Journal of neurotrauma
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Magnetic resonance imaging (MRI) is widely used to evaluate the consequences of traumatic brain injury (TBI) in both experimental and clinical studies. Improved assessment of experimental TBI using the same methods as those used in clinical investigations would help to translate laboratory research into clinical advances. Here our goal was to characterize lateral fluid percussion-induced TBI, with special emphasis on differentiating the contused cortex from the pericontusional subcortical tissue. ⋯ At the same site, NAA/Cr was decreased and Lac/Cr elevated during the first week after TBI. In the ipsilateral subcortical area, NAA/Cr was markedly decreased and Lac/Cr was elevated during the first week, although MRI showed no evidence of edema, suggesting that (1)H-MRS detected "invisible" damage. (1)H-MRS combined with MRI may improve the detection of brain injury. Extensive assessments of animal models may increase the chances of developing successful neuroprotective strategies.
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Journal of neurotrauma · Jan 2010
Efficacy of various durations of in vitro predegeneration on the cell count and purity of rat Schwann-cell cultures.
The efficacy of Schwann-cell cultivation can be enhanced by in vitro predegeneration of the harvested cells compared to immediate culture. The aim of this study was to improve Schwann-cell culture efficacy by comparing three different durations of predegeneration. The sciatic and median nerves of 6-8-week-old Lewis rats were harvested and subjected to either 2-day, 7-day, or 14-day predegeneration in Dulbecco's Modified Eagle's Medium supplemented with 10% fetal calf serum and 1% Penicillin/Streptomycin. ⋯ The number of cultivated rat Schwann cells is doubled by 7-day in vitro predegeneration in comparison to 2-day predegeneration. After 14-day predegeneration, however, the culture is significantly debased by fibroblasts. Therefore, 7-day in vitro predegeneration is an advisable predegeneration period.
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Journal of neurotrauma · Jan 2010
Simulated whiplash modulates expression of the glutamatergic system in the spinal cord suggesting spinal plasticity is associated with painful dynamic cervical facet loading.
The cervical facet joint and its capsule have been reported to be injured during whiplash scenarios and are a common source of chronic neck pain from whiplash. Both the metabotropic glutamate receptor 5 (mGluR5) and the excitatory amino acid carrier 1 (EAAC1) have pivotal roles in chronic pain. In this study, spinal mGluR5 and EAAC1 were quantified following painful facet joint distraction in a rat model of facet-mediated painful loading and were evaluated for their correlation with the severity of capsule loading. ⋯ Further, spinal mGluR5 expression was significantly positively correlated to capsule strain (p < 0.02) and mechanical allodynia (p < 0.02). Spinal EAAC1 expression was significantly negatively related to one of the strain metrics (p < 0.003) and mechanical allodynia at day 7 (p = 0.03). These results suggest that the spinal glutamatergic system may potentiate the persistent behavioral hypersensitivity that is produced following dynamic whiplash-like joint loading; chronic whiplash pain may be alleviated by blocking mGluR5 expression and/or enhancing glutamate transport through the neuronal transporter EAAC1.
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Journal of neurotrauma · Jan 2010
Effect of secondary insults upon aquaporin-4 water channels following experimental cortical contusion in rats.
Although secondary insults of hypoxia and hypotension (HH) are generally considered to cause fulminant brain edema in traumatic brain injury (TBI), the combined effect of TBI with HH on brain edema and specifically the expression of aquaporin-4 (AQP4) have not been fully elucidated. The goal of this study was to document the effect of secondary insults on brain water, AQP4 expression, electrolytes, and blood-brain barrier (BBB) permeability during the acute stage of edema development. ⋯ Moreover, a significant reduction of upregulation on AQP4 expression was observed in trauma, coupled with a mild secondary insult of hypoxia hypotension. These findings indicate that a secondary insult following CCI at 5 h post injury worsens brain edema, disrupts ionic homeostasis, and blunts the normal upregulation of AQP4 that occurs after trauma, suggesting that the blunting of AQP4 may contribute to the detrimental effects of secondary insults.
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Journal of neurotrauma · Jan 2010
Statistical parametric mapping and cluster counting analysis of [18F] FDG-PET imaging in traumatic brain injury.
In this study we investigated regional cerebral glucose metabolism abnormalities of [(18)F] fluorodeoxyglucose (FDG) positron emission tomography (PET) imaging in traumatic brain injury (TBI). PET images of 81 TBI patients and 68 normal controls were acquired and a word list learning task was administered during the uptake period. The TBI group included 35 patients with positive structural imaging (CT or MRI) findings soon after injury, 40 patients with negative findings, and 6 cases without structural imaging. ⋯ Cluster counting results indicated that TBI patients had a higher proportion of larger clusters than controls. These large low-FDG-uptake clusters of the TBI patients were closer to the brain edge than those of controls. These results suggest that deficits of cerebral metabolism in TBI are spread over multiple brain areas, that they are closer to the cortical surface than clusters in controls, and that group spatial patterns of abnormal cerebral metabolism may be similar in TBI patients with cognitive deficits with and without obvious acute abnormalities identified on structural imaging.