Fig. 3. Examples of the effects of InsP₃ receptor blockers. The traces in A and B were obtained from regions showing [Ca²⁺]_i oscillations in different cell cluster preparations. In A, after observing control [Ca²⁺]_i oscillations in the presence of nifedipine (2 µM) (Aa), 10 µM 2APB was applied. The trace Ab was recorded 3 minutes after 10 µM 2APB application. Blue and red lines indicate changes in [Ca²⁺]_i measured in two different regions at a distance of 50 µm. This distance is comparable to that for regions x and y shown in Fig. 1Ba1 and Fig. 2A1. In B, after observing a control in the presence of nifedipine (Ba), 10 µM xestospongin C was applied. The trace Bb was obtained 2 minutes after the application of xestospongin C.