Neurofilament redistribution in transected nerves: evidence for bidirectional transport of neurofilaments

JD Glass, JW Griffin - Journal of Neuroscience, 1991 - Soc Neuroscience
JD Glass, JW Griffin
Journal of Neuroscience, 1991Soc Neuroscience
Nerve fibers of the C57BL/6/Ola mouse exhibit very slow Wallerian degeneration following
axotomy, thus allowing prolonged observation of mammalian axons separated from their cell
bodies. The present study utilized teased-fiber preparations, silver histochemistry,
immunocytochemistry, and electron microscopy to examine the distribution of axonal
components in the distal stumps of axotomized sciatic nerves in C57BL/6/Ola mice. In
examining nerve segments at varying intervals after nerve transection, we found no …
Nerve fibers of the C57BL/6/Ola mouse exhibit very slow Wallerian degeneration following axotomy, thus allowing prolonged observation of mammalian axons separated from their cell bodies. The present study utilized teased-fiber preparations, silver histochemistry, immunocytochemistry, and electron microscopy to examine the distribution of axonal components in the distal stumps of axotomized sciatic nerves in C57BL/6/Ola mice. In examining nerve segments at varying intervals after nerve transection, we found no evidence of proximal-to-distal “emptying out” of the cytoskeleton, as would be predicted if the cytoskeleton in these transected nerves were undergoing anterograde transport as an assembled structure. Instead, we observed a gradual redistribution of cytoskeletal constituents over time, dominated by the progressive accumulation of neurofilaments at the severed ends of axons. In particular, there were massive accumulations at the proximal ends of the distal stumps. These results strongly suggest that, at least in transected nerve fibers, neurofilaments can be transported bidirectionally.
Soc Neuroscience