Fig. 4.

PMA does not affect the rate of vesicle mobilization. A, B, Sample recordings of Ca²⁺ currents (top) and capacitance jumps (bottom) induced by a pair of 10 msec step depolarizations (from −80 to +10 mV) with an interval of 400 msec before (A, Ctrl) and during (B) the application of 100 nm PMA. The labels and scales in A apply to B.C, The ratio between the second and the first ΔCm as a function of the paired pulse interval obtained in control and in the presence of PMA (100 nm). Data were obtained from experiments similar to those shown inA and B from 11 synapses. In control, the data were fit with a double-exponential function with time constants of 0.11 and 7.14 sec, respectively (solid curve). PMA does not affect these time constants and the relative contribution of these two components (dotted curve). The topand bottom panels show the same data in different scales.