ULTRASTRUCTURE AND FUNCTION OF GROWTH CONES AND AXONS OF CULTURED NERVE CELLS

摘要: Dorsal root ganglion nerve cells undergoing axon elongation in vitro have been analyzed ultrastructurally. The growth cone at the axonal tip contains smooth endoplasmic reticulum, vesicles, neurofilaments, occasional microtubules, and a network of 50-A diameter microfilaments. filamentous fills periphery is only structure found microspikes. Elements are oriented parallel to axis microspikes, but exhibit little orientation cone. Cytochalasin B causes rounding up cones, retraction cessation elongation. latter biological effect correlates with an ultrastructural alteration cones No other organelle appears be affected by drug. Removal cytochalasin allows reinitiation cone-microspike activity, begins anew. Such recovery will occur presence protein synthesis inhibitor cycloheximide, absence exogenous factor. neurofilaments microtubules axons regularly spaced. Fine filaments indistinguishable from those interconnect plasma membrane. This could provide structural basis for initiation lateral microspikes perhaps collateral axons, besides playing role transport.