The slow axonal transport of cytoskeletal proteins.

Once presumed to be relatively uniform, the axonal cytoskeleton can vary markedly in size and composition along its length. New studies emphasize the interactiveness of neurofilaments and identify a family of cytoskeletal proteins that may cross-link the various cytoskeletal polymers of the axon, and anchor this network to the membrane skeleton. These and other findings support a model of the axonal cytoskeleton as a stationary but dynamic structure. Current evidence continues to support the possibility that axonally transported polymers/oligomers and/or monomers may serve as precursors to the cytoskeleton in different situations. Although the motors for slow transport of cytoskeletal proteins remain elusive, possible candidates are emerging.