TBI-Induced Cerebral Metabolic Depression and Recovery

The central theme of this proposal is to identify the metabolic destination of cerebral glucose taken up after traumatic brain injury (TBI), thereby discovering alternative metabolic pathways receptive to interventions (metabolic therapy) to enhance cellular and functional recovery and ultimately change the future of TBI patient management. Two basic science projects will explore these fundamental issues, and are designed to lead as well as complement two clinical projects. Project 1 (Dr. Richard Sutton) addresses the administration of glucose and pyruvate following cortical controlled impact in the rat to examine their impact on cerebral metabolism, cellular protection and outcome. Project 2 (Dr. Mayumi Prins) will study postnatal day 35 and postnatal day 90 rats using the developmental maturation of fuel transporters as an independent variable. Transporters for the fuels glucose, lactate and ketones will be measured in terms of their expression and function. The focus of ketone metabolism is a unique feature in this project as it not only addresses the effect on outcome, but also rigorously studies the appropriate biochemical pathways. Project 3 (Dr. Paul Vespa) addresses the topic of glucose substrate supply for human TBI patients primarily from the perspective of management of serum glucose concentration. Using different levels of insulin therapy, the effect on global and regional cerebral metabolism will be compared to neurochemical and anatomical markers of cell distress. In a creative cross over experimental design preliminary data will be collected for a future clinical trail. Project 4 (Dr. Neil Martin) will utilize the Kety-Schmidt technique to address how glucose is consumed differently in the human injured brain. The investigators within this program will determine the change in the consumption of cerebral glucose, the effects of changes in transporters, and the effects of enhancing or restricting glucose delivery and the potential use of alternative fuels. This program project will be housed within the UCLA Brain Injury Research Center (Dr. David A. Hovda, Director) so as to assure appropriate imaging, administrative and laboratory support.