Measurement of DICR with cytoplasmic [Ca 2+ ]. (A) Typical results of time-lapse G-GECO1.1 fluorescence measurement in No BV (left) and 5 BV (right) cells. High [K+] solution ranging from 5 to 61 mM (shown at right) was applied at 30 s after starting (blue arrowheads). Note that a substantial Ca2+ transient was observed in No BV, indicating the existence of endogenous Ca2+ influx pathways by depolarization. (B) [K+] dependence of fluorescence change (F/F0) in No BV (black) or 5 BV cells (red). F/F0 was obtained by normalizing the fluorescence signal at 35 s (F, grey lines in A) to the averaged signals for the first 25 s (F0). Data are means ± SD (n = 6, N = 3). n is the number of wells and N is the number of independent experiments. Related to Fig. 1 C.