Journal of neurotrauma
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Journal of neurotrauma · Oct 2024
Cell-Specific Gene Expressions Underlie Selective White Matter Loss Vulnerability in Mild Traumatic Brain Injury.
Traumatic brain injury (TBI), a risk factor for later-life dementia, leads to salient brain atrophy, particularly in the white matter. It is not clear how white matter atrophy progresses or why some brain regions are damaged while others are spared. We hypothesized that spatial variations of cell-specific gene expression contributed to the selective white matter loss vulnerability following mild TBI (mTBI). ⋯ Crucially, the gene expression marking endothelial cells and S1 pyramidal neurons were associated with increased brain atrophy, whereas the gene expression marking microglia and CA1 pyramidal neurons were associated with decreased brain atrophy in mTBI patients at 3 months post-injury. Microglia and endothelial cells can explain 23.6% of regional variations in the white matter atrophy. These findings suggested that modulating cellular activation, especially by promoting microglial activation at 3 months post-injury, might be a promising approach to prevent white matter atrophy, enhance cognitive outcomes, and reduce the risk of later-life dementia.
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Journal of neurotrauma · Oct 2024
Spinal cord blood perfusion deficit is associated with clinical impairment after spinal cord injury.
Spinal cord injury (SCI) results in intramedullary microvasculature disruption and blood perfusion deficit at and remote from the injury site. However, the relationship between remote vascular impairment and functional recovery remains understudied. We characterized perfusion impairment in vivo, rostral to the injury, using magnetic resonance imaging (MRI), and investigated its association with lesion extent and impairment following SCI. ⋯ This study shows clinically eloquent perfusion deficit rostral to a SCI, its magnitude driven by injury severity. These findings indicate trauma-induced widespread microvascular alterations beyond the injury site. Perfusion MRI matrices in the spinal cord hold promise as biomarkers for monitoring treatment effects and dynamic changes in microvasculature integrity following SCI.
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Journal of neurotrauma · Oct 2024
microRNA Profile Changes in Brain, Cerebrospinal Fluid, and Blood Following Low-Level Repeated Blast Exposure in a Rat Model.
It is well documented that service members are exposed to repeated low-level blast overpressure during training with heavy weapons such as artillery, mortars and explosive breaching. Often, acute symptoms associated with these exposures are transient but cumulative effect of low-level repeated blast exposures (RBEs) can include persistent deficits in cognitive and behavioral health. Thus far, reliable diagnostic biomarkers which can guide countermeasure strategies have not been identified. ⋯ Contrarily, Let-7 family miRNAs have neuroprotective role and their downregulation suggests progression of blast induced traumatic brain injury (bTBI) with RBE at 14× -8.5 psi. Repeated blast caused alterations in miRNAs that are likely involved in vascular integrity, inflammation, and cell death. These results indicate that miRNAs are differentially dysregulated in response to blast injuries and may represent better prognostic and diagnostic biomarkers than traditional molecules to identify blast-specific brain injury.
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Journal of neurotrauma · Oct 2024
Behavioral and Cognitive Consequences of Spreading Depolarizations: A Translational Scoping Review.
Spreading depolarizations (SDs) are self-propagating waves of mass depolarization that cause silencing of brain activity and have the potential to impact brain function and behavior. In the eight decades following their initial discovery in 1944, numerous publications have studied the cellular and molecular underpinning of SDs, but fewer have focused on the impact of SDs on behavior and cognition. ⋯ This study summarizes the known behavioral and cognitive consequences of SDs based on historical studies on awake animals, recent experimental paradigms, and modern clinical examples. This scoping review showcases our current understanding of the impact of SDs on cognition and behavior and highlights the need for continued research on the consequences of SDs.
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Journal of neurotrauma · Oct 2024
Microstructural Alterations of Gray and White Matter in Active Young Boxers with Sports-Related Concussions.
The existing research on the microstructural alterations associated with sport-related concussions (SRCs) has primarily focused on deep white matter (DWM) fibers, while the impact of SRCs on the superficial white matter (SWM) and gray matter (GM) remains unknown. This study aimed to characterize the altered metrics obtained from neurite orientation dispersion and density imaging (NODDI) in boxers with SRCs, and thereby determine whether distinct regional patterns of microstructural alterations can offer valuable insights for accurate diagnosis and prognosis. Concussed boxers (n = 56) and healthy controls (HCs) with typically developing (n = 72) underwent comprehensive neuropsychological assessment and magnetic resonance imaging (MRI) examinations. ⋯ Moreover, the SRC group exhibited lower FA, NDI, orientation dispersion index, and ISOVF in the GM, as well as higher AD. The altered microstructure of both gray and white matter was found to be associated with deficits in working memory and vocabulary memory among boxers. In addition to characterizing the DWM impairment, NODDI further elucidated the effects of SRCs on the microstructure of GM and SWM, offering a reliable imaging biomarker for SRC diagnosis and shedding light on the pathophysiological changes underlying SRCs.