Fig. 3.
Large invaginations immediately next to the active zone are endocytic intermediates. Representative micrographs showing invaginations and large vesicles in the periactive zone at 50 ms (a), 100 ms (b,c) and 300 ms (d) after stimulation. Sample micrographs (e-g) showing ferritin uptake into these large endocytic structures at 100 ms after stimulation. (h) Diameter of large vesicles (82.0±1.2; n = 572) and endocytic invaginations (86.0±2.4 nm; n = 51; p = 0.33). (i) Number of shallow pits (< 40 nm), deep pits (> 40 nm), and large vesicles (<50 nm from plasma membrane) in the periactive zone at different time points after stimulation. (j) Number of shallow pits, deep pits, and large vesicles in the periactive zone at different time points after stimulation in Munc13 DKO. For detailed numbers and statistical analysis, see Supplementary Table 1. n.s., ‘not significant’. Error bars, s.e.m.