Figure 3.

Delay of FM2–10 washout reveals calcineurin-dependent slow endocytosis. A, FM2–10 was loaded using an identical protocol to Figure 1A except wash of dye was delayed 5 min after termination of KCl stimulation at both S1 and S2. Where indicated, cultures were preincubated with 10 μm CsA for 10 min before and during S2 loading. B, Cumulative histogram of the effect of CsA on dye loading in individual nerve terminals (ΔS2/ΔS1, n = 270 for both Ctrl and CsA). Open symbols, Control (Ctrl); gray symbols, CsA. For all experiments, n = 3.