Kir4.1-mediated spatial buffering of K(+): Experimental challenges in determination of its temporal and quantitative contribution to K(+) clearance in the brain

Brian Roland Larsen, Nanna MacAulay

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38 Citations (Scopus)

Abstract

Abstract Neuronal activity results in release of K(+) into the extracellular space of the central nervous system. If the excess K(+) is allowed to accumulate, neuronal firing will be compromised by the ensuing neuronal membrane depolarization. The surrounding glial cells are involved in clearing K(+) from the extracellular space by molecular mechanism(s), the identity of which have been a matter of controversy for over half a century. Kir4.1-mediated spatial buffering of K(+) has been promoted as a major contributor to K(+) removal although its quantitative and temporal contribution has remained undefined. We discuss the biophysical and experimental challenges regarding determination of the contribution of Kir4.1 to extracellular K(+) management during neuronal activity. It is concluded that 1) the geometry of the experimental preparation is crucial for detection of Kir4.1-mediated spatial buffering and 2) Kir4.1 enacts spatial buffering of K(+) during but not after neuronal activity.

Original languageEnglish
JournalChannels (Austin)
Volume8
Issue number6
Pages (from-to)544-550
Number of pages7
ISSN1933-6950
DOIs
Publication statusPublished - Oct 2014

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