FIGURE 4

FIGURE 4

Effects of blebbistatin on the zebrafish sinoatrial node (SAN), atrial, and ventricular action potential (AP). Representative AP (A–C) and measured parameters (D–K) in the SAN (green), atrium (red), and ventricle (blue) with (dark) and without (light) blebbistatin (10 μM for 30 min). APD₅₀ and APD₈₀, AP duration at 50% and 80% repolarisation; DD, diastolic depolarisation; dV/dt_max, maximum rate of change of membrane potential during the AP upstroke; MDP, maximum diastolic potential; V_m, membrane potential. Data shown as mean ± SEM. SAN, atrium, and ventricle compared by unpaired, one-way ANOVA and Tukey post hoc tests; ^#p < 0.05. Control and blebbistatin compared by unpaired, two-tailed, Student’s t-tests; *p < 0.05. n indicates number of impalements, which were acquired in N = 6 hearts.