Tyrode solution (in mmol/l): 135 NaCl, 5.4 KCl, 5 MgCl2, 1 CaCl2, 0.33 NaH2PO4, 10 HEPES, pH 7.3.
Ca-free Tyrode solution (in mmol/l): 135 NaCl, 5.4 KCl, 5 MgCl2, 0.02 CaCl2, 0.33 NaH2PO4, 10 HEPES, pH 7.3.
Enzyme solution (in mmol/l): 135 NaCl, 5.4 KCl, 5 MgCl2, 0.02 CaCl2, 0.33 NaH2PO4, 10 HEPES, 0.19 U ml−1 Liberase Blendzyme 3 (Roche Diagnostics, Basel, Switzerland), pH 7.3.
Storage solution (in mmol/l): 106 CH3SO3H, 106 KOH, 3.9 KCl, 2.4 MgSO4, 8 K2HPO4, 1 ethylene glycol-bis(2-aminoethylether)-N,N,N′,N′-tetraacetic acid (EGTA), 22 taurine, 22 glucose, pH 7.3.
Cacodylate buffer (in mmol/l): 150 Na cacodylate, 2 CaCl2, pH 7.3.
External solution (in mmol/l): 135 NaCl, 5.4 CsCl, 10 HEPES, 5 MgCl2, 0.33 NaH2PO4, 1 CaCl2, 0.01 IBMX, 0.02 TTX, pH 7.3.
Internal solution (in mmol/l): 135 CsCH3SO3, 10 CsCl, 10 HEPES, 2 EGTA, 2 CaEGTA, 3 MgSO4, 3 ATPNa2, 1 Oregon Green BAPTA-5N (Thermo Fisher Scientific, Brno, Czech Republic), 0.05 cAMP, pH 7.3; 100 nM free [Ca2+].
Chemicals were from Sigma-Aldrich (USA), if not stated otherwise.