Journal of neurotrauma
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Journal of neurotrauma · Feb 2006
Mechanisms and consequences of neuronal stretch injury in vitro differ with the model of trauma.
The deformation to the brain that occurs during traumatic brain injury (TBI) results in a complex strain distribution throughout the brain tissue. Recently, many in vitro models of neuronal injury have been developed to simplify the mechanics which occur during TBI. We hypothesized that the type of mechanical insult imparted onto neurons would significantly alter both the mechanism and severity of the neuronal response to injury. ⋯ Despite the large ([Ca2+]i) transients, neither injury profile resulted in death within 24 h of injury. Interestingly, though, uniaxially stretched neurons exhibited enhanced [Ca+2]i influx following NMDA stimulation 24 h after trauma, compared to both control and biaxially stretched neurons. These data point out that the type of mechanical insult will influence the acute mechanisms of injury in vitro, can cause differences in the response to potential secondary excitotoxic injury mechanisms, and emphasizes the need to further study how these mechanical conditions can separately affect cell fate following mechanical injury.
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Journal of neurotrauma · Feb 2006
Correlation between target reinnervation and distribution of motor axons in the injured rat sciatic nerve.
Peripheral nerve injuries are rarely followed by complete return of function. Deficits are particularly important for motor function, resulting in paralysis and muscle atrophy. In different groups, the sciatic nerve was either crushed or transected and repaired by direct suture or by tube repair using silicone or collagen tubes. ⋯ The normal fascicular architecture and grouping of ChAT+ fibers were maintained after nerve crush, but lost after section and repair, where motor fibers were scattered within small regenerated fascicles throughout the nerve. The loss of fascicular organization was related to the deficient recovery of locomotor function. Thus, labeling of motor axons by ChAT immunohistochemistry provides useful information for the study of the degree and specificity of nerve regeneration.