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Wang S, Tan J, Zhang Q. Cytosolic Escape of Mitochondrial DNA Triggers cGAS-STING Pathway-Dependent Neuronal PANoptosis in Response to Intermittent Hypoxia. Neurochem Res 2024; 49:2228-2248. [PMID: 38833090 DOI: 10.1007/s11064-024-04151-7] [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: 12/25/2023] [Revised: 05/04/2024] [Accepted: 05/10/2024] [Indexed: 06/06/2024]
Abstract
Intermittent hypoxia (IH) is the predominant pathophysiological disturbance in obstructive sleep apnea (OSA), characterized by neuronal cell death and neurocognitive impairment. We focus on the accumulated mitochondrial DNA (mtDNA) in the cytosol, which acts as a damage-associated molecular pattern (DAMP) and activates the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway, a known trigger for immune responses and neuronal death in degenerative diseases. However, the specific role and mechanism of the mtDNA-cGAS-STING axis in IH-induced neural damage remain largely unexplored. Here, we investigated the involvement of PANoptosis, a novel type of programmed cell death linked to cytosolic mtDNA accumulation and the cGAS-STING pathway activation, in neuronal cell death induced by IH. Our study found that PANoptosis occurred in primary cultures of hippocampal neurons and HT22 cell lines exposed to IH. In addition, we discovered that during IH, mtDNA released into the cytoplasm via the mitochondrial permeability transition pore (mPTP) activates the cGAS-STING pathway, exacerbating PANoptosis-associated neuronal death. Pharmacologically inhibiting mPTP opening or depleting mtDNA significantly reduced cGAS-STING pathway activation and PANoptosis in HT22 cells under IH. Moreover, our findings indicated that the cGAS-STING pathway primarily promotes PANoptosis by modulating endoplasmic reticulum (ER) stress. Inhibiting or silencing the cGAS-STING pathway substantially reduced ER stress-mediated neuronal death and PANoptosis, while lentivirus-mediated STING overexpression exacerbated these effects. In summary, our study elucidates that cytosolic escape of mtDNA triggers cGAS-STING pathway-dependent neuronal PANoptosis in response to IH, mainly through regulating ER stress. The discovery of the novel mechanism provides theoretical support for the prevention and treatment of neuronal damage and cognitive impairment in patients with OSA.
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Affiliation(s)
- Shuying Wang
- Department of Geriatrics, Tianjin Medical University General Hospital, Tianjin Geriatrics Institute, Tianjin, 300052, China
| | - Jin Tan
- Department of Geriatrics, Tianjin Medical University General Hospital, Tianjin Geriatrics Institute, Tianjin, 300052, China
| | - Qiang Zhang
- Department of Geriatrics, Tianjin Medical University General Hospital, Tianjin Geriatrics Institute, Tianjin, 300052, China.
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2
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Weil ZM, White B, Whitehead B, Karelina K. The role of the stress system in recovery after traumatic brain injury: A tribute to Bruce S. McEwen. Neurobiol Stress 2022; 19:100467. [PMID: 35720260 PMCID: PMC9201063 DOI: 10.1016/j.ynstr.2022.100467] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 05/25/2022] [Accepted: 06/02/2022] [Indexed: 11/21/2022] Open
Abstract
Traumatic brain injury (TBI) represents a major public health concern. Although the majority of individuals that suffer mild-moderate TBI recover relatively quickly, a substantial subset of individuals experiences prolonged and debilitating symptoms. An exacerbated response to physiological and psychological stressors after TBI may mediate poor functional recovery. Individuals with TBI can suffer from poor stress tolerance, impairments in the ability to evaluate stressors, and poor initiation (and cessation) of neuroendocrine stress responses, all of which can exacerbate TBI-mediated dysfunction. Here, we pay tribute to the pioneering neuroendocrinologist Dr. Bruce McEwen by discussing the ways in which his work on stress physiology and allostatic loading impacts the TBI patient population both before and after their injuries. Specifically, we will discuss the modulatory role of hypothalamic-pituitary-adrenal axis responses immediately after TBI and later in recovery. We will also consider the impact of stressors and stress responses in promoting post-concussive syndrome and post-traumatic stress disorders, two common sequelae of TBI. Finally, we will explore the role of early life stressors, prior to brain injuries, as modulators of injury outcomes.
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3
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Whitney K, Nikulina E, Rahman SN, Alexis A, Bergold PJ. Delayed dosing of minocycline plus N-acetylcysteine reduces neurodegeneration in distal brain regions and restores spatial memory after experimental traumatic brain injury. Exp Neurol 2021; 345:113816. [PMID: 34310944 DOI: 10.1016/j.expneurol.2021.113816] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 07/07/2021] [Accepted: 07/20/2021] [Indexed: 11/16/2022]
Abstract
Multiple drugs to treat traumatic brain injury (TBI) have failed clinical trials. Most drugs lose efficacy as the time interval increases between injury and treatment onset. Insufficient therapeutic time window is a major reason underlying failure in clinical trials. Few drugs have been developed with therapeutic time windows sufficiently long enough to treat TBI because little is known about which brain functions can be targeted if therapy is delayed hours to days after injury. We identified multiple injury parameters that are improved by first initiating treatment with the drug combination minocycline (MINO) plus N-acetylcysteine (NAC) at 72 h after injury (MN72) in a mouse closed head injury (CHI) experimental TBI model. CHI produces spatial memory deficits resulting in impaired performance on Barnes maze, hippocampal neuronal loss, and bilateral damage to hippocampal neurons, dendrites, spines and synapses. MN72 treatment restores Barnes maze acquisition and retention, protects against hippocampal neuronal loss, limits damage to dendrites, spines and synapses, and accelerates recovery of microtubule associated protein 2 (MAP2) expression, a key protein in maintaining proper dendritic architecture and synapse density. These data show that in addition to the structural integrity of the dendritic arbor, spine and synapse density can be successfully targeted with drugs first dosed days after injury. Retention of substantial drug efficacy even when first dosed 72 h after injury makes MINO plus NAC a promising candidate to treat clinical TBI.
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Affiliation(s)
- Kristen Whitney
- Department of Physiology and Pharmacology, State University of New York-Downstate Health Sciences University, Brooklyn, NY 11215, United States of America; Program in Neural and Behavioral Science, School of Graduate Studies, State University of New York-Downstate Health Sciences University, Brooklyn, NY 11215, United States of America
| | - Elena Nikulina
- Department of Physiology and Pharmacology, State University of New York-Downstate Health Sciences University, Brooklyn, NY 11215, United States of America
| | - Syed N Rahman
- Department of Physiology and Pharmacology, State University of New York-Downstate Health Sciences University, Brooklyn, NY 11215, United States of America
| | - Alisia Alexis
- Department of Physiology and Pharmacology, State University of New York-Downstate Health Sciences University, Brooklyn, NY 11215, United States of America
| | - Peter J Bergold
- Department of Physiology and Pharmacology, State University of New York-Downstate Health Sciences University, Brooklyn, NY 11215, United States of America; Program in Neural and Behavioral Science, School of Graduate Studies, State University of New York-Downstate Health Sciences University, Brooklyn, NY 11215, United States of America.
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4
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Lengel D, Sevilla C, Romm ZL, Huh JW, Raghupathi R. Stem Cell Therapy for Pediatric Traumatic Brain Injury. Front Neurol 2020; 11:601286. [PMID: 33343501 PMCID: PMC7738475 DOI: 10.3389/fneur.2020.601286] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 11/10/2020] [Indexed: 12/11/2022] Open
Abstract
There has been a growing interest in the potential of stem cell transplantation as therapy for pediatric brain injuries. Studies in pre-clinical models of pediatric brain injury such as Traumatic Brain Injury (TBI) and neonatal hypoxia-ischemia (HI) have contributed to our understanding of the roles of endogenous stem cells in repair processes and functional recovery following brain injury, and the effects of exogenous stem cell transplantation on recovery from brain injury. Although only a handful of studies have evaluated these effects in models of pediatric TBI, many studies have evaluated stem cell transplantation therapy in models of neonatal HI which has a considerable overlap of injury pathology with pediatric TBI. In this review, we have summarized data on the effects of stem cell treatments on histopathological and functional outcomes in models of pediatric brain injury. Importantly, we have outlined evidence supporting the potential for stem cell transplantation to mitigate pathology of pediatric TBI including neuroinflammation and white matter injury, and challenges that will need to be addressed to incorporate these therapies to improve functional outcomes following pediatric TBI.
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Affiliation(s)
- Dana Lengel
- Graduate Program in Neuroscience, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Cruz Sevilla
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Zoe L Romm
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Jimmy W Huh
- Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia, PA, United States
| | - Ramesh Raghupathi
- Graduate Program in Neuroscience, 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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5
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Ratliff WA, Delic V, Pick CG, Citron BA. Dendritic arbor complexity and spine density changes after repetitive mild traumatic brain injury and neuroprotective treatments. Brain Res 2020; 1746:147019. [PMID: 32681835 DOI: 10.1016/j.brainres.2020.147019] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 06/25/2020] [Accepted: 07/10/2020] [Indexed: 12/17/2022]
Abstract
Traumatic brain injury has been described as the signature affliction of recent military conflicts and repetitive TBIs, particularly associated with military and athletic activities, typically result in more severe clinical effects. The majority of TBIs are mild, but they can result in long term cognitive deficits for which there is no effective treatment. One of the most significant deficits observed in TBI patients is memory loss, which suggests that TBI can induce pathological changes within the hippocampus. tert-butylhydroquinone (tBHQ) and pioglitazone activate the Nrf2 and PPAR-γ transcription factors, respectively, and both have been shown to be neuroprotective in model systems. We examined the morphological changes within the hippocampus following repetitive mild TBI and simultaneous treatment with both factors. We utilized a closed head injury mouse model with five injuries over 5 weeks. Our results showed marked morphological changes among the dendrites and dendritic spines of the neurons of the dentate gyrus of the hippocampus. We observed decreases in overall dendritic length, as well as in the quantity and density of dendritic spines. Our treatment partially ameliorated these effects, suggesting that the Nrf2 and PPAR-γ transcription factors may be important targets for future drug development in the treatment of TBI in humans.
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Affiliation(s)
- Whitney A Ratliff
- Laboratory of Molecular Biology, Bay Pines VA Healthcare System, Research and Development 151, Bldg. 22 Rm. 123, 10000 Bay Pines Blvd, Bay Pines, FL 33744, United States
| | - Vedad Delic
- Laboratory of Molecular Biology, VA New Jersey Health Care System, Research & Development (15), Bldg. 16, Rm 16-176 385 Tremont Ave, East Orange, NJ 07018, United States
| | - Chaim G Pick
- Department of Anatomy and Anthropology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel; Dr. Miriam and Sheldon G. Adelson Chair and Center for the Biology of Addictive Diseases, Tel Aviv University, Tel Aviv, Israel
| | - Bruce A Citron
- Laboratory of Molecular Biology, VA New Jersey Health Care System, Research & Development (15), Bldg. 16, Rm 16-176 385 Tremont Ave, East Orange, NJ 07018, United States; Laboratory of Molecular Biology, Bay Pines VA Healthcare System, Research and Development 151, Bldg. 22 Rm. 123, 10000 Bay Pines Blvd, Bay Pines, FL 33744, United States; Department of Pharmacology, Physiology & Neuroscience, Rutgers-New Jersey Medical School, Newark, NJ 07103, United States.
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6
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Meningher I, Bernstein-Eliav M, Rubovitch V, Pick CG, Tavor I. Alterations in Network Connectivity after Traumatic Brain Injury in Mice. J Neurotrauma 2020; 37:2169-2179. [PMID: 32434427 DOI: 10.1089/neu.2020.7063] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Victims of mild traumatic brain injury (mTBI) usually do not display clear morphological brain defects, but frequently have long-lasting cognitive deficits, emotional difficulties, and behavioral disturbances. In the present study we used diffusion magnetic resonance imaging (dMRI) combined with graph theory measurements to investigate the effects of mTBI on brain network connectivity. We employed a non-invasive closed-head weight-drop mouse model to produce mTBI. Mice were scanned at two time points, 24 h before the injury and either 7 or 30 days following the injury. Connectivity matrices were computed for each animal at each time point, and these were subsequently used to extract graph theory measures reflecting network integration and segregation, on both the global (i.e., whole brain) and local (i.e., single regions) levels. We found that cluster coefficient, reflecting network segregation, decreased 7 days post-injury and then returned to baseline level 30 days following the injury. Global efficiency, reflecting network integration, demonstrated opposite patterns in the left and right hemispheres, with an increase of right hemisphere efficiency at 7 days and then a decrease in efficiency following 30 days, and vice versa in the left hemisphere. These findings suggest a possible compensation mechanism acting to moderate the influence of mTBI on the global network. Moreover, these results highlight the importance of tracking the dynamic changes in mTBI over time, and the potential of structural connectivity as a promising approach for studying network integrity and pathology progression in mTBI.
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Affiliation(s)
- Inbar Meningher
- Department of Anatomy and Anthropology, Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel.,Sagol School of Neuroscience, Tel-Aviv University, Tel-Aviv, Israel
| | - Michal Bernstein-Eliav
- Department of Anatomy and Anthropology, Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel.,Sagol School of Neuroscience, Tel-Aviv University, Tel-Aviv, Israel
| | - Vardit Rubovitch
- Department of Anatomy and Anthropology, Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Chaim G Pick
- Department of Anatomy and Anthropology, Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel.,Sagol School of Neuroscience, Tel-Aviv University, Tel-Aviv, Israel.,Dr. Miriam and Sheldon G. Adelson Chair and Center for the Biology of Addictive Diseases, Tel-Aviv University, Tel-Aviv, Israel
| | - Ido Tavor
- Department of Anatomy and Anthropology, Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel.,Sagol School of Neuroscience, Tel-Aviv University, Tel-Aviv, Israel
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7
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Effect of mild blast-induced TBI on dendritic architecture of the cortex and hippocampus in the mouse. Sci Rep 2020; 10:2206. [PMID: 32042033 PMCID: PMC7010659 DOI: 10.1038/s41598-020-59252-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 01/20/2020] [Indexed: 11/09/2022] Open
Abstract
Traumatic brain injury (TBI) has been designated as a signature injury of modern military conflicts. Blast trauma, in particular, has come to make up a significant portion of the TBIs which are sustained in warzones. Though most TBIs are mild, even mild TBI can induce long term effects, including cognitive and memory deficits. In our study, we utilized a mouse model of mild blast-related TBI (bTBI) to investigate TBI-induced changes within the cortex and hippocampus. We performed rapid Golgi staining on the layer IV and V pyramidal neurons of the parietal cortex and the CA1 basilar tree of the hippocampus and quantified dendritic branching and distribution. We found decreased dendritic branching within both the cortex and hippocampus in injured mice. Within parietal cortex, this decreased branching was most evident within the middle region, while outer and inner regions resembled that of control mice. This study provides important knowledge in the study of how the shockwave associated with a blast explosion impacts different brain regions.
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8
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Ratliff WA, Saykally JN, Mervis RF, Lin X, Cao C, Citron BA. Behavior, protein, and dendritic changes after model traumatic brain injury and treatment with nanocoffee particles. BMC Neurosci 2019; 20:44. [PMID: 31438853 PMCID: PMC6704525 DOI: 10.1186/s12868-019-0525-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 08/10/2019] [Indexed: 12/14/2022] Open
Abstract
Background Traumatic brain injury (TBI) is a widespread public health problem and a signature injury of our military in modern conflicts. Despite the long-term effects of even mild brain injuries, an effective treatment remains elusive. Coffee and several of its compounds, including caffeine, have been identified as having neuroprotective effects in studies of neurodegenerative disease. Given the molecular similarities between TBI and neurodegenerative disease, we have devised a study to test a nanocoffee extract in the treatment of a mouse model of mild TBI. Results After a single injury and two subsequent injections of nanocoffee, we identified treatment as being associated with improved behavioral outcomes, favorable molecular signaling changes, and dendritic changes suggestive of improved neuronal health. Conclusions We have identified coffee extracts as a potential viable multifaceted treatment approach to target the secondary injury associated with TBI.
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Affiliation(s)
- Whitney A Ratliff
- Bay Pines VA Healthcare System, Research and Development, 151, Bldg. 22 Rm. 123, 10000 Bay Pines Blvd, Bay Pines, FL, 33744, USA.,Department of Molecular Medicine, USF College of Medicine, 12901 Bruce B. Downs Blvd, MDC 7, Tampa, FL, 33612, USA
| | - Jessica N Saykally
- Bay Pines VA Healthcare System, Research and Development, 151, Bldg. 22 Rm. 123, 10000 Bay Pines Blvd, Bay Pines, FL, 33744, USA.,Department of Molecular Medicine, USF College of Medicine, 12901 Bruce B. Downs Blvd, MDC 7, Tampa, FL, 33612, USA
| | - Ronald F Mervis
- NeuroStructural Analytics, Inc, Columbus, OH, USA.,Center for Aging and Brain Repair, Department of Neurosurgery and Brain Repair, University of South Florida Morsani College of Medicine, 2 Tampa General Circle, Tampa, FL, 33606, USA
| | - Xiaoyang Lin
- The USF-Health Byrd Alzheimer's Institute, College of Pharmacy, University of South Florida, 4001 E. Fletcher Ave, Tampa, FL, 33613, USA.,Department of Pharmaceutical Sciences, USF College of Pharmacy, 12901 Bruce B. Downs Blvd, Tampa, FL, 33612, USA
| | - Chuanhai Cao
- The USF-Health Byrd Alzheimer's Institute, College of Pharmacy, University of South Florida, 4001 E. Fletcher Ave, Tampa, FL, 33613, USA. .,Department of Pharmaceutical Sciences, USF College of Pharmacy, 12901 Bruce B. Downs Blvd, Tampa, FL, 33612, USA.
| | - Bruce A Citron
- Bay Pines VA Healthcare System, Research and Development, 151, Bldg. 22 Rm. 123, 10000 Bay Pines Blvd, Bay Pines, FL, 33744, USA.,Department of Molecular Medicine, USF College of Medicine, 12901 Bruce B. Downs Blvd, MDC 7, Tampa, FL, 33612, USA.,VA New Jersey Health Care System, Research & Development, Bldg. 16, Rm. 16-176, 385 Tremont Ave, Mailstop 15, East Orange, NJ, 07018, USA.,Department of Pharmacology, Physiology & Neuroscience, Rutgers-New Jersey Medical School, 185 South Orange Ave., Newark, NJ, 07101, USA
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9
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Sta Maria NS, Sargolzaei S, Prins ML, Dennis EL, Asarnow RF, Hovda DA, Harris NG, Giza CC. Bridging the gap: Mechanisms of plasticity and repair after pediatric TBI. Exp Neurol 2019; 318:78-91. [PMID: 31055004 DOI: 10.1016/j.expneurol.2019.04.016] [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: 12/25/2018] [Revised: 03/09/2019] [Accepted: 04/25/2019] [Indexed: 01/25/2023]
Abstract
Traumatic brain injury is the leading cause of death and disability in the United States, and may be associated with long lasting impairments into adulthood. The multitude of ongoing neurobiological processes that occur during brain maturation confer both considerable vulnerability to TBI but may also provide adaptability and potential for recovery. This review will examine and synthesize our current understanding of developmental neurobiology in the context of pediatric TBI. Delineating this biology will facilitate more targeted initial care, mechanism-based therapeutic interventions and better long-term prognostication and follow-up.
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Affiliation(s)
- Naomi S Sta Maria
- Department of Physiology and Neuroscience, Zilkha Neurogenetic Institute, University of Southern California, 1501 San Pablo Street, ZNI115, Los Angeles, CA 90033, United States of America.
| | - Saman Sargolzaei
- UCLA Brain Injury Research Center, Department of Neurosurgery, University of California at Los Angeles, Box 956901, 300 Stein Plaza, Ste 562, 5th Floor, Los Angeles, CA 90095-6901, United States of America.
| | - Mayumi L Prins
- UCLA Brain Injury Research Center, Department of Neurosurgery, University of California at Los Angeles, Box 956901, 300 Stein Plaza, Ste 562, 5th Floor, Los Angeles, CA 90095-6901, United States of America; Steve Tisch BrainSPORT Program, University of California at Los Angeles, Los Angeles, CA, United States of America.
| | - Emily L Dennis
- Brigham and Women's Hospital/Harvard University and Department of Psychology, Stanford University, 1249 Boylston Street, Boston, MA 02215, United States of America.
| | - Robert F Asarnow
- Department of Psychiatry and Biobehavioral Sciences, University of California at Los Angeles, Box 951759, 760 Westwood Plaza, 48-240C Semel Institute, Los Angeles, CA 90095-1759, United States of America.
| | - David A Hovda
- UCLA Brain Injury Research Center, Department of Neurosurgery, University of California at Los Angeles, Box 956901, 300 Stein Plaza, Ste 562, 5th Floor, Los Angeles, CA 90095-6901, United States of America; Department of Medical and Molecular Pharmacology, University of California at Los Angeles, Box 956901, 300 Stein Plaza, Ste 562 & Semel 18-228A, Los Angeles, CA 90095-6901, United States of America.
| | - Neil G Harris
- UCLA Brain Injury Research Center, Department of Neurosurgery, University of California at Los Angeles, Box 956901, 300 Stein Plaza, Ste 562, 5th Floor, Los Angeles, CA 90095-6901, United States of America; Intellectual Development and Disabilities Research Center, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, United States of America.
| | - Christopher C Giza
- UCLA Brain Injury Research Center, Department of Neurosurgery, University of California at Los Angeles, Box 956901, 300 Stein Plaza, Ste 562, 5th Floor, Los Angeles, CA 90095-6901, United States of America; Steve Tisch BrainSPORT Program, University of California at Los Angeles, Los Angeles, CA, United States of America; Division of Pediatric Neurology, Mattel Children's Hospital - UCLA, Los Angeles, CA, United States of America.
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10
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Ratliff WA, Mervis RF, Citron BA, Schwartz B, Rubovitch V, Schreiber S, Pick CG. Mild blast-related TBI in a mouse model alters amygdalar neurostructure and circuitry. Exp Neurol 2019; 315:9-14. [PMID: 30711646 DOI: 10.1016/j.expneurol.2019.01.020] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 01/16/2019] [Accepted: 01/30/2019] [Indexed: 02/07/2023]
Abstract
Traumatic brain injury (TBI) continues to be a signature injury of our modern conflicts. Due in part to increased use of improvised explosive devices (IEDs), we have seen blast trauma make up a significant portion of TBIs sustained by deployed troops and civilians. In addition to the physical injury, TBI is also a common comorbidity with post-traumatic stress disorder (PTSD). Previous research suggests that PTSD is often associated with increased signaling within the amygdala, leading to feelings of fear and hyperarousal. In our study, we utilized a mouse model of mild blast-related TBI (bTBI) to investigate how TBI induces changes within the amygdala, which may provide favorable conditions for the development of PTSD. To do this, we performed Golgi staining on the stellate neurons of the basolateral amygdala and quantified dendritic amount, distribution, and complexity. We found increases in dendritic branching and in the density of dendritic spines in injured mice. Increases in spine density appears to be primarily due to increases in memory associated mushroom type dendritic spines. These changes observed in our bTBI model that are consistent with chronic stress models, suggesting an important connection between the physical changes induced by TBI and the neurological symptoms of PTSD.
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Affiliation(s)
- Whitney A Ratliff
- Bay Pines VA Healthcare System, Research and Development, 151, Bldg. 22 Rm. 123, 10000 Bay Pines Blvd, Bay Pines, FL 33744, USA; Department of Molecular Medicine, USF College of Medicine, 12901 Bruce B. Downs Blvd, MDC 7, Tampa, FL 33612, USA.
| | - Ronald F Mervis
- NeuroStructural Analytics, Inc., Columbus, OH, USA; Center for Aging and Brain Repair, Department of Neurosurgery and Brain Repair, University of South Florida Morsani College of Medicine, 2 Tampa General Circle, Tampa, FL 33606, USA
| | - Bruce A Citron
- Bay Pines VA Healthcare System, Research and Development, 151, Bldg. 22 Rm. 123, 10000 Bay Pines Blvd, Bay Pines, FL 33744, USA; Department of Molecular Medicine, USF College of Medicine, 12901 Bruce B. Downs Blvd, MDC 7, Tampa, FL 33612, USA; VA New Jersey Health Care System, Research & Development, Mailstop 15, Bldg. 16, Rm. 16-176, 385 Tremont Ave, East Orange, NJ 07018, USA; Department of Pharmacology, Physiology & Neuroscience, Rutgers- New Jersey Medical School, 185 South Orange Ave., Newark, NJ 07101, USA
| | - Brian Schwartz
- Department of Anatomy and Anthropology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Vardit Rubovitch
- Department of Anatomy and Anthropology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Shaul Schreiber
- Department of Psychiatry, Tel Aviv Sourasky Medical Center, Tel Aviv 64239, Israel; Department of Psychiatry, Tel Aviv University Sackler Faculty of Medicine, Tel Aviv 64239, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Chaim G Pick
- Department of Anatomy and Anthropology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel; Dr. Miriam and Sheldon G. Adelson Chair, Center for the Biology of Addictive Diseases, Tel Aviv University, Tel Aviv 69978, Israel
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11
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Taylor KM, Kioumourtzoglou MA, Clover J, Coull BA, Dennerlein JT, Bellinger DC, Weisskopf MG. Concussion History and Cognitive Function in a Large Cohort of Adolescent Athletes. Am J Sports Med 2018; 46:3262-3270. [PMID: 30230912 PMCID: PMC6940017 DOI: 10.1177/0363546518798801] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND The incidence of reported concussions in the adolescent population is increasing, yet research on the effects of concussions in this population is minimal and inconclusive. PURPOSE To assess the association between concussion and performance on a cognitive test battery. STUDY DESIGN Cross-sectional study; Level of evidence, 3. METHODS Using multivariate models, the authors assessed the association between concussion and performance on a cognitive test battery among 5616 high school and junior high school athletes. The researchers utilized a global cognitive score and scores for 5 domains: verbal memory, visual memory, visual motor, reaction time, and impulse control. Each cognitive score was converted to a z score with the mean and SD of the nonconcussed population. Results from each model were then interpreted as change in the standardized unit score. In the models, concussion was evaluated as ever having a concussion, number of concussions, time since last concussion, and age at first concussion. RESULTS Ever having a concussion was associated with a mean decrease of 0.11 standardized units (95% CI, -0.20 to -0.01) on the global cognitive score and lower scores in all cognitive domains. Each additional concussion was associated with lower scores on global cognitive function (effect estimate, -0.06; 95% CI, -0.11 to -0.02), verbal memory, visual memory, and impulse control. Concussion in early childhood was associated with lower global cognition (effect estimate, -0.05; 95% CI, -0.08 to -0.01), visual memory, and motor visual scores as compared with concussions in later childhood. The associations between time since last concussion and cognitive test scores were nonlinear, and on all tests, lower scores were observed even ≥1 year after the concussion. CONCLUSION On the basis of objective performance metrics for cognitive function, concussions had a more persistent effect on cognitive function than previously thought. The age at which an individual has his or her first concussion may be an important factor in determining long-lasting cognitive effects.
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Affiliation(s)
- Kathryn M. Taylor
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
- Military Performance Division, US Army Institute of Environmental Medicine, Natick, Massachusetts, USA
| | - Marianthi-Anna Kioumourtzoglou
- Department of Environmental Health Sciences, Joseph L. Mailman School of Public Health, Columbia University, New York, New York, USA
| | - Jim Clover
- The Sport Foundation, Riverside, California, USA
| | - Brent A. Coull
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
- Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Jack T. Dennerlein
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
- Department of Physical Therapy, Movement, and Rehabilitation Sciences, Northeastern University, Boston, Massachusetts, USA
| | - David C. Bellinger
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
- Children’s Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Marc G. Weisskopf
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
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12
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Rowe RK, Harrison JL, Ellis TW, Adelson PD, Lifshitz J. Midline (central) fluid percussion model of traumatic brain injury in pediatric and adolescent rats. J Neurosurg Pediatr 2018; 22:22-30. [PMID: 29676680 DOI: 10.3171/2018.1.peds17449] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Experimental traumatic brain injury (TBI) models hold significant validity to the human condition, with each model replicating a subset of clinical features and symptoms. TBI is the leading cause of mortality and morbidity in children and teenagers; thus, it is critical to develop preclinical models of these ages to test emerging treatments. Midline fluid percussion injury (FPI) might best represent mild and diffuse clinical brain injury because of the acute behavioral deficits, the late onset of behavioral morbidities, and the absence of gross histopathology. In this study, the authors sought to adapt a midline FPI to postnatal day (PND) 17 and 35 rats. The authors hypothesized that scaling the craniectomy size based on skull dimensions would result in a reproducible injury comparable to the standard midline FPI in adult rats. METHODS PND17 and PND35 rat skulls were measured, and trephines were scaled based on skull size. Custom trephines were made. Rats arrived on PND10 and were randomly assigned to one of 3 cohorts: PND17, PND35, and 2 months old. Rats were subjected to midline FPI, and the acute injury was characterized. The right reflex was recorded, injury-induced apnea was measured, injury-induced seizure was noted, and the brains were immediately examined for hematoma. RESULTS The authors' hypothesis was supported; scaling the trephines based on skull size led to a reproducible injury in the PND17 and PND35 rats that was comparable to the injury in a standard 2-month-old adult rat. The midline FPI suppressed the righting reflex in both the PND17 and PND35 rats. The injury induced apnea in PND17 rats that lasted significantly longer than that in PND35 and 2-month-old rats. The injury also induced seizures in 73% of PND17 rats compared with 9% of PND35 rats and 0% of 2-month-old rats. There was also a significant relationship between the righting reflex time and presence of seizure. Both PND17 and PND35 rats had visible hematomas with an intact dura, indicative of diffuse injury comparable to the injury observed in 2-month-old rats. CONCLUSIONS With these procedures, it becomes possible to generate brain-injured juvenile rats (pediatric [PND17] and adolescent [PND35]) for studies of injury-induced pathophysiology and behavioral deficits, for which rational therapeutic interventions can be implemented.
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Affiliation(s)
- Rachel K Rowe
- 1Barrow Neurological Institute at Phoenix Children's Hospital.,3Phoenix Veteran Affairs Healthcare System, Phoenix
| | - Jordan L Harrison
- 1Barrow Neurological Institute at Phoenix Children's Hospital.,2Department of Child Health, University of Arizona College of Medicine, Phoenix.,4Interdisciplinary Graduate Program in Neuroscience, Arizona State University, Tempe; and
| | - Timothy W Ellis
- 5Midwestern University, School of Osteopathic Medicine, Glendale, Arizona
| | - P David Adelson
- 1Barrow Neurological Institute at Phoenix Children's Hospital.,2Department of Child Health, University of Arizona College of Medicine, Phoenix
| | - Jonathan Lifshitz
- 1Barrow Neurological Institute at Phoenix Children's Hospital.,4Interdisciplinary Graduate Program in Neuroscience, Arizona State University, Tempe; and
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13
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Icariin Improves Cognitive Impairment after Traumatic Brain Injury by Enhancing Hippocampal Acetylation. Chin J Integr Med 2018; 24:366-371. [PMID: 29327125 DOI: 10.1007/s11655-018-2823-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Indexed: 12/21/2022]
Abstract
OBJECTIVE To examine the effect of icariin (ICA) on the cognitive impairment induced by traumatic brain injury (TBI) in mice and the underlying mechanisms related to changes in hippocampal acetylation level. METHODS The modifified free-fall method was used to establish the TBI mouse model. Mice with post-TBI cognitive impairment were randomly divided into 3 groups using the randomised block method (n=7): TBI (vehicle-treated), low-dose (75 mg/kg) and high-dose (150 mg/kg) of ICA groups. An additional sham-operated group (vehicle-treated) was employed. The vehicle or ICA was administrated by gavage for 28 consecutive days. The Morris water maze (MWM) test was conducted. Acetylcholine (ACh) content, mRNA and protein levels of choline acetyltransferase (ChAT), and protein levels of acetylated H3 (Ac-H3) and Ac-H4 were detected in the hippocampus. RESULTS Compared with the sham-operated group, the MWM performance, hippocampal ACh content, mRNA and protein levels of ChAT, and protein levels of Ac-H3 and Ac-H4 were signifificantly decreased in the TBI group (P<0.05). High-dose of ICA signifificantly ameliorated the TBI-induced weak MWM performance, increased hippocampal ACh content, and mRNA and protein levels of ChAT, as well as Ac-H3 protein level compared with the TBI group (P<0.05). CONCLUSION ICA improved post-TBI cognitive impairment in mice by enhancing hippocampal acetylation, which improved hippocampal cholinergic function and ultimately improved cognition.
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14
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DeMaster D, Johnson C, Juranek J, Ewing‐Cobbs L. Memory and the hippocampal formation following pediatric traumatic brain injury. Brain Behav 2017; 7:e00832. [PMID: 29299377 PMCID: PMC5745237 DOI: 10.1002/brb3.832] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 08/15/2017] [Indexed: 12/20/2022] Open
Abstract
Introduction Previous research indicates disruption of learning and memory in children who have experienced traumatic brain injury (TBI). Objective This research evaluates the impact of pediatric TBI on volumetric differences along the long axis of the hippocampus, a region of the brain that is critical for explicit memory. Methods Structural brain data and behavioral measures were collected 6 weeks following TBI or extracranial injury (EI), in children aged 8-15 years and from a group of age matched typically developing controls (TDC). Total hippocampal volume and hippocampal subregion volumes corresponding to hippocampal head, body, and tail were compared across groups and were examined in relation to verbal and visual memory. Results Group differences were evident such that hippocampal body volume was found to be smaller for TBI and EI groups compared to the TDC group. Analysis restricted to the TBI group indicated that hippocampal head volume was associated with severity of injury. The relation between severity of injury and hippocampal head volume is particularly important considering results from our investigation of hippocampal volume-to-memory performance relations indicating positive correlations between hippocampal head volume and performance on memory measures for both the TBI group and the TDC group. Significant negative correlations between hippocampal body volume and memory were evident for the TBI group but not EI or TDC groups. Correlations between memory performance and hippocampal tail volume were not significant for the TBI or TDC groups, although for the EI group, a positive correlation was found between hippocampal tail volume and memory. Conclusion Together these results underscore an important relation between hippocampal structure and memory function during the subacute stage of recovery from pediatric TBI.
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Affiliation(s)
- Dana DeMaster
- Department of PediatricsChildren's Leaning InstituteUniversity of Texas McGovern Medical SchoolHoustonTXUSA
| | - Chad Johnson
- Department of PediatricsChildren's Leaning InstituteUniversity of Texas McGovern Medical SchoolHoustonTXUSA
| | - Jenifer Juranek
- Department of PediatricsChildren's Leaning InstituteUniversity of Texas McGovern Medical SchoolHoustonTXUSA
| | - Linda Ewing‐Cobbs
- Department of PediatricsChildren's Leaning InstituteUniversity of Texas McGovern Medical SchoolHoustonTXUSA
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15
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Medaglia JD. Functional Neuroimaging in Traumatic Brain Injury: From Nodes to Networks. Front Neurol 2017; 8:407. [PMID: 28883806 PMCID: PMC5574370 DOI: 10.3389/fneur.2017.00407] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 07/28/2017] [Indexed: 12/16/2022] Open
Abstract
Since the invention of functional magnetic resonance imaging (fMRI), thousands of studies in healthy and clinical samples have enlightened our understanding of the organization of cognition in the human brain and neuroplastic changes following brain disease and injury. Increasingly, studies involve analyses rooted in complex systems theory and analysis applied to clinical samples. Given the complexity in available approaches, concise descriptions of the theoretical motivation of network techniques and their relationship to traditional approaches and theory are necessary. To this end, this review concerns the use of fMRI to understand basic cognitive function and dysfunction in the human brain scaling from emphasis on basic units (or "nodes") in the brain to interactions within and between brain networks. First, major themes and theoretical issues in the scientific study of the injured brain are introduced to contextualize these analyses, particularly concerning functional "brain reorganization." Then, analytic approaches ranging from the voxel level to the systems level using graph theory and related approaches are reviewed as complementary approaches to examine neurocognitive processes following TBI. Next, some major findings relevant to functional reorganization hypotheses are discussed. Finally, major open issues in functional network analyses in neurotrauma are discussed in theoretical, analytic, and translational terms.
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Affiliation(s)
- John D Medaglia
- Department of Psychology, University of Pennsylvania, Philadelphia, PA, United States
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16
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Does time heal all wounds? Experimental diffuse traumatic brain injury results in persisting histopathology in the thalamus. Behav Brain Res 2016; 340:137-146. [PMID: 28042008 DOI: 10.1016/j.bbr.2016.12.038] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 11/30/2016] [Accepted: 12/28/2016] [Indexed: 11/21/2022]
Abstract
BACKGROUND Thalamic dysfunction has been implicated in overall chronic neurological dysfunction after traumatic brain injury (TBI), however little is known about the underlying histopathology. In experimental diffuse TBI (dTBI), we hypothesize that persisting histopathological changes in the ventral posteromedial (VPM) nucleus of the thalamus is indicative of progressive circuit reorganization. Since circuit reorganization in the VPM impacts the whisker sensory system, the histopathology could explain the development of hypersensitivity to whisker stimulation by 28days post-injury; similar to light and sound hypersensitivity in human TBI survivors. METHODS Adult, male Sprague-Dawley rats underwent craniotomy and midline fluid percussion injury (FPI) (moderate severity; 1.8-2.0atm) or sham surgery. At 1d, 7d, and 28days post-FPI (d FPI) separate experiments confirmed the cytoarchitecture (Giemsa stain) and evaluated neuropathology (silver stain), activated astrocytes (GFAP), neuron morphology (Golgi stain) and microglial morphology (Iba-1) in the VPM. RESULTS Cytoarchitecture was unchanged throughout the time course, similar to previously published data; however, neuropathology and astrocyte activation were significantly increased at 7d and 28d and activated microglia were present at all time points. Neuron morphology was dynamic over the time course with decreased dendritic complexity (fewer branch points; decreased length of processes) at 7d FPI and return to sham values by 28d FPI. CONCLUSIONS These data indicate that dTBI results in persisting thalamic histopathology out to a chronic time point. While these changes can be indicative of either adaptive (recovery) or maladaptive (neurological dysfunction) circuit reorganization, they also provide a potential mechanism by which maladaptive circuit reorganization could contribute to the development of chronic neurological dysfunction. Understanding the processes that mediate circuit reorganization is critical to the development of future therapies for TBI patients.
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17
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Sex-dependent changes in neuronal morphology and psychosocial behaviors after pediatric brain injury. Behav Brain Res 2016; 319:48-62. [PMID: 27829127 DOI: 10.1016/j.bbr.2016.10.045] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 10/28/2016] [Accepted: 10/28/2016] [Indexed: 12/12/2022]
Abstract
Chronic social behavior problems after pediatric traumatic brain injury (TBI) significantly contribute to poor quality of life for survivors. Using a well-characterized mouse model of early childhood TBI, we have previously demonstrated that young brain-injured mice develop social deficits by adulthood. As biological sex may influence both normal and aberrant social development, we here evaluated potential sex differences in post-TBI psychosocial deficits by comparing the behavior of male and female mice at adulthood (8 weeks post-injury). Secondly, we hypothesized that pediatric TBI would influence neuronal morphology identified by Golgi-Cox staining in the hippocampus and prefrontal cortex, regions involved in social cognition and behavior, before the onset of social problems (3 weeks post-injury). Morphological analysis of pyramidal neurons in the ipsilateral prefrontal cortex and granule cells of the hippocampal dentate gyrus revealed a reduction in dendritic complexity after pediatric TBI. This was most apparent in TBI males, whereas neurons from females were less affected. At adulthood, consistent with previous studies, TBI males showed deficits in sociability and social recognition. TBI females also showed a reduction in sociability, but intact social recognition and increased sociosexual avoidance. Together, these findings indicate that sex is a determinant of regional neuroplasticity and social outcomes after pediatric TBI. Reduced neuronal complexity in the prefrontal cortex and hippocampus, several weeks after injury in male mice, appears to precede the subsequent emergence of social deficits. Sex-specific alterations in the social brain network are thus implicated as an underlying mechanism of social dysfunction after pediatric TBI.
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Abstract
This article reviews possible ways that traumatic brain injury (TBI) can induce migraine-type post-traumatic headaches (PTHs) in children, adults, civilians, and military personnel. Several cerebral alterations resulting from TBI can foster the development of PTH, including neuroinflammation that can activate neural systems associated with migraine. TBI can also compromise the intrinsic pain modulation system and this would increase the level of perceived pain associated with PTH. Depression and anxiety disorders, especially post-traumatic stress disorder (PTSD), are associated with TBI and these psychological conditions can directly intensify PTH. Additionally, depression and PTSD alter sleep and this will increase headache severity and foster the genesis of PTH. This article also reviews the anatomic loci of injury associated with TBI and notes the overlap between areas of injury associated with TBI and PTSD.
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19
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Hoffman AN, Paode PR, May HG, Ortiz JB, Kemmou S, Lifshitz J, Conrad CD, Currier Thomas T. Early and Persistent Dendritic Hypertrophy in the Basolateral Amygdala following Experimental Diffuse Traumatic Brain Injury. J Neurotrauma 2016; 34:213-219. [PMID: 27306143 DOI: 10.1089/neu.2015.4339] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
In the pathophysiology of traumatic brain injury (TBI), the amygdala remains understudied, despite involvement in processing emotional and stressful stimuli associated with anxiety disorders, such as post-traumatic stress disorder (PTSD). Because the basolateral amygdala (BLA) integrates inputs from sensory and other limbic structures coordinating emotional learning and memory, injury-induced changes in circuitry may contribute to psychiatric sequelae of TBI. This study quantified temporal changes in dendritic complexity of BLA neurons after experimental diffuse TBI, modeled by midline fluid percussion injury. At post-injury days (PIDs) 1, 7, and 28, brain tissue from sham and brain-injured adult, male rats was processed for Golgi, glial fibrillary acidic protein (GFAP), or silver stain and analyzed to quantify BLA dendritic branch intersections, activated astrocytes, and regional neuropathology, respectively. Compared to sham, brain-injured rats at all PIDs showed enhanced dendritic branch intersections in both pyramidal and stellate BLA neuronal types, as evidenced by Sholl analysis. GFAP staining in the BLA was significantly increased at PID1 and 7 in comparison to sham. However, the BLA was relatively spared from neuropathology, demonstrated by an absence of argyrophilic accumulation over time, in contrast to other brain regions. These data suggest an early and persistent enhancement of dendritic complexity within the BLA after a single diffuse TBI. Increased dendritic complexity would alter information processing into and through the amygdala, contributing to emotional symptoms post-TBI, including PTSD.
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Affiliation(s)
- Ann N Hoffman
- 1 Department of Psychology, Arizona State University , Tempe, Arizona.,5 Department of Psychology, UCLA , Los Angeles, California.,6 Brain Injury Research Center, Department of Neurosurgery, David Geffen School of Medicine at UCLA , Los Angeles, California
| | - Pooja R Paode
- 1 Department of Psychology, Arizona State University , Tempe, Arizona
| | - Hazel G May
- 2 Department of Child Health, University of Arizona College of Medicine-Phoenix , Phoenix, Arizona.,3 Barrow Neurological Institute at Phoenix Children's Hospital , Phoenix, Arizona.,7 Department of Biology and Biochemistry, University of Bath , Bath, United Kingdom
| | - J Bryce Ortiz
- 1 Department of Psychology, Arizona State University , Tempe, Arizona
| | - Salma Kemmou
- 1 Department of Psychology, Arizona State University , Tempe, Arizona
| | - Jonathan Lifshitz
- 1 Department of Psychology, Arizona State University , Tempe, Arizona.,2 Department of Child Health, University of Arizona College of Medicine-Phoenix , Phoenix, Arizona.,3 Barrow Neurological Institute at Phoenix Children's Hospital , Phoenix, Arizona.,4 Phoenix VA Healthcare System , Phoenix, Arizona
| | - Cheryl D Conrad
- 1 Department of Psychology, Arizona State University , Tempe, Arizona
| | - Theresa Currier Thomas
- 2 Department of Child Health, University of Arizona College of Medicine-Phoenix , Phoenix, Arizona.,3 Barrow Neurological Institute at Phoenix Children's Hospital , Phoenix, Arizona.,4 Phoenix VA Healthcare System , Phoenix, Arizona
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20
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Abstract
Due to a high incidence of traumatic brain injury (TBI) in children and adolescents, age-specific studies are necessary to fully understand the long-term consequences of injuries to the immature brain. Preclinical and translational research can help elucidate the vulnerabilities of the developing brain to insult, and provide model systems to formulate and evaluate potential treatments aimed at minimizing the adverse effects of TBI. Several experimental TBI models have therefore been scaled down from adult rodents for use in juvenile animals. The following chapter discusses these adapted models for pediatric TBI, and the importance of age equivalence across species during model development and interpretation. Many neurodevelopmental processes are ongoing throughout childhood and adolescence, such that neuropathological mechanisms secondary to a brain insult, including oxidative stress, metabolic dysfunction and inflammation, may be influenced by the age at the time of insult. The long-term evaluation of clinically relevant functional outcomes is imperative to better understand the persistence and evolution of behavioral deficits over time after injury to the developing brain. Strategies to modify or protect against the chronic consequences of pediatric TBI, by supporting the trajectory of normal brain development, have the potential to improve quality of life for brain-injured children.
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Affiliation(s)
- Bridgette D Semple
- Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC, Australia
| | - Jaclyn Carlson
- Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC, Australia
| | - Linda J Noble-Haeusslein
- Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA.
- Department of Physical Therapy and Rehabilitation Science, University of California School of Medicine, 513 Parnassus Ave., HSE 814, San Francisco, CA, 94143, USA.
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21
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Nichols J, Perez R, Wu C, Adelson PD, Anderson T. Traumatic brain injury induces rapid enhancement of cortical excitability in juvenile rats. CNS Neurosci Ther 2014; 21:193-203. [PMID: 25475223 DOI: 10.1111/cns.12351] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Revised: 10/15/2014] [Accepted: 10/20/2014] [Indexed: 11/29/2022] Open
Abstract
AIMS Following a traumatic brain injury (TBI), 5-50% of patients will develop posttraumatic epilepsy (PTE) with children being particularly susceptible. Currently, PTE cannot be prevented and there is limited understanding of the underlying epileptogenic mechanisms. We hypothesize that early after TBI the brain undergoes distinct cellular and synaptic reorganization that facilitates cortical excitability and promotes the development of epilepsy. METHODS To examine the effect of pediatric TBI on cortical excitability, we performed controlled cortical impact (CCI) on juvenile rats (postnatal day 17). Following CCI, animals were monitored for the presence of epileptiform activity by continuous in vivo electroencephalography (EEG) and/or sacrificed for in vitro whole-cell patch-clamp recordings. RESULTS Following a short latent period, all animals subjected to CCI developed spontaneous recurrent epileptiform activity within 14 days. Whole-cell patch-clamp recordings of layer V pyramidal neurons showed no changes in intrinsic excitability or spontaneous excitatory postsynaptic currents (sEPSCs) properties. However, the decay of spontaneous inhibitory postsynaptic currents (sIPSCs) was significantly increased. In addition, CCI induced over a 300% increase in excitatory and inhibitory synaptic bursting. Synaptic bursting was prevented by blockade of Na(+)-dependent action potentials or select antagonism of glutamate or GABA-A receptors, respectively. CONCLUSION Our results demonstrate that CCI in juvenile rats rapidly induces epileptiform activity and enhanced cortical synaptic bursting. Detection of epileptiform activity early after injury suggests it may be an important pathophysiological component and potential indicator of developing PTE.
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Affiliation(s)
- Joshua Nichols
- University of Arizona, College of Medicine - Phoenix, Phoenix, AZ, USA; School of Life Sciences, Arizona State University, Phoenix, AZ, USA
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