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Updated: Jun 21, 2026
Profiling Voltage-gated Potassium Channel mRNA Expression in Nigral Neurons using Single-cell RT-PCR Techniques
Published on: September 27, 2011
Characterization of voltage-gated potassium channels in human neural progenitor cells
Grit Schaarschmidt1, Florian Wegner, Sigrid C Schwarz
1Department of Neurology, University of Leipzig, Leipzig, Germany. grit.schaarschmidt@medizin.uni-leipzig.de
Background:
Voltage-gated potassium (K(v)) channels are among the earliest ion channels to appear during brain development, suggesting a functional requirement for progenitor cell proliferation and/or differentiation. We tested this hypothesis, using human neural progenitor cells (hNPCs) as a model system.
Methodology/Principal Findings:
In proliferating hNPCs a broad spectrum of K(v) channel subtypes was identified using quantitative real-time PCR with a predominant expression of the A-type channel K(v)4.2. In whole-cell patch-clamp recordings K(v) currents were separated into a large transient component characteristic for fast-inactivating A-type potassium channels (I(A)) and a small, sustained component produced by delayed-rectifying channels (I(K)). During differentiation the expression of I(A) as well as A-type channel transcripts dramatically decreased, while I(K) producing delayed-rectifiers were upregulated. Both K(v) currents were differentially inhibited by selective neurotoxins like phrixotoxin-1 and alpha-dendrotoxin as well as by antagonists like 4-aminopyridine, ammoniumchloride, tetraethylammonium chloride and quinidine. In viability and proliferation assays chronic inhibition of the A-type currents severely disturbed the cell cycle and precluded proper hNPC proliferation, while the blockade of delayed-rectifiers by alpha-dendrotoxin increased proliferation.
Conclusions/Significance:
These findings suggest that A-type potassium currents are essential for proper proliferation of immature multipotent hNPCs.
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