Specific properties of sodium currents in multipotent striatal progenitor cells.
European Journal of Neuroscience. 2008-09-01; 28(6): 1068-1079
DOI: 10.1111/j.1460-9568.2008.06427.x
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1. Eur J Neurosci. 2008 Sep;28(6):1068-79. doi: 10.1111/j.1460-9568.2008.06427.x.
Epub 2008 Sep 9.
Specific properties of sodium currents in multipotent striatal progenitor cells.
Wasner U(1), Geist B, Battefeld A, Bauer P, Müller J, Rolfs A, Strauss U.
Author information:
(1)Department of Neurology, University of Rostock, Rostock, Germany.
This study investigates the impact of intrinsic currents on early neural
development. A rat striatal ST14A cell line immortalized by SV40 large T antigen
was employed as a model system because these cells act as multipotent neural
progenitors when maintained at a permissive temperature of 33 degrees C. The
whole-cell patch-clamp, molecular and immunocytochemical experiments point to a
unique role of sodium currents in the multipotential stage of neural development.
In initial experiments, action potential-like responses were only present when
multipotential ST14A cells were substantially hyperpolarized. This led us to
presume that sodium channels were only recruited during deep hyperpolarization.
Subsequent voltage-clamp studies confirmed a remarkably hyperpolarized
steady-state inactivation of the sodium currents and also showed that the
underlying channels were tetrodotoxin resistant. Direct comparison with cells
whose neuronal fate was already determined, i.e. short-term cultured striatal
cells isolated at embryonic day 14 and after birth (post-natal day 0), showed
that both traits are unique to ST14A cells. However, sodium currents in all three
groups had a fast time- and voltage-dependent activation, as well as full
inactivation with roughly similar kinetics. The peculiarity in ST14A might be
explained by a relative excess of heart-type Na(V)1.5 and particularly its splice
variant Na(V)1.5a, as suggested by reverse transcription-polymerase chain
reaction results. We conclude that multipotent neural progenitor cells express
Na(+) channels in their membrane irrespective of their fate but these channels
have little effect due to their subunit composition, which is regulated by
alternative splicing.
DOI: 10.1111/j.1460-9568.2008.06427.x
PMID: 18783365 [Indexed for MEDLINE]