Glycogen Metabolism in CNS White Matter

Although the mammalian brain contains glycogen, located exclusively in astrocytes, the low concentration with which it occurs calls into question is functional relevance. The discovery that neurons can survive on ATP generated by nonglucose substrates has led to a resurgence of interest in brain glycogen, which is released from astrocytes as lactate. Brain glycogen is highly regulated and under active physiological control. A prominent role for brain glycogen as a provider of supplemental energy substrate during periods of increased tissue energy demand, when ambient normoglycaemic glucose is unable to meet immediate energy requirements, is gaining credibility. © 2009 Elsevier Ltd All rights reserved.