Figure 7.

Energy metabolism differences between astrocytes and neurons. The expression of several regulatory enzymes by astrocytes but not neurons allows astrocytes to adapt their metabolic flux to the energy state of the cell and to perform higher rate of aerobic glycolysis. Left, Diagram of energy metabolism pathways. Glycogen metabolism and glycolysis, which occur in the cytosol, and the tricarboxylic acid cycle, which occurs in the mitochondria, are shown. Steps highlighted with red asterisks are differentially regulated in astrocytes and neurons. Right, Detailed diagram of energy metabolism differences between astrocytes and neurons. Metabolic steps with key differences are labeled with numbers 1–4 and explained below the diagram. The rate of reactions is represented by the width of the arrows. The predominant metabolic products converted from pyruvate (lactate in astrocytes and acetyl-CoA in neurons) are highlighted in green.