Fig. 1.

Schematic of [U-¹³C]glucose in the brain. Simplified schematic of ¹³C-labeling patterns after the metabolism of [U-¹³C]glucose via glycolysis and the TCA cycle. Empty circles, ¹²C; black filled circle, ¹³C; gray filled circles, ¹³C derived from ¹³C-labeled oxaloacetate that enters the second turn of the TCA cycle (gray dotted lines). *Metabolites that were not measured in this study. GA3P, glyceraldehyde 3-phosphate; 13BPG, 1,3-bisphosphoglycerate; 3PG, 3-phosphoglycerate; 2PG, 2-phosphoglycerate; Ac-CoA, acetyl CoA; OAA, oxaloacetate.