AA modulates amplitude and kinetics of whole cell Ca_V1.3b currents. (A) Concentration–response curve of AA on Ca_V1.3b, β₃ currents. Concentrations of 0.01, 0.1, 1, 5, and 10 µM were bath applied, and current inhibition was measured after 1 min (n = 3–11). (B) Individual traces of Ca_V1.3b, β₃ currents before (CTL) and after the application of 0.1, 1, or 10 µM AA. (C) Individual traces from B were normalized, revealing that exposure to 10 µM AA decreases the TTP. (D) TTP and current amplitude for Ca_V1.3b, β₃ currents plotted versus time. Bars indicate where 10 µM AA and 1 mg/ml BSA were added. Both changes reverse after wash with BSA. (E) TTP and current amplitude for Ca_V1.3b, β_2a currents plotted versus time. Conditions are the same as in D. No TTP change is observed. AA still inhibits current over time that reversed by washing with BSA.