Figure 4. The β2 subunit is required for BK_i current decay and the diurnal difference in BK current magnitude in SCN neurons.

(a) Representative BK current traces and macroscopic decay time constants (τ_inact) for BK_s currents from β2 KO neurons. Voltage protocol same as in Figure 2. (b) All currents are BK_s from β2 KO SCNs, day or night. (c) β2 KO neurons do not show a day–night difference in BK current density. The β2 KO daytime BK current magnitude is larger than WT, comparable to WT levels at night. (d) The fractional BK current (I_30ms/I_peak) was similar during the day compared with night in β2 KO neurons. (e) τ_inact values from β2 KO BK_s currents are all >100 ms. All values are mean±s.e.m. n values: β2 KO, day (20) and night (20).