The effect of TTA-A2 on Ca²⁺ transients in ICC-MY. (A) Representative heat map showing the summated PTCLs recording of ICC-MY in control and TTA-A2 (1 µM). (B) Occurrence map of individually color-coded Ca²⁺ firing sites in the ICC-MY network in control and TTA-A2 conditions. (C) Traces of PTCL activity of the ICC-MY network in control conditions and in the presence of TTA-A2 showing PTCL area (dark blue) and PTCL count (brown). (D) Histogram showing the probability (%) that an individual Ca²⁺ firing site in the ICC-MY cell somata will fire during a CTC cycle in control conditions (black bars) and TTA-A2 (1 µM; red bars; n = 5, FOV = 6). (E) Histogram showing the probability (%) that an individual Ca²⁺ firing site in the ICC-MY cell processes will fire during a CTC cycle in control conditions (black bars) and TTA-A2 (1 µM; red bars; n = 5, FOV = 6). (F) The number of firing sites in the cell soma was reduced from 3.5 ± 0.6 in control to 0.3 ± 0.25 in TTA-A2 (1 µM; P = 0.006, n = 5, FOV = 6). (G) In the presence of TTA-A2 (1 µM), the PTCL area/frame in the cell somata was 0.07 ± 0.069 µm² compared with 11.4 ± 3.3 µm² in control (P = 0.0197, n = 5, FOV = 6). (H) The PTCL count/frame in the cell somata was reduced from 0.3 ± 0.03 in control to 0.005 ± 0.0039 in TTA-A2 (1 µM; P = 0.0007 n = 5, FOV = 6). (I) In the cell processes, the number of Ca²⁺ firing sites per FOV was reduced from 56.5 ± 7.4 in control to 8.7 ± 6.9 in TTA-A2 (1 µM; P = 0.0001, n = 5, FOV = 6). (J) The PTCL area/frame in the cell processes was reduced from 27.4 ± 4.8 µm² in control to 0.7 ± 0.59 µm² in the presence of TTA-A2 (1 µM; P = 0.0016 n = 5, FOV = 6). (K) In the cell processes, PTCL count/frame was reduced from 0.87 ± 0.15 in control to 0.05 ± 0.04 in TTA-A2 (1 µM; P = 0.0014 n = 5, FOV = 6). *, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001. Mean ± SE is shown.