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Syeda W, Ermine CM, Khilf MS, Wright D, Brait VH, Nithianantharajah J, Kolbe S, Johnston LA, Thompson LH, Brodtmann A. Long-term structural brain changes in adult rats after mild ischaemic stroke. Brain Commun 2022; 4:fcac185. [PMID: 35898722 PMCID: PMC9309495 DOI: 10.1093/braincomms/fcac185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Revised: 03/09/2022] [Accepted: 07/20/2022] [Indexed: 11/13/2022] Open
Abstract
Preclinical studies of remote degeneration have largely focused on brain changes over the first few days or weeks after stroke. Accumulating evidence suggests that neurodegeneration occurs in other brain regions remote to the site of infarction for months and even years following ischaemic stroke. Brain atrophy appears to be driven by both axonal degeneration and widespread brain inflammation. The evolution and duration of these changes are increasingly being described in human studies, using advanced brain imaging techniques. Here, we sought to investigate long-term structural brain changes in a model of mild focal ischaemic stroke following injection of endothlin-1 in adult Long–Evans rats (n = 14) compared with sham animals (n = 10), over a clinically relevant time-frame of 48 weeks. Serial structural and diffusion-weighted MRI data were used to assess dynamic volume and white matter trajectories. We observed dynamic regional brain volume changes over the 48 weeks, reflecting both normal changes with age in sham animals and neurodegeneration in regions connected to the infarct following ischaemia. Ipsilesional cortical volume loss peaked at 24 weeks but was less prominent at 36 and 48 weeks. We found significantly reduced fractional anisotropy in both ipsi- and contralesional motor cortex and cingulum bundle regions of infarcted rats (P < 0.05) from 4 to 36 weeks, suggesting ongoing white matter degeneration in tracts connected to but distant from the stroke. We conclude that there is evidence of significant cortical atrophy and white matter degeneration up to 48 weeks following infarct, consistent with enduring, pervasive stroke-related degeneration.
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Affiliation(s)
- Warda Syeda
- The Florey Institute of Neuroscience and Mental Health , Parkville, Victoria , Australia
- Melbourne Neuropsychiatry Centre, The University of Melbourne , Parkville, Victoria , Australia
| | - Charlotte M Ermine
- The Florey Institute of Neuroscience and Mental Health , Parkville, Victoria , Australia
| | - Mohamed Salah Khilf
- The Florey Institute of Neuroscience and Mental Health , Parkville, Victoria , Australia
| | - David Wright
- Department of Neuroscience, Monash University , Clayton , Australia
| | - Vanessa H Brait
- The Florey Institute of Neuroscience and Mental Health , Parkville, Victoria , Australia
| | - Jess Nithianantharajah
- The Florey Institute of Neuroscience and Mental Health , Parkville, Victoria , Australia
| | - Scott Kolbe
- Department of Neuroscience, Monash University , Clayton , Australia
| | - Leigh A Johnston
- The Melbourne Brain Centre Imaging Unit, The University of Melbourne , Parkville, Victoria , Australia
- Department of Biomedical Engineering, The University of Melbourne , Parkville, Victoria , Australia
| | - Lachlan H Thompson
- The Florey Institute of Neuroscience and Mental Health , Parkville, Victoria , Australia
| | - Amy Brodtmann
- The Florey Institute of Neuroscience and Mental Health , Parkville, Victoria , Australia
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Ermine CM, Chavez CA, Thompson LH. Histological characterization and quantification of newborn cells in the adult rodent brain. STAR Protoc 2021; 2:100614. [PMID: 34195672 PMCID: PMC8227830 DOI: 10.1016/j.xpro.2021.100614] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
This protocol describes the identification and characterization of newborn cells generated in the rodent brain after injury through birthdating with the thymidine analog 5-bromo-2′-deoxyuridine, followed by immunohistochemical labeling of fixed tissue sections. We also describe a software-assisted approach for automated detection and quantification of cells in large three-dimensional tissue volumes acquired using confocal microscopy. This approach facilitates the identification of low-frequency events that may be difficult to capture using manual counting methods, including stereology based on random sampling. For complete details on the use and execution of this protocol, please refer to Ermine et al. (2020). Newly generated cells can be immunolabeled using thymidine analogs such as BrdU High-quality 3D image capture allows for accurate software-based cell detection Automated cell detection quantifies immunolabeled cells in large tissue volumes Workflow to assist identification of low-frequency events in large cell populations
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Affiliation(s)
- Charlotte M Ermine
- The Florey Institute of Neuroscience and Mental Health, Melbourne, 3052 Australia
| | - Carolina A Chavez
- The Florey Institute of Neuroscience and Mental Health, Melbourne, 3052 Australia
| | - Lachlan H Thompson
- The Florey Institute of Neuroscience and Mental Health, Melbourne, 3052 Australia
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Kagan BJ, Ermine CM, Frausin S, Parish CL, Nithianantharajah J, Thompson LH. Focal Ischemic Injury to the Early Neonatal Rat Brain Models Cognitive and Motor Deficits with Associated Histopathological Outcomes Relevant to Human Neonatal Brain Injury. Int J Mol Sci 2021; 22:ijms22094740. [PMID: 33947043 PMCID: PMC8124303 DOI: 10.3390/ijms22094740] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 04/27/2021] [Accepted: 04/28/2021] [Indexed: 01/08/2023] Open
Abstract
Neonatal arterial ischemic stroke is one of the more severe birth complications. The injury can result in extensive neurological damage and is robustly associated with later diagnoses of cerebral palsy (CP). An important part of efforts to develop new therapies include the on-going refinement and understanding of animal models that capture relevant clinical features of neonatal brain injury leading to CP. The potent vasoconstrictor peptide, Endothelin-1 (ET-1), has previously been utilised in animal models to reduce local blood flow to levels that mimic ischemic stroke. Our previous work in this area has shown that it is an effective and technically simple approach for modelling ischemic injury at very early neonatal ages, resulting in stable deficits in motor function. Here, we aimed to extend this model to also examine the impact on cognitive function. We show that focal delivery of ET-1 to the cortex of Sprague Dawley rats on postnatal day 0 (P0) resulted in impaired learning in a touchscreen-based test of visual discrimination and correlated with important clinical features of CP including damage to large white matter structures.
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