{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,24]],"date-time":"2026-09-24T07:09:58Z","timestamp":1790233798668,"version":"4.1.0"},"reference-count":0,"publisher":"Wiley","issue":"1","license":[{"start":{"date-parts":[[1994,2,15]],"date-time":"1994-02-15T00:00:00Z","timestamp":761270400000},"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":[[1994,2,15]]},"abstract":"<jats:p>1. Voltage\u2010dependent currents of untreated (proliferating) and lipopolysaccharide (LPS)\u2010treated rat microglial cells in culture were recorded using the whole\u2010cell patch\u2010clamp technique. 2. Membrane potentials showed prominent peaks at \u201035 mV and \u201070 mV. Membrane potentials of LPS\u2010treated cells alternated between the two values. This may be due to a negative slope region of the I\u2010V relation resulting in two zero current potentials. 3. From a holding potential of \u201070 mV, hyperpolarizing steps evoked an inwardly rectifying current both in proliferating and in LPS\u2010treated cells, while depolarizing steps below \u201050 mV evoked an outwardly rectifying current only in LPS\u2010treated microglia. The currents were K+ selective, as indicated by their reversal potential of approximately 0 mV in symmetric K+ concentrations (150 mM both intra\u2010 and extracellularly) and the reversal potential of the outward tail currents of approximately \u201090 mV at a normal extracellular K+ concentration (4.5 mM). 4. The activation of the outward current could be fitted by Hodgkin\u2010Huxley\u2010type n4 kinetics. The time constant of activation depended on voltage. 5. The inactivation of the inward and outward currents could be fitted by a single exponential. The time constant of the inward current inactivation was dependent on voltage, whereas the time constant of the outward current inactivation was virtually independent of voltage, except near the threshold of activation. Recovery of the outward from inactivation was slow and could be fitted by two exponentials. Responses to depolarizing steps were stable at 0.125 Hz, but greatly decreased from the first to the second pulse at 1 Hz. 6. The inactivation of the inward, but not of the outward, current disappeared in a low Na(+)\u2010containing medium (5 mM). The inward current was selectively inhibited by extracellular Cs+ and Ba2+. The outward current was selectively inhibited by Cd2+, 4\u2010aminopyridine and charybdotoxin. Replacement of intracellular K+ by an equimolar concentration of Cs+, and the extracellular application of tetraethylammonium and quinine inhibited both currents. 7. An increase of extracellular Ca2+ from 2 to 20 mM resulted in outwardly rectifying K+ channels activating at more positive potentials. Omission of Ca2+ from the extracellular medium had the opposite effect. When the intracellular free Ca2+ was increased from 0.01 to 1 microM, the outward current amplitudes were depressed. The Ca2+ ionophore A23187 had a similar effect. 8. LPS\u2010treated microglial cells possess inwardly and outwardly rectifying K+ channels. The physiological and pharmacological characteristics of these two channel populations are markedly different.(ABSTRACT TRUNCATED AT 400 WORDS)<\/jats:p>","DOI":"10.1113\/jphysiol.1994.sp020046","type":"journal-article","created":{"date-parts":[[2014,12,17]],"date-time":"2014-12-17T12:55:47Z","timestamp":1418820947000},"page":"15-32","source":"Crossref","is-referenced-by-count":93,"title":["Voltage\u2010dependent potassium channels in activated rat microglia."],"prefix":"10.1113","volume":"475","author":[{"given":"W","family":"N\u00f6renberg","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"P J","family":"Gebicke\u2010Haerter","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"P","family":"Illes","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[1994,2,15]]},"container-title":["The Journal of Physiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1113%2Fjphysiol.1994.sp020046","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/physoc.onlinelibrary.wiley.com\/doi\/pdf\/10.1113\/jphysiol.1994.sp020046","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,10,24]],"date-time":"2023-10-24T01:02:54Z","timestamp":1698109374000},"score":1,"resource":{"primary":{"URL":"https:\/\/physoc.onlinelibrary.wiley.com\/doi\/10.1113\/jphysiol.1994.sp020046"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1994,2,15]]},"references-count":0,"journal-issue":{"issue":"1","published-print":{"date-parts":[[1994,2,15]]}},"alternative-id":["10.1113\/jphysiol.1994.sp020046"],"URL":"https:\/\/doi.org\/10.1113\/jphysiol.1994.sp020046","archive":["Portico"],"relation":{},"ISSN":["0022-3751","1469-7793"],"issn-type":[{"value":"0022-3751","type":"print"},{"value":"1469-7793","type":"electronic"}],"subject":[],"published":{"date-parts":[[1994,2,15]]}}}