Journal of neurotrauma
-
Journal of neurotrauma · Apr 2009
Comparative StudyStrain differences in response to traumatic brain injury in Long-Evans compared to Sprague-Dawley rats.
The selected strain of rodent used in experimental models of traumatic brain injury is typically dependent upon the experimental questions asked and the familiarity of the investigator with a specific rodent strain. This archival study compares the injury responsiveness and recovery profiles of two popular outbred strains, the Long-Evans (LE) and the Sprague-Dawley (SD), after brain injury induced by lateral fluid percussion injury (LFPI). ⋯ Cortical volume loss was not significantly different, but close inspection of the data suggests the possibility that LE rats may be more susceptible to damage in the hemisphere contralateral to the injury site than are SD rats. It is hoped that the information provided here encourages greater attention to the subtle differences and similarities between strains in future pre-clinical efficacy studies of traumatic brain injury.
-
Journal of neurotrauma · Apr 2009
Locomotor recovery after spinal cord lesions in the lamprey is associated with functional and ultrastructural changes below lesion sites.
While axonal regeneration continues to be the major focus of research into spinal injury, there is growing evidence for changes in functional properties below lesion sites. In this study we have used the lamprey, a model system for studying axonal regeneration after spinal injury, to examine whether functional and ultrastructural changes below lesion sites might also contribute to the recovery of locomotor function in this system. In the current study, the majority of the animals showed good functional recovery 10 weeks after lesioning, even when there was no physiological evidence for regeneration across the lesion site (although animals that recovered poorly always lacked regeneration). ⋯ There were also changes in synaptic ultrastructure, including a reduction of the synaptic gap and an increase in synaptic vesicle pools at asymmetric (putative excitatory) synapses. These results provide the first evidence for functional changes below lesion sites in the lamprey, and suggest that locomotor recovery reflects an interaction between regenerated axons and altered networks below lesion sites. The lamprey offers a tractable model system in which to investigate how interactions between altered locomotor networks and regenerated axons are organized to promote locomotor recovery.
-
Spinal cord injury (SCI) launches a complex cascade of events that leads to progressive damage and loss of function. Compromise of plasma membrane integrity due to the mechanical impact is an acute event that may contribute to cellular dysfunction. Therefore, the objective of this study was to better understand the extent of acute plasma membrane damage associated with SCI as a function of injury severity and membrane defect size. ⋯ In addition, after moderate injury, cell bodies and axons (located up to 2 mm and 3 mm from the epicenter, respectively) took up significantly more of the 3-kDa and 10-kDa dextran permeability marker compared to sham controls. Permeable neuronal cell bodies exhibited a morphological appearance characterized by pericellular blebbing, suggesting that plasma membrane compromise is associated with pathophysiological cellular alterations. Collectively, these results enhance our understanding of acute SCI and provide targets for developing novel treatment strategies.
-
Journal of neurotrauma · Mar 2009
ReviewHypothermia after cardiac arrest: lessons learned from national registries.
Therapeutic hypothermia has been shown to improve outcome in comatose survivors after cardiac arrest of cardiac origin. After the clinical implementation of this novel treatment, several international web-based registries were opened to facilitate the prospective collection of patient treatment data. The aim was to evaluate the actual use of hypothermia in clinical practice, safety aspects, resource utilization, and outcome in large cohorts of patients. ⋯ The three registries have different strengths and weaknesses, but the clinical outcome compares well with that of the two randomized trials. Our conclusions are that hypothermia is feasible to implement, that it seems reasonably safe, and that the outcome compares well with previous reports. We also conclude that the treatment with hypothermia after cardiac arrest is more widely applied than what is strictly evidence based.
-
Preclinical as well as clinical studies in traumatic brain injury (TBI) have established the likely association of secondary injury and outcome in adults in children following severe injury. Similarly, there is growing evidence in experimental laboratory studies that moderate hypothermia has a beneficial effect on outcome, though the exact mechanisms remain to be absolutely defined. ⋯ Further preliminary randomized clinical trials, both single institution and multicenter, have provided the initial data on safety and efficacy, though larger, Phase III studies are necessary to ensure both the safety and efficacy of hypothermia in pediatric TBI prior to implementation as part of the standard of care. It is expected that hypothermia initiated early after severe TBI will have a protective effect on the pediatric brain and can be done safely, but this still remains to be definitively tested.