Journal of Neuroscience, Vol 14, 3915-3921, Copyright © 1994 by Society for Neuroscience
Retrograde transport of radiolabeled cytoskeletal proteins in transected nerves
JD Glass and JW Griffin
Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287.
Slow axonal transport is the mechanism by which cytoskeletal proteins are
distributed within the axon. This function has traditionally been
considered an exclusively unidirectional, anterograde process. Previous
observations of cytoskeletal redistribution in surviving, transected axons
of the C57BL/Ola mouse led us to hypothesize a retrograde component of
cytoskeletal transport. To test this hypothesis against previous methods of
measuring slow transport of cytoskeleton, we radioactively pulse-labeled
proteins in sensory neurons of C57BL/Ola mice and followed their
redistribution by gel fluorography in ligated and unligated sciatic nerves.
Slow axonal transport of cytoskeletal proteins proceeded with the same
characteristics in C57BL/Ola as in standard C57BL/6 mice. In comparison to
the transport profiles from unligated control nerves, in ligated nerves
there was redistribution of radiolabeled neurofilament and tubulin proteins
back toward the cell body during the 14 d experimental period. These
observations demonstrate that pulse-labeled cytoskeletal proteins move
bidirectionally in this experimental system, and may provide insight into
the normal mechanisms of cytoskeletal maintenance.