Ceftriaxone Treatment Preserves Cortical Inhibitory Interneuron Function via Transient Salvage of GLT-1 in a Rat Traumatic Brain Injury Model

Abstract Traumatic brain injury (TBI) results in a decrease in glutamate transporter-1 (GLT-1) expression, the major mechanism for glutamate removal from synapses. Coupled with an increase in glutamate release from dead and dying neurons, this causes an increase in extracellular glutamate. The ensuing glutamate excitotoxicity disproportionately damages vulnerable GABAergic parvalbumin-positive inhibitory interneurons, resulting in a progressively worsening cortical excitatory:inhibitory imbalance due to a loss of GABAergic inhibitory tone, as evidenced by chronic post-traumatic symptoms such as epilepsy, and supported by neuropathologic findings. This loss of intracortical inhibition can be measured and followed noninvasively using long-interval paired-pulse transcranial magnetic stimulation with mechanomyography (LI-ppTMS-MMG). Ceftriaxone, a β-lactam antibiotic, is a potent stimulator of the expression of rodent GLT-1 and would presumably decrease excitotoxic damage to GABAergic interneurons. It may thus be a viable antiepileptogenic intervention. Using a rat fluid percussion injury TBI model, we utilized LI-ppTMS-MMG, quantitative PCR, and immunohistochemistry to test whether ceftriaxone treatment preserves intracortical inhibition and cortical parvalbumin-positive inhibitory interneuron function after TBI in rat motor cortex. We show that neocortical GLT-1 gene and protein expression are significantly reduced 1 week after TBI, and this transient loss is mitigated by ceftriaxone. Importantly, whereas intracortical inhibition declines progressively after TBI, 1 week of post-TBI ceftriaxone treatment attenuates the loss of inhibition compared to saline-treated controls. This finding is accompanied by significantly higher parvalbumin gene and protein expression in ceftriaxone-treated injured rats. Our results highlight prospects for ceftriaxone as an intervention after TBI to prevent cortical inhibitory interneuron dysfunction, partly by preserving GLT-1 expression.

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Traumatic Brain Injury Induces Alterations in Cortical Glutamate Uptake without a Reduction in Glutamate Transporter-1 Protein Expression

Journal of Neurotrauma ◽

10.1089/neu.2015.4372 ◽

2017 ◽

Vol 34 (1) ◽

pp. 220-234 ◽

Cited By ~ 22

Author(s):

Christopher R. Dorsett ◽

Jennifer L. McGuire ◽

Tracy L. Niedzielko ◽

Erica A.K. DePasquale ◽

Jaroslaw Meller ◽

...

Keyword(s):

Traumatic Brain Injury ◽

Brain Injury ◽

Protein Expression ◽

Glutamate Uptake ◽

Glutamate Transporter ◽

Glutamate Transporter 1

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FGF10 Attenuates Experimental Traumatic Brain Injury through TLR4/MyD88/NF-κB Pathway

Cells Tissues Organs ◽

10.1159/000511381 ◽

2021 ◽

pp. 1-9

Author(s):

Qinhan Hou ◽

Hongmou Chen ◽

Quan Liu ◽

Xianlei Yan

Keyword(s):

Traumatic Brain Injury ◽

Brain Injury ◽

Protein Expression ◽

Water Content ◽

Neurological Deficit ◽

Neuronal Apoptosis ◽

Neuronal Damage ◽

Intraventricular Injection ◽

Brain Water Content ◽

Brain Water

Traumatic brain injury (TBI) can induce neuronal apoptosis and neuroinflammation, resulting in substantial neuronal damage and behavioral disorders. Fibroblast growth factors (FGFs) have been shown to be critical mediators in tissue repair. However, the role of FGF10 in experimental TBI remains unknown. In this study, mice with TBI were established via weight-loss model and validated by increase of modified neurological severity scores (mNSS) and brain water content. Secondly, FGF10 levels were elevated in mice after TBI, whereas intraventricular injection of Ad-FGF10 decreased mNSS score and brain water content, indicating the remittance of neurological deficit and cerebral edema in TBI mice. In addition, neuronal damage could also be ameliorated by stereotactic injection of Ad-FGF10. Overexpression of FGF10 increased protein expression of Bcl-2, while it decreased Bax and cleaved caspase-3/PARP, and improved neuronal apoptosis in TBI mice. In addition, Ad-FGF10 relieved neuroinflammation induced by TBI and significantly reduced the level of interleukin 1β/6, tumor necrosis factor α, and monocyte chemoattractant protein-1. Moreover, Ad-FGF10 injection decreased the protein expression level of Toll-like receptor 4 (TLR4), MyD88, and phosphorylation of NF-κB (p-NF-κB), suggesting the inactivation of the TLR4/MyD88/NF-κB pathway. In conclusion, overexpression of FGF10 could ameliorate neurological deficit, neuronal apoptosis, and neuroinflammation through inhibition of the TLR4/MyD88/NF-κB pathway, providing a potential therapeutic strategy for brain injury in the future.

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Narrative Review of the Pathophysiology of Headaches and Photosensitivity in Mild Traumatic Brain Injury and Concussion

Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques ◽

10.1017/cjn.2018.361 ◽

2018 ◽

Vol 46 (1) ◽

pp. 14-22 ◽

Cited By ~ 12

Author(s):

Christopher Mares ◽

Jehane H. Dagher ◽

Mona Harissi-Dagher

Keyword(s):

Traumatic Brain Injury ◽

Brain Injury ◽

Mild Traumatic Brain Injury ◽

Primary Headache ◽

Underlying Mechanism ◽

Glutamate Excitotoxicity ◽

Secondary Headache ◽

Headache Disorders ◽

Primary Headache Disorders ◽

Post Traumatic

AbstractThe most common symptom of post-concussive syndrome (PCS) is post-traumatic headache (PTH) accompanied by photophobia. Post-traumatic headache is currently categorized as a secondary headache disorder with a clinical phenotype described by its main features and resembling one of the primary headache disorders: tension, migraine, migraine-like cluster. Although PTH is often treated with medication used for primary headache disorders, the underlying mechanism for PTH has yet to be elucidated. The goal of this narrative literature review is to determine the current level of knowledge of these PTHs and photophobia in mild traumatic brain injury (mTBI) in order to guide further research and attempt to discover the underlying mechanism to both symptoms. The ultimate purpose is to better understand the pathophysiology of these symptoms in order to provide better and more targeted care to afflicted patients. A review of the literature was conducted using the databases CINAHL, EMBASE, PubMed. All papers were screened for sections on pathophysiology of PTH or photophobia in mTBI patients. Our paper summarizes current hypotheses. Although the exact pathophysiology of PTH and photophobia in mTBI remains to be determined, we highlight several interesting findings and avenues for future research, including central and peripheral explanations for PTH, neuroinflammation, cortical spreading depolarization and the role of glutamate excitotoxicity. We discuss the possible neuroanatomical pathways for photophobia and hypothesize a possible common pathophysiological basis between PTH and photophobia.

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A 3D Tissue Model of Traumatic Brain Injury with Excitotoxicity That Is Inhibited by Chronic Exposure to Gabapentinoids

Biomolecules ◽

10.3390/biom10081196 ◽

2020 ◽

Vol 10 (8) ◽

pp. 1196

Author(s):

Nicolas Rouleau ◽

Mattia Bonzanni ◽

Joshua D. Erndt-Marino ◽

Katja Sievert ◽

Camila G. Ramirez ◽

...

Keyword(s):

Traumatic Brain Injury ◽

Brain Injury ◽

Glutamate Release ◽

Cell Types ◽

Screening Tools ◽

Secondary Brain Injury ◽

High Concentration ◽

Drug Induced ◽

The Individual ◽

Injury Progression

Injury progression associated with cerebral laceration is insidious. Following the initial trauma, brain tissues become hyperexcitable, begetting further damage that compounds the initial impact over time. Clinicians have adopted several strategies to mitigate the effects of secondary brain injury; however, higher throughput screening tools with modular flexibility are needed to expedite mechanistic studies and drug discovery that will contribute to the enhanced protection, repair, and even the regeneration of neural tissues. Here we present a novel bioengineered cortical brain model of traumatic brain injury (TBI) that displays characteristics of primary and secondary injury, including an outwardly radiating cell death phenotype and increased glutamate release with excitotoxic features. DNA content and tissue function were normalized by high-concentration, chronic administrations of gabapentinoids. Additional experiments suggested that the treatment effects were likely neuroprotective rather than regenerative, as evidenced by the drug-mediated decreases in cell excitability and an absence of drug-induced proliferation. We conclude that the present model of traumatic brain injury demonstrates validity and can serve as a customizable experimental platform to assess the individual contribution of cell types on TBI progression, as well as to screen anti-excitotoxic and pro-regenerative compounds.

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