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Clay AM, Carr RL, DuBien JL, To F. Short-term behavioral and histological findings following a single concussive and repeated subconcussive brain injury in a rodent model. Brain Inj 2024; 38:827-834. [PMID: 38704844 DOI: 10.1080/02699052.2024.2349144] [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: 03/19/2023] [Accepted: 04/23/2024] [Indexed: 05/07/2024]
Abstract
PRIMARY OBJECTIVE It is unclear of the correlation between a mild traumatic brain injury (mTBI) and repeated subconcussive (RSC) impacts with respect to injury biomechanics. Thus, the present study was designed to determine the behavioral and histological differences between a single mTBI impact and RSC impacts with subdivided cumulative kinetic energies of the single mTBI impact. RESEARCH DESIGN Adult male Sprague-Dawley rats were randomly assigned to a single mTBI impact, RSC impact, sham, or repeated sham groups. METHODS AND PROCEDURES Following a weight drop injury, anxiety-like behavior and general locomotive activity and were assessed using the open field test, while motor coordination was evaluated using a rotarod unit. Neuronal loss, astrogliosis, and microgliosis were assessed using NeuN, GFAP and Iba-1 immunohistochemistry. All assessments were undertaken at 3- and 7-days post impact. MAIN OUTCOMES AND RESULTS No behavioral disturbances were observed in injury groups, however, both injury groups did lead to microgliosis following 3-days post-impact. CONCLUSIONS No pathophysiological differences were observed between a single mTBI impact and RSC impacts of the same energy input. Even though a cumulative injury threshold for RSC impacts was not determined, a threshold still may exist where no pathodynamic shift occurs.
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Affiliation(s)
- Anna Marie Clay
- Department of Agricultural and Biological Engineering, Mississippi State University, Mississippi, USA
| | - Russell L Carr
- Center for Environmental Health Sciences, College of Veterinary Medicine, Mississippi University, Mississippi, USA
| | - Janice L DuBien
- Department of Statistics, Mississippi University, Mississippi, USA
| | - Filip To
- Department of Agricultural and Biological Engineering, Mississippi State University, Mississippi, USA
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2
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Cheng C, Lu CF, Hsieh BY, Huang SH, Kao YCJ. Anisotropy component of DTI reveals long-term neuroinflammation following repetitive mild traumatic brain injury in rats. Eur Radiol Exp 2024; 8:82. [PMID: 39046630 PMCID: PMC11269550 DOI: 10.1186/s41747-024-00490-w] [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: 03/21/2024] [Accepted: 06/18/2024] [Indexed: 07/25/2024] Open
Abstract
BACKGROUND This study aimed to investigate the long-term effects of repetitive mild traumatic brain injury (rmTBI) with varying inter-injury intervals by measuring diffusion tensor metrics, including mean diffusivity (MD), fractional anisotropy (FA), and diffusion magnitude (L) and pure anisotropy (q). METHODS Eighteen rats were randomly divided into three groups: short-interval rmTBI (n = 6), long-interval rmTBI (n = 6), and sham controls (n = 6). MD, FA, L, and q values were analyzed from longitudinal diffusion tensor imaging at days 50 and 90 after rmTBI. Immunohistochemical staining against neurons, astrocytes, microglia, and myelin was performed. Analysis of variance, Pearson correlation coefficient, and simple linear regression model were used. RESULTS At day 50 post-rmTBI, lower cortical FA and q values were shown in the short-interval group (p ≤ 0.038). In contrast, higher FA and q values were shown for the long-interval group (p ≤ 0.039) in the corpus callosum. In the ipsilesional external capsule and internal capsule, no significant changes were found in FA, while lower L and q values were shown in the short-interval group (p ≤ 0.028) at day 90. The q values in the external capsule and internal capsule were negatively correlated with the number of microglial cells and the total number of astroglial cells (p ≤ 0.035). CONCLUSION Tensor scalar measurements, such as L and q values, are sensitive to exacerbated chronic injury induced by rmTBI with shorter inter-injury intervals and reflect long-term astrogliosis induced by the cumulative injury. RELEVANCE STATEMENT Tensor scalar measurements, including L and q values, are potential DTI metrics for detecting long-term and subtle injury following rmTBI; in particular, q values may be used for quantifying remote white matter (WM) changes following rmTBI. KEY POINTS The alteration of L and q values was demonstrated after chronic repetitive mild traumatic brain injury. Changing q values were observed in the impact site and remote WM. The lower q values in the remote WM were associated with astrogliosis.
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Affiliation(s)
- Ching Cheng
- Department of Biomedical Imaging and Radiological Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Chia-Feng Lu
- Department of Biomedical Imaging and Radiological Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Bao-Yu Hsieh
- Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang-Gung University, Taoyuan, Taiwan
- Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
| | - Shu-Hui Huang
- Department of Biomedical Imaging and Radiological Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Yu-Chieh Jill Kao
- Department of Biomedical Imaging and Radiological Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan.
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3
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Lipton ML. A Promise to Keep, but Miles to Go Before We Sleep…. J Pharmacol Exp Ther 2024; 389:133-135. [PMID: 38637018 DOI: 10.1124/jpet.123.001939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 11/09/2023] [Indexed: 04/20/2024] Open
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Hoogenboom WS, Rubin TG, Ambadipudi K, Cui MH, Ye K, Foster H, Elkouby E, Liu J, Branch CA, Lipton ML. Evolving brain and behaviour changes in rats following repetitive subconcussive head impacts. Brain Commun 2023; 5:fcad316. [PMID: 38046094 PMCID: PMC10691880 DOI: 10.1093/braincomms/fcad316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 09/26/2023] [Accepted: 11/19/2023] [Indexed: 12/05/2023] Open
Abstract
There is growing concern that repetitive subconcussive head impacts, independent of concussion, alter brain structure and function, and may disproportionately affect the developing brain. Animal studies of repetitive subconcussive head impacts are needed to begin to characterize the pathological basis and mechanisms underlying imaging and functional effects of repetitive subconcussive head impacts seen in humans. Since repetitive subconcussive head impacts have been largely unexplored in animals, we aimed to characterize the evolution of imaging, behavioural and pathological effects of repetitive subconcussive head impacts in awake adolescent rodents. Awake male and female Sprague Dawley rats (postnatal Day 35) received 140 closed-head impacts over the course of a week. Impacted and sham-impacted animals were restrained in a plastic cone, and unrestrained control animals were included to account for effects of restraint and normal development. Animals (n = 43) underwent repeated diffusion tensor imaging prior to and over 1 month following the final impact. A separate cohort (n = 53) was assessed behaviourally for fine motor control, emotional-affective behaviour and memory at acute and chronic time points. Histological and immunohistochemical analyses, which were exploratory in nature due to smaller sample sizes, were completed at 1 month following the final impact. All animals tolerated the protocol with no overt changes in behaviour or stigmata of traumatic brain injury, such as alteration of consciousness, intracranial haemorrhage or skull fracture. We detected longitudinal, sex-dependent diffusion tensor imaging changes (fractional anisotropy and axial diffusivity decline) in corpus callosum and external capsule of repetitive subconcussive head impact animals, which diverged from both sham and control. Compared to sham animals, repetitive subconcussive head impact animals exhibited acute but transient mild motor deficits. Repetitive subconcussive head impact animals also exhibited chronic anxiety and spatial memory impairment that differed from the control animals, but these effects were not different from those seen in the sham condition. We observed trends in the data for thinning of the corpus callosum as well as regions with elevated Iba-1 in the corpus callosum and cerebral white matter among repetitive subconcussive head impact animals. While replication with larger study samples is needed, our findings suggest that subconcussive head impacts cause microstructural tissue changes in the developing rat brain, which are detectable with diffusion tensor imaging, with suggestion of correlates in tissue pathology and behaviour. The results point to potential mechanisms underpinning consequences of subconcussive head impacts that have been described in humans. The congruence of our imaging findings with human subconcussive head impacts suggests that neuroimaging could serve as a translational bridge to advance study of injury mechanisms and development of interventions.
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Affiliation(s)
- Wouter S Hoogenboom
- The Gruss Magnetic Resonance Research Center, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY 10641, USA
- Department of Clinical Investigation, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY 10641, USA
- Department of Radiology, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY 10461, USA
| | - Todd G Rubin
- Department of Neurology, Icahn School of Medicine at Mount Sinai, NewYork, NY 10029, USA
| | - Kamalakar Ambadipudi
- The Gruss Magnetic Resonance Research Center, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY 10641, USA
- Department of Radiology, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY 10461, USA
| | - Min-Hui Cui
- The Gruss Magnetic Resonance Research Center, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY 10641, USA
- Department of Radiology, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY 10461, USA
| | - Kenny Ye
- Department of Epidemiology & Population Health, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY 10461, USA
| | - Henry Foster
- The Gruss Magnetic Resonance Research Center, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY 10641, USA
| | - Esther Elkouby
- The Gruss Magnetic Resonance Research Center, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY 10641, USA
| | - Jinyuan Liu
- The Gruss Magnetic Resonance Research Center, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY 10641, USA
| | - Craig A Branch
- The Gruss Magnetic Resonance Research Center, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY 10641, USA
- Department of Radiology, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY 10461, USA
- Department of Physiology and Biophysics, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY 10461, USA
| | - Michael L Lipton
- Department of Radiology, Columbia University Irving Medical Center, NewYork, NY 10032, USA
- Department of Biomedical Engineering, Columbia University, NewYork, NY 10032, USA
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Rudolph M, Kopruszinski C, Wu C, Navratilova E, Schwedt TJ, Dodick DW, Porreca F, Anderson T. Identification of brain areas in mice with peak neural activity across the acute and persistent phases of post-traumatic headache. Cephalalgia 2023; 43:3331024231217469. [PMID: 38016977 PMCID: PMC11149587 DOI: 10.1177/03331024231217469] [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] [Indexed: 11/30/2023]
Abstract
BACKGROUND Post-traumatic headache is very common after a mild traumatic brain injury. Post-traumatic headache may persist for months to years after an injury in a substantial proportion of people. The pathophysiology underlying post-traumatic headache remains unknown but is likely distinct from other headache disorders. Identification of brain areas activated in acute and persistent phases of post-traumatic headache can provide insights into the underlying circuits mediating headache pain. We used an animal model of mild traumatic brain injury-induced post-traumatic headache and c-fos immunohistochemistry to identify brain regions with peak activity levels across the acute and persistent phases of post-traumatic headache. METHODS Male and female C57BL/6 J mice were briefly anesthetized and subjected to a sham procedure or a weight drop closed-head mild traumatic brain injury . Cutaneous allodynia was assessed in the periorbital and hindpaw regions using von Frey filaments. Immunohistochemical c-fos based neural activity mapping was then performed on sections from whole brain across the development of post-traumatic headache (i.e. peak of the acute phase at 2 days post- mild traumatic brain injury), start of the persistent phase (i.e. >14 days post-mild traumatic brain injury) or after provocation with stress (bright light). Brain areas with consistent and peak levels of c-fos expression across mild traumatic brain injury induced post-traumatic headache were identified and included for further analysis. RESULTS Following mild traumatic brain injury, periorbital and hindpaw allodynia was observed in both male and female mice. This allodynia was transient and subsided within the first 14 days post-mild traumatic brain injury and is representative of acute post-traumatic headache. After this acute post-traumatic headache phase, exposure of mild traumatic brain injury mice to a bright light stress reinstated periorbital and hindpaw allodynia for several hours - indicative of the development of persistent post-traumatic headache. Acute post-traumatic headache was coincident with an increase in neuronal c-fos labeling in the spinal nucleus of the trigeminal caudalis, primary somatosensory cortex, and the nucleus accumbens. Neuronal activation returned to baseline levels by the persistent post-traumatic headache phase in the spinal nucleus of the trigeminal caudalis and primary somatosensory cortex but remained elevated in the nucleus accumbens. In the persistent post-traumatic headache phase, coincident with allodynia observed following bright light stress, we observed bright light stress-induced c-fos neural activation in the spinal nucleus of the trigeminal caudalis, primary somatosensory cortex, and nucleus accumbens. CONCLUSION Examination of mild traumatic brain injury-induced changes in peak c-fos expression revealed brain regions with significantly increased neural activity across the acute and persistent phases of post-traumatic headache. Our findings suggest mild traumatic brain injury-induced post-traumatic headache produces neural activation along pain relevant pathways at time-points matching post-traumatic headache-like pain behaviors. These observations suggest that the spinal nucleus of the trigeminal caudalis, primary somatosensory cortex, and nucleus accumbens may contribute to both the induction and maintenance of post-traumatic headache.
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Affiliation(s)
- Megan Rudolph
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, Arizona, USA
- Department of Basic Medical Sciences, College of Medicine, University of Arizona, Phoenix, Arizona, USA
| | - Caroline Kopruszinski
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, Arizona, USA
| | - Chen Wu
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, Arizona, USA
- Department of Basic Medical Sciences, College of Medicine, University of Arizona, Phoenix, Arizona, USA
| | - Edita Navratilova
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, Arizona, USA
- Department of Neurology, Mayo Clinic, Phoenix, USA
| | | | - David W Dodick
- Mayo Clinic College of Medicine, Scottsdale, Arizona, USA
- Atria Academy of Science and Medicine, New York City, New York, USA
| | - Frank Porreca
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, Arizona, USA
| | - Trent Anderson
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, Arizona, USA
- Department of Basic Medical Sciences, College of Medicine, University of Arizona, Phoenix, Arizona, USA
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San Martín Molina I, Fratini M, Campi G, Burghammer M, Grünewald TA, Salo RA, Narvaez O, Aggarwal M, Tohka J, Sierra A. A multiscale tissue assessment in a rat model of mild traumatic brain injury. J Neuropathol Exp Neurol 2022; 82:71-83. [PMID: 36331507 PMCID: PMC9764078 DOI: 10.1093/jnen/nlac100] [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] [Indexed: 11/06/2022] Open
Abstract
Diffusion tensor imaging (DTI) has demonstrated the potential to assess the pathophysiology of mild traumatic brain injury (mTBI) but correlations of DTI findings and pathological changes in mTBI are unclear. We evaluated the potential of ex vivo DTI to detect tissue damage in a mild mTBI rat model by exploiting multiscale imaging methods, histology and scanning micro-X-ray diffraction (SμXRD) 35 days after sham-operation (n = 2) or mTBI (n = 3). There were changes in DTI parameters rostral to the injury site. When examined by histology and SμXRD, there was evidence of axonal damage, reduced myelin density, gliosis, and ultrastructural alterations in myelin that were ongoing at the experimental time point of 35 days postinjury. We assessed the relationship between the 3 imaging modalities by multiple linear regression analysis. In this analysis, DTI and histological parameters were moderately related, whereas SμXRD parameters correlated weakly with DTI and histology. These findings suggest that while DTI appears to distinguish tissue changes at the microstructural level related to the loss of myelinated axons and gliosis, its ability to visualize alterations in myelin ultrastructure is limited. The use of several imaging techniques represents a novel approach to reveal tissue damage and provides new insights into mTBI detection.
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Affiliation(s)
| | - Michela Fratini
- Institute of Nanotechnology-CNR c/o Physics Department, Sapienza University of Rome, Rome, Italy,IRCCS Fondazione Santa Lucia, Rome, Italy
| | | | | | - Tilman A Grünewald
- European Synchrotron Radiation Facility, Grenoble Cedex, France,Aix-Marseille Université, CNRS, Centrale Marseille, Institut Fresnel, Marseille, France
| | - Raimo A Salo
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Omar Narvaez
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Manisha Aggarwal
- Russell H. Morgan Department of Radiology and Radiological Science, John Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Jussi Tohka
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Alejandra Sierra
- Send correspondence to: Alejandra Sierra, PhD, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland (Kuopio Campus), PO Box 1627, Neulaniementie 2, FI-70211 Kuopio, Finland; E-mail:
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7
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Huang W, Hu W, Zhang P, Wang J, Jiang Y, Ma L, Zheng Y, Zhang J. Early Changes in the White Matter Microstructure and Connectome Underlie Cognitive Deficit and Depression Symptoms After Mild Traumatic Brain Injury. Front Neurol 2022; 13:880902. [PMID: 35847204 PMCID: PMC9279564 DOI: 10.3389/fneur.2022.880902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 06/01/2022] [Indexed: 11/18/2022] Open
Abstract
Cognitive and emotional impairments are frequent among patients with mild traumatic brain injury (mTBI) and may reflect alterations in the brain structural properties. The relationship between microstructural changes and cognitive and emotional deficits remains unclear in patients with mTBI at the acute stage. The purpose of this study was to analyze the alterations in white matter microstructure and connectome of patients with mTBI within 7 days after injury and investigate whether they are related to the clinical questionnaires. A total of 79 subjects (42 mTBI and 37 healthy controls) underwent neuropsychological assessment and diffusion-tensor MRI scan. The microstructure and connectome of white matter were characterized by tract-based spatial statistics (TBSSs) and graph theory approaches, respectively. Mini-mental state examination (MMSE) and self-rating depression scale (SDS) were used to evaluate the cognitive function and depressive symptoms of all the subjects. Patients with mTBI revealed early increases of fractional anisotropy in most areas compared with the healthy controls. Graph theory analyses showed that patients with mTBI had increased nodal shortest path length, along with decreased nodal degree centrality and nodal efficiency, mainly located in the bilateral temporal lobe and right middle occipital gyrus. Moreover, lower nodal shortest path length and higher nodal efficiency of the right middle occipital gyrus were associated with higher SDS scores. Significantly, the strength of the rich club connection in the mTBI group decreased and was associated with the MMSE. Our study demonstrated that the neuroanatomical alterations of mTBI in the acute stage might be an initial step of damage leading to cognitive deficits and depression symptoms, and arguably, these occur due to distinct mechanisms.
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Affiliation(s)
- Wenjing Huang
- Department of Magnetic Resonance, Lanzhou University Second Hospital, Lanzhou, China
- Second Clinical School, Lanzhou University, Lanzhou, China
- Gansu Province Clinical Research Center for Functional and Molecular Imaging, Lanzhou, China
| | - Wanjun Hu
- Department of Magnetic Resonance, Lanzhou University Second Hospital, Lanzhou, China
- Gansu Province Clinical Research Center for Functional and Molecular Imaging, Lanzhou, China
| | - Pengfei Zhang
- Department of Magnetic Resonance, Lanzhou University Second Hospital, Lanzhou, China
- Second Clinical School, Lanzhou University, Lanzhou, China
- Gansu Province Clinical Research Center for Functional and Molecular Imaging, Lanzhou, China
| | - Jun Wang
- Department of Magnetic Resonance, Lanzhou University Second Hospital, Lanzhou, China
- Second Clinical School, Lanzhou University, Lanzhou, China
- Gansu Province Clinical Research Center for Functional and Molecular Imaging, Lanzhou, China
| | - Yanli Jiang
- Department of Magnetic Resonance, Lanzhou University Second Hospital, Lanzhou, China
- Second Clinical School, Lanzhou University, Lanzhou, China
- Gansu Province Clinical Research Center for Functional and Molecular Imaging, Lanzhou, China
| | - Laiyang Ma
- Department of Magnetic Resonance, Lanzhou University Second Hospital, Lanzhou, China
- Second Clinical School, Lanzhou University, Lanzhou, China
- Gansu Province Clinical Research Center for Functional and Molecular Imaging, Lanzhou, China
| | - Yu Zheng
- Department of Magnetic Resonance, Lanzhou University Second Hospital, Lanzhou, China
- Second Clinical School, Lanzhou University, Lanzhou, China
- Gansu Province Clinical Research Center for Functional and Molecular Imaging, Lanzhou, China
| | - Jing Zhang
- Department of Magnetic Resonance, Lanzhou University Second Hospital, Lanzhou, China
- Gansu Province Clinical Research Center for Functional and Molecular Imaging, Lanzhou, China
- *Correspondence: Jing Zhang
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Detection of Chronic Blast-Related Mild Traumatic Brain Injury with Diffusion Tensor Imaging and Support Vector Machines. Diagnostics (Basel) 2022; 12:diagnostics12040987. [PMID: 35454035 PMCID: PMC9030428 DOI: 10.3390/diagnostics12040987] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 04/07/2022] [Accepted: 04/08/2022] [Indexed: 01/13/2023] Open
Abstract
Blast-related mild traumatic brain injury (bmTBI) often leads to long-term sequalae, but diagnostic approaches are lacking due to insufficient knowledge about the predominant pathophysiology. This study aimed to build a diagnostic model for future verification by applying machine-learning based support vector machine (SVM) modeling to diffusion tensor imaging (DTI) datasets to elucidate white-matter features that distinguish bmTBI from healthy controls (HC). Twenty subacute/chronic bmTBI and 19 HC combat-deployed personnel underwent DTI. Clinically relevant features for modeling were selected using tract-based analyses that identified group differences throughout white-matter tracts in five DTI metrics to elucidate the pathogenesis of injury. These features were then analyzed using SVM modeling with cross validation. Tract-based analyses revealed abnormally decreased radial diffusivity (RD), increased fractional anisotropy (FA) and axial/radial diffusivity ratio (AD/RD) in the bmTBI group, mostly in anterior tracts (29 features). SVM models showed that FA of the anterior/superior corona radiata and AD/RD of the corpus callosum and anterior limbs of the internal capsule (5 features) best distinguished bmTBI from HCs with 89% accuracy. This is the first application of SVM to identify prominent features of bmTBI solely based on DTI metrics in well-defined tracts, which if successfully validated could promote targeted treatment interventions.
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Miller LE, Urban JE, Espeland MA, Walkup MP, Holcomb JM, Davenport EM, Powers AK, Whitlow CT, Maldjian JA, Stitzel JD. Cumulative strain-based metrics for predicting subconcussive head impact exposure-related imaging changes in a cohort of American youth football players. J Neurosurg Pediatr 2022; 29:387-396. [PMID: 35061991 PMCID: PMC9404368 DOI: 10.3171/2021.10.peds21355] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 10/27/2021] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Youth football athletes are exposed to repetitive subconcussive head impacts during normal participation in the sport, and there is increasing concern about the long-term effects of these impacts. The objective of the current study was to determine if strain-based cumulative exposure measures are superior to kinematic-based exposure measures for predicting imaging changes in the brain. METHODS This prospective, longitudinal cohort study was conducted from 2012 to 2017 and assessed youth, male football athletes. Kinematic data were collected at all practices and games from enrolled athletes participating in local youth football organizations in Winston-Salem, North Carolina, and were used to calculate multiple risk-weighted cumulative exposure (RWE) kinematic metrics and 36 strain-based exposure metrics. Pre- and postseason imaging was performed at Wake Forest School of Medicine, and diffusion tensor imaging (DTI) measures, including fractional anisotropy (FA), and its components (CL, CP, and CS), and mean diffusivity (MD), were investigated. Included participants were youth football players ranging in age from 9 to 13 years. Exclusion criteria included any history of previous neurological illness, psychiatric illness, brain tumor, concussion within the past 6 months, and/or contraindication to MRI. RESULTS A total of 95 male athletes (mean age 11.9 years [SD 1.0 years]) participated between 2012 and 2017, with some participating for multiple seasons, resulting in 116 unique athlete-seasons. Regression analysis revealed statistically significant linear relationships between the FA, linear coefficient (CL), and spherical coefficient (CS) and all strain exposure measures, and well as the planar coefficient (CP) and 8 strain measures. For the kinematic exposure measures, there were statistically significant relationships between FA and RWE linear (RWEL) and RWE combined probability (RWECP) as well as CS and RWEL. According to area under the receiver operating characteristic (ROC) curve (AUC) analysis, the best-performing metrics were all strain measures, and included metrics based on tensile, compressive, and shear strain. CONCLUSIONS Using ROC curves and AUC analysis, all exposure metrics were ranked in order of performance, and the results demonstrated that all the strain-based metrics performed better than any of the kinematic metrics, indicating that strain-based metrics are better discriminators of imaging changes than kinematic-based measures. Studies relating the biomechanics of head impacts with brain imaging and cognitive function may allow equipment designers, care providers, and organizations to prevent, identify, and treat injuries in order to make football a safer activity.
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Affiliation(s)
- Logan E. Miller
- Department of Biomedical Engineering, Wake Forest School of Medicine, Winston-Salem,School of Biomedical Engineering and Sciences, Virginia Tech–Wake Forest University, Winston-Salem
| | - Jillian E. Urban
- Department of Biomedical Engineering, Wake Forest School of Medicine, Winston-Salem,School of Biomedical Engineering and Sciences, Virginia Tech–Wake Forest University, Winston-Salem
| | - Mark A. Espeland
- Department of Biostatistics and Data Science, Wake Forest University School of Medicine, Winston-Salem
| | - Michael P. Walkup
- Department of Biostatistics and Data Science, Wake Forest University School of Medicine, Winston-Salem
| | - James M. Holcomb
- Department of Radiology, University of Texas Southwestern Medical School, Dallas, Texas
| | | | - Alexander K. Powers
- Department of Biomedical Engineering, Wake Forest School of Medicine, Winston-Salem,Department of Neurosurgery, Wake Forest School of Medicine, Winston-Salem
| | - Christopher T. Whitlow
- Department of Biomedical Engineering, Wake Forest School of Medicine, Winston-Salem,Department of Radiology, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Joseph A. Maldjian
- Department of Radiology, University of Texas Southwestern Medical School, Dallas, Texas
| | - Joel D. Stitzel
- Department of Biomedical Engineering, Wake Forest School of Medicine, Winston-Salem,School of Biomedical Engineering and Sciences, Virginia Tech–Wake Forest University, Winston-Salem
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Selective activation of cannabinoid receptor-2 reduces white matter injury via PERK signaling in a rat model of traumatic brain injury. Exp Neurol 2021; 347:113899. [PMID: 34678230 DOI: 10.1016/j.expneurol.2021.113899] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 09/30/2021] [Accepted: 10/16/2021] [Indexed: 12/11/2022]
Abstract
BACKGROUND AND PURPOSE Traumatic brain injury (TBI) destroys white matter, and this destruction is aggravated by secondary neuroinflammatory reactions. Although white matter injury (WMI) is strongly correlated with poor neurological function, understanding of white matter integrity maintenance is limited, and no available therapies can effectively protect white matter. One candidate approach that may fulfill this goal is cannabinoid receptor 2 (CB2) agonist treatment. Here, we confirmed that a selective CB2 agonist, JWH133, protected white matter after TBI. METHODS The motor evoked potentials (MEPs), open field test, and Morris water maze test were used to assess neurobehavioral outcomes. Brain tissue loss, WM damage, Endoplasmic reticulum stress (ER stress), microglia responses were evaluated after TBI. The functional integrity of WM was measured by diffusion tensor imaging (DTI) and transmission electron microscopy (TEM). Primary microglia and oligodendrocyte cocultures were used for additional mechanistic studies. RESULTS JWH133 increased myelin basic protein (MBP) and neurofilament heavy chain (NF200) levels and anatomic preservation of myelinated axons revealed by DTI and TEM. JWH133 also increased the numbers of oligodendrocyte precursor cells and mature oligodendrocytes. Furthermore, JWH133 drove microglial polarization toward the protective M2 phenotype and modulated the redistribution of microglia in the striatum. Further investigation of the underlying mechanism revealed that JWH133 downregulated phosphorylation of the protein kinase R (PKR)-like endoplasmic reticulum (ER) kinase (PERK) signaling pathway and its downstream signals eukaryotic translation initiation factor 2 α (eIF2α), activating transcription factor 4 (ATF4) and Growth arrest and DNA damage-inducible protein (GADD34); this downregulation was followed by p-Protein kinase B(p-Akt) upregulation. In primary cocultures of microglia and oligodendrocytes, JWH133 decreased phosphorylated PERK expression in microglia stimulated with tunicamycin and facilitated oligodendrocyte survival. These data reveal that JWH133 ultimately alleviates WMI and improves neurological behavior following TBI. However, these effects were prevented by SR144528, a selective CB2 antagonist. CONCLUSIONS This work illustrates the PERK-mediated interaction between microglia and oligodendrocytes. In addition, the results are consistent with recent findings that microglial polarization switching accelerates WMI, highlighting a previously unexplored role for CB2 agonists. Thus, CB2 agonists are potential therapeutic agents for TBI and other neurological conditions involving white matter destruction.
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11
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McCunn P, Xu X, Moszczynski A, Li A, Brown A, Bartha R. Neurite orientation dispersion and density imaging in a rodent model of acute mild traumatic brain injury. J Neuroimaging 2021; 31:879-892. [PMID: 34473386 DOI: 10.1111/jon.12917] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 07/24/2021] [Accepted: 07/27/2021] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND AND PURPOSE Identification of changesin brain microstructure following mild traumatic brain injury (mTBI) could be instrumental in understanding the underlying pathophysiology. The purpose of this study was to apply neurite orientation dispersion and density imaging (NODDI) to a rodent model of mTBI to determine whether microstructural changes could be detected immediately following injury. METHODS Fifteen adult male Wistar rats were scanned on a Bruker 9.4 Tesla small animal MRI using a multi-shell acquisition (30 b = 1000 s/mm2 and 60 b = 2000 s/mm2 ). Nine animals experienced a single closed head controlled cortical impact followed by NODDI from 1 to 4 h post injury. Region of interest analysis focused on the corpus callosum and hippocampus. A mixed analysis of variance (ANOVA) was used to determine statistically significant interactions in neurite density index (NDI), orientation dispersion index (ODI), fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity. Follow up repeated-measures ANOVAs were used to determine individual changes over time. RESULTS NDI showed a significant increase in the hippocampus and corpus callosum following injury, while ODI showed increases in the corpus callosum. No significant changes were observed in the sham control animals. No changes were found in FA, MD, AD, or RD. Histological analysis revealed increased glial fibrillary acidic protein staining relative to controls in both the hippocampus and corpus callosum, with evidence of activated astrocytes in these regions. CONCLUSIONS Changes in NODDI metrics were detected as early as 1 h following mTBI. No changes were detected with conventional diffusion tensor imaging (DTI) metrics, suggesting that NODDI provides greater sensitivity to microstructural changes than conventional DTI.
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Affiliation(s)
- Patrick McCunn
- Robarts Research Institute, University of Western Ontario, London, Ontario, Canada.,Department of Medical Biophysics, University of Western Ontario, London, Ontario, Canada
| | - Xiaoyun Xu
- Robarts Research Institute, University of Western Ontario, London, Ontario, Canada
| | | | - Alex Li
- Robarts Research Institute, University of Western Ontario, London, Ontario, Canada.,Department of Medical Biophysics, University of Western Ontario, London, Ontario, Canada.,Departments of Psychiatry and Medical Imaging, University of Western Ontario, London, Ontario, Canada
| | - Arthur Brown
- Robarts Research Institute, University of Western Ontario, London, Ontario, Canada.,Department of Neuroscience, University of Western Ontario, London, Ontario, Canada
| | - Robert Bartha
- Robarts Research Institute, University of Western Ontario, London, Ontario, Canada.,Department of Medical Biophysics, University of Western Ontario, London, Ontario, Canada.,Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario, Canada
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12
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Structural connectivity and subcellular changes after antidepressant doses of ketamine and Ro 25-6981 in the rat: an MRI and immuno-labeling study. Brain Struct Funct 2021; 226:2603-2616. [PMID: 34363521 PMCID: PMC8448713 DOI: 10.1007/s00429-021-02354-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 07/26/2021] [Indexed: 12/28/2022]
Abstract
Ketamine has rapid and robust antidepressant effects. However, unwanted psychotomimetic effects limit its widespread use. Hence, several studies examined whether GluN2B-subunit selective NMDA antagonists would exhibit a better therapeutic profile. Although preclinical work has revealed some of the mechanisms of action of ketamine at cellular and molecular levels, the impact on brain circuitry is poorly understood. Several neuroimaging studies have examined the functional changes in the brain induced by acute administration of ketamine and Ro 25-6981 (a GluN2B-subunit selective antagonist), but the changes in the microstructure of gray and white matter have received less attention. Here, the effects of ketamine and Ro 25-6981 on gray and white matter integrity in male Sprague-Dawley rats were determined using diffusion-weighted magnetic resonance imaging (DWI). In addition, DWI-based structural brain networks were estimated and connectivity metrics were computed at the regional level. Immunohistochemical analyses were also performed to determine whether changes in myelin basic protein (MBP) and neurofilament heavy-chain protein (NF200) may underlie connectivity changes. In general, ketamine and Ro 25-6981 showed some opposite structural alterations, but both compounds coincided only in increasing the fractional anisotropy in infralimbic prefrontal cortex and dorsal raphe nucleus. These changes were associated with increments of NF200 in deep layers of the infralimbic cortex (together with increased MBP) and the dorsal raphe nucleus. Our results suggest that the synthesis of NF200 and MBP may contribute to the formation of new dendritic spines and myelination, respectively. We also suggest that the increase of fractional anisotropy of the infralimbic and dorsal raphe nucleus areas could represent a biomarker of a rapid antidepressant response.
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13
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Dumitru I, Zorilă MV, Ţolescu RŞ, Racilă L, Pascu CI, Oprica AC, Burghilă DV, Matei L, Vîlcea EJ, Popescu C, Badea-Voiculescu O, Mogoantă L. Experimental model for the study of traumatic brain injury. ROMANIAN JOURNAL OF MORPHOLOGY AND EMBRYOLOGY 2021; 61:729-737. [PMID: 33817714 PMCID: PMC8112795 DOI: 10.47162/rjme.61.3.11] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Traumatic brain injury (TBI) represents a public healthcare problem and a major economic burden, all over the world. It is estimated that every year, on the globe, there occur about two million severe TBI and over 42 million mild TBI. The main causes of TBI in civil population are fallings, followed by car accidents. In the last decades, the accelerated development of car industry and the poor development of traffic infrastructure in low- and average-income countries led to an increasing number of brain injuries, this becoming a major problem for medical health systems. According to some studies, approximately 1.35 million people die every year because of car accidents. In the last four decades, these types of injuries started to be studied in order to understand the lesion mechanisms for developing new safety equipment that may be installed on vehicles. The device presented by us for causing a TBI in a lab rat (mechanical pendulum) allows the performance of several major types of TBI, according to the kinetic energy, exposure area, contact surface, etc. The impact energies obtained by the device we presented may vary on a large scale, from less than 1 J up to 10 J, according to its weight, launching angle and impact head shape, thus being obtained minor, moderate or severe TBI.
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Affiliation(s)
- Ilie Dumitru
- Department of Forensic Medicine, University of Medicine and Pharmacy of Craiova, Romania;
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14
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Wiegand TLT, Sollmann N, Bonke EM, Umeasalugo KE, Sobolewski KR, Plesnila N, Shenton ME, Lin AP, Koerte IK. Translational neuroimaging in mild traumatic brain injury. J Neurosci Res 2021; 100:1201-1217. [PMID: 33789358 DOI: 10.1002/jnr.24840] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 03/09/2021] [Accepted: 03/17/2021] [Indexed: 01/26/2023]
Abstract
Traumatic brain injuries (TBIs) are common with an estimated 27.1 million cases per year. Approximately 80% of TBIs are categorized as mild TBI (mTBI) based on initial symptom presentation. While in most individuals, symptoms resolve within days to weeks, in some, symptoms become chronic. Advanced neuroimaging has the potential to characterize brain morphometric, microstructural, biochemical, and metabolic abnormalities following mTBI. However, translational studies are needed for the interpretation of neuroimaging findings in humans with respect to the underlying pathophysiological processes, and, ultimately, for developing novel and more targeted treatment options. In this review, we introduce the most commonly used animal models for the study of mTBI. We then summarize the neuroimaging findings in humans and animals after mTBI and, wherever applicable, the translational aspects of studies available today. Finally, we highlight the importance of translational approaches and outline future perspectives in the field of translational neuroimaging in mTBI.
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Affiliation(s)
- Tim L T Wiegand
- cBRAIN, Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Ludwig-Maximilians-Universität, Munich, Germany
| | - Nico Sollmann
- cBRAIN, Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Ludwig-Maximilians-Universität, Munich, Germany
- Department of Diagnostic and Interventional Neuroradiology, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
- TUM-Neuroimaging Center, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
- Department of Diagnostic and Interventional Radiology, University Hospital Ulm, Ulm, Germany
| | - Elena M Bonke
- cBRAIN, Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Ludwig-Maximilians-Universität, Munich, Germany
- Graduate School of Systemic Neurosciences, Ludwig-Maximilians-Universität, Munich, Germany
| | - Kosisochukwu E Umeasalugo
- cBRAIN, Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Ludwig-Maximilians-Universität, Munich, Germany
- Graduate School of Systemic Neurosciences, Ludwig-Maximilians-Universität, Munich, Germany
- Institute for Stroke and Dementia Research, Ludwig-Maximilians-Universität, Munich, Germany
| | - Kristen R Sobolewski
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
- Center for Clinical Spectroscopy, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Nikolaus Plesnila
- Institute for Stroke and Dementia Research, Ludwig-Maximilians-Universität, Munich, Germany
- Munich Cluster for Systems Neurology (Synergy), Munich, Germany
| | - Martha E Shenton
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
- Psychiatry Neuroimaging Laboratory, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Alexander P Lin
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
- Center for Clinical Spectroscopy, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
- Psychiatry Neuroimaging Laboratory, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Inga K Koerte
- cBRAIN, Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Ludwig-Maximilians-Universität, Munich, Germany
- Psychiatry Neuroimaging Laboratory, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
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15
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McCorkle TA, Barson JR, Raghupathi R. A Role for the Amygdala in Impairments of Affective Behaviors Following Mild Traumatic Brain Injury. Front Behav Neurosci 2021; 15:601275. [PMID: 33746719 PMCID: PMC7969709 DOI: 10.3389/fnbeh.2021.601275] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 01/29/2021] [Indexed: 11/30/2022] Open
Abstract
Mild traumatic brain injury (TBI) results in chronic affective disorders such as depression, anxiety, and fear that persist up to years following injury and significantly impair the quality of life for patients. Although a great deal of research has contributed to defining symptoms of mild TBI, there are no adequate drug therapies for brain-injured individuals. Preclinical studies have modeled these deficits in affective behaviors post-injury to understand the underlying mechanisms with a view to developing appropriate treatment strategies. These studies have also unveiled sex differences that contribute to the varying phenotypes associated with each behavior. Although clinical and preclinical studies have viewed these behavioral deficits as separate entities with unique neurobiological mechanisms, mechanistic similarities suggest that a novel approach is needed to advance research on drug therapy. This review will discuss the circuitry involved in the expression of deficits in affective behaviors following mild TBI in humans and animals and provide evidence that the manifestation of impairment in these behaviors stems from an amygdala-dependent emotional processing deficit. It will highlight mechanistic similarities between these different types of affective behaviors that can potentially advance mild TBI drug therapy by investigating treatments for the deficits in affective behaviors as one entity, requiring the same treatment.
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Affiliation(s)
- Taylor A. McCorkle
- Graduate Program in Neuroscience, Graduate School of Biomedical Sciences and Professional Studies, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Jessica R. Barson
- Graduate Program in Neuroscience, Graduate School of Biomedical Sciences and Professional Studies, Drexel University College of Medicine, Philadelphia, PA, United States
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Ramesh Raghupathi
- Graduate Program in Neuroscience, Graduate School of Biomedical Sciences and Professional Studies, Drexel University College of Medicine, Philadelphia, PA, United States
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, United States
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16
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Donat CK, Yanez Lopez M, Sastre M, Baxan N, Goldfinger M, Seeamber R, Müller F, Davies P, Hellyer P, Siegkas P, Gentleman S, Sharp DJ, Ghajari M. From biomechanics to pathology: predicting axonal injury from patterns of strain after traumatic brain injury. Brain 2021; 144:70-91. [PMID: 33454735 PMCID: PMC7990483 DOI: 10.1093/brain/awaa336] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 09/01/2020] [Accepted: 09/14/2020] [Indexed: 12/19/2022] Open
Abstract
The relationship between biomechanical forces and neuropathology is key to understanding traumatic brain injury. White matter tracts are damaged by high shear forces during impact, resulting in axonal injury, a key determinant of long-term clinical outcomes. However, the relationship between biomechanical forces and patterns of white matter injuries, associated with persistent diffusion MRI abnormalities, is poorly understood. This limits the ability to predict the severity of head injuries and the design of appropriate protection. Our previously developed human finite element model of head injury predicted the location of post-traumatic neurodegeneration. A similar rat model now allows us to experimentally test whether strain patterns calculated by the model predicts in vivo MRI and histology changes. Using a controlled cortical impact, mild and moderate injuries (1 and 2 mm) were performed. Focal and axonal injuries were quantified with volumetric and diffusion 9.4 T MRI at 2 weeks post injury. Detailed analysis of the corpus callosum was conducted using multi-shell diffusion MRI and histopathology. Microglia and astrocyte density, including process parameters, along with white matter structural integrity and neurofilament expression were determined by quantitative immunohistochemistry. Linear mixed effects regression analyses for strain and strain rate with the employed outcome measures were used to ascertain how well immediate biomechanics could explain MRI and histology changes. The spatial pattern of mechanical strain and strain rate in the injured cortex shows good agreement with the probability maps of focal lesions derived from volumetric MRI. Diffusion metrics showed abnormalities in the corpus callosum, indicating white matter changes in the segments subjected to high strain, as predicted by the model. The same segments also exhibited a severity-dependent increase in glia cell density, white matter thinning and reduced neurofilament expression. Linear mixed effects regression analyses showed that mechanical strain and strain rate were significant predictors of in vivo MRI and histology changes. Specifically, strain and strain rate respectively explained 33% and 28% of the reduction in fractional anisotropy, 51% and 29% of the change in neurofilament expression and 51% and 30% of microglia density changes. The work provides evidence that strain and strain rate in the first milliseconds after injury are important factors in determining patterns of glial and axonal injury and serve as experimental validators of our computational model of traumatic brain injury. Our results provide support for the use of this model in understanding the relationship of biomechanics and neuropathology and can guide the development of head protection systems, such as airbags and helmets.
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Affiliation(s)
- Cornelius K Donat
- Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
- Royal British Legion Centre for Blast Injury Studies, Imperial College London, London, UK
| | - Maria Yanez Lopez
- Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King’s College London, London, UK
| | - Magdalena Sastre
- Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
| | - Nicoleta Baxan
- Biological Imaging Centre, Central Biomedical Services, Imperial College London, London, UK
| | - Marc Goldfinger
- Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
| | - Reneira Seeamber
- Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
| | - Franziska Müller
- Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
| | - Polly Davies
- Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
| | - Peter Hellyer
- Centre for Neuroimaging Sciences, King’s College London, London, UK
| | | | - Steve Gentleman
- Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
| | - David J Sharp
- Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
- Royal British Legion Centre for Blast Injury Studies, Imperial College London, London, UK
- UK Dementia Research Institute, Care Research and Technology Centre; Imperial College London, London, UK
| | - Mazdak Ghajari
- Royal British Legion Centre for Blast Injury Studies, Imperial College London, London, UK
- Design Engineering, Imperial College London, UK
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17
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To XV, Nasrallah FA. A roadmap of brain recovery in a mouse model of concussion: insights from neuroimaging. Acta Neuropathol Commun 2021; 9:2. [PMID: 33407949 PMCID: PMC7789702 DOI: 10.1186/s40478-020-01098-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 12/01/2020] [Indexed: 12/17/2022] Open
Abstract
Concussion or mild traumatic brain injury is the most common form of traumatic brain injury with potentially long-term consequences. Current objective diagnosis and treatment options are limited to clinical assessment, cognitive rest, and symptom management, which raises the real danger of concussed patients being released back into activities where subsequent and cumulative injuries may cause disproportionate damages. This study conducted a cross-sectional multi-modal examination investigation of the temporal changes in behavioural and brain changes in a mouse model of concussion using magnetic resonance imaging. Sham and concussed mice were assessed at day 2, day 7, and day 14 post-sham or injury procedures following a single concussion event for motor deficits, psychological symptoms with open field assessment, T2-weighted structural imaging, diffusion tensor imaging (DTI), neurite orientation density dispersion imaging (NODDI), stimulus-evoked and resting-state functional magnetic resonance imaging (fMRI). Overall, a mismatch in the temporal onsets and durations of the behavioural symptoms and structural/functional changes in the brain was seen. Deficits in behaviour persisted until day 7 post-concussion but recovered at day 14 post-concussion. DTI and NODDI changes were most extensive at day 7 and persisted in some regions at day 14 post-concussion. A persistent increase in connectivity was seen at day 2 and day 14 on rsfMRI. Stimulus-invoked fMRI detected increased cortical activation at day 7 and 14 post-concussion. Our results demonstrate the capabilities of advanced MRI in detecting the effects of a single concussive impact in the brain, and highlight a mismatch in the onset and temporal evolution of behaviour, structure, and function after a concussion. These results have significant translational impact in developing methods for the detection of human concussion and the time course of brain recovery.
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18
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Müller HP, Roselli F, Rasche V, Kassubek J. Diffusion Tensor Imaging-Based Studies at the Group-Level Applied to Animal Models of Neurodegenerative Diseases. Front Neurosci 2020; 14:734. [PMID: 32982659 PMCID: PMC7487414 DOI: 10.3389/fnins.2020.00734] [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: 04/17/2020] [Accepted: 06/22/2020] [Indexed: 12/11/2022] Open
Abstract
The understanding of human and non-human microstructural brain alterations in the course of neurodegenerative diseases has substantially improved by the non-invasive magnetic resonance imaging (MRI) technique of diffusion tensor imaging (DTI). Animal models (including disease or knockout models) allow for a variety of experimental manipulations, which are not applicable to humans. Thus, the DTI approach provides a promising tool for cross-species cross-sectional and longitudinal investigations of the neurobiological targets and mechanisms of neurodegeneration. This overview with a systematic review focuses on the principles of DTI analysis as used in studies at the group level in living preclinical models of neurodegeneration. The translational aspect from in-vivo animal models toward (clinical) applications in humans is covered as well as the DTI-based research of the non-human brains' microstructure, the methodological aspects in data processing and analysis, and data interpretation at different abstraction levels. The aim of integrating DTI in multiparametric or multimodal imaging protocols will allow the interrogation of DTI data in terms of directional flow of information and may identify the microstructural underpinnings of neurodegeneration-related patterns.
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Affiliation(s)
| | - Francesco Roselli
- Department of Neurology, University of Ulm, Ulm, Germany.,German Center for Neurodegenerative Diseases (DZNE), Ulm, Germany
| | - Volker Rasche
- Core Facility Small Animal MRI, University of Ulm, Ulm, Germany
| | - Jan Kassubek
- Department of Neurology, University of Ulm, Ulm, Germany
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Warnock A, Toomey LM, Wright AJ, Fisher K, Won Y, Anyaegbu C, Fitzgerald M. Damage Mechanisms to Oligodendrocytes and White Matter in Central Nervous System Injury: The Australian Context. J Neurotrauma 2020; 37:739-769. [DOI: 10.1089/neu.2019.6890] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Affiliation(s)
- Andrew Warnock
- Curtin Health Innovation Research Institute, Curtin University, Bentley, Western Australia, Australia
| | - Lillian M. Toomey
- Curtin Health Innovation Research Institute, Curtin University, Bentley, Western Australia, Australia
- Perron Institute for Neurological and Translational Science, Nedlands, Western Australia, Australia
| | - Alexander J. Wright
- Curtin Health Innovation Research Institute, Curtin University, Bentley, Western Australia, Australia
| | - Katherine Fisher
- School of Human Sciences, The University of Western Australia, Perth, Western Australia, Australia
| | - Yerim Won
- School of Human Sciences, The University of Western Australia, Perth, Western Australia, Australia
| | - Chidozie Anyaegbu
- Curtin Health Innovation Research Institute, Curtin University, Bentley, Western Australia, Australia
| | - Melinda Fitzgerald
- Curtin Health Innovation Research Institute, Curtin University, Bentley, Western Australia, Australia
- Perron Institute for Neurological and Translational Science, Nedlands, Western Australia, Australia
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20
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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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21
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Mohamed AZ, Corrigan F, Collins-Praino LE, Plummer SL, Soni N, Nasrallah FA. Evaluating spatiotemporal microstructural alterations following diffuse traumatic brain injury. Neuroimage Clin 2019; 25:102136. [PMID: 31865019 PMCID: PMC6931220 DOI: 10.1016/j.nicl.2019.102136] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 12/12/2019] [Accepted: 12/13/2019] [Indexed: 12/13/2022]
Abstract
BACKGROUND Diffuse traumatic brain injury (TBI) is known to lead to microstructural changes within both white and grey matter detected in vivo with diffusion tensor imaging (DTI). Numerous studies have shown alterations in fractional anisotropy (FA) and mean diffusivity (MD) within prominent white matter tracts, but few have linked these to changes within the grey matter with confirmation via histological assessment. This is especially important as alterations in the grey matter may be predictive of long-term functional deficits. METHODS A total of 33 male Sprague Dawley rats underwent severe closed-head TBI. Eight animals underwent tensor-based morphometry (TBM) and DTI at baseline (pre-TBI), 24 hours (24 h), 7, 14, and 30 days post-TBI. Immunohistochemical analysis for the detection of ionised calcium-binding adaptor molecule 1 (IBA1) to assess microglia number and percentage of activated cells, β-amyloid precursor protein (APP) as a marker of axonal injury, and myelin basic protein (MBP) to investigate myelination was performed at each time-point. RESULTS DTI showed significant alterations in FA and RD in numerous white matter tracts including the corpus callosum, internal and external capsule, and optic tract and in the grey-matter in the cortex, thalamus, and hippocampus, with the most significant effects observed at 14 D post-TBI. TBM confirmed volumetric changes within the hippocampus and thalamus. Changes in DTI were in line with significant axonal injury noted at 24 h post-injury via immunohistochemical analysis of APP, with widespread microglial activation seen within prominent white matter tracts and the grey matter, which persisted to 30 D within the hippocampus and thalamus. Microstructural alterations in MBP+ve fibres were also noted within the hippocampus and thalamus, as well as the cortex. CONCLUSION This study confirms the widespread effects of diffuse TBI on white matter tracts which could be detected via DTI and extends these findings to key grey matter regions, with a comprehensive investigation of the whole brain. In particular, the hippocampus and thalamus appear to be vulnerable to ongoing pathology post-TBI, with DTI able to detect these alterations supporting the clinical utility in evaluating these regions post-TBI.
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Affiliation(s)
- Abdalla Z Mohamed
- Queensland Brain Institute, The University of Queensland, Building 79, Upland Road, Saint Lucia, Brisbane, QLD 4072, Australia
| | - Frances Corrigan
- Head Injury Laboratory, Division of Health Sciences, University of South Australia, Adelaide, SA 5000, Australia
| | - Lyndsey E Collins-Praino
- Cognition, Aging and Neurodegenerative Disease Laboratory (CANDL), Adelaide Medical School, University of Adelaide, Adelaide, SA 5005, Australia
| | - Stephanie L Plummer
- Translational Neuropathology Laboratory, Adelaide Medical School, University of Adelaide, Adelaide, SA 5005, Australia
| | - Neha Soni
- Queensland Brain Institute, The University of Queensland, Building 79, Upland Road, Saint Lucia, Brisbane, QLD 4072, Australia
| | - Fatima A Nasrallah
- Queensland Brain Institute, The University of Queensland, Building 79, Upland Road, Saint Lucia, Brisbane, QLD 4072, Australia.
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