Independent regulation of basal neurotransmitter release efficacy by variable Ca²+ influx and bouton size at small central synapses.
The efficacy of action potential evoked neurotransmitter release varies widely even among synapses supplied by the same axon, and the number of release-ready vesicles at each synapse is a major determinant of this heterogeneity. Here we identify a second, equally important, mechanism for release het...
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2012-01-01
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| Series: | PLoS Biology |
| Online Access: | https://journals.plos.org/plosbiology/article/file?id=10.1371/journal.pbio.1001396&type=printable |
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| author | Yaroslav S Ermolyuk Felicity G Alder Christian Henneberger Dmitri A Rusakov Dimitri M Kullmann Kirill E Volynski |
| author_facet | Yaroslav S Ermolyuk Felicity G Alder Christian Henneberger Dmitri A Rusakov Dimitri M Kullmann Kirill E Volynski |
| author_sort | Yaroslav S Ermolyuk |
| collection | DOAJ |
| description | The efficacy of action potential evoked neurotransmitter release varies widely even among synapses supplied by the same axon, and the number of release-ready vesicles at each synapse is a major determinant of this heterogeneity. Here we identify a second, equally important, mechanism for release heterogeneity at small hippocampal synapses, the inter-synaptic variation of the exocytosis probability of release-ready vesicles. Using concurrent measurements of vesicular pool sizes, vesicular exocytosis rates, and presynaptic Ca²⁺ dynamics, in the same small hippocampal boutons, we show that the average fusion probability of release-ready vesicles varies among synapses supplied by the same axon with the size of the spike-evoked Ca²⁺ concentration transient. We further show that synapses with a high vesicular release probability exhibit a lower Ca²⁺ cooperativity, arguing that this is a direct consequence of increased Ca²⁺ influx at the active zone. We conclude that variability of neurotransmitter release under basal conditions at small central synapses is accounted for not only by the number of release-ready vesicles, but also by their fusion probabilities, which are set independently of bouton size by variable spike-evoked presynaptic Ca²⁺ influx. |
| format | Article |
| id | doaj-art-e70fe9f217254b308ad98e93e29615e0 |
| institution | DOAJ |
| issn | 1544-9173 1545-7885 |
| language | English |
| publishDate | 2012-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS Biology |
| spelling | doaj-art-e70fe9f217254b308ad98e93e29615e02025-08-20T03:10:07ZengPublic Library of Science (PLoS)PLoS Biology1544-91731545-78852012-01-01109e100139610.1371/journal.pbio.1001396Independent regulation of basal neurotransmitter release efficacy by variable Ca²+ influx and bouton size at small central synapses.Yaroslav S ErmolyukFelicity G AlderChristian HennebergerDmitri A RusakovDimitri M KullmannKirill E VolynskiThe efficacy of action potential evoked neurotransmitter release varies widely even among synapses supplied by the same axon, and the number of release-ready vesicles at each synapse is a major determinant of this heterogeneity. Here we identify a second, equally important, mechanism for release heterogeneity at small hippocampal synapses, the inter-synaptic variation of the exocytosis probability of release-ready vesicles. Using concurrent measurements of vesicular pool sizes, vesicular exocytosis rates, and presynaptic Ca²⁺ dynamics, in the same small hippocampal boutons, we show that the average fusion probability of release-ready vesicles varies among synapses supplied by the same axon with the size of the spike-evoked Ca²⁺ concentration transient. We further show that synapses with a high vesicular release probability exhibit a lower Ca²⁺ cooperativity, arguing that this is a direct consequence of increased Ca²⁺ influx at the active zone. We conclude that variability of neurotransmitter release under basal conditions at small central synapses is accounted for not only by the number of release-ready vesicles, but also by their fusion probabilities, which are set independently of bouton size by variable spike-evoked presynaptic Ca²⁺ influx.https://journals.plos.org/plosbiology/article/file?id=10.1371/journal.pbio.1001396&type=printable |
| spellingShingle | Yaroslav S Ermolyuk Felicity G Alder Christian Henneberger Dmitri A Rusakov Dimitri M Kullmann Kirill E Volynski Independent regulation of basal neurotransmitter release efficacy by variable Ca²+ influx and bouton size at small central synapses. PLoS Biology |
| title | Independent regulation of basal neurotransmitter release efficacy by variable Ca²+ influx and bouton size at small central synapses. |
| title_full | Independent regulation of basal neurotransmitter release efficacy by variable Ca²+ influx and bouton size at small central synapses. |
| title_fullStr | Independent regulation of basal neurotransmitter release efficacy by variable Ca²+ influx and bouton size at small central synapses. |
| title_full_unstemmed | Independent regulation of basal neurotransmitter release efficacy by variable Ca²+ influx and bouton size at small central synapses. |
| title_short | Independent regulation of basal neurotransmitter release efficacy by variable Ca²+ influx and bouton size at small central synapses. |
| title_sort | independent regulation of basal neurotransmitter release efficacy by variable ca² influx and bouton size at small central synapses |
| url | https://journals.plos.org/plosbiology/article/file?id=10.1371/journal.pbio.1001396&type=printable |
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