Figure 8. Endocytic retrieval of synaptic vesicles is important for the recovery after 40 APs.
A, normalized fluorescence intensity for 93 synapses pre-incubated with medium containing 2 μm bafilomycin to block vesicle reacidification after endocytosis (grey) and 129 controls (black). All experiments performed at 25°C. The synapses were stimulated twice with 40 APs at 20 Hz with an interval of 20 s (arrows). The first train depletes the RRP and the second train probes its recovery during the interval. ΔF indicates linear curve fits to quantify the responses. Hatched lines are baselines used for correction of control responses being superimposed on the decaying fluorescence of the previous train. B, recovery of depression during 20 s in bafilomycin (black) and control (grey) conditions. Bafilomycin significantly reduced the extent of recovery (P = 0.044, Student's t test). Note that y-axis starts from 0.5. Error bars are s.e.m.