Figure 6. Single NSC channel current activated by S1P.
NSC channels were activated by application of 0.3 μm S1P and 3 μm GTP in the inside-out patch configuration. The holding potential was +40 mV. A, changes in the relative open-state probability of channels (NPo), which was calculated every 1024 ms, were plotted against time after the establishment of the excised inside-out (IO) configuration. B, the trace illustrated was obtained at the corresponding time indicated by ‘1′ in A and the amplitude histogram was constructed. The y-axis (% count) expresses the relative time (%) at the corresponding amplitude in each bin vs. the total recording. The dashed line indicates the zero current level and o1 the open channel level for one channel. The single channel current amplitude and NPo calculated from the histogram were 0.62 pA and 0.32, respectively. The bin width was 0.08 pA. The pipette and external solution mainly contained 110 mm caesium aspartate and 30 mm CsCl, and 120 mm KCl and 20 mm TEA-Cl, respectively.