As in the liver, ethanol metabolism in the brain involves two stages (Fig. 1A). It is first oxidized to acetaldehyde, followed by further oxidation to acetate (Zimatkin and Deitrich, 1997). While the second reaction is generally catalysed by aldehyde dehydrogenase-2 (ALDH2) located inside the mitochondria; the first reaction can utilize any of three distinct enzymes - alcohol dehydrogenase (ADH), catalase (CAT) or cytochrome P450 2E1 (CYP2E1), each located in different subcellular organelles.
