Regulation of potassium by glial cells in the centralnervous system

  • Paulo Kofuji
  • Eric A. Newman

Rapid changes in extracellular K+ concentration ([K+]o) in the mammalian central nervous system (CNS) are counteracted by simple passive diffusion as well as by cellular mechanisms of K+ clearance. Regulation of [K+]o can occur via glial or neuronal uptake of K+ ions through transporters or K+-selective ion channels. The best studied mechanism of [K+]o regulation in the brain is K+spatial buffering, wherein the glial syncytium disperses local extracellular K+ increases by transferring K+ from sites of elevated [K+]o to those with lower [K+]o. In recent years, K+ spatial buffering has been implicated or directly demonstrated by a variety of experimental approaches, including electrophysiological and optical methods. A specialized form of spatial buffering termed K+siphoning takes place in the vertebrate retina, where glial Müller cells express inwardly rectifying K+channels (Kir channels) positioned in membrane domains near to the vitreous humor and blood vessels. This highly...


Glial Cell Vitreous Humor Neurovascular Coupling Central Nervous System Region Dystrophin Glycoprotein Complex 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



Aquaporin 4


Central nervous system




Dystrophin glycoprotein complex


Intrinsic optic signal




Extracellular K+ concentration

Kir channel

Inwardly rectifying K+ channel

Na+ pump

Na+, K+-ATPase


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© Springer Science+Business Media, LLC 2009

Authors and Affiliations

  • Paulo Kofuji
    • 1
  • Eric A. Newman
    • 1
  1. 1.Department of NeuroscienceUniversity of MinnesotaMinneapolisUSA

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