Electrophysiological Characterization of Voltage-Dependent Potassium Channels in Human Neural Stem Cells |
Electrophysiological Characterization of Voltage-Dependent Potassium Channels in Human Neural Stem Cells |
배재훈 |
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Abstract |
Neural stem cells maybe allowed
using in development of
transplantation for treatment of neuronal disorders. This study has characterized
the profile of membrane ion channels in cultured human neural stem cells using
the patch clamp technique in the whole cell mode. In voltage clamp mode; the
cells expressed both outward and inward rectifying K+ currents with no evidence
for Na+ current. The outward delayed rectifying K+ current was activated by
depolarization to potential more positive than -30 mV without inactivation and
the reversal potential of this current was -54.1 mV; estimated from the
observation of tail current. The inward rectifying K+ current was activated by
hyperpolarization to potential more negative than -60 mV and this current had
two kinetics including a fast inactivating instantaneous current and a steady state
current according to time course of hyperpolarizing pulse. Both the outward and
the inward K+ currents were blocked by 5 mM tetraethylammonium (TEA) in the
same extent; but not by 2 mM 4-aminopyridine. It suggests that human neural
stem cells have both outward and inward rectifying K+ currents and the
characteristics of TEA-sensitive outward rectifying K+ currents without Na+
currents are similar to those of glial precursor or progenitor cells. |
Key Words:
Electrophysiology,
Neural stem cells, Voltage-dependent potassium
channels |