Differential Responses of Crab Neuromuscular Synapses to Cesium Ion
Excitatory postsynaptic potentials (EPSP's) generated in crab muscle fibers by a single motor axon, differ in amplitude and facilitation. Some EPSP's are large at low frequencies of stimulation and show little facilitation; others are smaller and show pronounced facilitation. When K+ is r...
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| Format: | Online |
| Language: | English |
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The Rockefeller University Press
1973
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| Online Access: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2203487/ |
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pubmed-2203487 |
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pubmed-22034872008-04-23 Differential Responses of Crab Neuromuscular Synapses to Cesium Ion Atwood, H. L. Lang, Fred Article Excitatory postsynaptic potentials (EPSP's) generated in crab muscle fibers by a single motor axon, differ in amplitude and facilitation. Some EPSP's are large at low frequencies of stimulation and show little facilitation; others are smaller and show pronounced facilitation. When K+ is replaced by Cs+ in the physiological solution, all EPSP's increase in amplitude, but small EPSP's increase proportionately more than large ones. Quantal content of transmission, determined by external recording at single synaptic regions, undergoes a much larger increase at facilitating synapses. The increase in quantal content of transmission is attributable to prolongation of the nerve terminal action potential in Cs+. After 1–2 h of Cs+ treatment, defacilitation of synaptic potentials occurs at synapses which initially showed facilitation. This indicates that Cs+ treatment drastically increases the fraction of the "immediately available" transmitter store released by each nerve impulse, especially at terminals with facilitating synapses. It is proposed that facilitating synapses normally release less of the "immediately available" store of transmitter than poorly facilitating synapses. Possible reasons for this difference in performance are discussed. The Rockefeller University Press 1973-06-01 /pmc/articles/PMC2203487/ /pubmed/4350699 Text en Copyright © 1973 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 |
Atwood, H. L. Lang, Fred |
| spellingShingle |
Atwood, H. L. Lang, Fred Differential Responses of Crab Neuromuscular Synapses to Cesium Ion |
| author_facet |
Atwood, H. L. Lang, Fred |
| author_sort |
Atwood, H. L. |
| title |
Differential Responses of Crab Neuromuscular Synapses to Cesium Ion |
| title_short |
Differential Responses of Crab Neuromuscular Synapses to Cesium Ion |
| title_full |
Differential Responses of Crab Neuromuscular Synapses to Cesium Ion |
| title_fullStr |
Differential Responses of Crab Neuromuscular Synapses to Cesium Ion |
| title_full_unstemmed |
Differential Responses of Crab Neuromuscular Synapses to Cesium Ion |
| title_sort |
differential responses of crab neuromuscular synapses to cesium ion |
| description |
Excitatory postsynaptic potentials (EPSP's) generated in crab muscle fibers by a single motor axon, differ in amplitude and facilitation. Some EPSP's are large at low frequencies of stimulation and show little facilitation; others are smaller and show pronounced facilitation. When K+ is replaced by Cs+ in the physiological solution, all EPSP's increase in amplitude, but small EPSP's increase proportionately more than large ones. Quantal content of transmission, determined by external recording at single synaptic regions, undergoes a much larger increase at facilitating synapses. The increase in quantal content of transmission is attributable to prolongation of the nerve terminal action potential in Cs+. After 1–2 h of Cs+ treatment, defacilitation of synaptic potentials occurs at synapses which initially showed facilitation. This indicates that Cs+ treatment drastically increases the fraction of the "immediately available" transmitter store released by each nerve impulse, especially at terminals with facilitating synapses. It is proposed that facilitating synapses normally release less of the "immediately available" store of transmitter than poorly facilitating synapses. Possible reasons for this difference in performance are discussed. |
| publisher |
The Rockefeller University Press |
| publishDate |
1973 |
| url |
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2203487/ |
| _version_ |
1611433437537763328 |