1
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Green TRF, Carey SD, Mannino G, Craig JA, Rowe RK, Zielinski MR. Sleep, inflammation, and hemodynamics in rodent models of traumatic brain injury. Front Neurosci 2024; 18:1361014. [PMID: 38426017 PMCID: PMC10903352 DOI: 10.3389/fnins.2024.1361014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2023] [Accepted: 01/29/2024] [Indexed: 03/02/2024] Open
Abstract
Traumatic brain injury (TBI) can induce dysregulation of sleep. Sleep disturbances include hypersomnia and hyposomnia, sleep fragmentation, difficulty falling asleep, and altered electroencephalograms. TBI results in inflammation and altered hemodynamics, such as changes in blood brain barrier permeability and cerebral blood flow. Both inflammation and altered hemodynamics, which are known sleep regulators, contribute to sleep impairments post-TBI. TBIs are heterogenous in cause and biomechanics, which leads to different molecular and symptomatic outcomes. Animal models of TBI have been developed to model the heterogeneity of TBIs observed in the clinic. This review discusses the intricate relationship between sleep, inflammation, and hemodynamics in pre-clinical rodent models of TBI.
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Affiliation(s)
- Tabitha R. F. Green
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, United States
| | - Sean D. Carey
- Veterans Affairs (VA) Boston Healthcare System, West Roxbury, MA, United States
- Department of Psychiatry, Harvard Medical School, West Roxbury, MA, United States
| | - Grant Mannino
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, United States
| | - John A. Craig
- Veterans Affairs (VA) Boston Healthcare System, West Roxbury, MA, United States
| | - Rachel K. Rowe
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, United States
| | - Mark R. Zielinski
- Veterans Affairs (VA) Boston Healthcare System, West Roxbury, MA, United States
- Department of Psychiatry, Harvard Medical School, West Roxbury, MA, United States
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2
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Hetzer SM, O'Connell C, Lallo V, Robson M, Evanson NK. Model matters: Differential outcomes in traumatic optic neuropathy pathophysiology between blunt and blast-wave mediated head injuries. Exp Neurol 2024; 372:114613. [PMID: 37995952 PMCID: PMC10870099 DOI: 10.1016/j.expneurol.2023.114613] [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: 05/25/2023] [Revised: 11/07/2023] [Accepted: 11/15/2023] [Indexed: 11/25/2023]
Abstract
Over 3 million people in the United States live with long-term disability because of a traumatic brain injury (TBI). The purpose of this study was to characterize and compare two different animal models of TBI (blunt head trauma and blast TBI) to determine common and divergent characteristics of these models. With recent literature reviews noting the prevalence of visual system injury in animal models of TBI, coupled with clinical estimates of 50-75% of all TBI cases, we decided to assess commonalities, if they existed, through visual system injury. A unilateral (left directed) blast and repeat blast model injury with coup-contra-coup injury patterns were compared to a midline blunt injury. Injuries were induced in adult male mice to observe and quantify visual deficits. Retinal ganglion cell loss and axonal degeneration in the optic tract, superior colliculus, and lateral geniculate nuclei were examined to trace injury outcomes throughout major vision-associated areas. Optokinetic response, immunohistochemistry, and western blots were analyzed. Where a single blunt injury produces significant visual deficits a single blast injury appears to have less severe visual consequences. Visual deficits after repeat blasts are similar to a single blast. Single blast injury induces contralateral damage to the right optic chiasm and tract whereas bilateral injury follows a single blunt TBI. Repeat blast injuries are required to see degeneration patterns in downstream regions similar to the damage seen in a single blunt injury. This finding is further supported by amyloid precursor protein (APP) staining in injured cohorts. Blunt injured groups present with staining 1.2 mm ahead of the optic nerve, indicating axonal breakage closer to the optic chiasm. In blast groups, APP was identifiable in a bilateral pattern only in the geniculate nucleus. Evidence for unilateral neuronal degeneration in brain tissue with bilateral axonal ruptures are pivotal discoveries in this model differentiation. Analysis of the two injury models suggests that there is a significant difference in the histological outcomes dependent on injury type, though visual system injury is likely present in more cases than are currently diagnosed clinically.
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Affiliation(s)
- S M Hetzer
- Neuroscience Graduate Program, University of Cincinnati College of Medicine, United States of America.
| | - C O'Connell
- Division of Pharmaceutical Sciences, James L. Winkle College of Pharmacy, University of Cincinnati, United States of America
| | - V Lallo
- College of Arts and Sciences, University of Cincinnati, United States of America
| | - M Robson
- Division of Pharmaceutical Sciences, James L. Winkle College of Pharmacy, University of Cincinnati, United States of America
| | - N K Evanson
- Department of Pediatrics, University of Cincinnati College of Medicine, United States of America; Division of Pediatric Rehabilitation Medicine, Cincinnati Children's Hospital Medical Center, United States of America
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3
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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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4
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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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5
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Honig MG, Del Mar NA, Moore BM, Reiner A. Raloxifene Mitigates Emotional Deficits after Mild Traumatic Brain Injury in Mice. Neurotrauma Rep 2022; 3:534-544. [DOI: 10.1089/neur.2022.0052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Affiliation(s)
- Marcia G. Honig
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Nobel A. Del Mar
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Bob M. Moore
- Department of Pharmaceutical Sciences, The University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Anton Reiner
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, Tennessee, USA
- Department of Ophthalmology, The University of Tennessee Health Science Center, Memphis, Tennessee, USA
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6
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McNamara EH, Tucker LB, Liu J, Fu AH, Kim Y, Vu PA, McCabe JT. Limbic Responses Following Shock Wave Exposure in Male and Female Mice. Front Behav Neurosci 2022; 16:863195. [PMID: 35747840 PMCID: PMC9210954 DOI: 10.3389/fnbeh.2022.863195] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 04/04/2022] [Indexed: 01/26/2023] Open
Abstract
Blast traumatic brain injury (bTBI) presents a serious threat to military personnel and often results in psychiatric conditions related to limbic system dysfunction. In this study, the functional outcomes for anxiety- and depressive-like behaviors and neuronal activation were evaluated in male and female mice after exposure to an Advanced Blast Simulator (ABS) shock wave. Mice were placed in a ventrally exposed orientation inside of the ABS test section and received primary and tertiary shock wave insults of approximately 15 psi peak pressure. Evans blue staining indicated cases of blood-brain barrier breach in the superficial cerebral cortex four, but not 24 h after blast, but the severity was variable. Behavioral testing with the elevated plus maze (EPM) or elevated zero maze (EZM), sucrose preference test (SPT), and tail suspension test (TST) or forced swim test (FST) were conducted 8 days–3.5 weeks after shock wave exposure. There was a sex difference, but no injury effect, for distance travelled in the EZM where female mice travelled significantly farther than males. The SPT and FST did not indicate group differences; however, injured mice were less immobile than sham mice during the TST; possibly indicating more agitated behavior. In a separate cohort of animals, the expression of the immediate early gene, c-Fos, was detected 4 h after undergoing bTBI or sham procedures. No differences in c-Fos expression were found in the cerebral cortex, but female mice in general displayed enhanced c-Fos activation in the paraventricular nucleus of the thalamus (PVT) compared to male mice. In the amygdala, more c-Fos-positive cells were observed in injured animals compared to sham mice. The observed sex differences in the PVT and c-Fos activation in the amygdala may correlate with the reported hyperactivity of females post-injury. This study demonstrates, albeit with mild effects, behavioral and neuronal activation correlates in female rodents after blast injury that could be relevant to the incidence of increased post-traumatic stress disorder in women.
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Affiliation(s)
- Eileen H. McNamara
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Laura B. Tucker
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
- Pre-Clinical Studies Core, Center for Neuroscience and Regenerative Medicine, Henry M. Jackson Foundation, Bethesda, MD, United States
| | - Jiong Liu
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Amanda H. Fu
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
- Pre-Clinical Studies Core, Center for Neuroscience and Regenerative Medicine, Henry M. Jackson Foundation, Bethesda, MD, United States
| | - Yeonho Kim
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
- Pre-Clinical Studies Core, Center for Neuroscience and Regenerative Medicine, Henry M. Jackson Foundation, Bethesda, MD, United States
| | - Patricia A. Vu
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Joseph T. McCabe
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
- Pre-Clinical Studies Core, Center for Neuroscience and Regenerative Medicine, Henry M. Jackson Foundation, Bethesda, MD, United States
- *Correspondence: Joseph T. McCabe,
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7
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Ratner MH, Farb DH. Probing the Neural Circuitry Targets of Neurotoxicants In Vivo Through High Density Silicon Probe Brain Implants. FRONTIERS IN TOXICOLOGY 2022; 4:836427. [PMID: 35548683 PMCID: PMC9081674 DOI: 10.3389/ftox.2022.836427] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 03/22/2022] [Indexed: 12/24/2022] Open
Abstract
Adverse effects of drugs on the human nervous system are rarely possible to anticipate based on preclinical neurotoxicity data, thus propagating the centuries long single most important obstacle to drug discovery and development for disorders of the nervous system. An emerging body of evidence indicates that in vivo electrophysiology using chronically implanted high-density electrodes (ciHDE) in freely moving animals is a rigorous method with enhanced potential for use in translational research. In particular, the structure and function of the hippocampal trisynaptic circuit (HTC) is conserved from rodents to primates, including Homo sapiens, suggesting that the effects of therapeutic agents and other potential neurologically active agents, whether beneficial or adverse, are likely to translate across species when interrogated using a conserved neural circuitry platform. This review explores science advances in the rapidly moving field of in vivo ciHDE in animal models of learning and memory. For this reason we focus on the HTC, where substantial research has investigated neural circuitry level responses and specific behaviors that reflect memory permitting a test of the ground truth validity of the findings. Examples of changes in neural network activity induced by endogenous neurotoxicants associated with neurodegenerative diseases, as well as exogenous therapeutics, drugs, and neurotoxicants are presented. Several illustrative examples of relevant findings that involve longer range neural circuitry outside of the HTC are discussed. Lastly, the limitations of in vivo ciHDE as applied to preclinical neurotoxicology are discussed with a view toward leveraging circuitry level actions to enhance our ability to project the specificity of in vitro target engagement with the desired psychopharmacological or neurological outcome. At the same time, the goal of reducing or eliminating significant neurotoxic adverse events in human is the desired endpoint. We believe that this approach will lead to enhanced discovery of high value neuroactive therapeutics that target neural circuitry domains as their primary mechanism of action, thus enhancing their ultimate contribution toward discovery of precision therapeutics.
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Affiliation(s)
- Marcia H. Ratner
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA, United States
- *Correspondence: Marcia H. Ratner,
| | - David H. Farb
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA, United States
- Center for Systems Neuroscience, Boston University, Boston, MA, United States
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8
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Honig MG, Del Mar NA, Henderson DL, O'Neal D, Yammanur M, Cox R, Li C, Perry AM, Moore BM, Reiner A. Raloxifene, a cannabinoid type-2 receptor inverse agonist, mitigates visual deficits and pathology and modulates microglia after ocular blast. Exp Eye Res 2022; 218:108966. [PMID: 35143834 DOI: 10.1016/j.exer.2022.108966] [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: 11/10/2021] [Revised: 01/04/2022] [Accepted: 01/24/2022] [Indexed: 11/19/2022]
Abstract
Visual deficits after ocular blast injury (OBI) are common, but pharmacological approaches to improve long-term outcomes have not been identified. Blast forces frequently damage the retina and optic nerves, and work on experimental animals has shown the pro-inflammatory actions of microglia can further exacerbate such injuries. Cannabinoid type-2 receptor (CB2) inverse agonists specifically target activated microglia, biasing them away from the harmful pro-inflammatory M1 state toward the helpful reparative M2 state. We previously found that treating mice with CB2 inverse agonists after traumatic brain injury, produced by either focal cranial air blast or dorsal cranial impact, greatly attenuated the visual deficits and pathology that otherwise resulted. Here we examined the consequences of single and repeat OBI and the benefit provided by raloxifene, an FDA-approved estrogen receptor drug that possesses noteworthy CB2 inverse agonism. After single OBI, although the amplitudes of the A- and B-waves of the electroretinogram and pupil light response appeared to be normal, the mice showed hints of deficits in contrast sensitivity and visual acuity, a trend toward optic nerve axon loss, and significantly increased light aversion, which were reversed by 2 weeks of daily treatment with raloxifene. Mice subjected to repeat OBI (5 blasts spaced 1 min apart), exhibited more severe visual deficits, including decreases in contrast sensitivity, visual acuity, the amplitudes of the A- and B-waves of the electroretinogram, light aversion, and resting pupil diameter (i.e. hyperconstriction), accompanied by the loss of photoreceptor cells and optic nerve axons, nearly all of which were mitigated by raloxifene. Interestingly, optic nerve axon abundance was strongly correlated with contrast sensitivity and visual acuity across all groups of experimental mice in the repeat OBI study, suggesting optic nerve axon loss with rOBI and its attenuation with raloxifene are associated with the extent of these two deficits while photoreceptor abundance was highly correlated with A-wave amplitude and resting pupil size, suggesting a prominent role for photoreceptors in these two deficits. Quantitative PCR (qPCR) showed levels of M1-type microglial markers (e.g. iNOS, IL1β, TNFα, and CD32) in retina, optic nerve, and thalamus were increased 3 days after repeat OBI. With raloxifene treatment, the overall expression of M1 markers was more similar to that in sham mice. Raloxifene treatment was also associated with the elevation of IL10 transcripts in all three tissues compared to repeat OBI alone, but the results for the three other M2 microglial markers we examined were more varied. Taken together, the qPCR results suggest that raloxifene benefit for visual function and pathology was associated with a lessening of the pro-inflammatory actions of microglia. The benefit we find for raloxifene following OBI provides a strong basis for phase-2 efficacy testing in human clinical trials for treating ocular injury.
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Affiliation(s)
- Marcia G Honig
- Department of Anatomy and Neurobiology(,) the University of Tennessee Health Science Center, Memphis, TN, 38163, USA
| | - Nobel A Del Mar
- Department of Anatomy and Neurobiology(,) the University of Tennessee Health Science Center, Memphis, TN, 38163, USA
| | - Desmond L Henderson
- Department of Anatomy and Neurobiology(,) the University of Tennessee Health Science Center, Memphis, TN, 38163, USA
| | - Dylan O'Neal
- Department of Anatomy and Neurobiology(,) the University of Tennessee Health Science Center, Memphis, TN, 38163, USA
| | - Meghna Yammanur
- Department of Anatomy and Neurobiology(,) the University of Tennessee Health Science Center, Memphis, TN, 38163, USA
| | - Rachel Cox
- Department of Anatomy and Neurobiology(,) the University of Tennessee Health Science Center, Memphis, TN, 38163, USA
| | - Chunyan Li
- Department of Anatomy and Neurobiology(,) the University of Tennessee Health Science Center, Memphis, TN, 38163, USA
| | - Aaron M Perry
- Department of Anatomy and Neurobiology(,) the University of Tennessee Health Science Center, Memphis, TN, 38163, USA
| | - Bob M Moore
- Department of Pharmaceutical Sciences, The University of Tennessee Health Science Center, Memphis, TN, 38163, USA
| | - Anton Reiner
- Department of Anatomy and Neurobiology(,) the University of Tennessee Health Science Center, Memphis, TN, 38163, USA; Department of Ophthalmology, The University of Tennessee Health Science Center, Memphis, TN, 38163, USA.
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9
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Siedhoff HR, Chen S, Song H, Cui J, Cernak I, Cifu DX, DePalma RG, Gu Z. Perspectives on Primary Blast Injury of the Brain: Translational Insights Into Non-inertial Low-Intensity Blast Injury. Front Neurol 2022; 12:818169. [PMID: 35095749 PMCID: PMC8794583 DOI: 10.3389/fneur.2021.818169] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 12/20/2021] [Indexed: 12/18/2022] Open
Abstract
Most traumatic brain injuries (TBIs) during military deployment or training are clinically "mild" and frequently caused by non-impact blast exposures. Experimental models were developed to reproduce the biological consequences of high-intensity blasts causing moderate to severe brain injuries. However, the pathophysiological mechanisms of low-intensity blast (LIB)-induced neurological deficits have been understudied. This review provides perspectives on primary blast-induced mild TBI models and discusses translational aspects of LIB exposures as defined by standardized physical parameters including overpressure, impulse, and shock wave velocity. Our mouse LIB-exposure model, which reproduces deployment-related scenarios of open-field blast (OFB), caused neurobehavioral changes, including reduced exploratory activities, elevated anxiety-like levels, impaired nesting behavior, and compromised spatial reference learning and memory. These functional impairments associate with subcellular and ultrastructural neuropathological changes, such as myelinated axonal damage, synaptic alterations, and mitochondrial abnormalities occurring in the absence of gross- or cellular damage. Biochemically, we observed dysfunctional mitochondrial pathways that led to elevated oxidative stress, impaired fission-fusion dynamics, diminished mitophagy, decreased oxidative phosphorylation, and compensated cell respiration-relevant enzyme activity. LIB also induced increased levels of total tau, phosphorylated tau, and amyloid β peptide, suggesting initiation of signaling cascades leading to neurodegeneration. We also compare translational aspects of OFB findings to alternative blast injury models. By scoping relevant recent research findings, we provide recommendations for future preclinical studies to better reflect military-operational and clinical realities. Overall, better alignment of preclinical models with clinical observations and experience related to military injuries will facilitate development of more precise diagnosis, clinical evaluation, treatment, and rehabilitation.
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Affiliation(s)
- Heather R. Siedhoff
- Department of Pathology and Anatomical Sciences, University of Missouri School of Medicine, Columbia, MO, United States
- Harry S. Truman Memorial Veterans' Hospital Research Service, Columbia, MO, United States
| | - Shanyan Chen
- Department of Pathology and Anatomical Sciences, University of Missouri School of Medicine, Columbia, MO, United States
- Harry S. Truman Memorial Veterans' Hospital Research Service, Columbia, MO, United States
| | - Hailong Song
- Department of Pathology and Anatomical Sciences, University of Missouri School of Medicine, Columbia, MO, United States
- Harry S. Truman Memorial Veterans' Hospital Research Service, Columbia, MO, United States
| | - Jiankun Cui
- Department of Pathology and Anatomical Sciences, University of Missouri School of Medicine, Columbia, MO, United States
- Harry S. Truman Memorial Veterans' Hospital Research Service, Columbia, MO, United States
| | - Ibolja Cernak
- Department of Biomedical Sciences, Mercer University School of Medicine, Macon, GA, United States
| | - David X. Cifu
- Department of Physical Medicine and Rehabilitation, Virginia Commonwealth University School of Medicine, Richmond, VA, United States
| | - Ralph G. DePalma
- Office of Research and Development, Department of Veterans Affairs, Washington, DC, United States
- Department of Surgery, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Zezong Gu
- Department of Pathology and Anatomical Sciences, University of Missouri School of Medicine, Columbia, MO, United States
- Harry S. Truman Memorial Veterans' Hospital Research Service, Columbia, MO, United States
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10
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Honig MG, Del Mar NA, Henderson DL, O'Neal D, Doty JB, Cox R, Li C, Perry AM, Moore BM, Reiner A. Raloxifene Modulates Microglia and Rescues Visual Deficits and Pathology After Impact Traumatic Brain Injury. Front Neurosci 2021; 15:701317. [PMID: 34776838 PMCID: PMC8585747 DOI: 10.3389/fnins.2021.701317] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 09/07/2021] [Indexed: 11/29/2022] Open
Abstract
Mild traumatic brain injury (TBI) involves widespread axonal injury and activation of microglia, which initiates secondary processes that worsen the TBI outcome. The upregulation of cannabinoid type-2 receptors (CB2) when microglia become activated allows CB2-binding drugs to selectively target microglia. CB2 inverse agonists modulate activated microglia by shifting them away from the harmful pro-inflammatory M1 state toward the helpful reparative M2 state and thus can stem secondary injury cascades. We previously found that treatment with the CB2 inverse agonist SMM-189 after mild TBI in mice produced by focal cranial blast rescues visual deficits and the optic nerve axon loss that would otherwise result. We have further shown that raloxifene, which is Food and Drug Administration (FDA)-approved as an estrogen receptor modulator to treat osteoporosis, but also possesses CB2 inverse agonism, yields similar benefit in this TBI model through its modulation of microglia. As many different traumatic events produce TBI in humans, it is widely acknowledged that diverse animal models must be used in evaluating possible therapies. Here we examine the consequences of TBI created by blunt impact to the mouse head for visual function and associated pathologies and assess raloxifene benefit. We found that mice subjected to impact TBI exhibited decreases in contrast sensitivity and the B-wave of the electroretinogram, increases in light aversion and resting pupil diameter, and optic nerve axon loss, which were rescued by daily injection of raloxifene at 5 or 10 mg/ml for 2 weeks. Raloxifene treatment was associated with reduced M1 activation and/or enhanced M2 activation in retina, optic nerve, and optic tract after impact TBI. Our results suggest that the higher raloxifene dose, in particular, may be therapeutic for the optic nerve by enhancing the phagocytosis of axonal debris that would otherwise promote inflammation, thereby salvaging less damaged axons. Our current work, together with our prior studies, shows that microglial activation drives secondary injury processes after both impact and cranial blast TBI and raloxifene mitigates microglial activation and visual system injury in both cases. The results thus provide a strong basis for phase 2 human clinical trials evaluating raloxifene as a TBI therapy.
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Affiliation(s)
- Marcia G Honig
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, United States
| | - Nobel A Del Mar
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, United States
| | - Desmond L Henderson
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, United States
| | - Dylan O'Neal
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, United States
| | - John B Doty
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, United States
| | - Rachel Cox
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, United States
| | - Chunyan Li
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, United States
| | - Aaron M Perry
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, United States
| | - Bob M Moore
- Department of Pharmaceutical Sciences, The University of Tennessee Health Science Center, Memphis, TN, United States
| | - Anton Reiner
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, United States.,Department of Ophthalmology, The University of Tennessee Health Science Center, Memphis, TN, United States
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11
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Faillot M, Chaillet A, Palfi S, Senova S. Rodent models used in preclinical studies of deep brain stimulation to rescue memory deficits. Neurosci Biobehav Rev 2021; 130:410-432. [PMID: 34437937 DOI: 10.1016/j.neubiorev.2021.08.012] [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: 02/08/2021] [Revised: 08/10/2021] [Accepted: 08/13/2021] [Indexed: 11/28/2022]
Abstract
Deep brain stimulation paradigms might be used to treat memory disorders in patients with stroke or traumatic brain injury. However, proof of concept studies in animal models are needed before clinical translation. We propose here a comprehensive review of rodent models for Traumatic Brain Injury and Stroke. We systematically review the histological, behavioral and electrophysiological features of each model and identify those that are the most relevant for translational research.
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Affiliation(s)
- Matthieu Faillot
- Neurosurgery department, Henri Mondor University Hospital, APHP, DMU CARE, Université Paris Est Créteil, Mondor Institute for Biomedical Research, INSERM U955, Team 15, Translational Neuropsychiatry, France
| | - Antoine Chaillet
- Laboratoire des Signaux et Systèmes (L2S-UMR8506) - CentraleSupélec, Université Paris Saclay, Institut Universitaire de France, France
| | - Stéphane Palfi
- Neurosurgery department, Henri Mondor University Hospital, APHP, DMU CARE, Université Paris Est Créteil, Mondor Institute for Biomedical Research, INSERM U955, Team 15, Translational Neuropsychiatry, France
| | - Suhan Senova
- Neurosurgery department, Henri Mondor University Hospital, APHP, DMU CARE, Université Paris Est Créteil, Mondor Institute for Biomedical Research, INSERM U955, Team 15, Translational Neuropsychiatry, France.
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12
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Mondal K, Takahashi H, Cole J, Del Mar NA, Li C, Stephenson DJ, Allegood J, Cowart LA, Chalfant CE, Reiner A, Mandal N. Systemic Elevation of n-3 Polyunsaturated Fatty Acids (n-3-PUFA) Is Associated with Protection against Visual, Motor, and Emotional Deficits in Mice following Closed-Head Mild Traumatic Brain Injury. Mol Neurobiol 2021; 58:5564-5580. [PMID: 34365584 DOI: 10.1007/s12035-021-02501-y] [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: 04/17/2021] [Accepted: 07/17/2021] [Indexed: 12/30/2022]
Abstract
Traumatic brain injury (TBI) causes neuroinflammation and neurodegeneration leading to various pathological complications such as motor and sensory (visual) deficits, cognitive impairment, and depression. N-3 polyunsaturated fatty acid (n-3 PUFA) containing lipids are known to be anti-inflammatory, whereas the sphingolipid, ceramide (Cer), is an inducer of neuroinflammation and degeneration. Using Fat1+-transgenic mice that contain elevated levels of systemic n-3 PUFA, we tested whether they are resistant to mild TBI-mediated sensory-motor and emotional deficits by subjecting Fat1-transgenic mice and their WT littermates to focal cranial air blast (50 psi) or sham blast (0 psi, control). We observed that visual function in WT mice was reduced significantly following TBI but not in Fat1+-blast animals. We also found Fat1+-blast mice were resistant to the decline in motor functions, depression, and fear-producing effects of blast, as well as the reduction in the area of oculomotor nucleus and increase in activated microglia in the optic tract in brain sections seen following blast in WT mice. Lipid and gene expression analyses confirmed an elevated level of the n-3 PUFA eicosapentaenoic acid (EPA) in the plasma and brain, blocking of TBI-mediated increase of Cer in the brain, and decrease in TBI-mediated induction of Cer biosynthetic and inflammatory gene expression in the brain of the Fat1+ mice. Our results demonstrate that suppression of ceramide biosynthesis and inflammatory factors in Fat1+-transgenic mice is associated with significant protection against the visual, motor, and emotional deficits caused by mild TBI. This study suggests that n-3 PUFA (especially, EPA) has a promising therapeutic role in preventing neurodegeneration after TBI.
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Affiliation(s)
- Koushik Mondal
- Department of Ophthalmology, The University of Tennessee Health Science Centre, TN, 38163, Memphis, USA
| | - Haruka Takahashi
- Department of Ophthalmology, The University of Tennessee Health Science Centre, TN, 38163, Memphis, USA.,Department of Animal Science, Iwate University, Morioka, Japan
| | - Jerome Cole
- Department of Ophthalmology, The University of Tennessee Health Science Centre, TN, 38163, Memphis, USA
| | - Nobel A Del Mar
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Centre, TN, 38163, Memphis, USA
| | - Chunyan Li
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Centre, TN, 38163, Memphis, USA
| | - Daniel J Stephenson
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL, 33620, USA
| | - Jeremy Allegood
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, VA, 23219, USA
| | - L Ashley Cowart
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, VA, 23219, USA.,Hunter Holmes McGuire VA Medical Center, Richmond, VA, 23249, USA
| | - Charles E Chalfant
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL, 33620, USA.,The Moffitt Cancer Center, Tampa, FL, 33620, USA.,Research Service, James A. Haley Veterans Hospital, Tampa, FL, 33612, USA
| | - Anton Reiner
- Department of Ophthalmology, The University of Tennessee Health Science Centre, TN, 38163, Memphis, USA.,Department of Anatomy and Neurobiology, The University of Tennessee Health Science Centre, TN, 38163, Memphis, USA
| | - Nawajes Mandal
- Department of Ophthalmology, The University of Tennessee Health Science Centre, TN, 38163, Memphis, USA. .,Department of Anatomy and Neurobiology, The University of Tennessee Health Science Centre, TN, 38163, Memphis, USA. .,Department of Pharmaceutical Sciences, College of Pharmacy, The University of Tennessee Health Science Centre, TN, 38163, Memphis, USA. .,Memphis VA Medical Center, Memphis, TN, 38104, USA.
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13
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Hetzer SM, Guilhaume-Correa F, Day D, Bedolla A, Evanson NK. Traumatic Optic Neuropathy Is Associated with Visual Impairment, Neurodegeneration, and Endoplasmic Reticulum Stress in Adolescent Mice. Cells 2021; 10:cells10050996. [PMID: 33922788 PMCID: PMC8146890 DOI: 10.3390/cells10050996] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 04/02/2021] [Accepted: 04/17/2021] [Indexed: 02/02/2023] Open
Abstract
Traumatic brain injury (TBI) results in a number of impairments, often including visual symptoms. In some cases, visual impairments after head trauma are mediated by traumatic injury to the optic nerve, termed traumatic optic neuropathy (TON), which has few effective options for treatment. Using a murine closed-head weight-drop model of head trauma, we previously reported in adult mice that there is relatively selective injury to the optic tract and thalamic/brainstem projections of the visual system. In the current study, we performed blunt head trauma on adolescent C57BL/6 mice and investigated visual impairment in the primary visual system, now including the retina and using behavioral and histologic methods at new time points. After injury, mice displayed evidence of decreased optomotor responses illustrated by decreased optokinetic nystagmus. There did not appear to be a significant change in circadian locomotor behavior patterns, although there was an overall decrease in locomotor behavior in mice with head injury. There was evidence of axonal degeneration of optic nerve fibers with associated retinal ganglion cell death. There was also evidence of astrogliosis and microgliosis in major central targets of optic nerve projections. Further, there was elevated expression of endoplasmic reticulum (ER) stress markers in retinas of injured mice. Visual impairment, histologic markers of gliosis and neurodegeneration, and elevated ER stress marker expression persisted for at least 30 days after injury. The current results extend our previous findings in adult mice into adolescent mice, provide direct evidence of retinal ganglion cell injury after head trauma and suggest that axonal degeneration is associated with elevated ER stress in this model of TON.
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Affiliation(s)
- Shelby M. Hetzer
- Neuroscience Graduate Program, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA; (S.M.H.); (D.D.); (A.B.)
| | - Fernanda Guilhaume-Correa
- Translational Biology, Medicine and Health, Virginia Polytechnic Institute and State University, Roanoke, VA 24016, USA;
| | - Dylan Day
- Neuroscience Graduate Program, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA; (S.M.H.); (D.D.); (A.B.)
| | - Alicia Bedolla
- Neuroscience Graduate Program, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA; (S.M.H.); (D.D.); (A.B.)
| | - Nathan K. Evanson
- Neuroscience Graduate Program, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA; (S.M.H.); (D.D.); (A.B.)
- Division of Pediatric Rehabilitation Medicine, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA
- Department of Pediatrics, University of Cincinnati, Cincinnati, OH 45229, USA
- Correspondence:
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14
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Nonaka M, Taylor WW, Bukalo O, Tucker LB, Fu AH, Kim Y, McCabe JT, Holmes A. Behavioral and Myelin-Related Abnormalities after Blast-Induced Mild Traumatic Brain Injury in Mice. J Neurotrauma 2021; 38:1551-1571. [PMID: 33605175 DOI: 10.1089/neu.2020.7254] [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] [Indexed: 12/19/2022] Open
Abstract
In civilian and military settings, mild traumatic brain injury (mTBI) is a common consequence of impacts to the head, sudden blows to the body, and exposure to high-energy atmospheric shockwaves from blast. In some cases, mTBI from blast exposure results in long-term emotional and cognitive deficits and an elevated risk for certain neuropsychiatric diseases. Here, we tested the effects of mTBI on various forms of auditory-cued fear learning and other measures of cognition in male C57BL/6J mice after single or repeated blast exposure (blast TBI; bTBI). bTBI produced an abnormality in the temporal organization of cue-induced freezing behavior in a conditioned trace fear test. Spatial working memory, evaluated by the Y-maze task performance, was also deleteriously affected by bTBI. Reverse-transcription quantitative real-time polymerase chain reaction (RT-qPCR) analysis for glial markers indicated an alteration in the expression of myelin-related genes in the hippocampus and corpus callosum 1-8 weeks after bTBI. Immunohistochemical and ultrastructural analyses detected bTBI-related myelin and axonal damage in the hippocampus and corpus callosum. Together, these data suggest a possible link between blast-induced mTBI, myelin/axonal injury, and cognitive dysfunction.
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Affiliation(s)
- Mio Nonaka
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health (NIH), Rockville, Maryland, USA
| | - William W Taylor
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health (NIH), Rockville, Maryland, USA
| | - Olena Bukalo
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health (NIH), Rockville, Maryland, USA
| | - Laura B Tucker
- Department of Anatomy, Physiology and Genetics, Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA.,Preclinical Studies Core, Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
| | - Amanda H Fu
- Department of Anatomy, Physiology and Genetics, Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA.,Preclinical Studies Core, Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
| | - Yeonho Kim
- Department of Anatomy, Physiology and Genetics, Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA.,Preclinical Studies Core, Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
| | - Joseph T McCabe
- Department of Anatomy, Physiology and Genetics, Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA.,Preclinical Studies Core, Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
| | - Andrew Holmes
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health (NIH), Rockville, Maryland, USA
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15
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Marsh JL, Bentil SA. Cerebrospinal Fluid Cavitation as a Mechanism of Blast-Induced Traumatic Brain Injury: A Review of Current Debates, Methods, and Findings. Front Neurol 2021; 12:626393. [PMID: 33776887 PMCID: PMC7994250 DOI: 10.3389/fneur.2021.626393] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 02/18/2021] [Indexed: 11/15/2022] Open
Abstract
Cavitation has gained popularity in recent years as a potential mechanism of blast-induced traumatic brain injury (bTBI). This review presents the most prominent debates on cavitation; how bubbles can form or exist within the cerebrospinal fluid (CSF) and brain vasculature, potential mechanisms of cellular, and tissue level damage following the collapse of bubbles in response to local pressure fluctuations, and a survey of experimental and computational models used to address cavitation research questions. Due to the broad and varied nature of cavitation research, this review attempts to provide a necessary synthesis of cavitation findings relevant to bTBI, and identifies key areas where additional work is required. Fundamental questions about the viability and likelihood of CSF cavitation during blast remain, despite a variety of research regarding potential injury pathways. Much of the existing literature on bTBI evaluates cavitation based off its prima facie plausibility, while more rigorous evaluation of its likelihood becomes increasingly necessary. This review assesses the validity of some of the common assumptions in cavitation research, as well as highlighting outstanding questions that are essential in future work.
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Affiliation(s)
- Jenny L Marsh
- The Bentil Group, Department of Mechanical Engineering, Iowa State University, Ames, IA, United States
| | - Sarah A Bentil
- The Bentil Group, Department of Mechanical Engineering, Iowa State University, Ames, IA, United States
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16
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McCorkle TA, Barson JR, Raghupathi R. A Role for the Amygdala in Impairments of Affective Behaviors Following Mild Traumatic Brain Injury. Front Behav Neurosci 2021; 15:601275. [PMID: 33746719 PMCID: PMC7969709 DOI: 10.3389/fnbeh.2021.601275] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 01/29/2021] [Indexed: 11/30/2022] Open
Abstract
Mild traumatic brain injury (TBI) results in chronic affective disorders such as depression, anxiety, and fear that persist up to years following injury and significantly impair the quality of life for patients. Although a great deal of research has contributed to defining symptoms of mild TBI, there are no adequate drug therapies for brain-injured individuals. Preclinical studies have modeled these deficits in affective behaviors post-injury to understand the underlying mechanisms with a view to developing appropriate treatment strategies. These studies have also unveiled sex differences that contribute to the varying phenotypes associated with each behavior. Although clinical and preclinical studies have viewed these behavioral deficits as separate entities with unique neurobiological mechanisms, mechanistic similarities suggest that a novel approach is needed to advance research on drug therapy. This review will discuss the circuitry involved in the expression of deficits in affective behaviors following mild TBI in humans and animals and provide evidence that the manifestation of impairment in these behaviors stems from an amygdala-dependent emotional processing deficit. It will highlight mechanistic similarities between these different types of affective behaviors that can potentially advance mild TBI drug therapy by investigating treatments for the deficits in affective behaviors as one entity, requiring the same treatment.
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Affiliation(s)
- Taylor A. McCorkle
- Graduate Program in Neuroscience, Graduate School of Biomedical Sciences and Professional Studies, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Jessica R. Barson
- Graduate Program in Neuroscience, Graduate School of Biomedical Sciences and Professional Studies, Drexel University College of Medicine, Philadelphia, PA, United States
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Ramesh Raghupathi
- Graduate Program in Neuroscience, Graduate School of Biomedical Sciences and Professional Studies, Drexel University College of Medicine, Philadelphia, PA, United States
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, United States
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17
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Correll EA, Ramser BJ, Knott MV, McCullumsmith RE, McGuire JL, Ngwenya LB. Deficits in pattern separation and dentate gyrus proliferation after rodent lateral fluid percussion injury. IBRO Neurosci Rep 2021; 10:31-41. [PMID: 33861814 PMCID: PMC8019949 DOI: 10.1016/j.ibneur.2020.11.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 11/27/2020] [Indexed: 12/15/2022] Open
Abstract
It has been demonstrated that adult born granule cells are generated after traumatic brain injury (TBI). There is evidence that these newly generated neurons are aberrant and are poised to contribute to poor cognitive function after TBI. Yet, there is also evidence that these newly generated neurons are important for cognitive recovery. Pattern separation is a cognitive task known to be dependent on the function of adult generated granule cells. Performance on this task and the relation to dentate gyrus dysfunction after TBI has not been previously studied. Here we subjected Sprague Dawley rats to lateral fluid percussion injury or sham and tested them on the dentate gyrus dependent task pattern separation. At 2 weeks after injury, we examined common markers of dentate gyrus function such as GSK3ß phosphorylation, Ki-67 immunohistochemistry, and generation of adult born granule cells. We found that injured animals have deficits in pattern separation. We additionally found a decrease in proliferative capacity at 2 weeks indicated by decreased phosphorylation of GSK3ß and Ki-67 immunopositivity as compared to sham animals. Lastly we found an increase in numbers of new neurons generated during the pattern separation task. These findings provide evidence that dentate gyrus dysfunction may be an important contributor to TBI pathology.
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Affiliation(s)
- Erika A Correll
- Department of Neurosurgery, University of Cincinnati, 231 Albert Sabin Way, Cincinnati, OH 45267, USA
| | - Benjamin J Ramser
- College of Medicine, University of Cincinnati, 231 Albert Sabin Way, Cincinnati, OH 45267, USA
| | - Maxon V Knott
- University of Cincinnati, 2600 Clifton Ave, Cincinnati, OH 45221, USA
| | - Robert E McCullumsmith
- College of Medicine and Life Sciences, University of Toledo, 2801W. Bancroft St, Toledo, OH 43606, USA.,ProMedica Toledo Hospital, 1 ProMedica Pkwy, Toledo, OH 43606, USA
| | - Jennifer L McGuire
- Department of Neurosurgery, University of Cincinnati, 231 Albert Sabin Way, Cincinnati, OH 45267, USA
| | - Laura B Ngwenya
- Department of Neurosurgery, University of Cincinnati, 231 Albert Sabin Way, Cincinnati, OH 45267, USA.,Department of Neurology and Rehabilitation Medicine, University of Cincinnati, 231 Albert Sabin Way, Cincinnati, OH 45267, USA
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18
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Popovitz J, Mysore SP, Adwanikar H. Neural Markers of Vulnerability to Anxiety Outcomes after Traumatic Brain Injury. J Neurotrauma 2020; 38:1006-1022. [PMID: 33050836 DOI: 10.1089/neu.2020.7320] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Anxiety outcomes after traumatic brain injury (TBI) are complex, and the underlying neural mechanisms are poorly understood. Here, we developed a multi-dimensional behavioral profiling approach to investigate anxiety-like outcomes in mice that takes into account individual variability. Departing from the tradition of comparing outcomes in TBI versus sham groups, we identified a subgroup within the TBI group that is vulnerable to anxiety dysfunction, and present increased exploration of the anxiogenic zone compared to sham controls or resilient injured animals, by applying dimensionality reduction, clustering, and post hoc validation to behavioral data obtained from multiple assays for anxiety at several post-injury time points. These vulnerable animals expressed distinct molecular profiles in the corticolimbic network, with downregulation in gamma-aminobutyric acid and glutamate and upregulation in neuropeptide Y markers. Indeed, among vulnerable animals, not resilient or sham controls, severity of anxiety-related outcomes correlated strongly with expression of molecular markers. Our results establish a foundational approach, with predictive power, for reliably identifying maladaptive anxiety outcomes after TBI and uncovering neural signatures of vulnerability to anxiety.
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Affiliation(s)
- Juliana Popovitz
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, Maryland, USA
| | - Shreesh P Mysore
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, Maryland, USA.,Department of Neuroscience, Johns Hopkins University, Baltimore, Maryland, USA
| | - Hita Adwanikar
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, Maryland, USA
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19
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Shultz SR, McDonald SJ, Corrigan F, Semple BD, Salberg S, Zamani A, Jones NC, Mychasiuk R. Clinical Relevance of Behavior Testing in Animal Models of Traumatic Brain Injury. J Neurotrauma 2020; 37:2381-2400. [DOI: 10.1089/neu.2018.6149] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
- Sandy R. Shultz
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
- Department of Medicine, The University of Melbourne, Parkville, Victoria, Australia
| | - Stuart J. McDonald
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
- Department of Physiology, Anatomy, and Microbiology, La Trobe University, Melbourne, Victoria, Australia
| | - Frances Corrigan
- Department of Anatomy, University of South Australia, Adelaide, South Australia, Australia
| | - Bridgette D. Semple
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
- Department of Medicine, The University of Melbourne, Parkville, Victoria, Australia
| | - Sabrina Salberg
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
| | - Akram Zamani
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
| | - Nigel C. Jones
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
- Department of Medicine, The University of Melbourne, Parkville, Victoria, Australia
| | - Richelle Mychasiuk
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
- Department of Psychology, University of Calgary, Calgary, Alberta, Canada
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20
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Blaze J, Choi I, Wang Z, Umali M, Mendelev N, Tschiffely AE, Ahlers ST, Elder GA, Ge Y, Haghighi F. Blast-Related Mild TBI Alters Anxiety-Like Behavior and Transcriptional Signatures in the Rat Amygdala. Front Behav Neurosci 2020; 14:160. [PMID: 33192359 PMCID: PMC7604767 DOI: 10.3389/fnbeh.2020.00160] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 08/11/2020] [Indexed: 12/21/2022] Open
Abstract
The short and long-term neurological and psychological consequences of traumatic brain injury (TBI), and especially mild TBI (mTBI) are of immense interest to the Veteran community. mTBI is a common and detrimental result of combat exposure and results in various deleterious outcomes, including mood and anxiety disorders, cognitive deficits, and post-traumatic stress disorder (PTSD). In the current study, we aimed to further define the behavioral and molecular effects of blast-related mTBI using a well-established (3 × 75 kPa, one per day on three consecutive days) repeated blast overpressure (rBOP) model in rats. We exposed adult male rats to the rBOP procedure and conducted behavioral tests for anxiety and fear conditioning at 1-1.5 months (sub-acute) or 12-13 months (chronic) following blast exposure. We also used next-generation sequencing to measure transcriptome-wide gene expression in the amygdala of sham and blast-exposed animals at the sub-acute and chronic time points. Results showed that blast-exposed animals exhibited an anxiety-like phenotype at the sub-acute timepoint but this phenotype was diminished by the chronic time point. Conversely, gene expression analysis at both sub-acute and chronic timepoints demonstrated a large treatment by timepoint interaction such that the most differentially expressed genes were present in the blast-exposed animals at the chronic time point, which also corresponded to a Bdnf-centric gene network. Overall, the current study identified changes in the amygdalar transcriptome and anxiety-related phenotypic outcomes dependent on both blast exposure and aging, which may play a role in the long-term pathological consequences of mTBI.
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Affiliation(s)
- Jennifer Blaze
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, United States.,Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Inbae Choi
- Research and Development Service, James J. Peters Veterans Affairs Medical Center, Bronx, NY, United States
| | - Zhaoyu Wang
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, United States.,Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Michelle Umali
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, United States.,Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Natalia Mendelev
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, United States.,Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Anna E Tschiffely
- Department of Neurotrauma, Operational and Undersea Medicine Directorate, Naval Medical Research Center, Silver Spring, MD, United States
| | - Stephen T Ahlers
- Department of Neurotrauma, Operational and Undersea Medicine Directorate, Naval Medical Research Center, Silver Spring, MD, United States
| | - Gregory A Elder
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States.,Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, United States.,Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, United States.,Neurology Service, James J. Peters Veterans Affairs Medical Center, Bronx, NY, United States
| | - Yongchao Ge
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Fatemeh Haghighi
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, United States.,Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States.,Research and Development Service, James J. Peters Veterans Affairs Medical Center, Bronx, NY, United States.,Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, United States
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21
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Improvement in cognitive dysfunction following blast induced traumatic brain injury by thymosin α1 in rats: Involvement of inhibition of tau phosphorylation at the Thr205 epitope. Brain Res 2020; 1747:147038. [PMID: 32738231 DOI: 10.1016/j.brainres.2020.147038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 07/25/2020] [Accepted: 07/27/2020] [Indexed: 12/13/2022]
Abstract
Cognitive impairment is a significant sequela of traumatic brain injury (TBI) especially blast induced traumatic brain injury (bTBI), which is characterized by rapid impairments of learning and memory ability. Although several neuroprotective agents have been postulated as promising drugs for bTBI in animal studies, very few ideal therapeutic options exist to improve cognitive impairment following bTBI. Thymosin α1(Tα1), a 28-amino-acid protein that possesses immunomodulatory functions, has exhibited beneficial effects in the treatment of infectious diseases, immunodeficiency diseases and cancers. However, it remains unclear whether Tα1 has a therapeutic role in bTBI. Thus, we hypothesized that Tα1 administration could reverse the outcomes of bTBI. The blast induced TBI (bTBI) rat model was established with the compressed gas driven blast injury model system. A consecutive Tα1 therapy (in 1 ml saline, twice a day) at a dose of 200 µg/kg or normal saline (NS) (1 ml, twice a day) for 3 days or 2 weeks was performed. Utilizing our newly designed bTBI model, we investigated the beneficial effects of Tα1 therapy on rats exposed to bTBI including: cognitive functions, general histology, regulatory T (Treg) cells, edema, inflammation reactions and the expression and phosphorylation level of tau via Morris Water Maze test (MWM test), HE staining, flow cytometry, brain water content (BWC) calculation, IL-6 assay and Western blotting, respectively. Tα1 treatment seemed to reduce the 24-hour mortality, albeit with no statistical significance. Moreover, Tα1 treatment markedly improved cognitive dysfunction by decreasing the escape latency in the acquisition phase, and increasing the crossing numbers in the probe phase of MWM test. More interestingly, Tα1 significantly inhibited tau phosphorylation at the Thr205 epitope, but not at the Ser404 and Ser262 epitopes. Tα1 increased the percentage of Treg cells and inhibited plasma IL-6 production on 3d post bTBI. Moreover, Tα1 suppressed brain edema as demonstrated by decrease of BWC. However, there was a lack of obvious change in histopathology in the brain upon Tα1 treatment. This is the first study showing that Tα1 improves neurological deficits after bTBI in rats, which is potentially related to the inhibition of tau phosphorylation at the Thr205 epitope, increased Treg cells and decreased inflammatory reactions and brain edema.
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22
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Honig MG, Dorian CC, Worthen JD, Micetich AC, Mulder IA, Sanchez KB, Pierce WF, Del Mar NA, Reiner A. Progressive long-term spatial memory loss following repeat concussive and subconcussive brain injury in mice, associated with dorsal hippocampal neuron loss, microglial phenotype shift, and vascular abnormalities. Eur J Neurosci 2020; 54:5844-5879. [PMID: 32090401 PMCID: PMC7483557 DOI: 10.1111/ejn.14711] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 02/18/2020] [Accepted: 02/19/2020] [Indexed: 12/14/2022]
Abstract
There is considerable concern about the long‐term deleterious effects of repeat head trauma on cognition, but little is known about underlying mechanisms and pathology. To examine this, we delivered four air blasts to the left side of the mouse cranium, a week apart, with an intensity that causes deficits when delivered singly and considered “concussive,” or an intensity that does not yield significant deficits when delivered singly and considered “subconcussive.” Neither repeat concussive nor subconcussive blast produced spatial memory deficits at 4 months, but both yielded deficits at 14 months, and dorsal hippocampal neuron loss. Hierarchical cluster analysis of dorsal hippocampal microglia across the three groups based on morphology and expression of MHCII, CX3CR1, CD68 and IBA1 revealed five distinct phenotypes. Types 1A and 1B microglia were more common in sham mice, linked to better neuron survival and memory, and appeared mildly activated. By contrast, 2B and 2C microglia were more common in repeat concussive and subconcussive mice, linked to poorer neuron survival and memory, and characterized by low expression levels and attenuated processes, suggesting they were de‐activated and dysfunctional. In addition, endothelial cells in repeat concussive mice exhibited reduced CD31 and eNOS expression, which was correlated with the prevalence of type 2B and 2C microglia. Our findings suggest that both repeat concussive and subconcussive head injury engender progressive pathogenic processes, possibly through sustained effects on microglia that over time lead to increased prevalence of dysfunctional microglia, adversely affecting neurons and blood vessels, and thereby driving neurodegeneration and memory decline.
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Affiliation(s)
- Marcia G Honig
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, USA
| | - Conor C Dorian
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, USA
| | - John D Worthen
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, USA
| | - Anthony C Micetich
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, USA
| | - Isabelle A Mulder
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, USA
| | - Katelyn B Sanchez
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, USA
| | - William F Pierce
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, USA
| | - Nobel A Del Mar
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, USA
| | - Anton Reiner
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, USA.,Department of Ophthalmology, The University of Tennessee Health Science Center, Memphis, TN, USA
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23
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A novel model of blast induced traumatic brain injury caused by compressed gas produced sustained cognitive deficits in rats: involvement of phosphorylation of tau at the Thr205 epitope. Brain Res Bull 2020; 157:149-161. [PMID: 32044361 DOI: 10.1016/j.brainresbull.2020.02.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 12/05/2019] [Accepted: 02/04/2020] [Indexed: 12/13/2022]
Abstract
Improvised explosive devices (IEDs) represent the leading causes for casualties among civilians and soldiers in the present war (including counter-terrorism). Traumatic brain injury (TBI) caused by IEDs results in different degrees of impairment of cognition and behavior, but the exact brain pathophysiological mechanism following exposure to blast has not been clearly investigated. Here, we sought to establish a rat model of closed-head blast injury using compressed gas to deliver a single blast only to the brain without systemic injuries. The cognitive functions of these bTBI models were assessed by Morris Water Maze test (MWM test). The HE staining, flow cytometry, ELISA and Western Blotting were used to measure the effects of shock wave on general histology, regulatory T (Treg) cells percentage, inflammatory reactions, the expression and phosphorylation level of tau, respectively. In addition, the brain water content and 24 -h mortality were also assessed. As the distance from the blast source increased, the input pressure did not change, the overpressure decreased, and the mortality decreased. Receiver operating characteristic (ROC) curves for predicting 24 -h mortality using peak overpressure fits with the following areas under ROC curves: 0.833. In 2 weeks after blast injury, cognitive tests revealed significantly decreased performance at 20 cm distance from the blast (about 136.44 kPa) as demonstrated by increased escape latency in the acquisition phase, and decreased crossing numbers in the probe phase of MWM test. Interestingly, a single blast exposure (at 20 cm) lead to significantly increased tau phosphorylation at the Thr205 epitope but not at the Ser404 and Ser262 epitopes at 12 h, 24 h, 3d, and 7d after blast injury. Blast decreased the percentage of CD4+T cells, CD8+T cells, Treg cells and lymphocytes at different time points after blast injury, and blast increased the percentage of neutrophils at 12 h after blast injury and significantly increased IL-6 production at 12 h, 24 h and 3d after blast injury. In addition, blast lead to an increase of brain edema at 24 h and 3d after blast injury. However, no obvious alterations in brain gross pathology were found acutely in the blast-exposed rats. In conclusion, we established a rat model of simple craniocerebral blast injury characterized by impairment of cognitive function, Thr205 phosphorylation of tau, decreased Treg cells and increased inflammatory reactions and brain edema. We expect this model may help clarify the underlying mechanism after blast injury and possibly serve as a useful animal model in the development of novel therapeutic and diagnostic approaches.
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24
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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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25
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Honig MG, Del Mar NA, Henderson DL, Ragsdale TD, Doty JB, Driver JH, Li C, Fortugno AP, Mitchell WM, Perry AM, Moore BM, Reiner A. Amelioration of visual deficits and visual system pathology after mild TBI via the cannabinoid Type-2 receptor inverse agonism of raloxifene. Exp Neurol 2019; 322:113063. [DOI: 10.1016/j.expneurol.2019.113063] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 08/09/2019] [Accepted: 09/07/2019] [Indexed: 11/29/2022]
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26
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Jha KA, Pentecost M, Lenin R, Gentry J, Klaic L, Del Mar N, Reiner A, Yang CH, Pfeffer LM, Sohl N, Gangaraju R. TSG-6 in conditioned media from adipose mesenchymal stem cells protects against visual deficits in mild traumatic brain injury model through neurovascular modulation. Stem Cell Res Ther 2019; 10:318. [PMID: 31690344 PMCID: PMC6833275 DOI: 10.1186/s13287-019-1436-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 09/21/2019] [Accepted: 09/30/2019] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Retinal inflammation affecting the neurovascular unit may play a role in the development of visual deficits following mild traumatic brain injury (mTBI). We have shown that concentrated conditioned media from adipose tissue-derived mesenchymal stem cells (ASC-CCM) can limit retinal damage from blast injury and improve visual function. In this study, we addressed the hypothesis that TNFα-stimulated gene-6 (TSG-6), an anti-inflammatory protein released by mesenchymal cells, mediates the observed therapeutic potential of ASCs via neurovascular modulation. METHODS About 12-week-old C57Bl/6 mice were subjected to 50-psi air pulse on the left side of the head overlying the forebrain resulting in an mTBI. Age-matched sham blast mice served as control. About 1 μl of ASC-CCM (siControl-ASC-CCM) or TSG-6 knockdown ASC-CCM (siTSG-6-ASC-CCM) was delivered intravitreally into both eyes. One month following injection, the ocular function was assessed followed by molecular and immunohistological analysis. In vitro, mouse microglial cells were used to evaluate the anti-inflammatory effect of ASC-CCM. Efficacy of ASC-CCM in normalizing retinal vascular permeability was assessed using trans-endothelial resistance (TER) and VE-cadherin expression in the presence of TNFα (1 ng/ml). RESULTS We show that intravitreal injection of ASC-CCM (siControl-ASC-CCM) but not the TSG-6 knockdown ASC-CCM (siTSG-6-ASC-CCM) mitigates the loss of visual acuity and contrast sensitivity, retinal expression of genes associated with microglial and endothelial activation, and retinal GFAP immunoreactivity at 4 weeks after blast injury. In vitro, siControl-ASC-CCM but not the siTSG-6-ASC-CCM not only suppressed microglial activation and STAT3 phosphorylation but also protected against TNFα-induced endothelial permeability as measured by transendothelial electrical resistance and decreased STAT3 phosphorylation. CONCLUSIONS Our findings suggest that ASCs respond to an inflammatory milieu by secreting higher levels of TSG-6 that mediates the resolution of the inflammatory cascade on multiple cell types and correlates with the therapeutic potency of the ASC-CCM. These results expand our understanding of innate mesenchymal cell function and confirm the importance of considering methods to increase the production of key analytes such as TSG-6 if mesenchymal stem cell secretome-derived biologics are to be developed as a treatment solution against the traumatic effects of blast injuries and other neurovascular inflammatory conditions of the retina.
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Affiliation(s)
- Kumar Abhiram Jha
- Department of Ophthalmology, University of Tennessee Health Science Center, College of Medicine, 930 Madison Ave, Suite#768, Memphis, TN, 38163, USA
| | - Mickey Pentecost
- Cell Care Therapeutics, Inc., Los Angeles, CA, USA.,Present Address: Pathways to Stem Cell Science, Monrovia, CA, USA
| | - Raji Lenin
- Department of Ophthalmology, University of Tennessee Health Science Center, College of Medicine, 930 Madison Ave, Suite#768, Memphis, TN, 38163, USA
| | - Jordy Gentry
- Department of Ophthalmology, University of Tennessee Health Science Center, College of Medicine, 930 Madison Ave, Suite#768, Memphis, TN, 38163, USA
| | - Lada Klaic
- Cell Care Therapeutics, Inc., Los Angeles, CA, USA
| | - Nobel Del Mar
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, College of Medicine, 855 Monroe Avenue, Suite#515, Memphis, TN, 38163, USA
| | - Anton Reiner
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, College of Medicine, 855 Monroe Avenue, Suite#515, Memphis, TN, 38163, USA
| | - Chuan He Yang
- Department of Pathology, University of Tennessee Health Science Center, College of Medicine, 19 South Manassas Street, Suite#214, Memphis, TN, 38163, USA
| | - Lawrence M Pfeffer
- Department of Pathology, University of Tennessee Health Science Center, College of Medicine, 19 South Manassas Street, Suite#214, Memphis, TN, 38163, USA
| | - Nicolas Sohl
- Cell Care Therapeutics, Inc., Los Angeles, CA, USA
| | - Rajashekhar Gangaraju
- Department of Ophthalmology, University of Tennessee Health Science Center, College of Medicine, 930 Madison Ave, Suite#768, Memphis, TN, 38163, USA. .,Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, College of Medicine, 855 Monroe Avenue, Suite#515, Memphis, TN, 38163, USA.
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27
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Guilhaume-Correa F, Cansler SM, Shalosky EM, Goodman MD, Evanson NK. Greater neurodegeneration and behavioral deficits after single closed head traumatic brain injury in adolescent versus adult male mice. J Neurosci Res 2019; 98:557-570. [PMID: 31541497 DOI: 10.1002/jnr.24535] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 09/06/2019] [Accepted: 09/09/2019] [Indexed: 12/28/2022]
Abstract
Traumatic brain injury (TBI) is a major public health concern affecting 2.8 million people per year in the United States, of whom about 1 million are children under 19 years old. Animal models of TBI have been developed and used in multiple ages of animals, but direct comparisons of adult and adolescent populations are rare. The current studies were undertaken to directly compare outcomes between adult and adolescent male mice, using a closed head, single-impact model of TBI. Six-week-old adolescent and 9-week-old adult male mice were subjected to mild-moderate TBI. Histological measures for neurodegeneration, gliosis, and microglial neuroinflammation, and behavioral tests of locomotion and memory were performed. Adolescent TBI mice have increased mortality (Χ2 = 20.72, p < 0.001) compared to adults. There is also evidence of hippocampal neurodegeneration in adolescents that is not present in adults. Hippocampal neurodegeneration correlates with histologic activation of microglia, but not with increased astrogliosis. Adults and adolescents have similar locomotion deficits after TBI that recover by 16 days postinjury. Adolescents have memory deficits as evidenced by impaired novel object recognition between 3-4 and 4-16 days postinjury (F1,26 = 5.23, p = 0.031) while adults do not. In conclusion, adults and adolescents within a close age range (6-9 weeks) respond to TBI differently. Adolescents are more severely affected by mortality, neurodegeneration, and inflammation in the hippocampus compared to adults. Adolescents, but not adults, have worse memory performance after TBI that lasts at least 16 days postinjury.
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Affiliation(s)
- Fernanda Guilhaume-Correa
- Division of Pediatric Rehabilitation Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Shelby M Cansler
- Division of Pediatric Rehabilitation Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Emily M Shalosky
- Department of Biological Sciences, University of Cincinnati, Cincinnati, Ohio
| | | | - Nathan K Evanson
- Division of Pediatric Rehabilitation Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.,Department of Pediatrics, University of Cincinnati, Cincinnati, Ohio
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28
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Bustamante MC, Cronin DS. Cavitation threshold evaluation of porcine cerebrospinal fluid using a Polymeric Split Hopkinson Pressure Bar-Confinement chamber apparatus. J Mech Behav Biomed Mater 2019; 100:103400. [PMID: 31476553 DOI: 10.1016/j.jmbbm.2019.103400] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 08/14/2019] [Accepted: 08/17/2019] [Indexed: 01/16/2023]
Abstract
Studies investigating mild Traumatic Brain Injury (mTBI) in the military population using experimental head surrogates and Finite Element (FE) head models have demonstrated the existence of transient negative pressures occurring within the head at the contrecoup location to the blast wave impingement. It has been hypothesized that this negative pressure may cause cavitation of cerebrospinal fluid (CSF) and possibly lead to brain tissue damage from cavitation bubble collapse. The cavitation pressure threshold of human CSF is presently unknown, although existing FE studies in the literature have assumed a value of -100 kPa. In the present study, the cavitation threshold of degassed porcine CSF at body temperature (37 °C) was measured using a unique modified Polymeric Split Hopkinson Pressure Bar apparatus, and compared to thresholds of distilled water at various conditions. The loading pulse generated in the apparatus was comparable to experimentally measured pressures resulting from blast exposure, and those predicted by an FE model. The occurrence of cavitation was identified using high-speed imaging and the corresponding pressures were determined using a computational model of the apparatus that was previously developed and validated. The probability of cavitation was calculated (ISO/TS, 18506) from forty-one experimental tests on porcine CSF, representing an upper bound for in vivo CSF. The 50% probability of cavitation for CSF (-0.467 MPa ± 7%) was lower than that of distilled water (-1.37 MPa ± 16%) under the same conditions. The lesser threshold of CSF could be related to the constituents such as blood cells and proteins. The results of this study can be used to inform FE head models subjected to blast exposure and improve prediction of the potential for CSF cavitation and response of brain tissue.
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Affiliation(s)
- M C Bustamante
- Department of Mechanical Engineering, University of Waterloo, 200 University Ave. W., Waterloo, ON, N2L3G1, Canada.
| | - D S Cronin
- Department of Mechanical Engineering, University of Waterloo, 200 University Ave. W., Waterloo, ON, N2L3G1, Canada.
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29
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Reduced avoidance coping in male, but not in female rats, after mild traumatic brain injury: Implications for depression. Behav Brain Res 2019; 373:112064. [PMID: 31278968 DOI: 10.1016/j.bbr.2019.112064] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 06/27/2019] [Accepted: 06/27/2019] [Indexed: 12/17/2022]
Abstract
Although there is evidence that traumatic brain injury (mTBI) induces emotional sequelae in rats, it is unclear whether the phenotype is reminiscent of major depressive disorder (MDD) or posttraumatic stress disorder (PTSD). Three behavioral protocols with oppositional indicators for MDD or PTSD were assessed: acoustic startle responses (ASRs), eyeblink conditioning, and instrumental escape/avoidance (E/A) learning. Female and male rats were exposed to lateral fluid percussion injury (LFPi) consistent with mild TBI (mTBI) or sham (SHAM) surgery. Experiment 1 suggested that the acquisition of the classically conditioned eyeblink responses was unaffected by mTBI infemale and male rats. In Experiment 2, male and female mTBI rats acquired instrumental escape responses similar to their SHAM counterparts. Avoidance expression of female mTBI rats did not differ appreciably from female SHAM rats. However, male mTBI rats expressed avoidance at a lower rate than male SHAM rats over training. Poor coping in male rats emerged with repeated exposure to stress, suggesting that depressive behaviors in mTBI develop over time and with continued demand from stress. Severely attenuated ASRs were evident in female and male mTBI rats compared to respective SHAM rats throughout testing across the two experiments. Overall, signs among the three bidirectional assessments during the subacute period after mTBI were more indicative of MDD-like, than PTSD-like sequelae.
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30
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Guley NM, Del Mar NA, Ragsdale T, Li C, Perry AM, Moore BM, Honig MG, Reiner A. Amelioration of visual deficits and visual system pathology after mild TBI with the cannabinoid type-2 receptor inverse agonist SMM-189. Exp Eye Res 2019; 182:109-124. [PMID: 30922891 DOI: 10.1016/j.exer.2019.03.013] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 03/11/2019] [Accepted: 03/19/2019] [Indexed: 12/20/2022]
Abstract
Mild TBI is often accompanied by visual system dysfunction and injury, which is at least partly caused by microglial neuroinflammatory processes initiated by the injury. Using our focal cranial blast mouse model of closed-skull mild TBI, we evaluated the ability of the cannabinoid type-2 (CB2) receptor inverse agonist SMM-189, which biases microglia from the harmful M1 state to the beneficial M2 state, to mitigate visual system dysfunction and injury after TBI. Male C57BL/6 or Thy1-EYFP reporter mice received a closed-head blast of either 0-psi (sham) or 50-psi to the left side of the cranium. Blast mice received vehicle or 6 mg/kg SMM-189 daily beginning 2 h after blast. Sham mice received vehicle. In some mice, retina and optic nerve/tract were assessed morphologically at 3-7 days after blast, while other mice were assessed functionally by Optomotry 30 days after blast and morphologically at ≥30 days after blast. Mice sacrificed at 3-7 days were treated daily until sacrificed, while those assessed ≥30 days after blast were treated daily for 2 weeks post blast. Axon damage was evident in the left optic nerve and its continuation as the right optic tract at 3 days post blast in vehicle-treated blast mice in the form of swollen axon bulbs, and was accompanied by a significant increase in the abundance of microglia. Testing at 30 days post blast revealed that the contrast sensitivity function was significantly reduced in both eyes in vehicle-treated blast mice compared to vehicle-treated sham blast mice, and axon counts at ≥30 days after blast revealed a ∼10% loss in left optic nerve in vehicle-treated blast mice. Left optic nerve axon loss was highly correlated with the left eye deficit in contrast sensitivity. Immunolabeling at 30 days post blast showed a significant increase in the abundance of microglia in the retinas of both eyes and in GFAP + Müller cell processes traversing the inner plexiform layer in the left eye of vehicle-treated blast mice. SMM-189 treatment reduced axon injury and microglial abundance at 3 days, and mitigated axon loss, contrast sensitivity deficits, microglial abundance, and Müller cell GFAP upregulation at ≥30 days after blast injury. Analysis of right optic tract microglia at 3 days post blast for M1 versus M2 markers revealed that SMM-189 biased microglia toward the M2 state, with this action of SMM-189 being linked to reduced axonal injury. Taken together, our results show that focal left side cranial blast resulted in impaired contrast sensitivity and retinal pathology bilaterally and optic nerve loss ipsilaterally. The novel cannabinoid drug SMM-189 significantly mitigated the functional deficit and the associated pathologies. Our findings suggest the value of combatting visual system injury after TBI by using CB2 inverse agonists such as SMM-189, which appear to target microglia and bias them away from the pro-inflammatory M1 state, toward the protective M2 state.
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Affiliation(s)
- Natalie M Guley
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN 38163, United States
| | - Nobel A Del Mar
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN 38163, United States
| | - Tyler Ragsdale
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN 38163, United States
| | - Chunyan Li
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN 38163, United States
| | - Aaron M Perry
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN 38163, United States
| | - Bob M Moore
- Dept. of Pharmaceutical Sciences, The University of Tennessee Health Science Center, Memphis, TN 38163, United States
| | - Marcia G Honig
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN 38163, United States
| | - Anton Reiner
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN 38163, United States; Department of Ophthalmology, The University of Tennessee Health Science Center, Memphis, TN 38163, United States.
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31
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Assessment of Fluid Cavitation Threshold Using a Polymeric Split Hopkinson Bar-Confinement Chamber Apparatus. CONFERENCE PROCEEDINGS OF THE SOCIETY FOR EXPERIMENTAL MECHANICS SERIES 2019. [DOI: 10.1007/978-3-319-95062-4_21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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32
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Clark AL, Merritt VC, Bigler ED, Bangen KJ, Werhane M, Sorg SF, Bondi MW, Schiehser DM, Delano-Wood L. Blast-Exposed Veterans With Mild Traumatic Brain Injury Show Greater Frontal Cortical Thinning and Poorer Executive Functioning. Front Neurol 2018; 9:873. [PMID: 30473678 PMCID: PMC6237912 DOI: 10.3389/fneur.2018.00873] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 09/27/2018] [Indexed: 11/13/2022] Open
Abstract
Objective: Blast exposure (BE) and mild traumatic brain injury (mTBI) have been independently linked to pathological brain changes. However, the combined effects of BE and mTBI on brain structure have yet to be characterized. Therefore, we investigated whether regional differences in cortical thickness exist between mTBI Veterans with and without BE while on deployment. We also examined whether cortical thickness (CT) and cognitive performance differed among mTBI Veterans with low vs. high levels of cumulative BE. Methods: 80 Veterans with mTBI underwent neuroimaging and completed neuropsychological testing and self-report symptom rating scales. Analyses of covariance (ANCOVA) were used to compare blast-exposed Veterans (mTBI+BE, n = 51) to those without BE (mTBI-BE, n = 29) on CT of frontal and temporal a priori regions of interest (ROIs). Next, multiple regression analyses were used to examine whether CT and performance on an executive functions composite differed among mTBI Veterans with low (mTBI+BE Low, n = 22) vs. high (mTBI+BE High, n = 26) levels of cumulative BE. Results: Adjusting for age, numer of TBIs, and PTSD symptoms, the mTBI+BE group showed significant cortical thinning in frontal regions (i.e., left orbitofrontal cortex [p = 0.045], left middle frontal gyrus [p = 0.023], and right inferior frontal gyrus [p = 0.034]) compared to the mTBI-BE group. No significant group differences in CT were observed for temporal regions (p's > 0.05). Multiple regression analyses revealed a significant cumulative BE × CT interaction for the left orbitofrontal cortex (p = 0.001) and left middle frontal gyrus (p = 0.020); reduced CT was associated with worse cognitive performance in the mTBI+BE High group but not the mTBI+BE Low group. Conclusions: Findings show that Veterans with mTBI and BE may be at risk for cortical thinning post-deployment. Moreover, our results demonstrate that reductions in CT are associated with worse executive functioning among Veterans with high levels of cumulative BE. Future longitudinal studies are needed to determine whether BE exacerbates mTBI-related cortical thinning or independently negatively influences gray matter structure.
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Affiliation(s)
- Alexandra L. Clark
- San Diego State University/University of California, San Diego (SDSU/UCSD) Joint Doctoral Program in Clinical Psychology, San Diego State University, University of California, San Diego, San Diego, CA, United States
- VA San Diego Healthcare System, San Diego, CA, United States
| | | | - Erin D. Bigler
- Department of Psychology and the Neuroscience Center, Brigham and Young University, San Diego, CA, United States
| | - Katherine J. Bangen
- VA San Diego Healthcare System, San Diego, CA, United States
- Department of Psychiatry, School of Medicine, University of California, San Diego, San Diego, CA, United States
| | - Madeleine Werhane
- San Diego State University/University of California, San Diego (SDSU/UCSD) Joint Doctoral Program in Clinical Psychology, San Diego State University, University of California, San Diego, San Diego, CA, United States
- VA San Diego Healthcare System, San Diego, CA, United States
| | - Scott F. Sorg
- VA San Diego Healthcare System, San Diego, CA, United States
- Department of Psychiatry, School of Medicine, University of California, San Diego, San Diego, CA, United States
| | - Mark W. Bondi
- VA San Diego Healthcare System, San Diego, CA, United States
- Department of Psychiatry, School of Medicine, University of California, San Diego, San Diego, CA, United States
| | - Dawn M. Schiehser
- VA San Diego Healthcare System, San Diego, CA, United States
- Department of Psychiatry, School of Medicine, University of California, San Diego, San Diego, CA, United States
- Center of Excellence for Stress and Mental Health, VA San Diego Healthcare System, San Diego, CA, United States
| | - Lisa Delano-Wood
- VA San Diego Healthcare System, San Diego, CA, United States
- Department of Psychiatry, School of Medicine, University of California, San Diego, San Diego, CA, United States
- Center of Excellence for Stress and Mental Health, VA San Diego Healthcare System, San Diego, CA, United States
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Gilman TL, Dutta S, Adkins JM, Cecil CA, Jasnow AM. Basolateral amygdala Thy1-expressing neurons facilitate the inhibition of contextual fear during consolidation, reconsolidation, and extinction. Neurobiol Learn Mem 2018; 155:498-507. [PMID: 30287384 DOI: 10.1016/j.nlm.2018.09.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 08/15/2018] [Accepted: 09/26/2018] [Indexed: 12/29/2022]
Abstract
Disrupted fear inhibition is a characteristic of many anxiety disorders. Investigations into the neural mechanisms responsible for inhibiting fear will improve understanding of the essential circuits involved, and facilitate development of treatments that promote their activity. Within the basolateral amygdala (BLA), Thy1-expressing neuron activity has been characterized by us and others as promoting fear inhibition to discrete fear cues by influencing consolidation of cued fear learning or cued fear extinction. Here, we evaluated how activating BLA Thy1-expressing neurons using DREADDs affected the consolidation, expression, reconsolidation, and extinction of contextual fear. Using an inhibitory avoidance paradigm, our present findings indicate a similar involvement of BLA Thy1-expressing neuron activity in the consolidation and extinction, but not expression, of fear. Importantly, our data also provide the first evidence for involvement of these neurons in inhibiting fear reconsolidation. Therefore, these data enhance our understanding of the roles that Thy1-expressing neurons within the BLA play in inhibiting fear when examining avoidance, in addition to the already established role in Pavlovian fear paradigms. Future investigations should further explore the circuits responsible for these contextual effects modulated by BLA Thy1 neuron activation, and could promulgate development of therapies targeting these neurons and their downstream effectors.
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Affiliation(s)
- T Lee Gilman
- Department of Psychological Sciences and Brain Health Research Institute, 144 Kent Hall, Kent State University, Kent, OH 44242, USA.
| | - Sohini Dutta
- Department of Psychological Sciences and Brain Health Research Institute, 144 Kent Hall, Kent State University, Kent, OH 44242, USA.
| | - Jordan M Adkins
- Department of Psychological Sciences and Brain Health Research Institute, 144 Kent Hall, Kent State University, Kent, OH 44242, USA.
| | - Cassandra A Cecil
- Department of Psychological Sciences and Brain Health Research Institute, 144 Kent Hall, Kent State University, Kent, OH 44242, USA.
| | - Aaron M Jasnow
- Department of Psychological Sciences and Brain Health Research Institute, 144 Kent Hall, Kent State University, Kent, OH 44242, USA.
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Russell AL, Tasker JG, Lucion AB, Fiedler J, Munhoz CD, Wu TYJ, Deak T. Factors promoting vulnerability to dysregulated stress reactivity and stress-related disease. J Neuroendocrinol 2018; 30:e12641. [PMID: 30144202 PMCID: PMC6181794 DOI: 10.1111/jne.12641] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 08/07/2018] [Accepted: 08/21/2018] [Indexed: 12/18/2022]
Abstract
Effective coordination of the biological stress response is integral for the behavioural well-being of an organism. Stress reactivity is coordinated by an interplay of the neuroendocrine system and the sympathetic nervous system. The hypothalamic-pituitary-adrenal (HPA) axis plays a key role in orchestrating the bodily responses to stress, and the activity of the axis can be modified by a wide range of experiential events. This review focuses on several factors that influence subsequent HPA axis reactivity. Some of these factors include early-life adversity, exposure to chronic stress, immune activation and traumatic brain injury. The central premise is that each of these experiences serves as a general vulnerability factor that accelerates future HPA axis reactivity in ways that make individuals more sensitive to stress challenges, therefore feeding forward into the exacerbation of ongoing (or greater susceptibility toward) future stress-related disease states, especially as they pertain to negative affect and overall brain health.
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Affiliation(s)
- Ashley L Russell
- Program in Neuroscience, Uniformed Services University, Bethesda, Maryland
- Center for Neuroscience and Regenerative Medicine, Bethesda, Maryland
| | - Jeffrey G Tasker
- Department of Cell and Molecular Biology, Tulane University, New Orleans, Los Angeles
| | - Aldo B Lucion
- Department of Physiology, Institute of Basic Health Sciences (ICBS), Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, Rio Grande do Sul, Brazil
| | - Jenny Fiedler
- Department of Biochemistry and Molecular Biology, Chemical and Pharmaceutical Sciences Faculty, Universidad de Chile, Santiago, Chile
| | - Carolina D Munhoz
- Deparment of Pharmacology, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil
| | - Tao-Yiao John Wu
- Program in Neuroscience, Uniformed Services University, Bethesda, Maryland
- Center for Neuroscience and Regenerative Medicine, Bethesda, Maryland
- Department of Obstetrics and Gynecology, Uniformed Services University of the Health Sciences, Bethesda, Maryland
| | - Terrence Deak
- Developmental Exposure Alcohol Research Center (DEARC), Department of Psychology, Behavioral Neuroscience Program, Binghamton University, Binghamton, New York
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Semple BD, Zamani A, Rayner G, Shultz SR, Jones NC. Affective, neurocognitive and psychosocial disorders associated with traumatic brain injury and post-traumatic epilepsy. Neurobiol Dis 2018; 123:27-41. [PMID: 30059725 DOI: 10.1016/j.nbd.2018.07.018] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2018] [Revised: 07/08/2018] [Accepted: 07/16/2018] [Indexed: 12/13/2022] Open
Abstract
Survivors of traumatic brain injury (TBI) often develop chronic neurological, neurocognitive, psychological, and psychosocial deficits that can have a profound impact on an individual's wellbeing and quality of life. TBI is also a common cause of acquired epilepsy, which is itself associated with significant behavioral morbidity. This review considers the clinical and preclinical evidence that post-traumatic epilepsy (PTE) acts as a 'second-hit' insult to worsen chronic behavioral outcomes for brain-injured patients, across the domains of emotional, cognitive, and psychosocial functioning. Surprisingly, few well-designed studies have specifically examined the relationship between seizures and behavioral outcomes after TBI. The complex mechanisms underlying these comorbidities remain incompletely understood, although many of the biological processes that precipitate seizure occurrence and epileptogenesis may also contribute to the development of chronic behavioral deficits. Further, the relationship between PTE and behavioral dysfunction is increasingly recognized to be a bidirectional one, whereby premorbid conditions are a risk factor for PTE. Clinical studies in this arena are often challenged by the confounding effects of anti-seizure medications, while preclinical studies have rarely examined an adequately extended time course to fully capture the time course of epilepsy development after a TBI. To drive the field forward towards improved treatment strategies, it is imperative that both seizures and neurobehavioral outcomes are assessed in parallel after TBI, both in patient populations and preclinical models.
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Affiliation(s)
- Bridgette D Semple
- Department of Neuroscience, Monash University, 99 Commercial Road, Melbourne, VIC, Australia; Department of Medicine (Royal Melbourne Hospital), The University of Melbourne, Royal Parade, Parkville, VIC, Australia.
| | - Akram Zamani
- Department of Neuroscience, Monash University, 99 Commercial Road, Melbourne, VIC, Australia.
| | - Genevieve Rayner
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre (Austin Campus), Heidelberg, VIC, Australia; Melbourne School of Psychological Sciences, The University of Melbourne, Parkville, VIC, Australia; Comprehensive Epilepsy Program, Alfred Health, Australia.
| | - Sandy R Shultz
- Department of Neuroscience, Monash University, 99 Commercial Road, Melbourne, VIC, Australia; Department of Medicine (Royal Melbourne Hospital), The University of Melbourne, Royal Parade, Parkville, VIC, Australia.
| | - Nigel C Jones
- Department of Neuroscience, Monash University, 99 Commercial Road, Melbourne, VIC, Australia; Department of Medicine (Royal Melbourne Hospital), The University of Melbourne, Royal Parade, Parkville, VIC, Australia.
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Hemostatic nanoparticles increase survival, mitigate neuropathology and alleviate anxiety in a rodent blast trauma model. Sci Rep 2018; 8:10622. [PMID: 30006635 PMCID: PMC6045585 DOI: 10.1038/s41598-018-28848-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 06/21/2018] [Indexed: 12/22/2022] Open
Abstract
Explosions account for 79% of combat related injuries and often lead to polytrauma, a majority of which include blast-induced traumatic brain injuries (bTBI). These injuries lead to internal bleeding in multiple organs and, in the case of bTBI, long term neurological deficits. Currently, there are no treatments for internal bleeding beyond fluid resuscitation and surgery. There is also a dearth of treatments for TBI. We have developed a novel approach using hemostatic nanoparticles that encapsulate an anti-inflammatory, dexamethasone, to stop the bleeding and reduce inflammation after injury. We hypothesize that this will improve not only survival but long term functional outcomes after blast polytrauma. Poly(lactic-co-glycolic acid) hemostatic nanoparticles encapsulating dexamethasone (hDNPs) were fabricated and tested following injury along with appropriate controls. Rats were exposed to a single blast wave using an Advanced Blast Simulator, inducing primary blast lung and bTBI. Survival was elevated in the hDNPs group compared to controls. Elevated anxiety parameters were found in the controls, compared to hDNPs. Histological analysis indicated that apoptosis and blood-brain barrier disruption in the amygdala were significantly increased in the controls compared to the hDNPs and sham groups. Immediate intervention is crucial to mitigate injury mechanisms that contribute to emotional deficits.
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Concentrated Conditioned Media from Adipose Tissue Derived Mesenchymal Stem Cells Mitigates Visual Deficits and Retinal Inflammation Following Mild Traumatic Brain Injury. Int J Mol Sci 2018; 19:ijms19072016. [PMID: 29997321 PMCID: PMC6073664 DOI: 10.3390/ijms19072016] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 07/03/2018] [Accepted: 07/09/2018] [Indexed: 02/08/2023] Open
Abstract
Blast concussions are a common injury sustained in military combat today. Inflammation due to microglial polarization can drive the development of visual defects following blast injuries. In this study, we assessed whether anti-inflammatory factors released by the mesenchymal stem cells derived from adipose tissue (adipose stem cells, ASC) can limit retinal tissue damage and improve visual function in a mouse model of visual deficits following mild traumatic brain injury. We show that intravitreal injection of 1 μL of ASC concentrated conditioned medium from cells pre-stimulated with inflammatory cytokines (ASC-CCM) mitigates loss of visual acuity and contrast sensitivity four weeks post blast injury. Moreover, blast mice showed increased retinal expression of genes associated with microglial activation and inflammation by molecular analyses, retinal glial fibrillary acidic protein (GFAP) immunoreactivity, and increased loss of ganglion cells. Interestingly, blast mice that received ASC-CCM improved in all parameters above. In vitro, ASC-CCM not only suppressed microglial activation but also protected against Tumor necrosis alpha (TNFα) induced endothelial permeability as measured by transendothelial electrical resistance. Biochemical and molecular analyses demonstrate TSG-6 is highly expressed in ASC-CCM from cells pre-stimulated with TNFα and IFNγ but not from unstimulated cells. Our findings suggest that ASC-CCM mitigates visual deficits of the blast injury through their anti-inflammatory properties on activated pro-inflammatory microglia and endothelial cells. A regenerative therapy for immediate delivery at the time of injury may provide a practical and cost-effective solution against the traumatic effects of blast injuries to the retina.
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Hansen KR, DeWalt GJ, Mohammed AI, Tseng HA, Abdulkerim ME, Bensussen S, Saligrama V, Nazer B, Eldred WD, Han X. Mild Blast Injury Produces Acute Changes in Basal Intracellular Calcium Levels and Activity Patterns in Mouse Hippocampal Neurons. J Neurotrauma 2018; 35:1523-1536. [PMID: 29343209 PMCID: PMC5998839 DOI: 10.1089/neu.2017.5029] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Mild traumatic brain injury (mTBI) represents a serious public health concern. Although much is understood about long-term changes in cell signaling and anatomical pathologies associated with mTBI, little is known about acute changes in neuronal function. Using large scale Ca2+ imaging in vivo, we characterized the intracellular Ca2+ dynamics in thousands of individual hippocampal neurons using a repetitive mild blast injury model in which blasts were directed onto the cranium of unanesthetized mice on two consecutive days. Immediately following each blast event, neurons exhibited two types of changes in Ca2+ dynamics at different time scales. One was a reduction in slow Ca2+ dynamics that corresponded to shifts in basal intracellular Ca2+ levels at a time scale of minutes, suggesting a disruption of biochemical signaling. The second was a reduction in the rates of fast transient Ca2+ fluctuations at the sub-second time scale, which are known to be closely linked to neural activity. Interestingly, the blast-induced changes in basal Ca2+ levels were independent of the changes in the rates of fast Ca2+ transients, suggesting that blasts had heterogeneous effects on different cell populations. Both types of changes recovered after ∼1 h. Together, our results demonstrate that mTBI induced acute, heterogeneous changes in neuronal function, altering intracellular Ca2+ dynamics across different time scales, which may contribute to the initiation of longer-term pathologies.
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Affiliation(s)
- Kyle R. Hansen
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts
| | | | - Ali I. Mohammed
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts
| | - Hua-an Tseng
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts
| | - Moona E. Abdulkerim
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts
| | - Seth Bensussen
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts
| | - Venkatesh Saligrama
- Department of Electrical and Computer Engineering, Boston University, Boston, Massachusetts
| | - Bobak Nazer
- Department of Electrical and Computer Engineering, Boston University, Boston, Massachusetts
| | | | - Xue Han
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts
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Preliminary Study of Diffusion Kurtosis Imaging in Mild Traumatic Brain Injury. IRANIAN JOURNAL OF RADIOLOGY 2018. [DOI: 10.5812/iranjradiol.56115] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Evanson NK, Guilhaume-Correa F, Herman JP, Goodman MD. Optic tract injury after closed head traumatic brain injury in mice: A model of indirect traumatic optic neuropathy. PLoS One 2018; 13:e0197346. [PMID: 29746557 PMCID: PMC5944994 DOI: 10.1371/journal.pone.0197346] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 05/01/2018] [Indexed: 12/14/2022] Open
Abstract
Adult male C57BL/6J mice have previously been reported to have motor and memory deficits after experimental closed head traumatic brain injury (TBI), without associated gross pathologic damage or neuroimaging changes detectable by magnetic resonance imaging or diffusion tensor imaging protocols. The presence of neurologic deficits, however, suggests neural damage or dysfunction in these animals. Accordingly, we undertook a histologic analysis of mice after TBI. Gross pathology and histologic analysis using Nissl stain and NeuN immunohistochemistry demonstrated no obvious tissue damage or neuron loss. However, Luxol Fast Blue stain revealed myelin injury in the optic tract, while Fluoro Jade B and silver degeneration staining revealed evidence of axonal neurodegeneration in the optic tract as well as the lateral geniculate nucleus of the thalamus and superior colliculus (detectable at 7 days, but not 24 hours, after injury). Fluoro Jade B staining was not detectable in other white matter tracts, brain regions or in cell somata. In addition, there was increased GFAP staining in these optic tract, lateral geniculate, and superior colliculus 7 days post-injury, and morphologic changes in optic tract microglia that were detectable 24 hours after injury but were more prominent 7 days post-injury. Interestingly, there were no findings of degeneration or gliosis in the suprachiasmatic nucleus, which is also heavily innervated by the optic tract. Using micro-computed tomography imaging, we also found that the optic canal appears to decrease in diameter with a dorsal-ventral load on the skull, which suggests that the optic canal may be the site of injury. These results suggest that there is axonal degeneration in the optic tract and a subset of directly innervated areas, with associated neuroinflammation and astrocytosis, which develop within 7 days of injury, and also suggest that this weight drop injury may be a model for studying indirect traumatic optic neuropathy.
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Affiliation(s)
- Nathan K. Evanson
- Division of Pediatric Rehabilitation Medicine, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
- Department of Pediatrics, University of Cincinnati, Cincinnati, Ohio, United States of America
- * E-mail:
| | - Fernanda Guilhaume-Correa
- Division of Pediatric Rehabilitation Medicine, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
| | - James P. Herman
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Michael D. Goodman
- Department of Surgery, University of Cincinnati, Cincinnati, Ohio, United States of America
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41
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Perez-Garcia G, Gama Sosa MA, De Gasperi R, Lashof-Sullivan M, Maudlin-Jeronimo E, Stone JR, Haghighi F, Ahlers ST, Elder GA. Chronic post-traumatic stress disorder-related traits in a rat model of low-level blast exposure. Behav Brain Res 2018; 340:117-125. [DOI: 10.1016/j.bbr.2016.09.061] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 09/25/2016] [Accepted: 09/26/2016] [Indexed: 01/01/2023]
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42
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Song H, Cui J, Simonyi A, Johnson CE, Hubler GK, DePalma RG, Gu Z. Linking blast physics to biological outcomes in mild traumatic brain injury: Narrative review and preliminary report of an open-field blast model. Behav Brain Res 2018; 340:147-158. [DOI: 10.1016/j.bbr.2016.08.037] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 08/13/2016] [Accepted: 08/19/2016] [Indexed: 12/14/2022]
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de la Tremblaye PB, O'Neil DA, LaPorte MJ, Cheng JP, Beitchman JA, Thomas TC, Bondi CO, Kline AE. Elucidating opportunities and pitfalls in the treatment of experimental traumatic brain injury to optimize and facilitate clinical translation. Neurosci Biobehav Rev 2018; 85:160-175. [PMID: 28576511 PMCID: PMC5709241 DOI: 10.1016/j.neubiorev.2017.05.022] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 05/12/2017] [Indexed: 12/19/2022]
Abstract
The aim of this review is to discuss the research presented in a symposium entitled "Current progress in characterizing therapeutic strategies and challenges in experimental CNS injury" which was presented at the 2016 International Behavioral Neuroscience Society annual meeting. Herein we discuss diffuse and focal traumatic brain injury (TBI) and ensuing chronic behavioral deficits as well as potential rehabilitative approaches. We also discuss the effects of stress on executive function after TBI as well as the response of the endocrine system and regulatory feedback mechanisms. The role of the endocannabinoids after CNS injury is also discussed. Finally, we conclude with a discussion of antipsychotic and antiepileptic drugs, which are provided to control TBI-induced agitation and seizures, respectively. The review consists predominantly of published data.
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Affiliation(s)
- Patricia B de la Tremblaye
- Department of Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA, United States; Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA, United States
| | - Darik A O'Neil
- Department of Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA, United States; Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA, United States
| | - Megan J LaPorte
- Department of Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA, United States; Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA, United States
| | - Jeffrey P Cheng
- Department of Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA, United States; Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA, United States
| | - Joshua A Beitchman
- Barrow Neurological Institute at Phoenix Children's Hospital, Phoenix, AZ, United States; Department of Child Health, University of Arizona College of Medicine, Phoenix, AZ, United States; Midwestern University, Glendale, AZ, United States
| | - Theresa Currier Thomas
- Barrow Neurological Institute at Phoenix Children's Hospital, Phoenix, AZ, United States; Department of Child Health, University of Arizona College of Medicine, Phoenix, AZ, United States; Phoenix VA Healthcare System, Phoenix, AZ, United States
| | - Corina O Bondi
- Department of Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA, United States; Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA, United States; Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, United States; Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA, United States
| | - Anthony E Kline
- Department of Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA, United States; Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA, United States; Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, United States; Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, United States; Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, United States; Department of Psychology, University of Pittsburgh, Pittsburgh, PA, United States.
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Abnormalities in Dynamic Brain Activity Caused by Mild Traumatic Brain Injury Are Partially Rescued by the Cannabinoid Type-2 Receptor Inverse Agonist SMM-189. eNeuro 2017; 4:eN-NWR-0387-16. [PMID: 28828401 PMCID: PMC5562300 DOI: 10.1523/eneuro.0387-16.2017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 06/26/2017] [Accepted: 07/03/2017] [Indexed: 12/23/2022] Open
Abstract
Mild traumatic brain injury (mTBI) can cause severe long-term cognitive and emotional deficits, including impaired memory, depression, and persevering fear, but the neuropathological basis of these deficits is uncertain. As medial prefrontal cortex (mPFC) and hippocampus play important roles in memory and emotion, we used multi-site, multi-electrode recordings of oscillatory neuronal activity in local field potentials (LFPs) in awake, head-fixed mice to determine if the functioning of these regions was abnormal after mTBI, using a closed-skull focal cranial blast model. We evaluated mPFC, hippocampus CA1, and primary somatosensory/visual cortical areas (S1/V1). Although mTBI did not alter the power of oscillations, it did cause increased coherence of θ (4-10 Hz) and β (10-30 Hz) oscillations within mPFC and S1/V1, reduced CA1 sharp-wave ripple (SWR)-evoked LFP activity in mPFC, downshifted SWR frequencies in CA1, and enhanced θ-γ phase-amplitude coupling (PAC) within mPFC. These abnormalities might be linked to the impaired memory, depression, and persevering fear seen after mTBI. Treatment with the cannabinoid type-2 (CB2) receptor inverse agonist SMM-189 has been shown to mitigate functional deficits and neuronal injury after mTBI in mice. We found that SMM-189 also reversed most of the observed neurophysiological abnormalities. This neurophysiological rescue is likely to stem from the previously reported reduction in neuron loss and/or the preservation of neuronal function and connectivity resulting from SMM-189 treatment, which appears to stem from the biasing of microglia from the proinflammatory M1 state to the prohealing M2 state by SMM-189.
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Ouyang J, Pace E, Lepczyk L, Kaufman M, Zhang J, Perrine SA, Zhang J. Blast-Induced Tinnitus and Elevated Central Auditory and Limbic Activity in Rats: A Manganese-Enhanced MRI and Behavioral Study. Sci Rep 2017; 7:4852. [PMID: 28687812 PMCID: PMC5501813 DOI: 10.1038/s41598-017-04941-w] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 04/27/2017] [Indexed: 02/06/2023] Open
Abstract
Blast-induced tinitus is the number one service-connected disability that currently affects military personnel and veterans. To elucidate its underlying mechanisms, we subjected 13 Sprague Dawley adult rats to unilateral 14 psi blast exposure to induce tinnitus and measured auditory and limbic brain activity using manganese-enhanced MRI (MEMRI). Tinnitus was evaluated with a gap detection acoustic startle reflex paradigm, while hearing status was assessed with prepulse inhibition (PPI) and auditory brainstem responses (ABRs). Both anxiety and cognitive functioning were assessed using elevated plus maze and Morris water maze, respectively. Five weeks after blast exposure, 8 of the 13 blasted rats exhibited chronic tinnitus. While acoustic PPI remained intact and ABR thresholds recovered, the ABR wave P1-N1 amplitude reduction persisted in all blast-exposed rats. No differences in spatial cognition were observed, but blasted rats as a whole exhibited increased anxiety. MEMRI data revealed a bilateral increase in activity along the auditory pathway and in certain limbic regions of rats with tinnitus compared to age-matched controls. Taken together, our data suggest that while blast-induced tinnitus may play a role in auditory and limbic hyperactivity, the non-auditory effects of blast and potential traumatic brain injury may also exert an effect.
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Affiliation(s)
- Jessica Ouyang
- Department of Otolaryngology and Head and Neck Surgery, Wayne State University School of Medicine, Detroit, MI, 48201, USA
| | - Edward Pace
- Department of Otolaryngology and Head and Neck Surgery, Wayne State University School of Medicine, Detroit, MI, 48201, USA
| | - Laura Lepczyk
- Department of Otolaryngology and Head and Neck Surgery, Wayne State University School of Medicine, Detroit, MI, 48201, USA
| | - Michael Kaufman
- Department of Otolaryngology and Head and Neck Surgery, Wayne State University School of Medicine, Detroit, MI, 48201, USA
| | - Jessica Zhang
- Department of Otolaryngology and Head and Neck Surgery, Wayne State University School of Medicine, Detroit, MI, 48201, USA
| | - Shane A Perrine
- Department of Psychiatry and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit, MI, 48201, USA
| | - Jinsheng Zhang
- Department of Otolaryngology and Head and Neck Surgery, Wayne State University School of Medicine, Detroit, MI, 48201, USA.
- Department of Communication Sciences & Disorders, Wayne State University College of Liberal Arts and Sciences, Detroit, MI, 48201, USA.
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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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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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Distinguishing the Unique Neuropathological Profile of Blast Polytrauma. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:5175249. [PMID: 28424745 PMCID: PMC5382305 DOI: 10.1155/2017/5175249] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 02/28/2017] [Indexed: 12/16/2022]
Abstract
Traumatic brain injury sustained after blast exposure (blast-induced TBI) has recently been documented as a growing issue for military personnel. Incidence of injury to organs such as the lungs has decreased, though current epidemiology still causes a great public health burden. In addition, unprotected civilians sustain primary blast lung injury (PBLI) at alarming rates. Often, mild-to-moderate cases of PBLI are survivable with medical intervention, which creates a growing population of survivors of blast-induced polytrauma (BPT) with symptoms from blast-induced mild TBI (mTBI). Currently, there is a lack of preclinical models simulating BPT, which is crucial to identifying unique injury mechanisms of BPT and its management. To meet this need, our group characterized a rodent model of BPT and compared results to a blast-induced mTBI model. Open field (OF) performance trials were performed on rodents at 7 days after injury. Immunohistochemistry was performed to evaluate cellular outcome at day seven following BPT. Levels of reactive astrocytes (GFAP), apoptosis (cleaved caspase-3 expression), and vascular damage (SMI-71) were significantly elevated in BPT compared to blast-induced mTBI. Downstream markers of hypoxia (HIF-1α and VEGF) were higher only after BPT. This study highlights the need for unique therapeutics and prehospital management when handling BPT.
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Race N, Lai J, Shi R, Bartlett EL. Differences in postinjury auditory system pathophysiology after mild blast and nonblast acute acoustic trauma. J Neurophysiol 2017; 118:782-799. [PMID: 28275059 DOI: 10.1152/jn.00710.2016] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 03/02/2017] [Accepted: 03/02/2017] [Indexed: 01/05/2023] Open
Abstract
Hearing difficulties are the most commonly reported disabilities among veterans. Blast exposures during explosive events likely play a role, given their propensity to directly damage both peripheral (PAS) and central auditory system (CAS) components. Postblast PAS pathophysiology has been well documented in both clinical case reports and laboratory investigations. In contrast, blast-induced CAS dysfunction remains understudied but has been hypothesized to contribute to an array of common veteran behavioral complaints, including learning, memory, communication, and emotional regulation. This investigation compared the effects of acute blast and nonblast acoustic impulse trauma in adult male Sprague-Dawley rats. An array of audiometric tests were utilized, including distortion product otoacoustic emissions (DPOAE), auditory brain stem responses (ABR), middle latency responses (MLR), and envelope following responses (EFRs). Generally, more severe and persistent postinjury central auditory processing (CAP) deficits were observed in blast-exposed animals throughout the auditory neuraxis, spanning from the cochlea to the cortex. DPOAE and ABR results captured cochlear and auditory nerve/brain stem deficits, respectively. EFRs demonstrated temporal processing impairments suggestive of functional damage to regions in the auditory brain stem and the inferior colliculus. MLRs captured thalamocortical transmission and cortical activation impairments. Taken together, the results suggest blast-induced CAS dysfunction may play a complementary pathophysiological role to maladaptive neuroplasticity of PAS origin. Even mild blasts can produce lasting hearing impairments that can be assessed with noninvasive electrophysiology, allowing these measurements to serve as simple, effective diagnostics.NEW & NOTEWORTHY Blasts exposures often produce hearing difficulties. Although cochlear damage typically occurs, the downstream effects on central auditory processing are less clear. Moreover, outcomes were compared between individuals exposed to the blast pressure wave vs. those who experienced the blast noise without the pressure wave. It was found that a single blast exposure produced changes at all stages of the ascending auditory path at least 4 wk postblast, whereas blast noise alone produced largely transient changes.
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Affiliation(s)
- Nicholas Race
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana.,School of Medicine, Indiana University, Indianapolis, Indiana
| | - Jesyin Lai
- Purdue University Inderdisciplinary Life Science (PULSe) Program, Purdue University, West Lafayette, Indiana; and
| | - Riyi Shi
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana.,Purdue University Inderdisciplinary Life Science (PULSe) Program, Purdue University, West Lafayette, Indiana; and.,Department of Basic Medical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, Indiana
| | - Edward L Bartlett
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana; .,Purdue University Inderdisciplinary Life Science (PULSe) Program, Purdue University, West Lafayette, Indiana; and
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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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