Journal of neurotrauma
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Journal of neurotrauma · Jun 2018
Survival Analysis-Based Human Head Injury Risk Curves: Focus on Skull Fracture.
Head contact-induced loads can result in skull fractures and/or brain injuries. While skull fractures have been produced from post-mortem human cadaver surrogates (PMHS), injury probability curves describing their structural responses have not been developed. The objectives of this study were to develop skull fracture-based injury risk curves and describe human tolerances using survival analysis. ⋯ Tightness-of-fit of risk curves for failure force, energy, and deflection were better than linear and secant stiffness variables. Force best represented skull fracture response based on BSM and NCIS, followed by deflection and energy, while two stiffness variables were least preferred metrics. These structural response-based set of risk curves, hitherto not reported, form a fundamental dataset for validating/assessing accuracy of outputs from computational models and serve as hierarchical skull fracture injury criteria under head contact loads.
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Journal of neurotrauma · Jun 2018
Diminished Dentate Gyrus Filtering of Cortical Input Leads to Enhanced Area Ca3 Excitability after Mild Traumatic Brain Injury.
Mild traumatic brain injury (mTBI) disrupts hippocampal function and can lead to long-lasting episodic memory impairments. The encoding of episodic memories relies on spatial information processing within the hippocampus. As the primary entry point for spatial information into the hippocampus, the dentate gyrus is thought to function as a physiological gate, or filter, of afferent excitation before reaching downstream area Cornu Ammonis (CA3). ⋯ Extracellular recordings and voltage-sensitive dye imaging demonstrated that perforant path activation leads to the aberrant spread of excitation from the dentate gyrus into area CA3 along the mossy fiber pathway. These results suggest that after mTBI, the dentate gyrus has a diminished capacity to regulate cortical input into the hippocampus, leading to increased CA3 network excitability. The loss of the dentate filtering efficacy reveals a potential mechanism by which hippocampal-dependent spatial information processing is disrupted, and may contribute to memory dysfunction after mTBI.
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Journal of neurotrauma · Jun 2018
MCC950, the Selective Inhibitor of Nucleotide Oligomerization Domain-Like Receptor Protein-3 Inflammasome, Protects Mice against Traumatic Brain Injury.
Nucleotide oligomerization domain (NOD)-like receptor protein-3 (NLRP3) inflammasome may intimately contribute to sustaining damage after traumatic brain injury (TBI). This study aims to examine whether specific modulation of NLPR3 inflammasome by MCC950, a novel selective NLRP3 inhibitor, confers protection after experimental TBI. Unilateral cortical impact injury was induced in young adult C57BL/6 mice. ⋯ MCC950 treatment also provided protection against proapoptotic activation of poly (ADP-ribose) polymerase and caspase-3 associated with TBI. A concurrent inhibition of inflammasome priming was also detectable at the nuclear factor kappa B/p65 and caspase-1 level. Our findings support the implication of NLRP3 inflammasome in the pathogenesis of TBI and further suggests the therapeutic potential of MCC950.
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Journal of neurotrauma · Jun 2018
Continuous Infusion of Phenelzine, Cyclosporine A, or Their Combination: Evaluation of Mitochondrial Bioenergetics, Oxidative Damage, and Cytoskeletal Degradation following Severe Controlled Cortical Impact Traumatic Brain Injury in Rats.
To date, all monotherapy clinical traumatic brain injury (TBI) trials have failed, and there are currently no Food and Drug Administration (FDA)-approved pharmacotherapies for the acute treatment of severe TBI. Due to the complex secondary injury cascade following injury, there is a need to develop multi-mechanistic combinational neuroprotective approaches for the treatment of acute TBI. As central mediators of the TBI secondary injury cascade, both mitochondria and lipid peroxidation-derived aldehydes make promising therapeutic targets. ⋯ Additionally, as the first 72 h represents a critical time period following injury, it follows that continuous drug infusion over the first 72 h following injury may also lead to optimal neuroprotective effects. This is the first study to examine the effects of a 72 h subcutaneous continuous infusion of PZ, CsA, and the combination of these two agents on mitochondrial respiration, mitochondrial bound 4-hydroxynonenal (4-HNE), and acrolein, and α-spectrin degradation 72 h following a severe controlled cortical impact injury in rats. Our results indicate that individually, both CsA and PZ are able to attenuate mitochondrial 4-HNE and acrolein, PZ is able to maintain mitochondrial respiratory control ratio and cytoskeletal integrity but together, PZ and CsA are unable to maintain neuroprotective effects.