Journal of neurotrauma
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Journal of neurotrauma · Apr 2016
Observational StudyRecovery of olfactory function following pediatric traumatic brain injury: A longitudinal follow-up.
There is increasing evidence that disruption of olfactory function after pediatric traumatic brain injury (TBI) is common. Olfactory dysfunction (OD) has been linked to significant functional implications in areas of health, safety, and quality of life, but longitudinal research investigating olfactory recovery is limited. This study aimed to investigate recovery trajectories for olfaction following pediatric TBI and explore predictors of early and late olfactory outcomes. ⋯ Predictors of early (0-3 month) and late (18 month) olfactory outcomes varied with site of impact, a significant predictor of later olfactory performance. In summary, while there was evidence of recovery of OD over time in pediatric TBI, the majority of children with severe OD did not show any recovery. In light of limited recovery of function for more severely affected children, the importance of appropriate education and implementation of rehabilitation management strategies is highlighted.
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Journal of neurotrauma · Apr 2016
Alterations in Daytime and Nighttime Activity in Piglets after Focal and Diffuse Brain Injury.
We have developed and implemented a noninvasive, objective neurofunctional assessment for evaluating the sustained effects of traumatic brain injury (TBI) in piglets with both diffuse and focal injury types. Derived from commercial actigraphy methods in humans, this assessment continuously monitors the day/night activity of piglets using close-fitting jackets equipped with tri-axial accelerometers to monitor movements of the thorax. ⋯ Compared to shams (N = 6) who acclimated to the animal facility 4 days after an anesthesia experience by blurring the distinction between day and night activity, post-TBI time-matched animals had larger fractions of inactive periods during the daytime than nighttime, and larger fractions of active time in the night were spent in high activity (e.g., constant walking, intermittent running) than during the day. These persistent disturbances in rest and activity are similar to those observed in human adults and children post-TBI, establishing actigraphy as a translational metric, used in both humans and large animals, for assessment of injury severity, progressions, and intervention.
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Journal of neurotrauma · Apr 2016
Combinatorial Motor Training Results In Functional Reorganization Of Remaining Motor Cortex After Controlled Cortical Impact In Rats.
Cortical reorganization subsequent to post-stroke motor rehabilitative training (RT) has been extensively examined in animal models and humans. However, similar studies focused on the effects of motor training after traumatic brain injury (TBI) are lacking. We previously reported that after a moderate/severe TBI in adult male rats, functional improvements in forelimb use were accomplished only with a combination of skilled forelimb reach training and aerobic exercise, with or without nonimpaired forelimb constraint. ⋯ RT also enlarged the area of motor cortical wrist representation, derived by intracortical microstimulation, compared to NoRT. These findings indicate that sufficient RT can greatly improve motor function and improve the functional integrity of remaining motor cortex after a moderate/severe CCI. When compared with findings from stroke models, these findings also suggest that more intense RT may be needed to improve motor function and remodel the injured cortex after TBI.
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Journal of neurotrauma · Apr 2016
Temporal profile of microRNA expression in contused cortex following traumatic brain injury in mice.
MicroRNAs (miRNAs) were recently identified as important regulators of gene expression under a wide range of physiological and pathophysiological conditions. Thus, they may represent a novel class of molecular targets for the management of traumatic brain injury (TBI). In this study, we investigated the temporal profile of miRNA expression during the development of secondary brain damage after experimental TBI. ⋯ Of these, 158 miRNAs were significantly upregulated or downregulated in TBI compared with sham-operated animals, and 52 miRNAs increased more than twofold. We validated the upregulation of five of the most differentially expressed miRNAs (miR-21*, miR-144, miR-184, miR-451, miR-2137) and the downregulation of four of the most differentially expressed miRNAs (miR-107, miR-137, miR-190, miR-541) by quantitative polymerase chain reaction (qPCR). miR-2137, the most differentially expressed miRNA after TBI, was further investigated by in situ hybridization and was found to be upregulated in neurons within the traumatic penumbra. This study gives a comprehensive picture of miRNA expression levels during secondary contusion expansion after TBI and may pave the way for the identification of novel targets for the management of brain trauma.
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Journal of neurotrauma · Apr 2016
Trigeminal pain molecules, allodynia, and photosensitivity are pharmacologically and genetically modulated in a model of traumatic brain injury.
The pain-signaling molecules, nitric oxide synthase (NOS) and calcitonin gene-related peptide (CGRP), are implicated in the pathophysiology of post-traumatic headache (PTH) as they are for migraine. This study assessed the changes of inducible NOS (iNOS) and its cellular source in the trigeminal pain circuit, as well as the relationship between iNOS and CGRP after controlled cortical impact (CCI) injury in mice. The effects of a CGRP antagonist (MK8825) and sumatriptan on iNOS messenger RNA (mRNA) and protein were compared to vehicle at 2 weeks postinjury. ⋯ CGRP immunoreactivity was found in the meningeal layers post-CCI, while negligible in controls. Findings support the importance of interactions between CGRP and iNOS in mediating allodynia, as well as the individual roles in photosensitivity. Mitigating prolonged increases in CGRP may be a promising intervention for treating acute PTH.