FIG. 13.

Dependencies on [Ca²⁺]_i and [InsP₃] of InsP₃R channel activity duration and recruitment. A: channel activity duration. Data points are averages of channel activity durations in ligand conditions as tabulated. Smooth curves in graphs in this figure were drawn by hand for clarity. B: ligand-dependent recruitment of InsP₃R. Data points are average number of active channels in membrane patches (N_A) in ligand concentrations as tabulated. C: ligand-dependent relative magnitude of InsP₃R-mediated Ca²⁺ release. The product N_AP_o, determined using data shown in Fig. 6B and Fig. 1D, in ligand concentrations as tabulated. [Modified from Ionescu et al. (196).]