Neuronal motility: the ultrastructure of veils and microspikes correlates with their motile activities

摘要: We have documented the ultrastructural characteristics that correlate with protrusion, adhesion and retraction of neuronal veils microspikes, by filming individual neurons chick ciliary ganglion examining same cells high-voltage electron microscopy. find new invariably contain only a cortical meshwork filaments are devoid microtubules, groups vesicles other organelles. At sites recent veil on substratum side underlies filament-free space containing vesicle clusters complexly folded upper membrane. Areas without activity smooth-surfaced three-dimensional lattice filaments. discuss implications these observations for mechanisms surface recruitment retrieval during motile activity. also ultrastructure moving attached extensions cell differs dramatically. Unattached microspikes actively extending an open, criss-cross array filaments, whereas more aligned which extend as small bundle into growth cone. These results suggest protrusion is mediated meshworks loosely packed More compact bundles probably generated at points.