Journal of neurotrauma
-
Journal of neurotrauma · Feb 2017
Neuropsychiatric symptom modeling in male and female C57BL/6J mice following experimental traumatic brain injury.
Psychiatric symptoms such as anxiety and depression are frequent and persistent complaints following traumatic brain injury (TBI). Modeling these symptoms in animal models of TBI affords the opportunity to determine mechanisms underlying behavioral pathologies and to test potential therapeutic agents. However, testing these symptoms in animal models of TBI has yielded inconsistent results. ⋯ Increased levels of activity were also measured in female mice and injured mice in these tests, and conclusions regarding anxiety should be taken with caution when experimental manipulations induce changes in baseline activity. These results underscore the irreconcilability of results from studies attempting to model TBI-induced neuropsychiatric symptoms. Changes in injury models or better attempts to replicate the clinical syndrome may improve the translational applicability of rodent models of TBI-induced anxiety and depression.
-
Journal of neurotrauma · Feb 2017
ReviewTranslational Relevance of Swine Models of Spinal Cord Injury.
Spinal cord injury (SCI) is a physically and psychologically devastating clinical condition. The typical treatment regimens of decompressive surgery and rehabilitation therapy still leave many patients with permanent disability. The development of new therapies and devices can be accelerated if relevant translational animal models are more effectively used in pre-clinical stages. ⋯ Several spine injury models have recently been developed for swine and are beginning to be used to evaluate new therapies. Swine models of SCI offer tremendous advantages for efficient translation of pre-clinical discoveries and the development of new therapies and devices. Future swine models will also be enhanced by advances in gene-editing technology to further elucidate the complex pathophysiology associated with SCI and provide a means to engineer specific spinal pathologies.
-
Journal of neurotrauma · Feb 2017
Disruption of locomotion in response to hindlimb muscle stretch at acute and chronic time points after a spinal cord injury in rats.
After spinal cord injury (SCI) muscle contractures develop in the plegic limbs of many patients. Physical therapists commonly use stretching as an approach to avoid contractures and to maintain the extensibility of soft tissues. We found previously that a daily stretching protocol has a negative effect on locomotor recovery in rats with mild thoracic SCI. ⋯ The current study extends our observations of the stretching phenomenon to a more clinically relevant moderately severe SCI animal model. The results are in agreement with our previous findings and further demonstrate that spinal cord locomotor circuitry is especially vulnerable to the negative effects of stretching at chronic time points. While the clinical relevance of this phenomenon remains unknown, we speculate that stretching may contribute to the lack of locomotor recovery in some patients.
-
Journal of neurotrauma · Feb 2017
High-Mobility Group Box 1 (HMGB1) is Elevated Systemically in Persons with Acute or Chronic Traumatic Spinal Cord Injury.
Inflammation in traumatic spinal cord injury (SCI) has been proposed to promote damage acutely and oppose functional recovery chronically. However, we do not yet understand the signals that initiate or prolong inflammation in persons with SCI. High-Mobility Group Box 1 (HMGB1) is a potent systemic inflammatory cytokine-or damage-associated molecular pattern molecule (DAMP)-studied in a variety of clinical settings. ⋯ In persons with acute SCI, average HMGB1 levels were significantly elevated within 0-3 days post-injury (6.00 ± 1.8 ng/mL, mean ± standard error of the mean [SEM]) or 4-7 (6.26 ± 1.3 ng/mL, mean ± SEM), compared with controls (1.26 ± 0.24 ng/mL, mean ± SEM; p ≤ 0.001 and p ≤ 0.01, respectively). In persons with chronic SCI who were injured for 15 ± 1.5 years (mean ± SEM), HMGB1 also was significantly elevated, compared with uninjured persons (3.7 ± 0.69 vs. 1.26 ± 0.24 ng/mL, mean ± SEM; p ≤ 0.0001). Together, these data suggest that HMGB1 may be a common, early, and persistent danger signal promoting inflammation in individuals with SCI.
-
Journal of neurotrauma · Feb 2017
Left ventricular mechanics in untrained and trained males with tetraplegia.
Reduced left ventricular (LV) function is common in tetraplegia, yet it is unknown whether intrinsic myocardial function is attenuated. This study examined the effect of SCI and exercise-training status on LV mechanics (intrinsic function) and LV systolic/diastolic function by comparing untrained (UT) and trained (TT) individuals with tetraplegia and able-bodied (AB) individuals. Individuals with tetraplegia had a traumatic, chronic, motor-complete cervical spinal cord injury. ⋯ Diastolic mechanics (apical circumferential strain rate) were significantly enhanced in TT (3.03 ± 0.83 s-1) compared to AB (1.85 ± 0.65 s-1; p < 0.05). There was a trend (p = 0.062) for a between-group difference in apical radial diastolic strain rate (UT: -2.51 ± 0.83 s-1; TT: -3.92 ± 1.96 s-1; AB: -1.84 ± 0.46 s-1). In tetraplegia, attenuated LV systolic function is not attributed to intrinsic dysfunction, whereas exercise-training status appears to improve both global LV diastolic function and LV mechanics.