Different Time Courses of Mono- and Bi-Liganded Bursts of Channel Openings of Adult nAChR Molecules Formed by the Reactions of Transmembrane Regions

We recorded transmembrane currents through single nicotinic acetylcholine receptors (nAChRs) in cell-attached patches at high temporal resolutions from cultured and transiently transfected HEK 293 cells. Receptor activation was elicited by acetylcholine (ACh) or epibatidine (Ebd) at concentrations r...

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Main Authors: Dmitrij Ljaschenko, Martin Pauli, Achmed Mrestani, Josef Dudel, Manfred Heckmann
Format: Article
Language:English
Published: MDPI AG 2024-12-01
Series:Cells
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Online Access:https://www.mdpi.com/2073-4409/13/24/2079
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author Dmitrij Ljaschenko
Martin Pauli
Achmed Mrestani
Josef Dudel
Manfred Heckmann
author_facet Dmitrij Ljaschenko
Martin Pauli
Achmed Mrestani
Josef Dudel
Manfred Heckmann
author_sort Dmitrij Ljaschenko
collection DOAJ
description We recorded transmembrane currents through single nicotinic acetylcholine receptors (nAChRs) in cell-attached patches at high temporal resolutions from cultured and transiently transfected HEK 293 cells. Receptor activation was elicited by acetylcholine (ACh) or epibatidine (Ebd) at concentrations ranging from 0.01 to 100 µM, binding to one (R<sub>αδ</sub> or R<sub>αε</sub>) or both extracellular ligand binding sites (R<sub>αδ+αε</sub>). Agonist binding to R<sub>αδ</sub> resulted in very short openings with mean durations of (τ<sub>o1</sub> < 5 µs), while the binding to R<sub>αε</sub> produced short (τ<sub>o2</sub> = 37 µs) and intermediate openings (τ<sub>o3</sub> = 187 µs). Binding at both sites (R<sub>αδ+αε</sub>) generated long openings (τ<sub>o4</sub> = 752 µs). All durations are noted in brackets since missed closures could shorten the results. Mono-liganded bursts were elicited at 0.01 µM ACh or Ebd, lasted less than a millisecond, displayed the typical current amplitude, and were interrupted by frequent microsecond-scale closures (µBs) that often did not reach the zero current. In contrast, bi-liganded bursts exhibited classical full amplitudes and long open states lasting up to several milliseconds, interspersed with rare µB closures of a similar duration to those observed in mono-liganded bursts.
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spelling doaj-art-edaf9f00924d4e17807c584dd10e198d2025-08-20T02:50:57ZengMDPI AGCells2073-44092024-12-011324207910.3390/cells13242079Different Time Courses of Mono- and Bi-Liganded Bursts of Channel Openings of Adult nAChR Molecules Formed by the Reactions of Transmembrane RegionsDmitrij Ljaschenko0Martin Pauli1Achmed Mrestani2Josef Dudel3Manfred Heckmann4Institute of Physiology, Department of Neurophysiology, University of Würzburg, Röntgenring 9, 97070 Würzburg, GermanyInstitute of Physiology, Department of Neurophysiology, University of Würzburg, Röntgenring 9, 97070 Würzburg, GermanyRudolf Schönheimer Institute of Biochemistry, Division of General Biochemistry, Medical Faculty, Leipzig University, Johannisallee 30, 04103 Leipzig, GermanyInstitute for Neuroscience, Technical University Munich, Biedersteinerstr. 29, 80802 München, GermanyInstitute of Physiology, Department of Neurophysiology, University of Würzburg, Röntgenring 9, 97070 Würzburg, GermanyWe recorded transmembrane currents through single nicotinic acetylcholine receptors (nAChRs) in cell-attached patches at high temporal resolutions from cultured and transiently transfected HEK 293 cells. Receptor activation was elicited by acetylcholine (ACh) or epibatidine (Ebd) at concentrations ranging from 0.01 to 100 µM, binding to one (R<sub>αδ</sub> or R<sub>αε</sub>) or both extracellular ligand binding sites (R<sub>αδ+αε</sub>). Agonist binding to R<sub>αδ</sub> resulted in very short openings with mean durations of (τ<sub>o1</sub> < 5 µs), while the binding to R<sub>αε</sub> produced short (τ<sub>o2</sub> = 37 µs) and intermediate openings (τ<sub>o3</sub> = 187 µs). Binding at both sites (R<sub>αδ+αε</sub>) generated long openings (τ<sub>o4</sub> = 752 µs). All durations are noted in brackets since missed closures could shorten the results. Mono-liganded bursts were elicited at 0.01 µM ACh or Ebd, lasted less than a millisecond, displayed the typical current amplitude, and were interrupted by frequent microsecond-scale closures (µBs) that often did not reach the zero current. In contrast, bi-liganded bursts exhibited classical full amplitudes and long open states lasting up to several milliseconds, interspersed with rare µB closures of a similar duration to those observed in mono-liganded bursts.https://www.mdpi.com/2073-4409/13/24/2079acetylcholineburstchannelendplatekineticsreceptor
spellingShingle Dmitrij Ljaschenko
Martin Pauli
Achmed Mrestani
Josef Dudel
Manfred Heckmann
Different Time Courses of Mono- and Bi-Liganded Bursts of Channel Openings of Adult nAChR Molecules Formed by the Reactions of Transmembrane Regions
Cells
acetylcholine
burst
channel
endplate
kinetics
receptor
title Different Time Courses of Mono- and Bi-Liganded Bursts of Channel Openings of Adult nAChR Molecules Formed by the Reactions of Transmembrane Regions
title_full Different Time Courses of Mono- and Bi-Liganded Bursts of Channel Openings of Adult nAChR Molecules Formed by the Reactions of Transmembrane Regions
title_fullStr Different Time Courses of Mono- and Bi-Liganded Bursts of Channel Openings of Adult nAChR Molecules Formed by the Reactions of Transmembrane Regions
title_full_unstemmed Different Time Courses of Mono- and Bi-Liganded Bursts of Channel Openings of Adult nAChR Molecules Formed by the Reactions of Transmembrane Regions
title_short Different Time Courses of Mono- and Bi-Liganded Bursts of Channel Openings of Adult nAChR Molecules Formed by the Reactions of Transmembrane Regions
title_sort different time courses of mono and bi liganded bursts of channel openings of adult nachr molecules formed by the reactions of transmembrane regions
topic acetylcholine
burst
channel
endplate
kinetics
receptor
url https://www.mdpi.com/2073-4409/13/24/2079
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