Figure 9. MβCD treatment decreases Ca²⁺ transients without significantly affecting their voltage dependence.

A, time course of the fluo-4 fluorescence intensity in response to 50 ms pulses from a holding potential of −80 mV to the indicated potential recorded in control and MβCD-treated fibres. B, average voltage dependence of the fluorescence variation recorded from 10 control and 9 MβCD-treated cells. Continuous lines correspond to a Boltzmann fit to the average populations. Parameters of the fit are F_max= 4.6 and 2.5, V_1/2,F= 0.2 and 2.7 mV and k_F= 11.5 and 12.1 mV for control and MβCD-treated cells, respectively. The dotted line corresponds to the normalization of the fit obtained in MβCD-treated cells with respect to the F_max value determined under control conditions.