{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,14]],"date-time":"2026-05-14T09:33:44Z","timestamp":1778751224251,"version":"3.51.4"},"reference-count":0,"publisher":"Wiley","issue":"1","license":[{"start":{"date-parts":[[1984,2,1]],"date-time":"1984-02-01T00:00:00Z","timestamp":444441600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["The Journal of Physiology"],"published-print":{"date-parts":[[1984,2]]},"abstract":"<jats:p>Ca currents flowing during voltage\u2010clamp depolarizations were examined in axotomized Aplysia neurones under conditions that virtually eliminated other currents. Moderate to large currents exhibited a two\u2010component time course of relaxation that can be approximated reasonably well by the sum of two exponentials. The rapid phase (tau 1 approximately equal to 70 ms at 0 mV) plus the slower phase (tau 2 approximately equal to 300 ms at 0 mV) ride upon a steady, non\u2010inactivating current, I infinity. Conditions that diminish the peak current amplitude, such as reduced stimulus depolarization, inactivation remaining from a prior depolarization, or partial blockade of the Ca conductance by Cd, slowed both phases of inactivation, and all selectively eliminated the tau 1 phase, such that weak currents exhibited only the slower phase of decline. Injection of EGTA slowed both phases of inactivation, decreased the extent of the tau 1 phase, and increased the intensity of I infinity and of the current during the tau 2 phase. For a given voltage, the rate of inactivation increased as the peak current strength was increased, and decreased as the peak current strength was decreased. For a given peak current the rate of inactivation decreased as depolarization was increased. The relation of inactivation to prior Ca2+ entry was essentially linear for small currents, but decreased in slope with time during strong currents. The relation also became shallower with increasing depolarization, suggesting an apparent decrease in the efficacy of Ca in causing inactivation at more positive potentials. The basic kinetics of Ca current inactivation along with experimentally induced changes in those kinetics were simulated with a binding\u2010site model in which inactivation develops during current flow as a function of the entry and accumulation of free Ca2+. This demonstrated that a single Ca\u2010mediated process can account for the two\u2010component time course of inactivation, and that the nearly bi\u2010exponential shape need not arise from two separate processes. The two\u2010component time course emerges as a consequence of a postulated hyperbolic reaction between diminishing probability of channels remaining open and the accumulation of intracellular free Ca2+. The occurrence of a single\u2010 or a two\u2010component time course of inactivation thus appears to depend on the levels of internal free Ca2+ traversed during current flow.<\/jats:p>","DOI":"10.1113\/jphysiol.1984.sp015066","type":"journal-article","created":{"date-parts":[[2014,12,19]],"date-time":"2014-12-19T06:51:20Z","timestamp":1418971880000},"page":"279-300","source":"Crossref","is-referenced-by-count":57,"title":["Kinetics of calcium\u2010dependent inactivation of calcium current in voltage\u2010clamped neurones of Aplysia californica."],"prefix":"10.1113","volume":"347","author":[{"given":"J","family":"Chad","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"R","family":"Eckert","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"D","family":"Ewald","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[1984,2]]},"container-title":["The Journal of Physiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1113%2Fjphysiol.1984.sp015066","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/physoc.onlinelibrary.wiley.com\/doi\/pdf\/10.1113\/jphysiol.1984.sp015066","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,10,19]],"date-time":"2023-10-19T20:25:27Z","timestamp":1697747127000},"score":1,"resource":{"primary":{"URL":"https:\/\/physoc.onlinelibrary.wiley.com\/doi\/10.1113\/jphysiol.1984.sp015066"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1984,2]]},"references-count":0,"journal-issue":{"issue":"1","published-print":{"date-parts":[[1984,2]]}},"alternative-id":["10.1113\/jphysiol.1984.sp015066"],"URL":"https:\/\/doi.org\/10.1113\/jphysiol.1984.sp015066","archive":["Portico"],"relation":{},"ISSN":["0022-3751","1469-7793"],"issn-type":[{"value":"0022-3751","type":"print"},{"value":"1469-7793","type":"electronic"}],"subject":[],"published":{"date-parts":[[1984,2]]}}}