{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,25]],"date-time":"2026-03-25T18:21:31Z","timestamp":1774462891825,"version":"3.50.1"},"reference-count":24,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2020,3,16]],"date-time":"2020-03-16T00:00:00Z","timestamp":1584316800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"\u0420\u043e\u0441\u0441\u0438\u0439\u0441\u043a\u0438\u0439 \u0424\u043e\u043d\u0434 \u0424\u0443\u043d\u0434\u0430\u043c\u0435\u043d\u0442\u0430\u043b\u044c\u043d\u044b\u0445 \u0418\u0441\u0441\u043b\u0435\u0434\u043e\u0432\u0430\u043d\u0438\u0439 (\u0420\u0424\u0424\u0418)","award":["18-34-00189"],"award-info":[{"award-number":["18-34-00189"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>The ability of P2X7 receptors to potentiate rhythmically evoked acetylcholine (ACh) release through Ca2+ entry via P2X7 receptors and via L-type voltage-dependent Ca2+ channels (VDCCs) was compared by loading Ca2+ chelators into motor nerve terminals. Neuromuscular preparations of the diaphragms of wild-type (WT) mice and pannexin-1 knockout (Panx1\u2212\/\u2212) mice, in which ACh release is potentiated by the disinhibition of the L-type VDCCs upon the activation of P2X7 receptors, were used. Miniature end-plate potentials (MEPPs) and evoked end-plate potentials (EPPs) were recorded when the motor terminals were loaded with slow or fast Ca2+ chelators (EGTA-AM or BAPTA-AM, respectively, 50 \u03bcM). In WT and Panx1\u2212\/\u2212 mice, EGTA-AM did not change either spontaneous or evoked ACh release, while BAPTA-AM inhibited synaptic transmission by suppressing the quantal content of EPPs throughout the course of the short rhythmic train (50 Hz, 1 s). In the motor synapses of either WT or Panx1\u2212\/\u2212 mice in the presence of BAPTA-AM, the activation of P2X7 receptors by BzATP (30 \u03bcM) returned the EPP quantal content to the control level. In the neuromuscular junctions (NMJs) of Panx1\u2212\/\u2212 mice, EGTA-AM completely prevented the BzATP-induced increase in EPP quantal content. After Panx1\u2212\/\u2212 NMJs were treated with BAPTA-AM, BzATP lost its ability to enhance the EPP quantal content to above the control level. Nitrendipine (1 \u03bcM), an inhibitor of L-type VDCCs, was unable to prevent this BzATP-induced enhancement of EPP quantal content to the control level. We propose that the activation of P2X7 receptors may provide additional Ca2+ entry into motor nerve terminals, which, independent of the modulation of L-type VDCC activity, can partially reduce the buffering capacity of Ca2+ chelators, thereby providing sufficient Ca2+ signals for ACh secretion at the control level. However, the activity of both Ca2+ chelators was sufficient to eliminate Ca2+ entry via L-type VDCCs activated by P2X7 receptors and increase the EPP quantal content in the NMJs of Panx1\u2212\/\u2212 mice to above the control level.<\/jats:p>","DOI":"10.3390\/ijms21062034","type":"journal-article","created":{"date-parts":[[2020,3,18]],"date-time":"2020-03-18T08:20:44Z","timestamp":1584519644000},"page":"2034","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":13,"title":["Interaction between Calcium Chelators and the Activity of P2X7 Receptors in Mouse Motor Synapses"],"prefix":"10.3390","volume":"21","author":[{"given":"Anna","family":"Miteva","sequence":"first","affiliation":[{"name":"Department of Human &amp; Animal Physiology, Lomonosov Moscow State University, Leninskie Gory 1\/12, Moscow 119991, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1963-1382","authenticated-orcid":false,"given":"Alexander","family":"Gaydukov","sequence":"additional","affiliation":[{"name":"Department of Human &amp; Animal Physiology, Lomonosov Moscow State University, Leninskie Gory 1\/12, Moscow 119991, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Olga","family":"Balezina","sequence":"additional","affiliation":[{"name":"Department of Human &amp; Animal Physiology, Lomonosov Moscow State University, Leninskie Gory 1\/12, Moscow 119991, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,3,16]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"817","DOI":"10.1111\/j.1460-9568.1997.tb01431.x","article-title":"Multiple types of Ca2+ channels in mouse motor nerve terminals","volume":"9","author":"Lin","year":"1997","journal-title":"Eur. 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