FIGURE 7.

LCa_v3 currents are larger and faster when Ba²⁺ is the charge carrier. Sample traces (A) and current-voltage relationships (B) of LCa_v3 currents were generated from depolarizing voltage steps from a holding potential of −110 mV while microperfusing extracellular solution containing either 5 mm Ba²⁺ or 5 mm Ca²⁺. Whole cell Ba²⁺ conductance was estimated to be ∼50% greater than Ca²⁺ conductance at all voltages (C). Kinetics of activation (time to peak current, ms) (D) and inactivation decay (tau curve fit, ms) (E) are faster when barium instead of calcium is the charge carrier.