Journal of neurotrauma
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Journal of neurotrauma · Jun 2013
Remote brain network changes after unilateral cortical impact injury and their modulation by acetylcholinesterase inhibition.
We explored whether cerebral cortical impact injury (CCI) effects extend beyond direct lesion sites to affect remote brain networks, and whether acetylcholinesterase (AChE) inhibition elicits discrete changes in functional activation of motor circuits following CCI. Adult male rats underwent unilateral motor-sensory CCI or sham injury. Physostigmine (AChE inhibitor) or saline were administered subcutaneously continuously via implanted minipumps (1.6 micromoles/kg/day) for 3 weeks, followed by cerebral perfusion mapping during treadmill walking using [(14)C]-iodoantipyrine. ⋯ This phenomenon, augmented by physostigmine, may partially compensate motor deficits. FC decreased inter-hemispherically and in negative, but not positive, intra-hemispherical FC, and it was not affected by physostigmine. Circuit-based approaches into functional brain reorganization may inform future behavioral or molecular strategies to augment targeted neurorehabilitation.
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Journal of neurotrauma · Jun 2013
An oligomeric diet limits the response to injury in traumatic brain-injured rats.
Adequate nutritional support is a major challenge in brain injury patients, because malnutrition cannot be reversed by standard enteral nutrition. We hypothesized that an oligomeric formula could improve nutritional status by restoring intestinal trophicity. Eighteen male Sprague-Dawley rats (300-330 g) underwent gastrostomy on day-7 (D-7) and traumatic brain injury (TBI) by hydraulic percussion (D0) and were then fed for 4 days with either a polymeric formula (Sondalis® HP, TBIP, n = 9), or an oligomeric formula (Peptamen® HN, TBIO, n = 9). ⋯ TBIP, p < 0.05). Glutamine (GLN) concentration was improved by the oligomeric diet in both plasma (TBIO: 688 ± 19 vs. control: 591 ± 45 and TBIP: 615 ± 42 μmol/L, p < 0.05) and soleus muscle. These results show that the use of an oligomeric diet may limit response to injury after brain injury and could be a simple nutritional strategy in this setting.
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Journal of neurotrauma · Jun 2013
Multi-modal approach for investigating brain and behavior changes in an animal model of traumatic brain injury.
Use of novel approaches in imaging modalities is needed for enhancing diagnostic and therapeutic outcomes of persons with a traumatic brain injury (TBI). This study explored the feasibility of using functional magnetic resonance imaging (fMRI) in conjunction with behavioral measures to target dynamic changes in specific neural circuitries in an animal model of TBI. Wistar rats were randomly assigned to one of two groups (traumatic brain injury/sham operation). ⋯ The Morris water maze test indicated that cognitive deficits persisted for the first week after injury and, to a large extent, resolved thereafter. Resting state functional connectivity (rsFC) analysis detected initially diminished connectivity between cortical areas involved in cognition for the TBI group; however, the connectivity patterns normalized at 1 week and remained so at the 3 weeks post-injury time point. Taken together, we have demonstrated an objective in vivo marker for mapping functional brain changes correlated with injury-associated cognitive behavior deficits and offer an animal model for testing potential therapeutic interventions options.
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Journal of neurotrauma · Jun 2013
The Glasgow Outcome at Discharge Scale: an inpatient assessment of disability after brain injury.
This study assesses the validity and reliability of the Glasgow Outcome at Discharge Scale (GODS), which is a tool that is designed to assess disability after brain injury in an inpatient setting. It is derived from the Glasgow Outcome Scale-Extended (GOS-E), which assesses disability in the community after brain injury. ⋯ In terms of predictive validity the GODS is highly associated with the GOS-E after discharge (Spearman correlation 0.512; 95% CI 0.281, 0.687), with the DRS, and with physical, fatigue, and social subscales of the SF-36. The GODS is recommended as an assessment tool for disability after brain injury pre-discharge and can be used in conjunction with the GOS-E to monitor disability between hospital and the community.
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Journal of neurotrauma · May 2013
Chronic at- and below-level pain after moderate unilateral cervical spinal cord contusion in rats.
Chronic neuropathic pain is a significant consequence of spinal cord injury (SCI) that is associated with evoked pain, including allodynia and/or hyperalgesia. Allodynia is defined as a painful response to normally innocuous stimuli, and hyperalgesia occurs when there is an amplified pain response to normally noxious stimuli. We describe a model of a unilateral cervical level (C5) contusion injury where sensory recovery was assessed weekly for 6 weeks in 32 adult, female, Sprague-Dawley rats. ⋯ The contralesional forepaw and both hindpaws of rats showed a slight increase in paw withdrawal threshold to tactile stimuli acutely after SCI, corresponding to ipsilesional forelimb motor deficits that resolve over time. That there is no difference among allodynic and non-allodynic groups in overall spared tissue or specifically of the dorsal column or ventrolateral white matter where ascending sensory tracts reside suggests that SCI-induced pain does not depend solely on the size or extent of the lesion, but that other mechanisms are in play. These observations provide a valid model system for future testing of therapeutic interventions to prevent the onset or to reduce the debilitating effects of chronic neuropathic pain after SCI.