Figure 4.

R930H does not alter activation and inactivation parameters of Cav1.3_S and Cav1.3_L. (a) Voltage-dependence of activation of the wild-type and mutant Cav1.3_S and (b) Cav1.3_L variants. (c) Voltage-dependence of inactivation of wild-type Cav1.3_S versus R930H_S and (d) wild-type Cav1.3_L versus R930H_L. (e) Recovery from inactivation of wild-type Cav1.3_S versus R930H_S (τ Cav1.3_S: 270.1 ± 14.4 ms, n = 10; τ R930H_S: 261.9 ± 18.2 ms, n = 12; not significant, unpaired Student’s t-test) and (f) wild-type Cav1.3_L versus R930H_L (τ Cav1.3_L: 166.1 ± 20.56 ms, n = 5; τ R930H_L: 180.6 ± 36.4 ms, n = 5; not significant, unpaired Student’s t-test. Consistent with the literature, recovery from inactivation was faster in the Cav1.3_L variant (τ Cav1.3_L vs. τ Cav1.3_S p = 0.0011, unpaired Student’s t-test) [20]. However, this parameter was not affected by the R930H variant. Recovery from inactivation was determined by 10 ms test pulses to V_max at different time points after a 5-s conditioning pulse to the potential of the peak currents followed by a test pulse, as described in the Materials and Methods section. Data were fitted using a mono-exponential function. Data in (a–d) are shown as mean ± S.E.M. For parameters and statistics see Table 2.