{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,10]],"date-time":"2026-06-10T17:00:25Z","timestamp":1781110825237,"version":"3.54.1"},"reference-count":0,"publisher":"National Academy of Sciences","issue":"10","content-domain":{"domain":["www.pnas.org"],"crossmark-restriction":true},"short-container-title":["Proc. Natl. Acad. Sci. U.S.A."],"published-print":{"date-parts":[[1994,5,10]]},"abstract":"<jats:p>The toxin fraction (FTX) and peptide omega-Aga-IVA from the venom of the funnel-web spider Agelenopsis aperta, as well as a synthetic analogue of FTX, specifically block the P-type voltage-dependent Ca2+ channel (VDCC). The effects of these toxins on synaptic transmission were studied in the neuromuscular synapses of the crayfish opener muscle, which has a single excitatory and a single inhibitory motoneuron. FTX selectively and reversibly blocked excitatory and inhibitory postsynaptic currents and potentials in a dose-dependent manner. FTX had no effect on (i) resting and postsynaptic membrane conductance, (ii) postsynaptic L-type VDCC, and (iii) both glutamate- and gamma-aminobutyric acid-induced postsynaptic responses. Mean amplitude and frequency of miniature postsynaptic potentials were unchanged by FTX. The postsynaptic VDCC was inhibited by nifedipine, a selective dihydropyridine antagonist of L-type VDCC, whereas synaptic transmission was unaffected. Transmission was also undisturbed by omega-conotoxin, suggesting that N-type VDCCs are not involved. The peptide omega-Aga-IVA blocked excitatory and inhibitory transmission without affecting postsynaptic VDCC. Synaptic transmission was also blocked by synthetic FTX. We conclude that presynaptic P-type VDCCs are involved in both evoked excitatory and inhibitory transmitter release in crayfish neuromuscular synapses.<\/jats:p>","DOI":"10.1073\/pnas.91.10.4224","type":"journal-article","created":{"date-parts":[[2006,5,31]],"date-time":"2006-05-31T08:46:31Z","timestamp":1149065191000},"page":"4224-4228","update-policy":"https:\/\/doi.org\/10.1073\/pnas.cm10313","source":"Crossref","is-referenced-by-count":37,"title":["P-type Ca2+ channels mediate excitatory and inhibitory synaptic transmitter release in crayfish muscle."],"prefix":"10.1073","volume":"91","author":[{"given":"A","family":"Araque","sequence":"first","affiliation":[{"name":"Instituto Cajal Consejo Superior de Investigaciones Cientificas, Madrid, Spain."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"F","family":"Clarac","sequence":"additional","affiliation":[{"name":"Instituto Cajal Consejo Superior de Investigaciones Cientificas, Madrid, Spain."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"W","family":"Bu\u00f1o","sequence":"additional","affiliation":[{"name":"Instituto Cajal Consejo Superior de Investigaciones Cientificas, Madrid, Spain."}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"341","published-online":{"date-parts":[[1994,5,10]]},"container-title":["Proceedings of the National Academy of Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pnas.org\/doi\/pdf\/10.1073\/pnas.91.10.4224","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,4,13]],"date-time":"2022-04-13T13:42:09Z","timestamp":1649857329000},"score":1,"resource":{"primary":{"URL":"https:\/\/pnas.org\/doi\/full\/10.1073\/pnas.91.10.4224"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1994,5,10]]},"references-count":0,"journal-issue":{"issue":"10","published-print":{"date-parts":[[1994,5,10]]}},"alternative-id":["10.1073\/pnas.91.10.4224"],"URL":"https:\/\/doi.org\/10.1073\/pnas.91.10.4224","relation":{},"ISSN":["0027-8424","1091-6490"],"issn-type":[{"value":"0027-8424","type":"print"},{"value":"1091-6490","type":"electronic"}],"subject":[],"published":{"date-parts":[[1994,5,10]]},"assertion":[{"value":"1994-05-10","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}