Figure 4. The Bruchpilot mutant.

Average EPSCs during trains plus recovery (A), PPF (B), and at SSL (C), in controls (left column) and BRP mutants (right column), overlaid with descriptions of the experimental data by model 6 (solid lines). (D) Examples of single experiments in controls and BRP mutants to confirm the reliability of model parameters (symbols identify single experiments in the summary). (E) Summary of model parameters. Values from single experiments are given by symbols and their averages by solid lines±SEM (n=6 and 5 for 1 mM and 0.4 mM [Ca²⁺]_e in controls, n=5 and 4 for 2 mM and 1 mM [Ca²⁺]_e in BRP mutants). The parameters obtained from fitting all STP protocols in both [Ca²⁺]_e are denoted by dotted lines. According to model 6, BRP mutant active zones have a low p_r [defined by α (Trommershäuser et al., 2003)], less supply vesicles (N_supply), and refill the supply pool (τ_supply) more slowly than controls.