Fig. 4.
Acetyl-CoA synthesis supported by β-hydroxybutyrate (βOHB), fatty acids β-oxidation, and acetyl-l-carnitine metabolism. Acetyl-CoA can be generated from pyruvate, βOHB, β-oxidation of fatty acids (particularly in astrocytes), and from acetyl-l-carnitine. During these metabolic reactions NAD+ is reduced to NADH.