Figure 5.

Integration of metabolic pathways operating in oligodendrocytes in the context of metabolic interactions with astrocytes and neurons/axons. The pathways investigated in this study are highlighted in red in the oligodendrocyte: glucose is taken up and subsequently metabolized either via glycolysis only (1) or also via the pentose phosphate pathway (2); the resulting pyruvate (PYR) produced can be reduced to lactate (LAC) (3) which can be released and taken up by cells with lower lactate concentration. Moreover, pyruvate can be carboxylated via PC or malic enzyme (ME) into oxaloacetate (OAA) or malate (MAL) or enter the TCA cycle after being converted to acetyl CoA (Ac‐CoA) via PDH (4). The TCA cycle intermediate α‐ketoglutarate (α‐KG) gives rise to glutamate (GLU) and, subsequently, glutamine (GLN), but none of these aminoacids appear to be significantly released. Pyruvate can be further completely oxidized if it is decarboxylated via ME, a pathway called pyruvate recycling (5), which also seems to be present in this cell type. Oligodendrocytes can also metabolize acetate into acetyl CoA (6) that can be then incorporated into lipids or oxidized in the TCA cycle. [Color figure can be viewed in the online issue, which is available at wileyonlinelibrary.com.]