Interaction of DDT with the Components of Lobster Nerve Membrane Conductance

The falling phase of action potential of lobster giant axons is markedly prolonged by treatment with DDT, and a plateau phase appears as in cardiac action potentials. Repetitive afterdischarge is very often superimposed on the plateau. Voltage-clamp experiments with the axons treated with DDT and w...

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Main Authors: Narahashi, Toshio, Haas, Hans G.
Format: Online
Language:English
Published: The Rockefeller University Press 1968
Online Access:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2201121/
id pubmed-2201121
recordtype oai_dc
spelling pubmed-22011212008-04-23 Interaction of DDT with the Components of Lobster Nerve Membrane Conductance Narahashi, Toshio Haas, Hans G. Article The falling phase of action potential of lobster giant axons is markedly prolonged by treatment with DDT, and a plateau phase appears as in cardiac action potentials. Repetitive afterdischarge is very often superimposed on the plateau. Voltage-clamp experiments with the axons treated with DDT and with DDT plus tetrodotoxin or saxitoxin have revealed the following: DDT markedly slows the turning-off process of peak transient current and suppresses the steady-state current. The falling phase of the peak transient current in the DDT-poisoned axon is no longer expressed by a single exponential function as in normal axons, but by two or more exponential functions with much longer time constants. The maximum peak transient conductance is not significantly affected by DDT. DDT did not induce a shift of the curve relating the peak transient conductance to membrane potential along the potential axis. The time to peak transient current and the time for the steady-state current to reach its half-maximum are prolonged by DDT to a small extent. The finding that, under the influence of DDT, the steady-state current starts flowing while the peak transient current is partially maintained supports the hypothesis of two operationally separate ion channels in the nerve membrane. The Rockefeller University Press 1968-02-01 /pmc/articles/PMC2201121/ /pubmed/5641634 Text en Copyright © 1968 by The Rockefeller University 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/).
repository_type Open Access Journal
institution_category Foreign Institution
institution US National Center for Biotechnology Information
building NCBI PubMed
collection Online Access
language English
format Online
author Narahashi, Toshio
Haas, Hans G.
spellingShingle Narahashi, Toshio
Haas, Hans G.
Interaction of DDT with the Components of Lobster Nerve Membrane Conductance
author_facet Narahashi, Toshio
Haas, Hans G.
author_sort Narahashi, Toshio
title Interaction of DDT with the Components of Lobster Nerve Membrane Conductance
title_short Interaction of DDT with the Components of Lobster Nerve Membrane Conductance
title_full Interaction of DDT with the Components of Lobster Nerve Membrane Conductance
title_fullStr Interaction of DDT with the Components of Lobster Nerve Membrane Conductance
title_full_unstemmed Interaction of DDT with the Components of Lobster Nerve Membrane Conductance
title_sort interaction of ddt with the components of lobster nerve membrane conductance
description The falling phase of action potential of lobster giant axons is markedly prolonged by treatment with DDT, and a plateau phase appears as in cardiac action potentials. Repetitive afterdischarge is very often superimposed on the plateau. Voltage-clamp experiments with the axons treated with DDT and with DDT plus tetrodotoxin or saxitoxin have revealed the following: DDT markedly slows the turning-off process of peak transient current and suppresses the steady-state current. The falling phase of the peak transient current in the DDT-poisoned axon is no longer expressed by a single exponential function as in normal axons, but by two or more exponential functions with much longer time constants. The maximum peak transient conductance is not significantly affected by DDT. DDT did not induce a shift of the curve relating the peak transient conductance to membrane potential along the potential axis. The time to peak transient current and the time for the steady-state current to reach its half-maximum are prolonged by DDT to a small extent. The finding that, under the influence of DDT, the steady-state current starts flowing while the peak transient current is partially maintained supports the hypothesis of two operationally separate ion channels in the nerve membrane.
publisher The Rockefeller University Press
publishDate 1968
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2201121/
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