Characteristics of the fast transport system in mammalian nerve fibers

✍ Scribed by Ochs, S. ;Ranish, N.

• Publisher: John Wiley and Sons
• Year: 1969
• Tongue: English
• Weight: 817 KB
• Volume: 1
• Category: Article
• ISSN: 0022-3034
• DOI: 10.1002/neu.480010211

✦ Synopsis

The rate of the fast transport system in cat sensory nerve fibers shown by the distal displacement of a peak of isotopic activity in sciatic nerves after L7 ganglion injection with 3H-leucine, is 401 + 35 mm/'day. A similar rate of fast transport was also found for motor fibers in a smaller number of studies. An intra-axonic locus of the labelled material was determined by freeze-block experiments.

Fast transport was differentiated from the slow mechanism of axoplasmic flow by injecting 3H-leucine into one L7 ganglion and "P-orthophosphate into the opposite one of the same animals, the labelled components of the latter moving down the nerve at the much slower rate characteristic of slow axoplasmic transport.

The mechanism underlying fast transport is locally present all along the nerve fibers; the soma is not responsible for propulsion. This was shown by "pulse" experiments where ligations were made just distal to the injected ganglion at times from 1-3 hrs afterwards and the same rate of outward movement of labelled materials was found in these fibers without soma1 continuity.