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The Initiation of Spike Potential in Barnacle Muscle Fibers under Low Intracellular Ca(++)

Electrical properties of the muscle fiber membrane were studied in the barnacle, Balanus nubilus Darw. by using intracellular electrode techniques. A depolarization of the membrane does not usually produce an all-or-none spike potential in the normal muscle fiber even though a mechanical response is...

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Autores principales: Hagiwara, Susumu, Naka, Ken-ichi
Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 1964
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2195400/
https://www.ncbi.nlm.nih.gov/pubmed/14212145
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author Hagiwara, Susumu
Naka, Ken-ichi
author_facet Hagiwara, Susumu
Naka, Ken-ichi
author_sort Hagiwara, Susumu
collection PubMed
description Electrical properties of the muscle fiber membrane were studied in the barnacle, Balanus nubilus Darw. by using intracellular electrode techniques. A depolarization of the membrane does not usually produce an all-or-none spike potential in the normal muscle fiber even though a mechanical response is elicited. The intracellular injection of Ca(++)-binding agents (K(2)SO(4) and K salt of EDTA solution, K(3) citrate solution, etc.) renders the fiber capable of initiating all-or-none spikes. The overshoot of such a spike potential increases with increasing external Ca concentration, the increment for a tenfold increase in Ca concentration being about 29 mv. The threshold membrane potential for the spike and also for the K conductance increase shifts to more positive membrane potentials with increasing [Ca(++)](out). The removal of Na ions from the external medium does not change the configuration of the spike potential. In the absence of Ca(++) in the external medium, the spike potential is restored by Ba(++) and Sr(++) but not by Mg(++). The overshoot of the spike potential increases with increasing [Ba(++)](out) or [Sr(++)](out). The Ca influx through the membrane of the fiber treated with K(2)SO(4) and EDTA was examined with Ca(45). The influx was 14 pmol per sec. per cm(2) for the resting membrane and 35 to 85 pmol per cm(2) for one spike. From these results it is concluded that the spike potential of the barnacle muscle fiber results from the permeability increase of the membrane to Ca(++) (Ba(++) or Sr(++)).
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spelling pubmed-21954002008-04-23 The Initiation of Spike Potential in Barnacle Muscle Fibers under Low Intracellular Ca(++) Hagiwara, Susumu Naka, Ken-ichi J Gen Physiol Article Electrical properties of the muscle fiber membrane were studied in the barnacle, Balanus nubilus Darw. by using intracellular electrode techniques. A depolarization of the membrane does not usually produce an all-or-none spike potential in the normal muscle fiber even though a mechanical response is elicited. The intracellular injection of Ca(++)-binding agents (K(2)SO(4) and K salt of EDTA solution, K(3) citrate solution, etc.) renders the fiber capable of initiating all-or-none spikes. The overshoot of such a spike potential increases with increasing external Ca concentration, the increment for a tenfold increase in Ca concentration being about 29 mv. The threshold membrane potential for the spike and also for the K conductance increase shifts to more positive membrane potentials with increasing [Ca(++)](out). The removal of Na ions from the external medium does not change the configuration of the spike potential. In the absence of Ca(++) in the external medium, the spike potential is restored by Ba(++) and Sr(++) but not by Mg(++). The overshoot of the spike potential increases with increasing [Ba(++)](out) or [Sr(++)](out). The Ca influx through the membrane of the fiber treated with K(2)SO(4) and EDTA was examined with Ca(45). The influx was 14 pmol per sec. per cm(2) for the resting membrane and 35 to 85 pmol per cm(2) for one spike. From these results it is concluded that the spike potential of the barnacle muscle fiber results from the permeability increase of the membrane to Ca(++) (Ba(++) or Sr(++)). The Rockefeller University Press 1964-09-01 /pmc/articles/PMC2195400/ /pubmed/14212145 Text en Copyright © 1965 by The Rockefeller Institute Press 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/).
spellingShingle Article
Hagiwara, Susumu
Naka, Ken-ichi
The Initiation of Spike Potential in Barnacle Muscle Fibers under Low Intracellular Ca(++)
title The Initiation of Spike Potential in Barnacle Muscle Fibers under Low Intracellular Ca(++)
title_full The Initiation of Spike Potential in Barnacle Muscle Fibers under Low Intracellular Ca(++)
title_fullStr The Initiation of Spike Potential in Barnacle Muscle Fibers under Low Intracellular Ca(++)
title_full_unstemmed The Initiation of Spike Potential in Barnacle Muscle Fibers under Low Intracellular Ca(++)
title_short The Initiation of Spike Potential in Barnacle Muscle Fibers under Low Intracellular Ca(++)
title_sort initiation of spike potential in barnacle muscle fibers under low intracellular ca(++)
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2195400/
https://www.ncbi.nlm.nih.gov/pubmed/14212145
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