Figure 2
SmCa v β-dependent run-down of Ca v 2.3 currents. A. Relative peak amplitude of currents produced by Cav2.3 channels alone (circles) and in combination with SmCavβ (triangles), plotted as a function of time. Currents were normalized with respect to those measured immediately after rupturing the patch membrane (t = 0). Ca2+ currents (filled symbols) and Ba2+ currents (open symbols) are shown. Data points represent mean ± s.e.m. B. Relative amplitude of currents produced by Cav2.3 in combination with Cavβ2a (squares) or SmCavβvar (triangles), plotted as a function of time. As in A, currents were normalized with respect of those at time 0, measured immediately after break-in. Data points represent mean ± s.e.m, N = 3 – 5. C. Ca2+ currents generated by Cav2.3 in the presence of SmCavβ at t = 0 min and at t = 2 min. Note that the kinetics of macroscopic inactivation remains unchanged. D. Voltage-dependence of inactivation (steady-state inactivation) at t = 0 min (filled circles) and at t = 2 min (open circles). Solid lines represent fits to the Boltzmann function.