Glycogen serves as an important energy reservoir in the human body. Despite the abundance of glycogen in the liver and skeletal muscles, its concentration in the brain is relatively low, hence its significance has been questioned. A major challenge in studying brain glycogen metabolism has been the lack of availability of non-invasive techniques for quantification of brain glycogen in vivo. Invasive methods for brain glycogen quantification such as post mortem extraction following high energy microwave irradiation are not applicable in the human brain. With the advent of 13C Magnetic Resonance Spectroscopy (MRS), it has been possible to measure brain glycogen concentrations and turnover in physiological conditions, as well as under the influence of stressors such as hypoglycemia and visual stimulation. This review presents an overview of the principles of the 13C MRS methodology and its applications in both animals and humans to further our understanding of glycogen metabolism under normal physiological and pathophysiological conditions such as hypoglycemia unawareness.
Bibliographical noteFunding Information:
The preparation of this manuscript was supported by the National Institute of Neurological Disorders and Stroke (NINDS) grant R01 NS035192 (ERS, GÖ). The Center for Magnetic Resonance Research is supported by National Center for Research Resources (NCRR) biotechnology research resource grant P41 RR008079, National Institute of Biomedical Imaging and Bioengineering (NIBIB) grant P41 EB015894 and the Institutional Center Cores for Advanced Neuroimaging award P30 NS076408.
© 2014, Springer Science+Business Media New York.
- Brain glycogen
- Magnetic Resonance Spectroscopy (MRS)
- Stress response