M-type potassium current in dissociated sympathetic ganglion cells of Xenopus laevis.
Whole-cell/voltage-clamp recordings were made from dissociated sympathetic neurons of Xenopus laevis. Step depolarization (10-70 mV, 0.5 s) from the holding potential of -65 mV activated a non-inactivating potassium current which was selectively blocked by barium (1 mM). The current did not require an inward calcium current for its activation. The steady-state activation curve of the current was centered at -35 mV with a slope factor of 8.6 mV. The time constant for activation of the current was about 115 ms when measured at -35 mV and the effective valence of the voltage-sensing particle was 2.9. This potassium current was identified as a particular set of potassium currents usually referred to as M-current.
Department of Physiology, Tokai University School of Medicine, Isehara, Japan. tokimasa@is.icc.u-tokai.ac.jp
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D000818:Animals; D005728:Ganglia, Sympathetic / Q000502:physiology*; D066298:In Vitro Techniques; D018408:Patch-Clamp Techniques; D015221:Potassium Channels / Q000502:physiology*; D014982:Xenopus laevis
D015221:Potassium Channels