Fig. 4.

Fluo-3AM treated muscles cells display Ca²⁺ signals: a representative calcium trace of a muscle exposed to 10 mM CaCl₂ that was maintained in regular bath solution before stimulus application. Gray box represents stimulus application. b Representative calcium trace in response to 10 mM CaCl₂ in a muscle maintained in low CaCl₂ (1 mM) bath solution. Gray box represents stimulus application. c Amplitudes of calcium signals in muscles perfused with low calcium bath solution, 10 mM CaCl₂ in regular bath solution and 10 mM CaCl₂ in low CaCl₂ bath solution. ***Significantly different from untreated (untreated vs. 10 mM CaCl₂ regular buffer; P < 0.0001, t = 6.792, df = 25, unpaired t test), (untreated vs. 10 mM CaCl₂ low CaCl₂ buffer; P < 0.0001, t = 8.273, df = 30, unpaired t test). † = significantly different to 10 mM CaCl₂ in regular buffer (10 mM CaCl₂ in regular buffer vs. 10 mM CaCl₂ in low CaCl₂ buffer P = < 0.0001, t = 8.108, df = 33, unpaired t test). Untreated n = 12; 10 mM CaCl₂ in regular buffer n = 15, 10 mM CaCl₂ in low CaCl₂ buffer n = 20. All values are represented as mean ± SEM