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How to Properly Measure a Current-Voltage Relation?—Interpolation vs. Ramp Methods Applied to Studies of GABA(A) Receptors

The relation between current and voltage, I-V relation, is central to functional analysis of membrane ion channels. A commonly used method, since the introduction of the voltage-clamp technique, to establish the I-V relation depends on the interpolation of current amplitudes recorded at different st...

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Autores principales: Yelhekar, Tushar D., Druzin, Michael, Karlsson, Urban, Blomqvist, Erii, Johansson, Staffan
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4735409/
https://www.ncbi.nlm.nih.gov/pubmed/26869882
http://dx.doi.org/10.3389/fncel.2016.00010
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author Yelhekar, Tushar D.
Druzin, Michael
Karlsson, Urban
Blomqvist, Erii
Johansson, Staffan
author_facet Yelhekar, Tushar D.
Druzin, Michael
Karlsson, Urban
Blomqvist, Erii
Johansson, Staffan
author_sort Yelhekar, Tushar D.
collection PubMed
description The relation between current and voltage, I-V relation, is central to functional analysis of membrane ion channels. A commonly used method, since the introduction of the voltage-clamp technique, to establish the I-V relation depends on the interpolation of current amplitudes recorded at different steady voltages. By a theoretical computational approach as well as by experimental recordings from GABA(A)-receptor mediated currents in mammalian central neurons, we here show that this interpolation method may give reversal potentials and conductances that do not reflect the properties of the channels studied under conditions when ion flux may give rise to concentration changes. Therefore, changes in ion concentrations may remain undetected and conclusions on changes in conductance, such as during desensitization, may be mistaken. In contrast, an alternative experimental approach, using rapid voltage ramps, enable I-V relations that much better reflect the properties of the studied ion channels.
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spelling pubmed-47354092016-02-11 How to Properly Measure a Current-Voltage Relation?—Interpolation vs. Ramp Methods Applied to Studies of GABA(A) Receptors Yelhekar, Tushar D. Druzin, Michael Karlsson, Urban Blomqvist, Erii Johansson, Staffan Front Cell Neurosci Neuroscience The relation between current and voltage, I-V relation, is central to functional analysis of membrane ion channels. A commonly used method, since the introduction of the voltage-clamp technique, to establish the I-V relation depends on the interpolation of current amplitudes recorded at different steady voltages. By a theoretical computational approach as well as by experimental recordings from GABA(A)-receptor mediated currents in mammalian central neurons, we here show that this interpolation method may give reversal potentials and conductances that do not reflect the properties of the channels studied under conditions when ion flux may give rise to concentration changes. Therefore, changes in ion concentrations may remain undetected and conclusions on changes in conductance, such as during desensitization, may be mistaken. In contrast, an alternative experimental approach, using rapid voltage ramps, enable I-V relations that much better reflect the properties of the studied ion channels. Frontiers Media S.A. 2016-02-02 /pmc/articles/PMC4735409/ /pubmed/26869882 http://dx.doi.org/10.3389/fncel.2016.00010 Text en Copyright © 2016 Yelhekar, Druzin, Karlsson, Blomqvist and Johansson. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Neuroscience
Yelhekar, Tushar D.
Druzin, Michael
Karlsson, Urban
Blomqvist, Erii
Johansson, Staffan
How to Properly Measure a Current-Voltage Relation?—Interpolation vs. Ramp Methods Applied to Studies of GABA(A) Receptors
title How to Properly Measure a Current-Voltage Relation?—Interpolation vs. Ramp Methods Applied to Studies of GABA(A) Receptors
title_full How to Properly Measure a Current-Voltage Relation?—Interpolation vs. Ramp Methods Applied to Studies of GABA(A) Receptors
title_fullStr How to Properly Measure a Current-Voltage Relation?—Interpolation vs. Ramp Methods Applied to Studies of GABA(A) Receptors
title_full_unstemmed How to Properly Measure a Current-Voltage Relation?—Interpolation vs. Ramp Methods Applied to Studies of GABA(A) Receptors
title_short How to Properly Measure a Current-Voltage Relation?—Interpolation vs. Ramp Methods Applied to Studies of GABA(A) Receptors
title_sort how to properly measure a current-voltage relation?—interpolation vs. ramp methods applied to studies of gaba(a) receptors
topic Neuroscience
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4735409/
https://www.ncbi.nlm.nih.gov/pubmed/26869882
http://dx.doi.org/10.3389/fncel.2016.00010
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