Abstract
The signals detected during physiological activation of the brain with 18F - deoxyglucose (FDG) Positron Emission Tomography (PET) reflect predominantly uptake of this tracer into astrocytes. This notion provides a cellular and molecular basis for the FDG PET technique. In this paper, we present two new computational models of the molecular interactions governing the brain energy metabolism. The first model describes the glutamate-stimulated glucose uptake and use into astrocytes.The second includes also the effects of inter-cellular waves of Na+ and Ca 2+ generated by astrocytes on the glucose metabolism. The kinetic rates constants of the models have been identified by fitting the sets of ordinary differential equations to dynamic PET scans of 31 patients.