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rdf:type |
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lifeskim:mentions |
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pubmed:dateCreated |
1990-1-5
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pubmed:abstractText |
1. Two different types of acetylcholine receptor channels can be detected on the post-junctional membrane of slow muscle fibres in garter snakes. Here they are designated T-type and S-type channels. Only T-type channels can also be found at twitch fibre neuromuscular junctions. 2. The physiological properties of slow fibre T-type channels are similar to those of acetylcholine receptor channels in end-plates of twitch fibres in these animals. 3. S-type channels had a smaller conductance than T-type channels (32 vs. 49 pS), but a similar reversal potential near 0 mV. 4. Both S- and T-type channels were found together in most patches of slow fibre end-plate membrane, but some patches displayed just one type or the other. 5. The activity of both S- and T-type channels desensitized in the presence of micromolar concentrations of acetylcholine. S-type channels desensitized less rapidly and less completely than did T-type channels. 6. Desensitized channels of both types recovered and produced bursts of activity, then went silent again. During a burst, channels did not appear to change type. 7. The activation of channels of either type was not correlated with activity in channels of the other type. 8. The open-duration distribution of S-type channels required two exponential components to be well fitted, with time constants in the range of 1-2 ms and 3-10 ms. In contrast, the open-duration distribution of T-type channels was a single exponential with a time constant similar in magnitude to the slower S-type component. 9. Desensitization-resistant S-type acetylcholine receptor channels could allow slow muscle end-plates to retain their sensitivity to acetylcholine during periods of heavy use. Under non-desensitizing conditions, differences in the decay properties of slow fibre end-plate currents compared to those in twitch fibres can be explained by the activation kinetics of S-type channels.
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pubmed:grant |
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pubmed:commentsCorrections |
http://linkedlifedata.com/resource/pubmed/commentcorrection/2479737-1081139,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2479737-1081230,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2479737-1086359,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2479737-13463799,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2479737-185583,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2479737-2410047,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2479737-2419552,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2479737-2423151,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2479737-2423878,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2479737-2436235,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2479737-2440981,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2479737-2446258,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2479737-309004,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2479737-3681728,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2479737-4904270,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2479737-5071933,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2479737-6086429,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2479737-6086900,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2479737-6248795,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2479737-6256772,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2479737-6262502,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2479737-6262503,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2479737-6270629,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2479737-6291654,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2479737-6320016,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2479737-6324899,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2479737-6474189,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2479737-655944,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2479737-683330,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2479737-6875926,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2479737-6972007
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pubmed:language |
eng
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pubmed:journal |
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pubmed:citationSubset |
IM
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pubmed:chemical |
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pubmed:status |
MEDLINE
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pubmed:month |
Feb
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pubmed:issn |
0022-3751
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pubmed:author |
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pubmed:issnType |
Print
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pubmed:volume |
409
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
313-31
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pubmed:dateRevised |
2009-11-18
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pubmed:meshHeading |
pubmed-meshheading:2479737-Acetylcholine,
pubmed-meshheading:2479737-Action Potentials,
pubmed-meshheading:2479737-Animals,
pubmed-meshheading:2479737-Ion Channels,
pubmed-meshheading:2479737-Kinetics,
pubmed-meshheading:2479737-Motor Endplate,
pubmed-meshheading:2479737-Neuromuscular Junction,
pubmed-meshheading:2479737-Receptors, Cholinergic,
pubmed-meshheading:2479737-Receptors, Nicotinic,
pubmed-meshheading:2479737-Snakes,
pubmed-meshheading:2479737-Time Factors
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pubmed:year |
1989
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pubmed:articleTitle |
Two types of nicotinic acetylcholine receptor channels at slow fibre end-plates of the garter snake.
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pubmed:affiliation |
Department of Pharmacology, University of California San Diego, La Jolla 92093.
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pubmed:publicationType |
Journal Article,
In Vitro,
Research Support, U.S. Gov't, P.H.S.
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