Document Type

Article

Publication Date

7-2017

Publication Title

PLoS One

Volume

12

Issue

7

Pages

e0181002 (1-20)

DOI

10.1371/journal.pone.0181002

Abstract

This study examined the effect of 5 ns electric pulses on macroscopic ionic currents in whole-cell voltage-clamped adrenal chromaffin cells. Current-voltage (I-V) relationships first established that the early peak inward current was primarily composed of a fast voltage-dependent Na+ current (INa), whereas the late outward current was composed of at least three ionic currents: a voltage-gated Ca2+ current (ICa), a Ca2+-activated K+ current (IK(Ca)), and a sustained voltage-dependent delayed rectifier K+ current (IKV). A constant-voltage step protocol was next used to monitor peak inward and late outward currents before and after cell exposure to a 5 ns pulse. A single pulse applied at an electric (E)-field amplitude of 5 MV/m resulted in an instantaneous decrease of ~4% in peak INa that then declined exponentially to a level that was ~85% of the initial level after 10 min. Increasing the E-field amplitude to 8 or 10 MV/m caused a twofold greater inhibitory effect on peak INa. The decrease in INa was not due to a change in either the steady-state inactivation or activation of the Na+ channel but instead was associated with a decrease in maximal Na+ conductance. Late outward current was not affected by a pulse applied at 5 MV/m. However, for a pulse applied at the higher E-field amplitudes of 8 and 10 MV/m, late outward current in some cells underwent a progressive ~22% decline over the course of the first 20 s following pulse exposure, with no further decline. The effect was most likely concentrated on ICa and IK(Ca) as IKV was not affected. The results of this study indicate that in whole-cell patch clamped adrenal chromaffin cells, a 5 ns pulse differentially inhibits specific voltage-gated ionic currents in a manner that can be manipulated by tuning E-field amplitude.

Comments

This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Original Publication Citation

Yang, L., Craviso, G. L., Vernier, P. T., Chatterjee, I., & Leblanc, N. (2017). Nanosecond electric pulses differentially affect inward and outward currents in patch clamped adrenal chromaffin cells. PLoS One, 12(7), e0181002. doi:10.1371/journal.pone.0181002

ORCID

0000-0003-2335-1500 (Vernier)

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