Heterogeneous regional and temporal energetic impairment following controlled cortical impact injury in rats

Abstract Objectives: Following traumatic brain injury metabolic stability is impaired. Duration and reversibility of these changes might be important to guide specific interventions. Methods: To characterize temporal and regional changes in cerebral metabolism, 68 male Sprague–Dawley rats were subjected to a focal cortical contusion. Lesion progression and mitochondrial impairment were determined by magnetic resonance imaging (MRI) and triphenyl tetrazolium chloride (TTC) staining, respectively. Metabolic alterations were determined at hours 6 and 24 and day 7 by measuring extracellular glucose, lactate and hypoxanthine levels with microdialysis catheters placed adjacent and distant to the contusion and by quantifying changes in tissue ATP, lactate and glucose using bioluminescence imaging. Results: The cortical lesion reached its maximal extent at hour 24 and remained confined to the ipsilateral hemisphere. In microdialysate, at hour 6, extracellular hypoxanthine and lactate reached maximal values, there...