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. 1998 May 1;111(5):625–638. doi: 10.1085/jgp.111.5.625

Figure 1.

Figure 1

Ionic currents in inactivating ShH4 (A) and noninactivating ShH4 Δ6-46 (B) channels. On this time scale, no inactivation can be detected in ShH4 Δ6-46 currents, but ShH4 currents are quickly inactivated with a single exponential time course (3–10 ms, depending on pulse potential and variations from oocyte to oocyte). 40-ms pulses from −40 to 30 mV in 10-mV increments from HP = −90 mV. Records were subtracted (P/−4) with SHP = −120 mV (A) or −90 mV (B). All the recordings were made in NaMES Ca2 K2; data were sampled at 20 kHz and filtered at 4 kHz; one sweep per trace; 10 s between sweeps for A to allow a full recovery from inactivation. (C and D) Gating currents are shown from the inactivating (ShH4) and noninactivating (ShH4 Δ6-46) K+ channels, respectively, recorded in potassium-free solutions (continuous lines). The external solution was NMDG-MES Ca2 while the oocyte was internally perfused with NMDG-MES. HP = −90 mV, the pulse potential is indicated next to the traces. The dashed lines correspond to the time integrals. The records are unsubtracted. (B) Data were sampled at 5 kHz and filtered at 1 kHz. The duration of the ON pulse was 50 ms, 0.5 s between sweeps. (C) Data were sampled at 25 kHz and filtered at 5 kHz. ON pulse duration was 60 ms.