» Articles » PMID: 22357855

Sodium-activated Potassium Channels Are Functionally Coupled to Persistent Sodium Currents

Overview
Journal J Neurosci
Specialty Neurology
Date 2012 Feb 24
PMID 22357855
Citations 46
Authors
Affiliations
Soon will be listed here.
Abstract

We report a novel coupled system of sodium-activated potassium currents (I(KNa)) and persistent sodium currents (I(NaP)), the components of which are widely distributed throughout the brain. Its existence and importance has not been previously recognized. Although I(KNa) was known to exist in many cell types, the source of Na(+) which activates I(KNa) remained a mystery. We now show in single membrane patches generated from the somas of rat neurons that sodium influx through I(NaP) is sufficient for activation of K(Na) channels, without substantial contribution from the transient sodium current or bulk [Na(+)](i). I(NaP) was found to be active at cell membrane resting potentials, a finding that may explain why I(KNa) can be evoked from negative holding potentials. These results show an unanticipated role for I(NaP) in activating a negative feedback system countering the excitable effects I(NaP); the interrelatedness of I(NaP) and I(KNa) suggests new ways neurons can tune their excitability.

Citing Articles

Heterozygous expression of a gain-of-function variant has differential effects on somatostatin- and parvalbumin-expressing cortical GABAergic neurons.

Shore A, Li K, Safari M, Qunies A, Spitznagel B, Weaver C Elife. 2024; 13.

PMID: 39392867 PMC: 11469685. DOI: 10.7554/eLife.92915.


SLO2.1/NALCN Functional Complex Activity in Mouse Myometrial Smooth Muscle Cells During Pregnancy.

Ferreira J, Kent L, McCarthy R, Butler A, Ma X, Peramsetty N bioRxiv. 2024; .

PMID: 38853884 PMC: 11160795. DOI: 10.1101/2024.05.29.596465.


Loose-patch clamp analysis applied to voltage-gated ionic currents following pharmacological ryanodine receptor modulation in murine hippocampal cornu ammonis-1 pyramidal neurons.

Bertagna F, Ahmad S, Lewis R, Silva S, McFadden J, Huang C Front Physiol. 2024; 15:1359560.

PMID: 38720787 PMC: 11076846. DOI: 10.3389/fphys.2024.1359560.


A molecular switch in RCK2 triggers sodium-dependent activation of K1.1 (KCNT1) potassium channels.

Cole B, Kalli A, Pilati N, Muench S, Lippiat J Biophys J. 2024; 123(14):2145-2153.

PMID: 38605520 PMC: 11309980. DOI: 10.1016/j.bpj.2024.04.007.


Disease-causing Slack potassium channel mutations produce opposite effects on excitability of excitatory and inhibitory neurons.

Wu J, Quraishi I, Zhang Y, Bromwich M, Kaczmarek L Cell Rep. 2024; 43(3):113904.

PMID: 38457342 PMC: 11013952. DOI: 10.1016/j.celrep.2024.113904.


References
1.
Bhattacharjee A, Kaczmarek L . For K+ channels, Na+ is the new Ca2+. Trends Neurosci. 2005; 28(8):422-8. DOI: 10.1016/j.tins.2005.06.003. View

2.
Scott L, Mathews P, Golding N . Perisomatic voltage-gated sodium channels actively maintain linear synaptic integration in principal neurons of the medial superior olive. J Neurosci. 2010; 30(6):2039-50. PMC: 2827923. DOI: 10.1523/JNEUROSCI.2385-09.2010. View

3.
Stafstrom C, Schwindt P, CRILL W . Repetitive firing in layer V neurons from cat neocortex in vitro. J Neurophysiol. 1984; 52(2):264-77. DOI: 10.1152/jn.1984.52.2.264. View

4.
Barnes S, Hille B . Veratridine modifies open sodium channels. J Gen Physiol. 1988; 91(3):421-43. PMC: 2216135. DOI: 10.1085/jgp.91.3.421. View

5.
Bhattacharjee A, von Hehn C, Mei X, Kaczmarek L . Localization of the Na+-activated K+ channel Slick in the rat central nervous system. J Comp Neurol. 2005; 484(1):80-92. DOI: 10.1002/cne.20462. View