Figure 5.
Averaged single-channel currents at negative potential after predepolarization from Cav1.3−/− and Cav1.2DHP−/− cerebellar granule cells in the presence of the Ca2+ channel activator (+)-(S)-202-791. A normalized ensemble average current at −40 mV (after a 500 ms depolarization to +40 mV) pooled from several patches containing (≥2 in most patches) anomalous LTCCs, six patches (n = 236 traces) from Cav1.2DHP−/− mice and five patches (n = 205 traces) from Cav1.3−/− mice, is shown. In both cases, the decaying average was best fitted by a single exponential as indicated by the gray line. The time constants of the best-fitting exponentials were 104.3 and 28.4 ms for Cav1.3−/− and Cav1.2DHP−/−, respectively. The difference was significant (p < 0.0001; F test).