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

TY - JOUR

T1 - Kir4.1-mediated spatial buffering of K(+)

T2 - Experimental challenges in determination of its temporal and quantitative contribution to K(+) clearance in the brain

AU - Larsen, Brian Roland

AU - MacAulay, Nanna

PY - 2014/11/1

Y1 - 2014/11/1

N2 - 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.

AB - 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.

U2 - 10.4161/19336950.2014.970448

DO - 10.4161/19336950.2014.970448

M3 - Journal article

C2 - 25483287

SN - 1933-6950

VL - 8

SP - 544

EP - 550

JO - Channels (Austin)

JF - Channels (Austin)

IS - 6

ER -