Journal of neurotrauma
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Journal of neurotrauma · Jan 2017
Inhibition of Endocannabinoid Degradation Improves Outcomes from Mild Traumatic Brain Injury: A Mechanistic Role for Synaptic Hyperexcitability.
Traumatic brain injury (TBI) is an increasingly prevalent condition affecting soldiers, athletes, and motor vehicle accident victims. Unfortunately, it currently lacks effective therapeutic interventions. TBI is defined as a primary mechanical insult followed by a secondary cascade involving inflammation, apoptosis, release of reactive oxygen species, and excitotoxicity, all of which can cause synaptic changes, altered neuronal signaling, and, ultimately, behavioral changes. ⋯ JZL184 administration significantly attenuated the increased pGluR1S845/GluR1 and pERK 1/2/ERK and the increases in miniature excitatory postsynaptic potential (mEPSC) frequency and amplitude observed in layer 5 pyramidal neurons at 10 days post-TBI. These results suggest a neuroprotective role for ECs in ameliorating the TBI-induced neurobehavioral, neuroinflammatory, and glutamate dyshomeostasis from mTBI. Further studies elucidating the cellular mechanisms involved are warranted.
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Journal of neurotrauma · Jan 2017
Greater attention to task-relevant threat due to orbitofrontal lesion.
Injury to the orbitofrontal cortex (OFC) is a frequent consequence of head injury and may lead to dysfunctional regulation of emotional and social behavior. Dysfunctional emotional behavior may partly be related to the role of the OFC in emotion-attention interaction, as reported previously. In order to better understand its role in emotion-attention and emotion-cognitive control interactions, we investigated attention allocation to task-relevant and task-irrelevant threat-related emotional stimuli during a task requiring cognitive control in patients with lesion to the OFC. ⋯ This study provides new evidence for the role of the OFC in emotion-attention and emotion-cognitive control interactions. Further, the OFC seems to contribute to the balance between voluntary and involuntary attention networks in context of emotional stimuli. Better understanding of alterations in emotion-attention interaction offers insight into affective dysfunction due to OFC lesion.
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Journal of neurotrauma · Jan 2017
Long-term motor deficits after controlled cortical impact in rats can be detected by fine motor skill tests but not by automated gait analysis.
Animal models with constant, long-lasting motor deficits together with the right tests to assess behavioral abnormalities are needed to study the effectiveness of potential therapies to restore motor functions. In the current study, controlled cortical impact (CCI) was applied in rats to induce damage to the forelimb area of the motor cortex and the dorsal striatum. ⋯ In striking contrast to previous studies on CCI in mice, neither forelimb impairments, nor general changes in gait, were detected with the CatWalk XT. These data suggest that the adhesive removal test, the cylinder test, and the Montoya staircase test are the methods of choice to detect long-term unilateral motor deficits in rats after CCI, whereas the use of automated gait analysis systems might not be suitable to measure these behavioral deviations.
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Journal of neurotrauma · Jan 2017
Consistency of Self-reported Concussion History in Adolescent Athletes.
Relying on self-reported concussion injury history is common in both clinical care and research. However, young athletes may not provide consistent medical information. To date, little is known about the reliability of self-reported concussion history in high school students. ⋯ Only a small proportion of student athletes provided inconsistent concussion histories. Male gender, ADHD, and greater number of baseline concussions were significantly associated with inconsistency in reporting. Overall, these findings suggest that student athletes are quite consistent when reporting their concussion history when surveyed twice during high school.
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Journal of neurotrauma · Jan 2017
Adolescent Mice Demonstrate a Distinct Pattern of Injury after Repetitive Mild Traumatic Brain Injury.
Recently, there has been increasing interest in outcomes after repetitive mild traumatic brain injury (rmTBI) (e.g., sports concussions). Although most of the scientific attention has focused on elite athlete populations, the sequelae of rmTBI in children and young adults have not been well studied. Prior TBI studies have suggested that developmental differences in response to injury, including differences in excitotoxicity and inflammation, could result in differences in functional and histopathological outcomes after injury. ⋯ Three months after injury, adolescent and adult mice demonstrated increased ionized calcium binding adaptor 1 (IbA1) immunolabeling compared with sham controls. Compared with sham controls, NMDA receptor subtype 2B (NR2B) expression in the hippocampus was reduced by ∼20% in both adolescent and adult injured mice. The data suggest that injured adolescent mice may show a distinct pattern of functional deficits after injury that warrants further mechanistic studies.