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The Role of Brain Glycogen in Supporting Physiological Function
Laura R Rich1, William Harris1, Angus M Brown1,2
1School of Life Sciences, University of Nottingham, Nottingham, United Kingdom.
Frontiers in Neuroscience
|November 22, 2019
Summary
Brain glycogen, primarily in astrocytes, fuels neurons by providing lactate. This energy transfer is crucial for functions like memory formation and maintaining axon conduction, especially during high energy demand or low glucose conditions.
Area of Science:
- Neuroscience
- Cellular Metabolism
- Astrocyte Biology
Background:
- Mammalian brain glycogen exists at low concentrations, not typical for energy reserves.
- Glycogen is exclusively found in astrocytes but benefits neurons.
- This suggests a non-conventional energy transfer mechanism between glial and neural cells.
Purpose of the Study:
- To investigate the role of astrocyte glycogen in supporting neuronal function.
- To elucidate the metabolic pathways and transport mechanisms of brain glycogen.
- To understand glycogen's contribution to physiological brain processes like memory.
Main Methods:
- Utilized rodent optic nerve and hippocampus models.
- Assessed glycogen's role in axon conduction and memory formation.
- Investigated lactate as a metabolic intermediary.
Main Results:
- Astrocyte glycogen supports axon conduction via lactate transfer in the optic nerve.
- Glycogen-derived lactate supplements axonal metabolism during hypoglycemia, aglycemia, and high energy demand.
- Glycogen is vital for neuronal lactate supply during memory formation in the hippocampus.
Conclusions:
- Brain glycogen serves as a critical energy source for neurons, primarily through lactate.
- Astrocyte glycogen plays an indispensable role in supporting vital brain functions, including learning and memory.
- The glial-neuronal metabolic coupling involving glycogen is essential for brain physiology.
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