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Sutar S, Ganpule SG. In Silico Investigation of Biomechanical Response of a Human Brain Subjected to Primary Blast. J Biomech Eng 2024; 146:081007. [PMID: 38421339 DOI: 10.1115/1.4064968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 02/23/2024] [Indexed: 03/02/2024]
Abstract
The brain response to the explosion-induced primary blast waves is actively sought. Over the past decade, reasonable progress has been made in the fundamental understanding of blast traumatic brain injury (bTBI) using head surrogates and animal models. Yet, the current understanding of how blast waves interact with human is in nascent stages, primarily due to the lack of data in human. The biomechanical response in human is critically required to faithfully establish the connection to the aforementioned bTBI models. In this work, the biomechanical cascade of the brain under a primary blast has been elucidated using a detailed, full-body human model. The full-body model allowed us to holistically probe short- (<5 ms) and long-term (200 ms) brain responses. The full-body model has been extensively validated against impact loading in the past. We have further validated the head model against blast loading. We have also incorporated the structural anisotropy of the brain white matter. The blast wave transmission, and linear and rotational motion of the head were dominant pathways for the loading of the brain, and these loading paradigms generated distinct biomechanical fields within the brain. Blast transmission and linear motion of the head governed the volumetric response, whereas the rotational motion of the head governed the deviatoric response. Blast induced head rotation alone produced diffuse injury pattern in white matter fiber tracts. The biomechanical response under blast was comparable to the impact event. These insights will augment laboratory and clinical investigations of bTBI and help devise better blast mitigation strategies.
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Affiliation(s)
- Sunil Sutar
- Department of Mechanical and Industrial Engineering, Indian Institute of Technology Roorkee, Roorkee 247667, Uttarakhand, India
| | - S G Ganpule
- Department of Mechanical and Industrial Engineering, Indian Institute of Technology Roorkee, Roorkee 247667, Uttarakhand, India
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Sachdeva T, Ganpule SG. Twenty Years of Blast-Induced Neurotrauma: Current State of Knowledge. Neurotrauma Rep 2024; 5:243-253. [PMID: 38515548 PMCID: PMC10956535 DOI: 10.1089/neur.2024.0001] [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: 03/23/2024] Open
Abstract
Blast-induced neurotrauma (BINT) is an important injury paradigm of neurotrauma research. This short communication summarizes the current knowledge of BINT. We divide the BINT research into several broad categories-blast wave generation in laboratory, biomechanics, pathology, behavioral outcomes, repetitive blast in animal models, and clinical and neuroimaging investigations in humans. Publications from 2000 to 2023 in each subdomain were considered. The analysis of the literature has brought out salient aspects. Primary blast waves can be simulated reasonably in a laboratory using carefully designed shock tubes. Various biomechanics-based theories of BINT have been proposed; each of these theories may contribute to BINT by generating a unique biomechanical signature. The injury thresholds for BINT are in the nascent stages. Thresholds for rodents are reasonably established, but such thresholds (guided by primary blast data) are unavailable in humans. Single blast exposure animal studies suggest dose-dependent neuronal pathologies predominantly initiated by blood-brain barrier permeability and oxidative stress. The pathologies were typically reversible, with dose-dependent recovery times. Behavioral changes in animals include anxiety, auditory and recognition memory deficits, and fear conditioning. The repetitive blast exposure manifests similar pathologies in animals, however, at lower blast overpressures. White matter irregularities and cortical volume and thickness alterations have been observed in neuroimaging investigations of military personnel exposed to blast. Behavioral changes in human cohorts include sleep disorders, poor motor skills, cognitive dysfunction, depression, and anxiety. Overall, this article provides a concise synopsis of current understanding, consensus, controversies, and potential future directions.
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Affiliation(s)
- Tarun Sachdeva
- Department of Mechanical and Industrial Engineering, Indian Institute of Technology Roorkee, Roorkee, India
| | - Shailesh G. Ganpule
- Department of Mechanical and Industrial Engineering, Indian Institute of Technology Roorkee, Roorkee, India
- Department of Design, Indian Institute of Technology Roorkee, Roorkee, India
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Ding L, Patel A, Shankar S, Driscoll N, Zhou C, Rex TS, Vitale F, Gallagher MJ. An Open-Source Mouse Chronic EEG Array System with High-Density MXene-Based Skull Surface Electrodes. eNeuro 2024; 11:ENEURO.0512-22.2023. [PMID: 38388423 PMCID: PMC10884564 DOI: 10.1523/eneuro.0512-22.2023] [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: 12/16/2022] [Revised: 11/12/2023] [Accepted: 12/18/2023] [Indexed: 02/24/2024] Open
Abstract
Electroencephalography (EEG) is an indispensable tool in epilepsy, sleep, and behavioral research. In rodents, EEG recordings are typically performed with metal electrodes that traverse the skull into the epidural space. In addition to requiring major surgery, intracranial EEG is difficult to perform for more than a few electrodes, is time-intensive, and confounds experiments studying traumatic brain injury. Here, we describe an open-source cost-effective refinement of this technique for chronic mouse EEG recording. Our alternative two-channel (EEG2) and sixteen-channel high-density EEG (HdEEG) arrays use electrodes made of the novel, flexible 2D nanomaterial titanium carbide (Ti3C2T x ) MXene. The MXene electrodes are placed on the surface of the intact skull and establish an electrical connection without conductive gel or paste. Fabrication and implantation times of MXene EEG electrodes are significantly shorter than the standard approach, and recorded resting baseline and epileptiform EEG waveforms are similar to those obtained with traditional epidural electrodes. Applying HdEEG to a mild traumatic brain injury (mTBI) model in mice of both sexes revealed that mTBI significantly increased spike-wave discharge (SWD) preictal network connectivity with frequencies of interest in the β-spectral band (12-30 Hz). These findings indicate that the fabrication of MXene electrode arrays is a cost-effective, efficient technology for multichannel EEG recording in mice that obviates the need for skull-penetrating surgery. Moreover, increased preictal β-frequency network connectivity may contribute to the development of early post-mTBI SWDs.
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Affiliation(s)
- Li Ding
- Department of Neurology, Vanderbilt University School of Medicine, Nashville 37232, Tennessee
| | - Aashvi Patel
- Department of Neurology, Vanderbilt University School of Medicine, Nashville 37232, Tennessee
| | - Sneha Shankar
- Departments of Bioengineering and Neurology, Center for Neuroengineering & Therapeutics, University of Pennsylvania, Philadelphia 19104, Pennsylvania
| | - Nicolette Driscoll
- Departments of Bioengineering and Neurology, Center for Neuroengineering & Therapeutics, University of Pennsylvania, Philadelphia 19104, Pennsylvania
| | - Chengwen Zhou
- Department of Neurology, Vanderbilt University School of Medicine, Nashville 37232, Tennessee
| | - Tonia S Rex
- Department of Ophthalmology & Visual Sciences, Vanderbilt University School of Medicine, Nashville 37232, Tennessee
| | - Flavia Vitale
- Departments of Bioengineering and Neurology, Center for Neuroengineering & Therapeutics, University of Pennsylvania, Philadelphia 19104, Pennsylvania
- Center for Neurotrauma, Neurodegeneration, and Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia 19104, Pennsylvania
| | - Martin J Gallagher
- Department of Neurology, Vanderbilt University School of Medicine, Nashville 37232, Tennessee
- Department of Veteran's Affairs, Tennessee Valley Health System, Nashville 37212, Tennessee
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Campos-Pires R, Ong BE, Koziakova M, Ujvari E, Fuller I, Boyles C, Sun V, Ko A, Pap D, Lee M, Gomes L, Gallagher K, Mahoney PF, Dickinson R. Repetitive, but Not Single, Mild Blast TBI Causes Persistent Neurological Impairments and Selective Cortical Neuronal Loss in Rats. Brain Sci 2023; 13:1298. [PMID: 37759899 PMCID: PMC10526452 DOI: 10.3390/brainsci13091298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 08/29/2023] [Accepted: 09/04/2023] [Indexed: 09/29/2023] Open
Abstract
Exposure to repeated mild blast traumatic brain injury (mbTBI) is common in combat soldiers and the training of Special Forces. Evidence suggests that repeated exposure to a mild or subthreshold blast can cause serious and long-lasting impairments, but the mechanisms causing these symptoms are unclear. In this study, we characterise the effects of single and tightly coupled repeated mbTBI in Sprague-Dawley rats exposed to shockwaves generated using a shock tube. The primary outcomes are functional neurologic function (unconsciousness, neuroscore, weight loss, and RotaRod performance) and neuronal density in brain regions associated with sensorimotor function. Exposure to a single shockwave does not result in functional impairments or histologic injury, which is consistent with a mild or subthreshold injury. In contrast, exposure to three tightly coupled shockwaves results in unconsciousness, along with persistent neurologic impairments. Significant neuronal loss following repeated blast was observed in the motor cortex, somatosensory cortex, auditory cortex, and amygdala. Neuronal loss was not accompanied by changes in astrocyte reactivity. Our study identifies specific brain regions particularly sensitive to repeated mbTBI. The reasons for this sensitivity may include exposure to less attenuated shockwaves or proximity to tissue density transitions, and this merits further investigation. Our novel model will be useful in elucidating the mechanisms of sensitisation to injury, the temporal window of sensitivity and the evaluation of new treatments.
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Affiliation(s)
- Rita Campos-Pires
- Anaesthetics, Pain Medicine and Intensive Care Division, Department of Surgery and Cancer, Imperial College London, London SW7 2AZ, UK
- Royal British Legion Centre for Blast Injury Studies, Imperial College London, London SW7 2AZ, UK
| | - Bee Eng Ong
- Anaesthetics, Pain Medicine and Intensive Care Division, Department of Surgery and Cancer, Imperial College London, London SW7 2AZ, UK
| | - Mariia Koziakova
- Anaesthetics, Pain Medicine and Intensive Care Division, Department of Surgery and Cancer, Imperial College London, London SW7 2AZ, UK
| | - Eszter Ujvari
- Anaesthetics, Pain Medicine and Intensive Care Division, Department of Surgery and Cancer, Imperial College London, London SW7 2AZ, UK
| | - Isobel Fuller
- Anaesthetics, Pain Medicine and Intensive Care Division, Department of Surgery and Cancer, Imperial College London, London SW7 2AZ, UK
| | - Charlotte Boyles
- Anaesthetics, Pain Medicine and Intensive Care Division, Department of Surgery and Cancer, Imperial College London, London SW7 2AZ, UK
| | - Valerie Sun
- Anaesthetics, Pain Medicine and Intensive Care Division, Department of Surgery and Cancer, Imperial College London, London SW7 2AZ, UK
| | - Andy Ko
- Anaesthetics, Pain Medicine and Intensive Care Division, Department of Surgery and Cancer, Imperial College London, London SW7 2AZ, UK
| | - Daniel Pap
- Anaesthetics, Pain Medicine and Intensive Care Division, Department of Surgery and Cancer, Imperial College London, London SW7 2AZ, UK
| | - Matthew Lee
- Anaesthetics, Pain Medicine and Intensive Care Division, Department of Surgery and Cancer, Imperial College London, London SW7 2AZ, UK
| | - Lauren Gomes
- Anaesthetics, Pain Medicine and Intensive Care Division, Department of Surgery and Cancer, Imperial College London, London SW7 2AZ, UK
| | - Kate Gallagher
- Anaesthetics, Pain Medicine and Intensive Care Division, Department of Surgery and Cancer, Imperial College London, London SW7 2AZ, UK
| | - Peter F. Mahoney
- Royal British Legion Centre for Blast Injury Studies, Imperial College London, London SW7 2AZ, UK
- Department of Bioengineering, Imperial College London, London SW7 2AZ, UK
| | - Robert Dickinson
- Anaesthetics, Pain Medicine and Intensive Care Division, Department of Surgery and Cancer, Imperial College London, London SW7 2AZ, UK
- Royal British Legion Centre for Blast Injury Studies, Imperial College London, London SW7 2AZ, UK
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Du Z, Wang P, Luo P, Fei Z, Zhuang Z, Liu Z. Mechanical mechanism and indicator of diffuse axonal injury under blast-type acceleration. J Biomech 2023; 156:111674. [PMID: 37300977 DOI: 10.1016/j.jbiomech.2023.111674] [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: 12/01/2022] [Revised: 05/31/2023] [Accepted: 06/02/2023] [Indexed: 06/12/2023]
Abstract
Diffuse axonal injury (DAI) caused by acceleration is one of the most prominent forms of blast-induced Traumatic Brain Injury. However, the mechanical mechanism and indicator of axonal deformation-induced injury under blast-type acceleration with high peak and short duration are unclear. This study constructed a multilayer head model that can reflect the response characteristics of translational and rotational acceleration (the peak time of which is within 0.5 ms). Based on von Mises stress, axonal strain and axonal strain rate indicators, the physical process of axonal injury is studied, and the vulnerable area under blast-type acceleration load is given. In the short term (within 1.75 ms), dominated by sagittal rotational acceleration peaks, the constraint of falx and tentorium rapidly imposes the inertial load on the brain tissue, resulting in a high-rate deformation of axons (axonal strain rate of which exceed 100 s-1). For a long term (after 1.75 ms), fixed-point rotation of the brain following the head causes excessive distortion of brain tissue (von Mises stress of which exceeds 15 kPa), resulting in a large axonal stretch strain where the main axonal orientation coincides with the principal strain direction. It is found that the axonal strain rate can better indicate the pathological axonal injury area and coincides with external inertial loading in the risk areas, which suggests that DAI under blast-type acceleration overload is mainly caused by the rapid axonal deformation instead of by the excessive axonal strain. The research in this paper helps understand and diagnose blast-induced DAI.
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Affiliation(s)
- Zhibo Du
- School of Aerospace Engineering, Tsinghua University, Beijing 100084, PR China
| | - Peng Wang
- School of Aerospace Engineering, Tsinghua University, Beijing 100084, PR China; School of Aerospace Engineering and Applied Mechanics, Tongji University, Shanghai 200092, PR China
| | - Peng Luo
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, PR China
| | - Zhou Fei
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, PR China
| | - Zhuo Zhuang
- School of Aerospace Engineering, Tsinghua University, Beijing 100084, PR China
| | - Zhanli Liu
- School of Aerospace Engineering, Tsinghua University, Beijing 100084, PR China.
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Liu Y, Lu Y, Shao Y, Wu Y, He J, Wu C. Mechanism of the traumatic brain injury induced by blast wave using the energy assessment method. Med Eng Phys 2022; 101:103767. [DOI: 10.1016/j.medengphy.2022.103767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 01/20/2022] [Accepted: 02/06/2022] [Indexed: 11/26/2022]
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Bishop R, Won SJ, Irvine KA, Basu J, Rome ES, Swanson RA. Blast-induced axonal degeneration in the rat cerebellum in the absence of head movement. Sci Rep 2022; 12:143. [PMID: 34996954 PMCID: PMC8741772 DOI: 10.1038/s41598-021-03744-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Accepted: 12/02/2021] [Indexed: 11/16/2022] Open
Abstract
Blast exposure can injure brain by multiple mechanisms, and injury attributable to direct effects of the blast wave itself have been difficult to distinguish from that caused by rapid head displacement and other secondary processes. To resolve this issue, we used a rat model of blast exposure in which head movement was either strictly prevented or permitted in the lateral plane. Blast was found to produce axonal injury even with strict prevention of head movement. This axonal injury was restricted to the cerebellum, with the exception of injury in visual tracts secondary to ocular trauma. The cerebellar axonal injury was increased in rats in which blast-induced head movement was permitted, but the pattern of injury was unchanged. These findings support the contentions that blast per se, independent of head movement, is sufficient to induce axonal injury, and that axons in cerebellar white matter are particularly vulnerable to direct blast-induced injury.
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Affiliation(s)
- Robin Bishop
- Department of Neurology, University of California at San Francisco, San Francisco, CA, 94158, USA
- (127)Neurology, San Francisco Veterans Affairs Medical Center, San Francisco, CA, 94121, USA
| | - Seok Joon Won
- Department of Neurology, University of California at San Francisco, San Francisco, CA, 94158, USA.
- (127)Neurology, San Francisco Veterans Affairs Medical Center, San Francisco, CA, 94121, USA.
| | - Karen-Amanda Irvine
- Department of Neurology, University of California at San Francisco, San Francisco, CA, 94158, USA
- (127)Neurology, San Francisco Veterans Affairs Medical Center, San Francisco, CA, 94121, USA
- Anesthesiology Service, Veterans Affairs Palo Alto Health Care System, 3801 Miranda Ave (E4-220), Palo Alto, CA, 94304, USA
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University, School of Medicine, Stanford, CA, 94305, USA
| | - Jayinee Basu
- Department of Neurology, University of California at San Francisco, San Francisco, CA, 94158, USA
- (127)Neurology, San Francisco Veterans Affairs Medical Center, San Francisco, CA, 94121, USA
| | - Eric S Rome
- Department of Neurology, University of California at San Francisco, San Francisco, CA, 94158, USA
- (127)Neurology, San Francisco Veterans Affairs Medical Center, San Francisco, CA, 94121, USA
| | - Raymond A Swanson
- Department of Neurology, University of California at San Francisco, San Francisco, CA, 94158, USA
- (127)Neurology, San Francisco Veterans Affairs Medical Center, San Francisco, CA, 94121, USA
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Subramaniam DR, Unnikrishnan G, Sundaramurthy A, Rubio JE, Kote VB, Reifman J. Cerebral Vasculature Influences Blast-Induced Biomechanical Responses of Human Brain Tissue. Front Bioeng Biotechnol 2021; 9:744808. [PMID: 34805106 PMCID: PMC8599150 DOI: 10.3389/fbioe.2021.744808] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 10/18/2021] [Indexed: 11/13/2022] Open
Abstract
Multiple finite-element (FE) models to predict the biomechanical responses in the human brain resulting from the interaction with blast waves have established the importance of including the brain-surface convolutions, the major cerebral veins, and using non-linear brain-tissue properties to improve model accuracy. We hypothesize that inclusion of a more detailed network of cerebral veins and arteries can further enhance the model-predicted biomechanical responses and help identify correlates of blast-induced brain injury. To more comprehensively capture the biomechanical responses of human brain tissues to blast-wave exposure, we coupled a three-dimensional (3-D) detailed-vasculature human-head FE model, previously validated for blunt impact, with a 3-D shock-tube FE model. Using the coupled model, we computed the biomechanical responses of a human head facing an incoming blast wave for blast overpressures (BOPs) equivalent to 68, 83, and 104 kPa. We validated our FE model, which includes the detailed network of cerebral veins and arteries, the gyri and the sulci, and hyper-viscoelastic brain-tissue properties, by comparing the model-predicted intracranial pressure (ICP) values with previously collected data from shock-tube experiments performed on cadaver heads. In addition, to quantify the influence of including a more comprehensive network of brain vessels, we compared the biomechanical responses of our detailed-vasculature model with those of a reduced-vasculature model and a no-vasculature model for the same blast-loading conditions. For the three BOPs, the predicted ICP values matched well with the experimental results in the frontal lobe, with peak-pressure differences of 4-11% and phase-shift differences of 9-13%. As expected, incorporating the detailed cerebral vasculature did not influence the ICP, however, it redistributed the peak brain-tissue strains by as much as 30% and yielded peak strain differences of up to 7%. When compared to existing reduced-vasculature FE models that only include the major cerebral veins, our high-fidelity model redistributed the brain-tissue strains in most of the brain, highlighting the importance of including a detailed cerebral vessel network in human-head FE models to more comprehensively account for the biomechanical responses induced by blast exposure.
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Affiliation(s)
- Dhananjay Radhakrishnan Subramaniam
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Development Command, Fort Detrick, MD, United States
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, United States
| | - Ginu Unnikrishnan
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Development Command, Fort Detrick, MD, United States
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, United States
| | - Aravind Sundaramurthy
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Development Command, Fort Detrick, MD, United States
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, United States
| | - Jose E. Rubio
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Development Command, Fort Detrick, MD, United States
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, United States
| | - Vivek Bhaskar Kote
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Development Command, Fort Detrick, MD, United States
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, United States
| | - Jaques Reifman
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Development Command, Fort Detrick, MD, United States
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Dependence of visual and cognitive outcomes on animal holder configuration in a rodent model of blast overpressure exposure. Vision Res 2021; 188:162-173. [PMID: 34333201 DOI: 10.1016/j.visres.2021.07.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 05/24/2021] [Accepted: 07/14/2021] [Indexed: 02/04/2023]
Abstract
Blast-induced traumatic brain injury is the signature injury of modern military conflicts. To more fully understand the effects of blast exposure, we placed rats in different holder configurations, exposed them to blast overpressure, and assessed the degree of eye and brain injury. Anesthetized Long-Evans rats received blast exposures directed at the head (63 kPa, 195 dB-SPL) in either an "open holder" (head and neck exposed; n = 7), or an "enclosed holder" (window for blast exposure to eye; n = 15) and were compared to non-blast exposed (control) rats (n = 22). Outcomes included optomotor response (OMR), electroretinography (ERG), and spectral domain optical coherence tomography (SD-OCT) at 2, 4, and 6 months post-blast, and cognitive function (Y-maze) at 3 months. Spatial frequency and contrast sensitivity were reduced in ipsilateral blast-exposed eyes in both holders (p < 0.01), while contralateral eyes showed greater deficits with the enclosed holder (p < 0.05). Thinner retinas (p < 0.001) and reduced ERG a- and b- wave amplitudes (p < 0.05) were observed for both ipsilateral and contralateral eyes with the enclosed, but not the open, holder. Rats in the open holder showed cognitive deficits compared to rats in the enclosed holder (p < 0.05). Overall, the animal holder configuration used in blast exposure studies can significantly affect outcomes. Enclosed holders may cause secondary damage to the contralateral eye by concussive injury or blast wave reflection off the holder wall. Open holders may damage the brain via rapid head movement (contrecoup injury). These results highlight additional factors to be considered when evaluating patients with blast exposure or developing models of blast injury.
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Sundar S, Ponnalagu A. Biomechanical Analysis of Head Subjected to Blast Waves and the Role of Combat Protective Headgear Under Blast Loading: A Review. J Biomech Eng 2021; 143:1108858. [PMID: 33954580 DOI: 10.1115/1.4051047] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Indexed: 01/10/2023]
Abstract
Blast-induced traumatic brain injury (bTBI) is a rising health concern of soldiers deployed in modern-day military conflicts. For bTBI, blast wave loading is a cause, and damage incurred to brain tissue is the effect. There are several proposed mechanisms for the bTBI, such as direct cranial entry, skull flexure, thoracic compression, blast-induced acceleration, and cavitation that are not mutually exclusive. So the cause-effect relationship is not straightforward. The efficiency of protective headgears against blast waves is relatively unknown as compared with other threats. Proper knowledge about standard problem space, underlying mechanisms, blast reconstruction techniques, and biomechanical models are essential for protective headgear design and evaluation. Various researchers from cross disciplines analyze bTBI from different perspectives. From the biomedical perspective, the physiological response, neuropathology, injury scales, and even the molecular level and cellular level changes incurred during injury are essential. From a combat protective gear designer perspective, the spatial and temporal variation of mechanical correlates of brain injury such as surface overpressure, acceleration, tissue-level stresses, and strains are essential. This paper outlines the key inferences from bTBI studies that are essential in the protective headgear design context.
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Affiliation(s)
- Shyam Sundar
- Department of Civil Engineering, Indian Institute of Technology Madras, Chennai 600036, India
| | - Alagappan Ponnalagu
- Department of Civil Engineering, Indian Institute of Technology Madras, Chennai 600036, India
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11
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Eskandari F, Shafieian M, Aghdam MM, Laksari K. Structural Anisotropy vs. Mechanical Anisotropy: The Contribution of Axonal Fibers to the Material Properties of Brain White Matter. Ann Biomed Eng 2020; 49:991-999. [PMID: 33025318 DOI: 10.1007/s10439-020-02643-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 09/28/2020] [Indexed: 11/27/2022]
Abstract
Brain's micro-structure plays a critical role in its macro-structure material properties. Since the structural anisotropy in the brain white matter has been introduced due to axonal fibers, considering the direction of axons in the continuum models has been mediated to improve the results of computational simulations. The aim of the current study was to investigate the role of fiber direction in the material properties of brain white matter and compare the mechanical behavior of the anisotropic white matter and the isotropic gray matter. Diffusion tensor imaging (DTI) was employed to detect the direction of axons in white matter samples, and tensile stress-relaxation loads up to 20% strains were applied on bovine gray and white matter samples. In order to calculate the nonlinear and time-dependent properties of white matter and gray matter, a visco-hyperelastic model was used. The results indicated that the mechanical behavior of white matter in two orthogonal directions, parallel and perpendicular to axonal fibers, are significantly different. This difference indicates that brain white matter could be assumed as an anisotropic material and axons have contribution in the mechanical properties. Also, up to 15% strain, white matter samples with axons parallel to the force direction are significantly stiffer than both the gray matter samples and white matter samples with axons perpendicular to the force direction. Moreover, the elastic moduli of white matter samples with axons both parallel and perpendicular to the loading direction and gray matter samples at 15-20% strain are not significantly different. According to these observations, it is suggested that axons have negligible roles in the material properties of white matter when it is loaded in the direction perpendicular to the axon direction. Finally, this observation showed that the anisotropy of brain tissue not only has effects on the elastic behavior, but also has effects on the viscoelastic behavior.
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Affiliation(s)
- Faezeh Eskandari
- Department of Biomedical Engineering, Amirkabir University of Technology, 424 Hafez Ave, Tehran, Iran
| | - Mehdi Shafieian
- Department of Biomedical Engineering, Amirkabir University of Technology, 424 Hafez Ave, Tehran, Iran.
| | - Mohammad M Aghdam
- Department of Mechanical Engineering, Amirkabir University of Technology, Tehran, Iran
| | - Kaveh Laksari
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ, USA
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Aravind A, Ravula AR, Chandra N, Pfister BJ. Behavioral Deficits in Animal Models of Blast Traumatic Brain Injury. Front Neurol 2020; 11:990. [PMID: 33013653 PMCID: PMC7500138 DOI: 10.3389/fneur.2020.00990] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 07/29/2020] [Indexed: 01/30/2023] Open
Abstract
Blast exposure has been identified to be the most common cause for traumatic brain injury (TBI) in soldiers. Over the years, rodent models to mimic blast exposures and the behavioral outcomes observed in veterans have been developed extensively. However, blast tube design and varying experimental parameters lead to inconsistencies in the behavioral outcomes reported across research laboratories. This review aims to curate the behavioral outcomes reported in rodent models of blast TBI using shockwave tubes or open field detonations between the years 2008–2019 and highlight the important experimental parameters that affect behavioral outcome. Further, we discuss the role of various design parameters of the blast tube that can affect the nature of blast exposure experienced by the rodents. Finally, we assess the most common behavioral tests done to measure cognitive, motor, anxiety, auditory, and fear conditioning deficits in blast TBI (bTBI) and discuss the advantages and disadvantages of these tests.
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Affiliation(s)
- Aswati Aravind
- Department of Biomedical Engineering, Center for Injury Biomechanics, Materials and Medicine, New Jersey Institute of Technology, Newark, NJ, United States
| | - Arun Reddy Ravula
- Department of Biomedical Engineering, Center for Injury Biomechanics, Materials and Medicine, New Jersey Institute of Technology, Newark, NJ, United States
| | - Namas Chandra
- Department of Biomedical Engineering, Center for Injury Biomechanics, Materials and Medicine, New Jersey Institute of Technology, Newark, NJ, United States
| | - Bryan J Pfister
- Department of Biomedical Engineering, Center for Injury Biomechanics, Materials and Medicine, New Jersey Institute of Technology, Newark, NJ, United States
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13
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Aravind A, Kosty J, Chandra N, Pfister BJ. Blast exposure predisposes the brain to increased neurological deficits in a model of blast plus blunt traumatic brain injury. Exp Neurol 2020; 332:113378. [PMID: 32553593 DOI: 10.1016/j.expneurol.2020.113378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 05/20/2020] [Accepted: 06/08/2020] [Indexed: 10/24/2022]
Abstract
Soldiers are often exposed to more than one traumatic brain injury (TBI) over the course of their service. In recent years, more attention has been drawn to the increased risk of neurological deficits caused by the 'blast plus' polytrauma, which typically is a blast trauma combined with other forms of TBI. In this study, we investigated the behavioral and neuronal deficits resulting from a blast plus injury involving a mild-moderate blast followed by a mild blunt trauma using the fluid percussion injury model. We identified that the blast injury predisposed the brain to increased cognitive deficits, chronic ventricular enlargement, increased neurodegeneration at acute time points and chronic neuronal loss. Interestingly, a single blast and single blunt injury differed in their onset and manifestation of cognitive and regional neuronal loss. We also identified the presence of cleaved RIP1 from caspase 8 mediated apoptosis in the blunt injury while the blast injury did not activate immediate apoptosis but led to decreased hilar neuronal survival over time.
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Affiliation(s)
- Aswati Aravind
- Center for Injury Biomechanics, Materials and Medicine, Department of Biomedical Engineering, New Jersey Institute of Technology, 323 Dr M.L.K. Jr. Blvd, Newark, NJ 07102, USA
| | - Julianna Kosty
- Center for Injury Biomechanics, Materials and Medicine, Department of Biomedical Engineering, New Jersey Institute of Technology, 323 Dr M.L.K. Jr. Blvd, Newark, NJ 07102, USA
| | - Namas Chandra
- Center for Injury Biomechanics, Materials and Medicine, Department of Biomedical Engineering, New Jersey Institute of Technology, 323 Dr M.L.K. Jr. Blvd, Newark, NJ 07102, USA
| | - Bryan J Pfister
- Center for Injury Biomechanics, Materials and Medicine, Department of Biomedical Engineering, New Jersey Institute of Technology, 323 Dr M.L.K. Jr. Blvd, Newark, NJ 07102, USA.
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14
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Venkatasubramanian PN, Keni P, Gastfield R, Li L, Aksenov D, Sherman SA, Bailes J, Sindelar B, Finan JD, Lee J, Bailes JE, Wyrwicz AM. Diffusion Tensor Imaging Detects Acute and Subacute Changes in Corpus Callosum in Blast-Induced Traumatic Brain Injury. ASN Neuro 2020; 12:1759091420922929. [PMID: 32403948 PMCID: PMC7238783 DOI: 10.1177/1759091420922929] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
There is a critical need for understanding the progression of neuropathology in blast-induced traumatic brain injury using valid animal models to develop diagnostic approaches. In the present study, we used diffusion imaging and magnetic resonance (MR) morphometry to characterize axonal injury in white matter structures of the rat brain following a blast applied via blast tube to one side of the brain. Diffusion tensor imaging was performed on acute and subacute phases of pathology from which fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity were calculated for corpus callosum (CC), cingulum bundle, and fimbria. Ventricular volume and CC thickness were measured. Blast-injured rats showed temporally varying bilateral changes in diffusion metrics indicating persistent axonal pathology. Diffusion changes in the CC suggested vasogenic edema secondary to axonal injury in the acute phase. Axonal pathology persisted in the subacute phase marked by cytotoxic edema and demyelination which was confirmed by ultrastructural analysis. The evolution of pathology followed a different pattern in the cingulum bundle: axonal injury and demyelination in the acute phase followed by cytotoxic edema in the subacute phase. Spatially, structures close to midline were most affected. Changes in the genu were greater than in the body and splenium; the caudal cingulum bundle was more affected than the rostral cingulum. Thinning of CC and ventriculomegaly were greater only in the acute phase. Our results reveal the persistent nature of blast-induced axonal pathology and suggest that diffusion imaging may have potential for detecting the temporal evolution of blast injury.
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Affiliation(s)
- Palamadai N Venkatasubramanian
- Center for Basic M.R. Research, Department of Radiology, NorthShore University HealthSystem, Evanston, Illinois, United States
| | - Prachi Keni
- Department of Neurosurgery, NorthShore University HealthSystem, Evanston, Illinois, United States
| | - Roland Gastfield
- Center for Basic M.R. Research, Department of Radiology, NorthShore University HealthSystem, Evanston, Illinois, United States
| | - Limin Li
- Center for Basic M.R. Research, Department of Radiology, NorthShore University HealthSystem, Evanston, Illinois, United States
| | - Daniil Aksenov
- Center for Basic M.R. Research, Department of Radiology, NorthShore University HealthSystem, Evanston, Illinois, United States
| | - Sydney A Sherman
- Department of Neurosurgery, NorthShore University HealthSystem, Evanston, Illinois, United States
| | - Julian Bailes
- Department of Neurosurgery, NorthShore University HealthSystem, Evanston, Illinois, United States
| | - Brian Sindelar
- Department of Neurosurgery, NorthShore University HealthSystem, Evanston, Illinois, United States
| | - John D Finan
- Department of Neurosurgery, NorthShore University HealthSystem, Evanston, Illinois, United States
| | - John Lee
- Department of Pathology, NorthShore University HealthSystem, Evanston, Illinois, United States
| | - Julian E Bailes
- Department of Neurosurgery, NorthShore University HealthSystem, Evanston, Illinois, United States
| | - Alice M Wyrwicz
- Center for Basic M.R. Research, Department of Radiology, NorthShore University HealthSystem, Evanston, Illinois, United States
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15
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Direct Observation of Low Strain, High Rate Deformation of Cultured Brain Tissue During Primary Blast. Ann Biomed Eng 2019; 48:1196-1206. [DOI: 10.1007/s10439-019-02437-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 12/08/2019] [Indexed: 10/25/2022]
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16
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Sutar S, Ganpule S. Investigation of wave propagation through head layers with focus on understanding blast wave transmission. Biomech Model Mechanobiol 2019; 19:875-892. [PMID: 31745681 DOI: 10.1007/s10237-019-01256-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 11/06/2019] [Indexed: 11/25/2022]
Abstract
Blast-induced traumatic brain injury (bTBI) is a critical health concern. This issue is being addressed in terms of identifying a cause-effect relationship between the mechanical insult in the form of a blast and resulting injury to the brain. Understanding wave propagation through the head is an important aspect in this regard. The objective of this work was to study the blast wave propagation through the layered architecture of the head with an emphasis on understanding the wave transmission mechanism. Toward this end, one-dimensional (1D) finite element head model is built for a simplified surrogate, human, and rat. Motivated from experimental investigations, four different head layer configurations have been considered. These configurations are: (A) Skull-Brain, (B) Skin-Skull-Brain, (C) Skin-Skull-Dura-Arachnoid-CSF-Pia-Brain, (D) Skin-Skull-Dura-Arachnoid-AT-Pia-Brain. The validated head model is subjected to flattop and Friedlander loading implied in the blast, and the resulting response is evaluated in terms of brain pressures. Our results suggest that wave propagation through head parenchyma plays an important role in blast wave transmission. The thickness, material properties of head layers, and rise time of an input pulse govern the temporal evolution of pressure in the brain. The key findings of this work are: (a) Skin and meninges amplify the applied input pressure, whereas air sinus has an attenuation effect. (b) Model is able to describe experimentally recorded peak pressures and rise times in the brain, including variations within the aforementioned experimental head models of TBI. This reinforces that the wave transmission is an important loading pathway to the brain. (c) Equivalent layer theory for modeling meningeal layers as a single layer has been proposed, and it gives reasonable agreement with each meningeal layer modeled explicitly. This modeling approach has a great utility in 3D head models. The potential applications of 1D head model in evaluation of new helmet materials, brain sensor calibration, and brain pressure estimation for a given explosive strength have also been demonstrated. Overall, these results provide important insights into the understanding of mechanics of blast wave transmission in the head.
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Affiliation(s)
- Sunil Sutar
- Department of Mechanical and Industrial Engineering, Indian Institute of Technology Roorkee, Roorkee, 247667, India
| | - S Ganpule
- Department of Mechanical and Industrial Engineering, Indian Institute of Technology Roorkee, Roorkee, 247667, India.
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17
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Ko J, Hemphill M, Yang Z, Sewell E, Na YJ, Sandsmark DK, Haber M, Fisher SA, Torre EA, Svane KC, Omelchenko A, Firestein BL, Diaz-Arrastia R, Kim J, Meaney DF, Issadore D. Diagnosis of traumatic brain injury using miRNA signatures in nanomagnetically isolated brain-derived extracellular vesicles. LAB ON A CHIP 2018; 18:3617-3630. [PMID: 30357245 PMCID: PMC6334845 DOI: 10.1039/c8lc00672e] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The accurate diagnosis and clinical management of traumatic brain injury (TBI) is currently limited by the lack of accessible molecular biomarkers that reflect the pathophysiology of this heterogeneous disease. To address this challenge, we developed a microchip diagnostic that can characterize TBI more comprehensively using the RNA found in brain-derived extracellular vesicles (EVs). Our approach measures a panel of EV miRNAs, processed with machine learning algorithms to capture the state of the injured and recovering brain. Our diagnostic combines surface marker-specific nanomagnetic isolation of brain-derived EVs, biomarker discovery using RNA sequencing, and machine learning processing of the EV miRNA cargo to minimally invasively measure the state of TBI. We achieved an accuracy of 99% identifying the signature of injured vs. sham control mice using an independent blinded test set (N = 77), where the injured group consists of heterogeneous populations (injury intensity, elapsed time since injury) to model the variability present in clinical samples. Moreover, we successfully predicted the intensity of the injury, the elapsed time since injury, and the presence of a prior injury using independent blinded test sets (N = 82). We demonstrated the translatability in a blinded test set by identifying TBI patients from healthy controls (AUC = 0.9, N = 60). This approach, which can detect signatures of injury that persist across a variety of injury types and individual responses to injury, more accurately reflects the heterogeneity of human TBI injury and recovery than conventional diagnostics, opening new opportunities to improve treatment of traumatic brain injuries.
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Affiliation(s)
- J Ko
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - M Hemphill
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - Z Yang
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - E Sewell
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - Y J Na
- Department of Medicine, Division of Nephrology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - D K Sandsmark
- Department of Neurology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - M Haber
- Department of Neurology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - S A Fisher
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - E A Torre
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - K C Svane
- Department of Cell Biology and Neuroscience, Rutgers, the State University of New Jersey, NJ 08854, USA
| | - A Omelchenko
- Department of Cell Biology and Neuroscience, Rutgers, the State University of New Jersey, NJ 08854, USA
| | - B L Firestein
- Department of Cell Biology and Neuroscience, Rutgers, the State University of New Jersey, NJ 08854, USA
| | - R Diaz-Arrastia
- Department of Neurology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - J Kim
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA and Department of Computer and Information Science, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - D F Meaney
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA. and Department of Neurosurgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - D Issadore
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA. and Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA
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18
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Evans LP, Newell EA, Mahajan M, Tsang SH, Ferguson PJ, Mahoney J, Hue CD, Vogel EW, Morrison B, Arancio O, Nichols R, Bassuk AG, Mahajan VB. Acute vitreoretinal trauma and inflammation after traumatic brain injury in mice. Ann Clin Transl Neurol 2018; 5:240-251. [PMID: 29560370 PMCID: PMC5846452 DOI: 10.1002/acn3.523] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 11/30/2017] [Accepted: 12/01/2017] [Indexed: 12/16/2022] Open
Abstract
Objective Limited attention has been given to ocular injuries associated with traumatic brain injury (TBI). The retina is an extension of the central nervous system and evaluation of ocular damage may offer a less‐invasive approach to gauge TBI severity and response to treatment. We aim to characterize acute changes in the mouse eye after exposure to two different models of TBI to assess the utility of eye damage as a surrogate to brain injury. Methods A model of blast TBI (bTBI) using a shock tube was compared to a lateral fluid percussion injury model (LFPI) using fluid pressure applied directly to the brain. Whole eyes were collected from mice 3 days post LFPI and 24 days post bTBI and were evaluated histologically using a hematoxylin and eosin stain. Results bTBI mice showed evidence of vitreous detachment in the posterior chamber in addition to vitreous hemorrhage with inflammatory cells. Subretinal hemorrhage, photoreceptor degeneration, and decreased cellularity in the retinal ganglion cell layer was also seen in bTBI mice. In contrast, eyes of LFPI mice showed evidence of anterior uveitis and subcapsular cataracts. Interpretation We demonstrated that variations in the type of TBI can result in drastically different phenotypic changes within the eye. As such, molecular and phenotypic changes in the eye following TBI may provide valuable information regarding the mechanism, severity, and ongoing pathophysiology of brain injury. Because vitreous samples are easily obtained, molecular changes within the eye could be utilized as biomarkers of TBI in human patients.
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Affiliation(s)
- Lucy P Evans
- Medical Scientist Training Program University of Iowa Iowa City Iowa.,Department of Pediatrics University of Iowa Iowa City Iowa
| | | | - MaryAnn Mahajan
- Omics Laboratory Department of Ophthalmology Stanford University Palo Alto California
| | - Stephen H Tsang
- Bernard and Shirlee Brown Glaucoma Laboratory and Barbara Donald Jonas Laboratory of Regenerative Medicine Columbia University New York New York.,Edward S. Harkness Eye Institute Columbia University New York New York.,Departments of Ophthalmology, Pathology & Cell Biology Institute of Human Nutrition Columbia University New York New York
| | | | | | - Christopher D Hue
- Department of Biomedical Engineering Columbia University New York New York
| | - Edward W Vogel
- Department of Biomedical Engineering Columbia University New York New York
| | - Barclay Morrison
- Department of Biomedical Engineering Columbia University New York New York
| | - Ottavio Arancio
- Department of Pathology & Cell Biology Taub Institute Columbia University New York New York
| | - Russell Nichols
- Department of Pathology & Cell Biology Taub Institute Columbia University New York New York
| | | | - Vinit B Mahajan
- Omics Laboratory Department of Ophthalmology Stanford University Palo Alto California.,Palo Alto Veterans Administration Palo Alto California
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19
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Skotak M, Alay E, Chandra N. On the Accurate Determination of Shock Wave Time-Pressure Profile in the Experimental Models of Blast-Induced Neurotrauma. Front Neurol 2018; 9:52. [PMID: 29467718 PMCID: PMC5808170 DOI: 10.3389/fneur.2018.00052] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2017] [Accepted: 01/19/2018] [Indexed: 01/04/2023] Open
Abstract
Measurement issues leading to the acquisition of artifact-free shock wave pressure-time profiles are discussed. We address the importance of in-house sensor calibration and data acquisition sampling rate. Sensor calibration takes into account possible differences between calibration methodology in a manufacturing facility, and those used in the specific laboratory. We found in-house calibration factors of brand new sensors differ by less than 10% from their manufacturer supplied data. Larger differences were noticeable for sensors that have been used for hundreds of experiments and were as high as 30% for sensors close to the end of their useful lifetime. These observations were despite the fact that typical overpressures in our experiments do not exceed 50 psi for sensors that are rated at 1,000 psi maximum pressure. We demonstrate that sampling rate of 1,000 kHz is necessary to capture the correct rise time values, but there were no statistically significant differences between peak overpressure and impulse values for low-intensity shock waves (Mach number <2) at lower rates. We discuss two sources of experimental errors originating from mechanical vibration and electromagnetic interference on the quality of a waveform recorded using state-of-the-art high-frequency pressure sensors. The implementation of preventive measures, pressure acquisition artifacts, and data interpretation with examples, are provided in this paper that will help the community at large to avoid these mistakes. In order to facilitate inter-laboratory data comparison, common reporting standards should be developed by the blast TBI research community. We noticed the majority of published literature on the subject limits reporting to peak overpressure; with much less attention directed toward other important parameters, i.e., duration, impulse, and dynamic pressure. These parameters should be included as a mandatory requirement in publications so the results can be properly compared with others.
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Affiliation(s)
- Maciej Skotak
- Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, United States
| | - Eren Alay
- Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, United States
| | - Namas Chandra
- Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, United States
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20
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Fievisohn E, Bailey Z, Guettler A, VandeVord P. Primary Blast Brain Injury Mechanisms: Current Knowledge, Limitations, and Future Directions. J Biomech Eng 2018; 140:2666247. [DOI: 10.1115/1.4038710] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2017] [Indexed: 12/18/2022]
Abstract
Mild blast traumatic brain injury (bTBI) accounts for the majority of brain injury in United States service members and other military personnel worldwide. The mechanisms of primary blast brain injury continue to be disputed with little evidence to support one or a combination of theories. The main hypotheses addressed in this review are blast wave transmission through the skull orifices, direct cranial transmission, skull flexure dynamics, thoracic surge, acceleration, and cavitation. Each possible mechanism is discussed using available literature with the goal of focusing research efforts to address the limitations and challenges that exist in blast injury research. Multiple mechanisms may contribute to the pathology of bTBI and could be dependent on magnitudes and orientation to blast exposure. Further focused biomechanical investigation with cadaver, in vivo, and finite element models would advance our knowledge of bTBI mechanisms. In addition, this understanding could guide future research and contribute to the greater goal of developing relevant injury criteria and mandates to protect our soldiers on the battlefield.
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Affiliation(s)
- Elizabeth Fievisohn
- Department of Biomedical Engineering and Mechanics, Virginia Tech, 440 Kelly Hall, 325 Stanger Street, Blacksburg, VA 24061 e-mail:
| | - Zachary Bailey
- Department of Biomedical Engineering and Mechanics, Virginia Tech, 440 Kelly Hall, 325 Stanger Street, Blacksburg, VA 24061 e-mail:
| | - Allison Guettler
- Department of Mechanical Engineering, Virginia Tech, 440 Kelly Hall, 325 Stanger Street, Blacksburg, VA 24061 e-mail:
| | - Pamela VandeVord
- Department of Biomedical Engineering and Mechanics, Virginia Tech, 317 Kelly Hall, 325 Stanger Street, Blacksburg, VA 24061; Salem Veterans Affairs Medical Center, Salam, VA 24153 e-mail:
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21
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Reduction in Temporary and Permanent Audiological Injury Through Internal Jugular Vein Compression in a Rodent Blast Injury Model. Otol Neurotol 2017; 38:1205-1212. [DOI: 10.1097/mao.0000000000001500] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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22
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Vogel EW, Morales FN, Meaney DF, Bass CR, Morrison B. Phosphodiesterase-4 inhibition restored hippocampal long term potentiation after primary blast. Exp Neurol 2017; 293:91-100. [PMID: 28366471 PMCID: PMC6016024 DOI: 10.1016/j.expneurol.2017.03.025] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 03/08/2017] [Accepted: 03/30/2017] [Indexed: 01/03/2023]
Abstract
Due to recent military conflicts and terrorist attacks, blast-induced traumatic brain injury (bTBI) presents a health concern for military and civilian personnel alike. Although secondary blast (penetrating injury) and tertiary blast (inertia-driven brain deformation) are known to be injurious, the effects of primary blast caused by the supersonic shock wave interacting with the skull and brain remain debated. Our group previously reported that in vitro primary blast exposure reduced long-term potentiation (LTP), the electrophysiological correlate of learning and memory, in rat organotypic hippocampal slice cultures (OHSCs) and that primary blast affects key proteins governing LTP. Recent studies have investigated phosphodiesterase-4 (PDE4) inhibition as a therapeutic strategy for reducing LTP deficits following inertia-driven TBI. We investigated the therapeutic potential of PDE4 inhibitors, specifically roflumilast, to ameliorate primary blast-induced deficits in LTP. We found that roflumilast at concentrations of 1nM or greater prevented deficits in neuronal plasticity measured 24h post-injury. We also observed a therapeutic window of at least 6h, but <23h. Additionally, we investigated molecular mechanisms that could elucidate this therapeutic effect. Roflumilast treatment (1nM delivered 6h post-injury) significantly increased total AMPA glutamate receptor 1 (GluR1) subunit expression, phosphorylation of the GluR1 subunit at the serine-831 site, and phosphorylation of stargazin at the serine-239/240 site upon LTP induction, measured 24h following injury. Roflumilast treatment significantly increased PSD-95 regardless of LTP induction. These findings indicate that further investigation into the translation of PDE4 inhibition as a therapy following bTBI is warranted.
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Affiliation(s)
- Edward W Vogel
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA
| | - Fatima N Morales
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA
| | - David F Meaney
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Cameron R Bass
- Department of Biomedical Engineering, Duke University, Durham, NC 27705, USA
| | - Barclay Morrison
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA.
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23
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DeWalt GJ, Eldred WD. Visual system pathology in humans and animal models of blast injury. J Comp Neurol 2017; 525:2955-2967. [PMID: 28560719 DOI: 10.1002/cne.24252] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 05/12/2017] [Accepted: 05/14/2017] [Indexed: 12/20/2022]
Abstract
Injury from blast exposure is becoming a more prevalent cause of death and disability worldwide. The devastating neurological impairments that result from blasts are significant and lifelong. Progress in the development of effective therapies to treat injury has been slowed by its heterogeneous pathology and the dearth of information regarding the cellular mechanisms involved. Within the last decade, a number of studies have documented visual dysfunction following injury. This brief review examines damage to the visual system in both humans and animal models of blast injury. The in vivo use of the retina as a surrogate to evaluate brain injury following exposure to blast is also highlighted.
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Affiliation(s)
- Gloria J DeWalt
- Department of Biology, Boston University, Boston, Massachusetts
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24
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Mammadova N, Ghaisas S, Zenitsky G, Sakaguchi DS, Kanthasamy AG, Greenlee JJ, West Greenlee MH. Lasting Retinal Injury in a Mouse Model of Blast-Induced Trauma. THE AMERICAN JOURNAL OF PATHOLOGY 2017; 187:1459-1472. [PMID: 28606756 DOI: 10.1016/j.ajpath.2017.03.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Accepted: 03/02/2017] [Indexed: 01/22/2023]
Abstract
Traumatic brain injury due to blast exposure is currently the most prevalent of war injuries. Although secondary ocular blast injuries due to flying debris are more common, primary ocular blast exposure resulting from blast wave pressure has been reported among survivors of explosions, but with limited understanding of the resulting retinal pathologies. Using a compressed air-driven shock tube system, adult male and female C57BL/6 mice were exposed to blast wave pressure of 300 kPa (43.5 psi) per day for 3 successive days, and euthanized 30 days after injury. We assessed retinal tissues using immunofluorescence for glial fibrillary acidic protein, microglia-specific proteins Iba1 and CD68, and phosphorylated tau (AT-270 pThr181 and AT-180 pThr231). Primary blast wave pressure resulted in activation of Müller glia, loss of photoreceptor cells, and an increase in phosphorylated tau in retinal neurons and glia. We found that 300-kPa blasts yielded no detectable cognitive or motor deficits, and no neurochemical or biochemical evidence of injury in the striatum or prefrontal cortex, respectively. These changes were detected 30 days after blast exposure, suggesting the possibility of long-lasting retinal injury and neuronal inflammation after primary blast exposure.
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Affiliation(s)
- Najiba Mammadova
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa; Immunobiology Graduate Program, Iowa State University, Ames, Iowa; Neuroscience Graduate Program, Iowa State University, Ames, Iowa
| | - Shivani Ghaisas
- Immunobiology Graduate Program, Iowa State University, Ames, Iowa; Department of Biomedical Sciences, Iowa State University College of Veterinary Medicine, Ames, Iowa
| | - Gary Zenitsky
- Department of Biomedical Sciences, Iowa State University College of Veterinary Medicine, Ames, Iowa
| | - Donald S Sakaguchi
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa; Neuroscience Graduate Program, Iowa State University, Ames, Iowa
| | - Anumantha G Kanthasamy
- Department of Biomedical Sciences, Iowa State University College of Veterinary Medicine, Ames, Iowa
| | - Justin J Greenlee
- Virus and Prion Research Unit, National Animal Disease Center, US Department of Agriculture, Agricultural Research Service, Ames, Iowa
| | - M Heather West Greenlee
- Immunobiology Graduate Program, Iowa State University, Ames, Iowa; Neuroscience Graduate Program, Iowa State University, Ames, Iowa; Department of Biomedical Sciences, Iowa State University College of Veterinary Medicine, Ames, Iowa.
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25
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Kawoos U, McCarron RM, Chavko M. Protective Effect of N-Acetylcysteine Amide on Blast-Induced Increase in Intracranial Pressure in Rats. Front Neurol 2017. [PMID: 28634463 PMCID: PMC5459930 DOI: 10.3389/fneur.2017.00219] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Blast-induced traumatic brain injury is associated with acute and possibly chronic elevation of intracranial pressure (ICP). The outcome after TBI is dependent on the progression of complex processes which are mediated by oxidative stress. So far, no effective pharmacological protection against TBI exists. In this study, rats were exposed to a single or repetitive blast overpressure (BOP) at moderate intensities of 72 or 110 kPa in a compressed air-driven shock tube. The degree and duration of the increase in ICP were proportional to the intensity and frequency of the blast exposure(s). In most cases, a single dose of antioxidant N-acetylcysteine amide (NACA) (500 mg/kg) administered intravenously 2 h after exposure to BOP significantly attenuated blast-induced increase in ICP. A single dose of NACA was not effective in improving the outcome in the group of animals that were subjected to repetitive blast exposures at 110 kPa on the same day. In this group, two treatments with NACA at 2 and 4 h post-BOP exposure resulted in significant attenuation of elevated ICP. Treatment with NACA prior to BOP exposure completely prevented the elevation of ICP. The findings indicate that oxidative stress plays an important role in blast-induced elevated ICP as treatment with NACA-ameliorated ICP increase, which is frequently related to poor functional recovery after TBI.
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Affiliation(s)
- Usmah Kawoos
- Department of Neurotrauma, Naval Medical Research Center, Silver Spring, MD, United States
| | - Richard M McCarron
- Department of Neurotrauma, Naval Medical Research Center, Silver Spring, MD, United States.,Department of Surgery, Uniformed Services University of the Health Sciences, Walter Reed National Military Medical Center, Bethesda, MD, United States
| | - Mikulas Chavko
- Department of Neurotrauma, Naval Medical Research Center, Silver Spring, MD, United States
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26
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Protection against Blast-Induced Traumatic Brain Injury by Increase in Brain Volume. BIOMED RESEARCH INTERNATIONAL 2017; 2017:2075463. [PMID: 28553646 PMCID: PMC5434276 DOI: 10.1155/2017/2075463] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 02/13/2017] [Accepted: 03/23/2017] [Indexed: 11/18/2022]
Abstract
Blast-induced traumatic brain injury (bTBI) is a leading cause of injuries in recent military conflicts and it is responsible for an increased number of civilian casualties by terrorist attacks. bTBI includes a variety of neuropathological changes depending on the intensity of blast overpressure (BOP) such as brain edema, neuronal degeneration, diffuse axonal damage, and vascular dysfunction with neurological manifestations of psychological and cognitive abnormalities. Internal jugular vein (IJV) compression is known to reduce intracranial compliance by causing an increase in brain volume and was shown to reduce brain damage during closed impact-induced TBI. We investigated whether IJV compression can attenuate signs of TBI in rats after exposure to BOP. Animals were exposed to three 110 ± 5 kPa BOPs separated by 30 min intervals. Exposure to BOP resulted in a significant decrease of neuronal nuclei (NeuN) together with upregulation of aquaporin-4 (AQP-4), 3-nitrotyrosine (3-NT), and endothelin 1 receptor A (ETRA) expression in frontal cortex and hippocampus one day following exposures. IJV compression attenuated this BOP-induced increase in 3-NT in cortex and ameliorated the upregulation of AQP-4 in hippocampus. These results suggest that elevated intracranial pressure and intracerebral volume have neuroprotective potential in blast-induced TBI.
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27
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Internal Jugular Vein Compression: A Novel Approach to Mitigate Blast Induced Hearing Injury. Otol Neurotol 2017; 38:591-598. [DOI: 10.1097/mao.0000000000001332] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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28
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Miller AP, Shah AS, Aperi BV, Kurpad SN, Stemper BD, Glavaski-Joksimovic A. Acute death of astrocytes in blast-exposed rat organotypic hippocampal slice cultures. PLoS One 2017; 12:e0173167. [PMID: 28264063 PMCID: PMC5338800 DOI: 10.1371/journal.pone.0173167] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 02/16/2017] [Indexed: 01/06/2023] Open
Abstract
Blast traumatic brain injury (bTBI) affects civilians, soldiers, and veterans worldwide and presents significant health concerns. The mechanisms of neurodegeneration following bTBI remain elusive and current therapies are largely ineffective. It is important to better characterize blast-evoked cellular changes and underlying mechanisms in order to develop more effective therapies. In the present study, our group utilized rat organotypic hippocampal slice cultures (OHCs) as an in vitro system to model bTBI. OHCs were exposed to either 138 ± 22 kPa (low) or 273 ± 23 kPa (high) overpressures using an open-ended helium-driven shock tube, or were assigned to sham control group. At 2 hours (h) following injury, we have characterized the astrocytic response to a blast overpressure. Immunostaining against the astrocytic marker glial fibrillary acidic protein (GFAP) revealed acute shearing and morphological changes in astrocytes, including clasmatodendrosis. Moreover, overlap of GFAP immunostaining and propidium iodide (PI) indicated astrocytic death. Quantification of the number of dead astrocytes per counting area in the hippocampal cornu Ammonis 1 region (CA1), demonstrated a significant increase in dead astrocytes in the low- and high-blast, compared to sham control OHCs. However only a small number of GFAP-expressing astrocytes were co-labeled with the apoptotic marker Annexin V, suggesting necrosis as the primary type of cell death in the acute phase following blast exposure. Moreover, western blot analyses revealed calpain mediated breakdown of GFAP. The dextran exclusion additionally indicated membrane disruption as a potential mechanism of acute astrocytic death. Furthermore, although blast exposure did not evoke significant changes in glutamate transporter 1 (GLT-1) expression, loss of GLT-1-expressing astrocytes suggests dysregulation of glutamate uptake following injury. Our data illustrate the profound effect of blast overpressure on astrocytes in OHCs at 2 h following injury and suggest increased calpain activity and membrane disruption as potential underlying mechanisms.
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Affiliation(s)
- Anna P. Miller
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin, United States of America
| | - Alok S. Shah
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin, United States of America
| | - Brandy V. Aperi
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin, United States of America
| | - Shekar N. Kurpad
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin, United States of America
| | - Brian D. Stemper
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin, United States of America
| | - Aleksandra Glavaski-Joksimovic
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin, United States of America
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29
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Feng K, Zhang L, Jin X, Chen C, Kallakuri S, Saif T, Cavanaugh J, King A. Biomechanical Responses of the Brain in Swine Subject to Free-Field Blasts. Front Neurol 2016; 7:179. [PMID: 27822197 PMCID: PMC5075707 DOI: 10.3389/fneur.2016.00179] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 10/04/2016] [Indexed: 01/05/2023] Open
Abstract
Blast-induced traumatic brain injury (bTBI) is a signature wound of modern warfare. The current incomplete understanding of its injury mechanism impedes the development of strategies for effective protection of bTBI. Despite a considerable amount of experimental animal studies focused on the evaluation of brain neurotrauma caused by blast exposure, there is very limited knowledge on the biomechanical responses of the gyrenecephalic brain subjected to primary free-field blast waves imposed in vivo. This study aims to evaluate the external and internal mechanical responses of the brain against different levels of blast loading with Yucatan swine in free field. The incident overpressure (IOP) was generated using 3.6 kg of C4 charge placed at three standoff distances from the swine. Five swine were exposed to a total of 19 blasts. The three average peak IOP pressure levels in this study were 148.8, 278.9, and 409.2 kPa as measured by a pencil probe. The duration of the first positive wave was in the range of 2.1–3 ms. Pressure changes in the brain and head kinematics were recorded with intracranial pressure (ICP) sensors, linear accelerometers, and angular rate sensors. The corresponding average peak ICPs were in the range of 79–143, 210–281, and 311–414 kPa designated as low, medium, and high blast level, respectively. Peak head linear accelerations were in the range of 120–412 g. A positive correlation between IOP and its corresponding biomechanical responses of the brain was also observed. These experimental data can be used to validate computer models of bTBI.
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Affiliation(s)
- Ke Feng
- Department of Biomedical Engineering, Wayne State University , Detroit, MI , USA
| | - Liying Zhang
- Department of Biomedical Engineering, Wayne State University , Detroit, MI , USA
| | - Xin Jin
- Department of Biomedical Engineering, Wayne State University , Detroit, MI , USA
| | - Chaoyang Chen
- Department of Biomedical Engineering, Wayne State University , Detroit, MI , USA
| | - Srinivasu Kallakuri
- Department of Biomedical Engineering, Wayne State University , Detroit, MI , USA
| | - Tal Saif
- Department of Biomedical Engineering, Wayne State University , Detroit, MI , USA
| | - John Cavanaugh
- Department of Biomedical Engineering, Wayne State University , Detroit, MI , USA
| | - Albert King
- Department of Biomedical Engineering, Wayne State University , Detroit, MI , USA
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30
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Ko J, Hemphill MA, Gabrieli D, Wu L, Yelleswarapu V, Lawrence G, Pennycooke W, Singh A, Meaney DF, Issadore D. Smartphone-enabled optofluidic exosome diagnostic for concussion recovery. Sci Rep 2016; 6:31215. [PMID: 27498963 PMCID: PMC4976377 DOI: 10.1038/srep31215] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 07/15/2016] [Indexed: 01/23/2023] Open
Abstract
A major impediment to improving the treatment of concussion is our current inability to identify patients that will experience persistent problems after the injury. Recently, brain-derived exosomes, which cross the blood-brain barrier and circulate following injury, have shown great potential as a noninvasive biomarker of brain recovery. However, clinical use of exosomes has been constrained by their small size (30–100 nm) and the extensive sample preparation (>24 hr) needed for traditional exosome measurements. To address these challenges, we developed a smartphone-enabled optofluidic platform to measure brain-derived exosomes. Sample-to-answer on our chip is 1 hour, 10x faster than conventional techniques. The key innovation is an optofluidic device that can detect enzyme amplified exosome biomarkers, and is read out using a smartphone camera. Using this approach, we detected and profiled GluR2+ exosomes in the post-injury state using both in vitro and murine models of concussion.
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Affiliation(s)
- Jina Ko
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania. Philadelphia, Pennsylvania, United States
| | - Matthew A Hemphill
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania. Philadelphia, Pennsylvania, United States
| | - David Gabrieli
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania. Philadelphia, Pennsylvania, United States
| | - Leon Wu
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania. Philadelphia, Pennsylvania, United States
| | - Venkata Yelleswarapu
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania. Philadelphia, Pennsylvania, United States
| | - Gladys Lawrence
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania. Philadelphia, Pennsylvania, United States
| | - Wesley Pennycooke
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania. Philadelphia, Pennsylvania, United States
| | - Anup Singh
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania. Philadelphia, Pennsylvania, United States
| | - Dave F Meaney
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania. Philadelphia, Pennsylvania, United States.,Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - David Issadore
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania. Philadelphia, Pennsylvania, United States.,Department of Electrical and Systems Engineering, School of Engineering and Applied Sciences, University of Pennsylvania. Philadelphia, Pennsylvania, United States
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31
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Mao H, Unnikrishnan G, Rakesh V, Reifman J. Untangling the Effect of Head Acceleration on Brain Responses to Blast Waves. J Biomech Eng 2016; 137:124502. [PMID: 26458125 DOI: 10.1115/1.4031765] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Indexed: 01/19/2023]
Abstract
Multiple injury-causing mechanisms, such as wave propagation, skull flexure, cavitation, and head acceleration, have been proposed to explain blast-induced traumatic brain injury (bTBI). An accurate, quantitative description of the individual contribution of each of these mechanisms may be necessary to develop preventive strategies against bTBI. However, to date, despite numerous experimental and computational studies of bTBI, this question remains elusive. In this study, using a two-dimensional (2D) rat head model, we quantified the contribution of head acceleration to the biomechanical response of brain tissues when exposed to blast waves in a shock tube. We compared brain pressure at the coup, middle, and contre-coup regions between a 2D rat head model capable of simulating all mechanisms (i.e., the all-effects model) and an acceleration-only model. From our simulations, we determined that head acceleration contributed 36-45% of the maximum brain pressure at the coup region, had a negligible effect on the pressure at the middle region, and was responsible for the low pressure at the contre-coup region. Our findings also demonstrate that the current practice of measuring rat brain pressures close to the center of the brain would record only two-thirds of the maximum pressure observed at the coup region. Therefore, to accurately capture the effects of acceleration in experiments, we recommend placing a pressure sensor near the coup region, especially when investigating the acceleration mechanism using different experimental setups.
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32
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Beamer M, Tummala SR, Gullotti D, Kopil C, Gorka S, Bass CRD, Morrison B, Cohen AS, Meaney DF. Primary blast injury causes cognitive impairments and hippocampal circuit alterations. Exp Neurol 2016; 283:16-28. [PMID: 27246999 DOI: 10.1016/j.expneurol.2016.05.025] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 05/14/2016] [Accepted: 05/20/2016] [Indexed: 11/17/2022]
Abstract
Blast-induced traumatic brain injury (bTBI) and its long term consequences are a major health concern among veterans. Despite recent work enhancing our knowledge about bTBI, very little is known about the contribution of the blast wave alone to the observed sequelae. Herein, we isolated its contribution in a mouse model by constraining the animals' heads during exposure to a shockwave (primary blast). Our results show that exposure to primary blast alone results in changes in hippocampus-dependent behaviors that correspond with electrophysiological changes in area CA1 and are accompanied by reactive gliosis. Specifically, five days after exposure, behavior in an open field and performance in a spatial object recognition (SOR) task were significantly different from sham. Network electrophysiology, also performed five days after injury, demonstrated a significant decrease in excitability and increase in inhibitory tone. Immunohistochemistry for GFAP and Iba1 performed ten days after injury showed a significant increase in staining. Interestingly, a threefold increase in the impulse of the primary blast wave did not exacerbate these measures. However, we observed a significant reduction in the contribution of the NMDA receptors to the field EPSP at the highest blast exposure level. Our results emphasize the need to account for the effects of primary blast loading when studying the sequelae of bTBI.
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Affiliation(s)
- Matthew Beamer
- Department of Bioengineering(1), University of Pennsylvania, Philadelphia, PA, USA
| | - Shanti R Tummala
- Department of Bioengineering(1), University of Pennsylvania, Philadelphia, PA, USA
| | - David Gullotti
- Department of Bioengineering(1), University of Pennsylvania, Philadelphia, PA, USA
| | - Catherine Kopil
- Department of Bioengineering(1), University of Pennsylvania, Philadelphia, PA, USA
| | - Samuel Gorka
- Department of Bioengineering(1), University of Pennsylvania, Philadelphia, PA, USA
| | | | - Barclay Morrison
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
| | - Akiva S Cohen
- Department of Anesthesiology and Critical Care Medicine, University of Pennsylvania, Philadelphia, PA, USA; Division of Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - David F Meaney
- Department of Bioengineering(1), University of Pennsylvania, Philadelphia, PA, USA; Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA, USA.
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33
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Effgen GB, Ong T, Nammalwar S, Ortuño AI, Meaney DF, 'Dale' Bass CR, Morrison B. Primary Blast Exposure Increases Hippocampal Vulnerability to Subsequent Exposure: Reducing Long-Term Potentiation. J Neurotrauma 2016; 33:1901-1912. [PMID: 26699926 DOI: 10.1089/neu.2015.4327] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Up to 80% of injuries sustained by U.S. soldiers in Operation Enduring Freedom and Operation Iraqi Freedom were the result of blast exposure from improvised explosive devices. Some soldiers experience multiple blasts while on duty, and it has been suggested that symptoms of repetitive blast are similar to those that follow multiple non-blast concussions, such as sport-related concussion. Despite the interest in the effects of repetitive blast exposure, it remains unknown whether an initial blast renders the brain more vulnerable to subsequent exposure, resulting in a synergistic injury response. To investigate the effect of multiple primary blasts on the brain, organotypic hippocampal slice cultures were exposed to single or repetitive (two or three total) primary blasts of varying intensities. Long-term potentiation was significantly reduced following two Level 2 (92.7 kPa, 1.4 msec, 38.5 kPa·msec) blasts delivered 24 h apart without altering basal evoked response. This deficit persisted when the interval between injuries was increased to 72 h but not when the interval was extended to 144 h. The repeated blast exposure with a 24 h interval increased microglia staining and activation significantly but did not significantly increase cell death or damage axons, dendrites, or principal cell layers. Lack of overt structural damage and change in basal stimulated neuron response suggest that injury from repetitive primary blast exposure may specifically affect long-term potentiation. Our studies suggest repetitive primary blasts can exacerbate injury dependent on the injury severity and interval between exposures.
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Affiliation(s)
- Gwen B Effgen
- 1 Department of Biomedical Engineering, Columbia University , New York, New York
| | - Tiffany Ong
- 1 Department of Biomedical Engineering, Columbia University , New York, New York
| | - Shruthi Nammalwar
- 1 Department of Biomedical Engineering, Columbia University , New York, New York
| | - Andrea I Ortuño
- 1 Department of Biomedical Engineering, Columbia University , New York, New York
| | - David F Meaney
- 2 Department of Bioengineering, University of Pennsylvania , Philadelphia, Pennsylvania
| | | | - Barclay Morrison
- 1 Department of Biomedical Engineering, Columbia University , New York, New York
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34
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Xu L, Schaefer ML, Linville RM, Aggarwal A, Mbuguiro W, Wester BA, Koliatsos VE. Neuroinflammation in primary blast neurotrauma: Time course and prevention by torso shielding. Exp Neurol 2016; 277:268-274. [DOI: 10.1016/j.expneurol.2016.01.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 12/02/2015] [Accepted: 01/13/2016] [Indexed: 01/12/2023]
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35
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VandeVord PJ, Leonardi ADC, Ritzel D. Bridging the Gap of Standardized Animals Models for Blast Neurotrauma: Methodology for Appropriate Experimental Testing. Methods Mol Biol 2016; 1462:101-18. [PMID: 27604715 DOI: 10.1007/978-1-4939-3816-2_7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Recent military combat has heightened awareness to the complexity of blast-related traumatic brain injuries (bTBI). Experiments using animal, cadaver, or biofidelic physical models remain the primary measures to investigate injury biomechanics as well as validate computational simulations, medical diagnostics and therapies, or protection technologies. However, blast injury research has seen a range of irregular and inconsistent experimental methods for simulating blast insults generating results which may be misleading, cannot be cross-correlated between laboratories, or referenced to any standard for exposure. Both the US Army Medical Research and Materiel Command and the National Institutes of Health have noted that there is a lack of standardized preclinical models of TBI. It is recommended that the blast injury research community converge on a consistent set of experimental procedures and reporting of blast test conditions. This chapter describes the blast conditions which can be recreated within a laboratory setting and methodology for testing in vivo models within the appropriate environment.
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Affiliation(s)
- Pamela J VandeVord
- Biomedical Engineering and Mechanics, Virginia Tech, 447 Kelly Hall, 325 Stanger St., Blacksburg, VA, 24061, USA.
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36
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Bailey ZS, Hubbard WB, VandeVord PJ. Cellular Mechanisms and Behavioral Outcomes in Blast-Induced Neurotrauma: Comparing Experimental Setups. Methods Mol Biol 2016; 1462:119-138. [PMID: 27604716 DOI: 10.1007/978-1-4939-3816-2_8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Blast-induced neurotrauma (BINT) has increased in incidence over the past decades and can result in cognitive issues that have debilitating consequences. The exact primary and secondary mechanisms of injury have not been elucidated and appearance of cellular injury can vary based on many factors, such as blast overpressure magnitude and duration. Many methodologies to study blast neurotrauma have been employed, ranging from open-field explosives to experimental shock tubes for producing free-field blast waves. While there are benefits to the various methods, certain specifications need to be accounted for in order to properly examine BINT. Primary cell injury mechanisms, occurring as a direct result of the blast wave, have been identified in several studies and include cerebral vascular damage, blood-brain barrier disruption, axonal injury, and cytoskeletal damage. Secondary cell injury mechanisms, triggered subsequent to the initial insult, result in the activation of several molecular cascades and can include, but are not limited to, neuroinflammation and oxidative stress. The collective result of these secondary injuries can lead to functional deficits. Behavioral measures examining motor function, anxiety traits, and cognition/memory problems have been utilized to determine the level of injury severity. While cellular injury mechanisms have been identified following blast exposure, the various experimental models present both concurrent and conflicting results. Furthermore, the temporal response and progression of pathology after blast exposure have yet to be detailed and remain unclear due to limited resemblance of methodologies. This chapter summarizes the current state of blast neuropathology and emphasizes the need for a standardized preclinical model of blast neurotrauma.
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Affiliation(s)
- Zachary S Bailey
- School of Biomedical Engineering and Sciences, Virginia Tech, 447 Kelly Hall, 325 Stanger Street, Blacksburg, VA, 24061, USA
| | - W Brad Hubbard
- School of Biomedical Engineering and Sciences, Virginia Tech, 447 Kelly Hall, 325 Stanger Street, Blacksburg, VA, 24061, USA
| | - Pamela J VandeVord
- School of Biomedical Engineering and Sciences, Virginia Tech, 447 Kelly Hall, 325 Stanger Street, Blacksburg, VA, 24061, USA.
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37
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Vogel EW, Effgen GB, Patel TP, Meaney DF, Bass CRD, Morrison B. Isolated Primary Blast Inhibits Long-Term Potentiation in Organotypic Hippocampal Slice Cultures. J Neurotrauma 2015; 33:652-61. [PMID: 26414012 DOI: 10.1089/neu.2015.4045] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Over the last 13 years, traumatic brain injury (TBI) has affected over 230,000 U.S. service members through the conflicts in Iraq and Afghanistan, mostly as a result of exposure to blast events. Blast-induced TBI (bTBI) is multi-phasic, with the penetrating and inertia-driven phases having been extensively studied. The effects of primary blast injury, caused by the shockwave interacting with the brain, remain unclear. Earlier in vivo studies in mice and rats have reported mixed results for primary blast effects on behavior and memory. Using a previously developed shock tube and in vitro sample receiver, we investigated the effect of isolated primary blast on the electrophysiological function of rat organotypic hippocampal slice cultures (OHSC). We found that pure primary blast exposure inhibited long-term potentiation (LTP), the electrophysiological correlate of memory, with a threshold between 9 and 39 kPa·ms impulse. This deficit occurred well below a previously identified threshold for cell death (184 kPa·ms), supporting our previously published finding that primary blast can cause changes in brain function in the absence of cell death. Other functional measures such as spontaneous activity, network synchronization, stimulus-response curves, and paired-pulse ratios (PPRs) were less affected by primary blast exposure, as compared with LTP. This is the first study to identify a tissue-level tolerance threshold for electrophysiological changes in neuronal function to isolated primary blast.
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Affiliation(s)
- Edward W Vogel
- 1 Department of Biomedical Engineering, Columbia University , New York, New York
| | - Gwen B Effgen
- 1 Department of Biomedical Engineering, Columbia University , New York, New York
| | - Tapan P Patel
- 2 Department of Bioengineering, University of Pennsylvania , Philadelphia, Pennsylvania
| | - David F Meaney
- 2 Department of Bioengineering, University of Pennsylvania , Philadelphia, Pennsylvania
| | - Cameron R Dale Bass
- 3 Department of Biomedical Engineering, Duke University , Durham, North Carolina
| | - Barclay Morrison
- 1 Department of Biomedical Engineering, Columbia University , New York, New York
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38
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Hue CD, Cho FS, Cao S, Nicholls RE, Vogel Iii EW, Sibindi C, Arancio O, Dale Bass CR, Meaney DF, Morrison Iii B. Time Course and Size of Blood-Brain Barrier Opening in a Mouse Model of Blast-Induced Traumatic Brain Injury. J Neurotrauma 2015; 33:1202-11. [PMID: 26414212 DOI: 10.1089/neu.2015.4067] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
An increasing number of studies have reported blood-brain barrier (BBB) dysfunction after blast-induced traumatic brain injury (bTBI). Despite this evidence, there is limited quantitative understanding of the extent of BBB opening and the time course of damage after blast injury. In addition, many studies do not report kinematic parameters of head motion, making it difficult to separate contributions of primary and tertiary blast-loading. Detailed characterization of blast-induced BBB damage may hold important implications for serum constituents that may potentially cross the compromised barrier and contribute to neurotoxicity, neuroinflammation, and persistent neurologic deficits. Using an in vivo bTBI model, systemic administration of sodium fluorescein (NaFl; 376 Da), Evans blue (EB; 69 kDa when bound to serum albumin), and dextrans (3-500 kDa) was used to estimate the pore size of BBB opening and the time required for recovery. Exposure to blast with 272 ± 6 kPa peak overpressure, 0.69 ± 0.01 ms duration, and 65 ± 1 kPa*ms impulse resulted in significant acute extravasation of NaFl, 3 kDa dextran, and EB. However, there was no significant acute extravasation of 70 kDa or 500 kDa dextrans, and minimal to no extravasation of NaFl, dextrans, or EB 1 day after exposure. This study presents a detailed analysis of the time course and pore size of BBB opening after bTBI, supported by a characterization of kinematic parameters associated with blast-induced head motion.
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Affiliation(s)
- Christopher D Hue
- 1 Department of Biomedical Engineering, Columbia University , New York, New York
| | - Frances S Cho
- 1 Department of Biomedical Engineering, Columbia University , New York, New York
| | - Siqi Cao
- 1 Department of Biomedical Engineering, Columbia University , New York, New York
| | - Russell E Nicholls
- 2 Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University , New York, New York
| | - Edward W Vogel Iii
- 1 Department of Biomedical Engineering, Columbia University , New York, New York
| | - Cosmas Sibindi
- 1 Department of Biomedical Engineering, Columbia University , New York, New York
| | - Ottavio Arancio
- 2 Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University , New York, New York
| | - Cameron R Dale Bass
- 3 Department of Biomedical Engineering, Duke University , Durham, North Carolina
| | - David F Meaney
- 4 Department of Bioengineering, University of Pennsylvania , Philadelphia, Pennsylvania
| | - Barclay Morrison Iii
- 1 Department of Biomedical Engineering, Columbia University , New York, New York
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39
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Patel TP, Gullotti DM, Hernandez P, O'Brien WT, Capehart BP, Morrison B, Bass C, Eberwine JE, Abel T, Meaney DF. An open-source toolbox for automated phenotyping of mice in behavioral tasks. Front Behav Neurosci 2014; 8:349. [PMID: 25339878 PMCID: PMC4189437 DOI: 10.3389/fnbeh.2014.00349] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2014] [Accepted: 09/18/2014] [Indexed: 12/04/2022] Open
Abstract
Classifying behavior patterns in mouse models of neurological, psychiatric and neurodevelopmental disorders is critical for understanding disease causality and treatment. However, complete characterization of behavior is time-intensive, prone to subjective scoring, and often requires specialized equipment. Although several reports describe automated home-cage monitoring and individual task scoring methods, we report the first open source, comprehensive toolbox for automating the scoring of several common behavior tasks used by the neuroscience community. We show this new toolbox is robust and achieves equal or better consistency when compared to manual scoring methods. We use this toolbox to study the alterations in behavior that occur following blast-induced traumatic brain injury (bTBI), and study if these behavior patterns are altered following genetic deletion of the transcription factor Ets-like kinase 1 (Elk-1). Due to the role of Elk-1 in neuronal survival and proposed role in synaptic plasticity, we hypothesized that Elk-1 deletion would improve some neurobehavioral deficits, while impairing others, following blast exposure. In Elk-1 knockout (KO) animals, deficits in open field, spatial object recognition (SOR) and elevated zero maze performance after blast exposure disappeared, while new significant deficits appeared in spatial and associative memory. These are the first data suggesting a molecular mediator of anxiety deficits following bTBI, and represent the utility of the broad screening tool we developed. More broadly, we envision this open-source toolbox will provide a more consistent and rapid analysis of behavior across many neurological diseases, promoting the rapid discovery of novel pathways mediating disease progression and treatment.
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Affiliation(s)
- Tapan P Patel
- Department of Bioengineering, University of Pennsylvania Philadelphia, PA, USA
| | - David M Gullotti
- Department of Bioengineering, University of Pennsylvania Philadelphia, PA, USA
| | - Pepe Hernandez
- Department of Biology, University of Pennsylvania Philadelphia, PA, USA
| | - W Timothy O'Brien
- Department of Neuroscience, University of Pennsylvania Philadelphia, PA, USA
| | - Bruce P Capehart
- Department of Psychiatry and Behavioral Sciences, Duke University Durham, NC, USA
| | - Barclay Morrison
- Department of Biomedical Engineering, Columbia University New York, NY, USA
| | - Cameron Bass
- Department of Biomedical Engineering, Duke University Durham, NC, USA
| | - James E Eberwine
- Department of Pharmacology, University of Pennsylvania Philadelphia, PA, USA
| | - Ted Abel
- Department of Biology, University of Pennsylvania Philadelphia, PA, USA
| | - David F Meaney
- Department of Bioengineering, University of Pennsylvania Philadelphia, PA, USA ; Department of Neurosurgery, University of Pennsylvania Philadelphia, PA, USA
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