Baseline (bottom trace) and time-course (120 minutes) 13C MRS spectra acquired from an individual rat brain during intravenous infusion of [13C6]-D-glucose. Each spectrum was averaged for 20 minutes. Parameters for data processing: lb = −15, gb = 0.12. Glu-C5: glutamate C5, Gln-C5: glutamine C5, Asp-C4: aspartate C4, Glu-C1: glutamate C1, Gln-C1: glutamine C1.