Distribution of endocytosis in the growth cone central and peripheral domains. (A) Schematic illustration of the growth cone peripheral and central regions (light and dark gray, respectively) used to determine the spatial distribution of endocytic vesicle formation (B-C). (B) Summary of the number of endocytic events in the indicated regions. Individual vesicles were counted 15 s after membrane labeling and classified based on their origin in peripheral or central regions as defined in (A). Colors (light and dark gray) correspond to (A). (C) Summary of the endocytic density in peripheral and central regions as defined in (A). Vesicles were counted as in (B) and the density reflects the number of endocytic vesicles per μm2. Data are the mean ± standard error of the mean obtained from 20 individual growth cones. N.S., P > 0.05, *P < 0.005, t-test. (D) Summary illustration of the endocytic modes described in Figures 2-10. A top-view (coronal section) of the growth cone is shown at the left. A side-view (sagittal section) is shown at the right where dorsal is up and ventral is down. The colors of labeled vesicles, tubules, and vacuoles correspond to the legend at the upper right. (E) Summary of the percentage of growth cones that displayed individual endocytic modes during the focal membrane labeling assays. The colors for each bar correspond to the legend and illustration in (A). (F) Summary of the frequency of individual endocytic modes observed during the FM dye assays. Spatial modes were counted in 20 individual growth cones and are displayed as the number of events per minute.