlieren, Switzerland,Neuroscience Center Zurich, University of Zurich and Eidgenössische Technische Hochschule (ETH) Zurich, Zurich, Switzerland
| | - Ruslan Rust
- Institute for Regenerative Medicine, University of Zurich, Schlieren, Switzerland,Neuroscience Center Zurich, University of Zurich and Eidgenössische Technische Hochschule (ETH) Zurich, Zurich, Switzerland,*Correspondence: Ruslan Rust,
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Van der Linden A, Hoehn M. Monitoring Neuronal Network Disturbances of Brain Diseases: A Preclinical MRI Approach in the Rodent Brain. Front Cell Neurosci 2022; 15:815552. [PMID: 35046778 PMCID: PMC8761853 DOI: 10.3389/fncel.2021.815552] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 12/06/2021] [Indexed: 12/20/2022] Open
Abstract
Functional and structural neuronal networks, as recorded by resting-state functional MRI and diffusion MRI-based tractography, gain increasing attention as data driven whole brain imaging methods not limited to the foci of the primary pathology or the known key affected regions but permitting to characterize the entire network response of the brain after disease or injury. Their connectome contents thus provide information on distal brain areas, directly or indirectly affected by and interacting with the primary pathological event or affected regions. From such information, a better understanding of the dynamics of disease progression is expected. Furthermore, observation of the brain's spontaneous or treatment-induced improvement will contribute to unravel the underlying mechanisms of plasticity and recovery across the whole-brain networks. In the present review, we discuss the values of functional and structural network information derived from systematic and controlled experimentation using clinically relevant animal models. We focus on rodent models of the cerebral diseases with high impact on social burdens, namely, neurodegeneration, and stroke.
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Affiliation(s)
- Annemie Van der Linden
- Bio-Imaging Lab, Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
- μNEURO Research Centre of Excellence, University of Antwerp, Antwerp, Belgium
| | - Mathias Hoehn
- Research Center Jülich, Institute 3 for Neuroscience and Medicine, Jülich, Germany
- *Correspondence: Mathias Hoehn
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Blaschke SJ, Hensel L, Minassian A, Vlachakis S, Tscherpel C, Vay SU, Rabenstein M, Schroeter M, Fink GR, Hoehn M, Grefkes C, Rueger MA. Translating Functional Connectivity After Stroke: Functional Magnetic Resonance Imaging Detects Comparable Network Changes in Mice and Humans. Stroke 2021; 52:2948-2960. [PMID: 34281374 DOI: 10.1161/strokeaha.120.032511] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Stefan J Blaschke
- Faculty of Medicine and University Hospital, Department of Neurology, University of Cologne, Germany (S.J.B., L.H., S.V., C.T., S.U.V., M.R., M.S., G.R.F., C.G., M.A.R.)
- In-Vivo NMR Laboratory, Max Planck Institute for Metabolism Research, Cologne, Germany (S.J.B., A.M., S.V., M.R., M.S., M.H., C.G., M.A.R.)
- Cognitive Neuroscience Section, Institute of Neuroscience and Medicine (INM-3), Research Centre Juelich, Germany (S.J.B., L.H., C.T., M.S., G.R.F., M.H., C.G., M.A.R.)
| | - Lukas Hensel
- Faculty of Medicine and University Hospital, Department of Neurology, University of Cologne, Germany (S.J.B., L.H., S.V., C.T., S.U.V., M.R., M.S., G.R.F., C.G., M.A.R.)
- Cognitive Neuroscience Section, Institute of Neuroscience and Medicine (INM-3), Research Centre Juelich, Germany (S.J.B., L.H., C.T., M.S., G.R.F., M.H., C.G., M.A.R.)
| | - Anuka Minassian
- In-Vivo NMR Laboratory, Max Planck Institute for Metabolism Research, Cologne, Germany (S.J.B., A.M., S.V., M.R., M.S., M.H., C.G., M.A.R.)
| | - Susan Vlachakis
- Faculty of Medicine and University Hospital, Department of Neurology, University of Cologne, Germany (S.J.B., L.H., S.V., C.T., S.U.V., M.R., M.S., G.R.F., C.G., M.A.R.)
- In-Vivo NMR Laboratory, Max Planck Institute for Metabolism Research, Cologne, Germany (S.J.B., A.M., S.V., M.R., M.S., M.H., C.G., M.A.R.)
| | - Caroline Tscherpel
- Faculty of Medicine and University Hospital, Department of Neurology, University of Cologne, Germany (S.J.B., L.H., S.V., C.T., S.U.V., M.R., M.S., G.R.F., C.G., M.A.R.)
- Cognitive Neuroscience Section, Institute of Neuroscience and Medicine (INM-3), Research Centre Juelich, Germany (S.J.B., L.H., C.T., M.S., G.R.F., M.H., C.G., M.A.R.)
| | - Sabine U Vay
- Faculty of Medicine and University Hospital, Department of Neurology, University of Cologne, Germany (S.J.B., L.H., S.V., C.T., S.U.V., M.R., M.S., G.R.F., C.G., M.A.R.)
| | - Monika Rabenstein
- Faculty of Medicine and University Hospital, Department of Neurology, University of Cologne, Germany (S.J.B., L.H., S.V., C.T., S.U.V., M.R., M.S., G.R.F., C.G., M.A.R.)
- In-Vivo NMR Laboratory, Max Planck Institute for Metabolism Research, Cologne, Germany (S.J.B., A.M., S.V., M.R., M.S., M.H., C.G., M.A.R.)
| | - Michael Schroeter
- Faculty of Medicine and University Hospital, Department of Neurology, University of Cologne, Germany (S.J.B., L.H., S.V., C.T., S.U.V., M.R., M.S., G.R.F., C.G., M.A.R.)
- In-Vivo NMR Laboratory, Max Planck Institute for Metabolism Research, Cologne, Germany (S.J.B., A.M., S.V., M.R., M.S., M.H., C.G., M.A.R.)
- Cognitive Neuroscience Section, Institute of Neuroscience and Medicine (INM-3), Research Centre Juelich, Germany (S.J.B., L.H., C.T., M.S., G.R.F., M.H., C.G., M.A.R.)
| | - Gereon R Fink
- Faculty of Medicine and University Hospital, Department of Neurology, University of Cologne, Germany (S.J.B., L.H., S.V., C.T., S.U.V., M.R., M.S., G.R.F., C.G., M.A.R.)
- Cognitive Neuroscience Section, Institute of Neuroscience and Medicine (INM-3), Research Centre Juelich, Germany (S.J.B., L.H., C.T., M.S., G.R.F., M.H., C.G., M.A.R.)
| | - Mathias Hoehn
- Cognitive Neuroscience Section, Institute of Neuroscience and Medicine (INM-3), Research Centre Juelich, Germany (S.J.B., L.H., C.T., M.S., G.R.F., M.H., C.G., M.A.R.)
| | - Christian Grefkes
- Faculty of Medicine and University Hospital, Department of Neurology, University of Cologne, Germany (S.J.B., L.H., S.V., C.T., S.U.V., M.R., M.S., G.R.F., C.G., M.A.R.)
- In-Vivo NMR Laboratory, Max Planck Institute for Metabolism Research, Cologne, Germany (S.J.B., A.M., S.V., M.R., M.S., M.H., C.G., M.A.R.)
- Cognitive Neuroscience Section, Institute of Neuroscience and Medicine (INM-3), Research Centre Juelich, Germany (S.J.B., L.H., C.T., M.S., G.R.F., M.H., C.G., M.A.R.)
| | - Maria A Rueger
- Faculty of Medicine and University Hospital, Department of Neurology, University of Cologne, Germany (S.J.B., L.H., S.V., C.T., S.U.V., M.R., M.S., G.R.F., C.G., M.A.R.)
- In-Vivo NMR Laboratory, Max Planck Institute for Metabolism Research, Cologne, Germany (S.J.B., A.M., S.V., M.R., M.S., M.H., C.G., M.A.R.)
- Cognitive Neuroscience Section, Institute of Neuroscience and Medicine (INM-3), Research Centre Juelich, Germany (S.J.B., L.H., C.T., M.S., G.R.F., M.H., C.G., M.A.R.)
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Minassian A, Green C, Diedenhofen M, Vogel S, Hess S, Stoeber M, Radmilovic MD, Wiedermann D, Kloppenburg P, Hoehn M. Human Neural Stem Cell Induced Functional Network Stabilization After Cortical Stroke: A Longitudinal Resting-State fMRI Study in Mice. Front Cell Neurosci 2020; 14:86. [PMID: 32317940 PMCID: PMC7155295 DOI: 10.3389/fncel.2020.00086] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 03/20/2020] [Indexed: 12/12/2022] Open
Abstract
Most stroke studies dealing with functional deficits and assessing stem cell therapy produce extensive hemispheric damage and can be seen as a model for severe clinical strokes. However, mild strokes have a better prospect for functional recovery. Recently, anatomic and behavioral changes have been reported for distal occlusion of the middle cerebral artery (MCA), generating a well-circumscribed and small cortical lesion, which can thus be proposed as mild to moderate cortical stroke. Using this cortical stroke model of moderate severity in the nude mouse, we have studied the functional networks with resting-state functional magnetic resonance imaging (fMRI) for 12 weeks following stroke induction. Further, human neural stem cells (hNSCs) were implanted adjacent to the ischemic lesion, and the stable graft vitality was monitored with bioluminescence imaging (BLI). Differentiation of the grafted neural stem cells was analyzed by immunohistochemistry and by patch-clamp electrophysiology. Following stroke induction, we found a pronounced and continuously rising hypersynchronicity of the sensorimotor networks including both hemispheres, in contrast to the severe stroke filament model where profound reduction of the functional connectivity had been reported by us earlier. The vitality of grafted neural stem cells remained stable throughout the whole 12 weeks observation period. In the stem cell treated animals, functional connectivity did not show hypersynchronicity but was globally slightly reduced below baseline at 2 weeks post-stroke, normalizing thereafter completely. Our resting-state fMRI (rsfMRI) studies on cortical stroke reveal for the first time a hypersynchronicity of the functional brain networks. This hypersynchronicity appears as a hallmark of mild cortical strokes, in contrast to severe strokes with striatal involvement where exclusively hyposynchronicity has been reported. The effect of the stem cell graft was an early and persistent normalization of the functional sensorimotor networks across the whole brain. These novel functional results may help interpret future outcome investigations after stroke and demonstrate the highly promising potential of stem cell treatment for functional outcome improvement after stroke.
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Affiliation(s)
- Anuka Minassian
- In-Vivo-NMR Laboratory, Max Planck Institute for Metabolism Research, Cologne, Germany
| | - Claudia Green
- In-Vivo-NMR Laboratory, Max Planck Institute for Metabolism Research, Cologne, Germany
| | - Michael Diedenhofen
- In-Vivo-NMR Laboratory, Max Planck Institute for Metabolism Research, Cologne, Germany
| | - Stefanie Vogel
- In-Vivo-NMR Laboratory, Max Planck Institute for Metabolism Research, Cologne, Germany
| | - Simon Hess
- Biocenter, Institute for Zoology, University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Maren Stoeber
- In-Vivo-NMR Laboratory, Max Planck Institute for Metabolism Research, Cologne, Germany
| | - Marina Dobrivojevic Radmilovic
- In-Vivo-NMR Laboratory, Max Planck Institute for Metabolism Research, Cologne, Germany.,Department of Histology and Embryology, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Dirk Wiedermann
- In-Vivo-NMR Laboratory, Max Planck Institute for Metabolism Research, Cologne, Germany
| | - Peter Kloppenburg
- Biocenter, Institute for Zoology, University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Mathias Hoehn
- In-Vivo-NMR Laboratory, Max Planck Institute for Metabolism Research, Cologne, Germany.,Department of Radiology, Leiden University Medical Center, Leiden University, Leiden, Netherlands
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