Insights & Perspectives
Why does the brain (not) have glycogen?
Article first published online: 21 FEB 2011
Copyright © 2011 WILEY Periodicals, Inc.
Volume 33, Issue 5, pages 319–326, May 2011
How to Cite
DiNuzzo, M., Maraviglia, B. and Giove, F. (2011), Why does the brain (not) have glycogen?. Bioessays, 33: 319–326. doi: 10.1002/bies.201000151
- Issue published online: 18 APR 2011
- Article first published online: 21 FEB 2011
- brain glycogen;
- neuronal activation
In the present paper we formulate the hypothesis that brain glycogen is a critical determinant in the modulation of carbohydrate supply at the cellular level. Specifically, we propose that mobilization of astrocytic glycogen after an increase in AMP levels during enhanced neuronal activity controls the concentration of glucose phosphates in astrocytes. This would result in modulation of glucose phosphorylation by hexokinase and upstream cell glucose uptake. This mechanism would favor glucose channeling to activated neurons, supplementing the already rich neuron-astrocyte metabolic and functional partnership with important implications for the energy compounds used to sustain neuronal activity. The hypothesis is based on recent modeling evidence suggesting that rapid glycogen breakdown can profoundly alter the short-term kinetics of glucose delivery to neurons and astrocytes. It is also based on review of the literature relevant to glycogen metabolism during physiological brain activity, with an emphasis on the metabolic pathways identifying both the origin and the fate of this glucose reserve.