FIGURE 6.

Simultaneous recordings of STOCs and Ca²⁺ sparks in WT and KO myocytes. A, fluorescent images surrounded by a dotted line in the transmitted light images (upper) were collected at the time points indicated by arrowheads in the membrane current recordings (middle). The fluorescent images were also shown in supplemental Movies 3 and 4. Changes in cytosolic Ca²⁺ levels at the two sites (a and b) circled in the fluorescent images are correspondingly shown (lower). B, the mean STOC amplitude and frequency in WT (n = 5) and KO (n = 10) cells are summarized (**, p < 0.01, versus WT). C, the mean Ca²⁺ spark amplitude and frequency in WT (n = 5) and KO (n = 10) cells are summarized (p > 0.05).