Looking into growth cones.

The growth cone is a crucial structure in effecting neurite elongation and guiding the neurite onto correct pathways by responding to environmental cues. Recently developed techniques in light and electron microscopy have greatly improved our understanding of the dynamic organization of membrane and cytoskeleton within the growth cone. The growth cone can now be directly observed to undergo a sequence of developmental changes to produce the neurite. The importance, in elongation and steering, of pulling of growth cone protrusions against adhesive contacts on the substrate is re-evaluated in the light of these findings.