Fig. 5.

A kinetic scheme with a faulty SV state reproduces the timecourse of aberrant delayed release observed in Cplx-deficient calyx synapses. (A) Proposed extension for the kinetic scheme shown in Fig. 1A by adding a branch to a FS. (B) Comparison of numerical simulations and experimental data for spontaneous and delayed ξ(t) following conditioning stimulation (100 Hz, 15 APs) for wt (black) and ko (red) synapses. The timecourse of the effective global [Ca²⁺]_i is shown for comparison (green) on the right axis and in the Inset. (C) Ca²⁺ dependence of fusion for FS SVs (Ci, purple) in comparison to TS SVs in wt (Cii, black) and ko (Cii, red) synapses. The dynamic range of the Ca²⁺ dependence of fusion is greatly reduced for FS SVs. (D) Timecourses of occupancy of FS (dark lines, right axis) and TS (pale lines, left axis) in wt (black) and ko (red) synapses. The period of 100 Hz conditioning stimulations is indicated by the gray box. (E) The timecourse of decay of the delayed quantal release following conditioning stimulation (100 Hz, 15 APs; left gray box) in ko synapses is largely unchanged when delivering an additional test AP (right gray box).