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pubmed-2215260
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| recordtype |
oai_dc
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| spelling |
pubmed-22152602008-04-23 Effects of ammonium ions on endplate channels Articles Miniature endplate currents, recorded from voltage-clamped toad sartorius muscle fibers in solutions containing ammonium ions substituted for sodium ions, were increased in amplitude and decayed exponentially with a slower time constant than in control (Na) solution. The peak conductance of miniature endplate currents was also greater in ammonium solutions. The acetylcholine null potential was - 2.8 +/- 0.8 mV in control solution, and shifted to 0.9 +/- 1.6 mV in solutions in which NH4Cl replaced half the NaCl. In solutions containing NH4Cl substituted for all the NaCl, the null potential was 6.5 +/- 1.3 mV. Single channel conductance and average channel lifetime were both increased in solutions containing ammonium ions. The exponential relationship between the time constant of decay of miniature endplate currents or channel lifetime and membrane potential was unchanged in ammonium solutions. A slight but consistent increase in peak conductance during miniature endplate currents and single channel conductance was seen as membrane potential became more positive (depolarized) in both control and ammonium solutions. Net charge transfer was greater in ammonium solutions than in control solution, whether measured during a miniature endplate current or through a single channel. The results presented here are consistent with an endplate channel model containing high field strength, neutral sites. The Rockefeller University Press 1980-05-01 /pmc/articles/PMC2215260/ /pubmed/6247424 Text en This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/).
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| repository_type |
Open Access Journal
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| institution_category |
Foreign Institution
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| institution |
US National Center for Biotechnology Information
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| building |
NCBI PubMed
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| collection |
Online Access
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| language |
English
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| format |
Online
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| title |
Effects of ammonium ions on endplate channels
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| spellingShingle |
Effects of ammonium ions on endplate channels
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| title_short |
Effects of ammonium ions on endplate channels
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| title_full |
Effects of ammonium ions on endplate channels
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| title_fullStr |
Effects of ammonium ions on endplate channels
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| title_full_unstemmed |
Effects of ammonium ions on endplate channels
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| title_sort |
effects of ammonium ions on endplate channels
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| description |
Miniature endplate currents, recorded from voltage-clamped toad sartorius muscle fibers in solutions containing ammonium ions substituted for sodium ions, were increased in amplitude and decayed exponentially with a slower time constant than in control (Na) solution. The peak conductance of miniature endplate currents was also greater in ammonium solutions. The acetylcholine null potential was - 2.8 +/- 0.8 mV in control solution, and shifted to 0.9 +/- 1.6 mV in solutions in which NH4Cl replaced half the NaCl. In solutions containing NH4Cl substituted for all the NaCl, the null potential was 6.5 +/- 1.3 mV. Single channel conductance and average channel lifetime were both increased in solutions containing ammonium ions. The exponential relationship between the time constant of decay of miniature endplate currents or channel lifetime and membrane potential was unchanged in ammonium solutions. A slight but consistent increase in peak conductance during miniature endplate currents and single channel conductance was seen as membrane potential became more positive (depolarized) in both control and ammonium solutions. Net charge transfer was greater in ammonium solutions than in control solution, whether measured during a miniature endplate current or through a single channel. The results presented here are consistent with an endplate channel model containing high field strength, neutral sites.
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| publisher |
The Rockefeller University Press
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| publishDate |
1980
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| url |
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2215260/
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| _version_ |
1611435017639034880
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