Fig. 2.
Kinetics of membrane staining depended on dye concentration. A, Image of a terminal stained with 20 μm FM1–43. B, The intensity of pixels along the solid line in A plotted as a function of radial distance. The arrow indicates the location of the surface membrane. C, The intensity in the surface membrane plotted as a function of time. The cell was superfused with two concentrations of FM1–43 as indicated by thehorizontal bars. The peak intensity along a radial spoke (see B) was integrated around the circumference, except for the region from which the axon arose (as indicated by thedotted line in A). D, Intensity of membrane staining as a function of dye concentration.E, The t1/2 for the onset of staining as a function of dye concentration. F, Apparent exponential time constant for destaining as a function of dye concentration.