Figure 4.

Selected metabolic rates (µmol/g/min) for cerebral cortex (CX), cerebellum (CB), hippocampus (HP) and striatum (ST) reported as best estimate (crossed circles) obtained from fitting of data to the three-compartment model and box-and-whiskers reporting minimum, 25th percentile, median, 75th percentile, and maximum for the frequency distribution determined from the Monte-Carlo analysis (MC). Definitions: Vpc, rate of anaplerosis via pyruvate carboxylase; Vgln, rate of glutamine synthesis via glutamine synthetase; Vgad, rate of GABA synthesis via glutamate decarboxylase (GAD); Vtca_Tot (=Vtca_N + Vtca_A + Vtca_GA), rate of total TCA cycle; Vtca_N, Vtca_GA and Vtca_A rate of TCA cycling in glutamatergic and GABAergic neurons, and astroglia, respectively; Vcyc_GluGln, rate of glutamate-glutamine cycling; Vcyc_GABAGln, rate of GABA-glutamine cycling. Vcyc_GluGln, Vcyc_GABAGln and Vtca_N were iterated, whereas the other rates shown were calculated as specified in the model equations given in supplementary information Table S1. In supplementary information, additional rates appear in Table S4 and the frequency distribution for Vpc for all four brain regions are shown in Figure S5.