Journal of neurotrauma
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Journal of neurotrauma · Dec 1995
Severe controlled cortical impact in rats: assessment of cerebral edema, blood flow, and contusion volume.
Controlled cortical impact (CCI) is a contemporary model of experimental cerebral contusion. We examined the cerebrovascular and neuropathologic effects of a severe CCI in rats. The utility of magnetic resonance imaging (MRI) for the assessment of contusion volume after severe CCI was also established. ⋯ Estimates of contusion volume by MRI and histology were closely correlated (r = 0.941, p < 0.017). Severe CCI in rats is accompanied by contusion, reproducible edema, and marked hypoperfusion, involving over 14% of the injured hemisphere, and can be produced with minimal mortality. T2-weighted MRI successfully and noninvasively identifies contusion volume in this model.
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Journal of neurotrauma · Dec 1995
Regional concentrations of cyclic nucleotides after experimental brain injury.
Regional concentrations of lactate, glucose, cAMP, and cGMP were measured after lateral fluid percussion brain injury in rats. At 5 min after injury, while tissue concentrations of lactate were elevated in the cortices and hippocampi of both the ipsilateral and contralateral hemispheres, those of glucose were decreased in these brain regions. By 20 min after injury, increases of lactate concentrations and decreases of glucose concentrations were observed only in the cortices and in the hippocampus of the ipsilateral hemisphere. ⋯ The tissue concentrations of cGMP were found to be elevated only in the ipsilateral hippocampus at 5 min after injury. The present observation that tissue glucose decreases in the injured cortex and the ipsilateral hippocampus are consistent with the published findings of increased hyperglycolysis and oxidative metabolism in brain immediately after injury. The present findings that the concentrations of cAMP and cGMP change in the cortex and hippocampus provide biochemical evidence for the neurotransmitter's surge after brain injury.