{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,22]],"date-time":"2026-10-22T13:06:45Z","timestamp":1792674405386,"version":"4.5.0"},"reference-count":0,"publisher":"Maximum Academic Press","issue":"3","license":[{"start":{"date-parts":[[2000,5,1]],"date-time":"2000-05-01T00:00:00Z","timestamp":957139200000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/www.cambridge.org\/core\/terms"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Vis Neurosci"],"published-print":{"date-parts":[[2000,5]]},"abstract":"<jats:p>Crayfish photoreceptors exhibit a voltage-dependent \npotassium conductance, <jats:italic>G<\/jats:italic><jats:sub>K<\/jats:sub>, that is \ngenerally similar to the delayed rectifier channel described \nin neurons and other arthropod retinular cells. \n<jats:italic>G<\/jats:italic><jats:sub>K<\/jats:sub> activation (i.e. the apparent threshold, \n<jats:italic>V<\/jats:italic><jats:sub>th<\/jats:sub>) occurs near the resting potential and \n<jats:italic>G<\/jats:italic><jats:sub>K<\/jats:sub> is substantially reduced by 25 mM \nextracellular tetraethylammonium (TEA) and by intracellular \nCs<jats:sup>+<\/jats:sup> injections. Light exposure, sufficient to \nreduce visual sensitivity 100-fold, increases \n<jats:italic>V<\/jats:italic><jats:sub>th<\/jats:sub> (shifts it in the depolarizing \ndirection) by about 20 mV. The light-dependent change in \n<jats:italic>V<\/jats:italic><jats:sub>th<\/jats:sub> does not depend upon the corresponding \nincrease (depolarization) of the steady-state membrane potential \nnor does it depend upon inward calcium currents. <jats:italic>V<\/jats:italic><jats:sub>th<\/jats:sub> \nis slightly influenced by fluctuations in K<jats:sub>o<\/jats:sub> \nassociated with the light-elicited currents. During light \nexposure K<jats:sub>o<\/jats:sub> (measured with K<jats:sup>+<\/jats:sup>-sensitive \nelectrodes) increases by 2.1 mM (equivalent to an 8 mV \nincrease in <jats:italic>E<\/jats:italic><jats:sub>K<\/jats:sub>). This increase in \n<jats:italic>E<\/jats:italic><jats:sub>K<\/jats:sub> makes only a modest contribution \nto the light-dependent change in <jats:italic>V<\/jats:italic><jats:sub>th<\/jats:sub> as \ndetermined by perfusion with high potassium salines. Intracellular \ncalcium injections increase V<jats:sub>th<\/jats:sub> by 10 to 20 \nmV and reduce visual sensitivity by 5- to 10-fold. The \nresults imply that during exposure to high levels of illumination, \nK<jats:sup>+<\/jats:sup> currents at the steady-state membrane potential \nare diminished by a calcium-dependent change in <jats:italic>G<\/jats:italic><jats:sub>K<\/jats:sub> \ngating and, to a smaller degree, by a reduced K<jats:sup>+<\/jats:sup> \nconcentration gradient. It is notable that Ca<jats:sup>2+<\/jats:sup> appears \nto inhibit both <jats:italic>G<\/jats:italic><jats:sub>K<\/jats:sub> and the light-elicited \nconductance from both inside and outside the plasma membrane. As a \nconsequence of the light-dependent change in <jats:italic>V<\/jats:italic><jats:sub>th<\/jats:sub>, <jats:italic>G<\/jats:italic><jats:sub>K<\/jats:sub> makes only modest contributions to the changes \nin sensitivity and speed normally associated with light adaption. \nThese functions are regulated by the transduction pathway and are \nrevealed at the resting potential in the time course and magnitude \nof the light-elicited currents.<\/jats:p>","DOI":"10.1017\/s0952523800173043","type":"journal-article","created":{"date-parts":[[2002,7,27]],"date-time":"2002-07-27T13:39:08Z","timestamp":1027777148000},"page":"353-368","source":"Crossref","is-referenced-by-count":9,"title":["Visual adaptation modulates a potassium conductance in retinular \ncells of the crayfish"],"prefix":"10.48130","volume":"17","author":[{"given":"C.S.","family":"MILLER","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"R.M.","family":"GLANTZ","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"27968","published-online":{"date-parts":[[2000,5,1]]},"container-title":["Visual Neuroscience"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.cambridge.org\/core\/services\/aop-cambridge-core\/content\/view\/S0952523800173043","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,1,2]],"date-time":"2025-01-02T20:00:23Z","timestamp":1735848023000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.cambridge.org\/core\/product\/identifier\/S0952523800173043\/type\/journal_article"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2000,5]]},"references-count":0,"journal-issue":{"issue":"3","published-print":{"date-parts":[[2000,5]]}},"alternative-id":["S0952523800173043"],"URL":"https:\/\/doi.org\/10.1017\/s0952523800173043","relation":{},"ISSN":["0952-5238","1469-8714"],"issn-type":[{"value":"0952-5238","type":"print"},{"value":"1469-8714","type":"electronic"}],"subject":[],"published":{"date-parts":[[2000,5]]}}}