Slowing of the axonal transport of neurofilament proteins during development

Journal Article · Mon Aug 01 04:00:00 EDT 1983 · J. Neurosci.; (United States)

OSTI ID:5605340

Hoffman, P N; Lasek, R J; Griffin, J W; Price, D L

We examined age-dependent changes in neurofilament transport in motor axons of the rat sciatic nerve. SDS-PAGE and gel fluorography confirmed that the distribution of labeled neurofilament triplet protein coincides with the major slow component a (SCa) wave in these neurons. The velocity of neurofilament transport was calculated on the basis of the location of the 50th percentile of radioactivity in this wave 33 days after motor neurons were labeled by the intraspinal administration of (/sup 3/H)leucine and (/sup 3/H)lysine. Overall, the velocity fell from 1.95 mm/day at 3 weeks of age to 1.12 mm/day at 20 weeks. Between 3 and 10 weeks, it fell at a 6-fold higher rate (0.096 mm/day/week) than between 10 and 20 weeks (0.016 mm/day/week). We also found a marked change in the shape of the slow component wave during development. It appeared to consist of several overlapping peaks moving at slightly different velocities in animals 10 weeks of age or less as compared to a single slower moving peak at 20 weeks. We propose that the velocity of slow axonal transport reflects the level of maturation of the neuron, and that the presence of several overlapping peaks of transported radioactivity in the sciatic nerve of younger animals reflects the presence of several populations of motor axons at different stages of development. We also discuss the relationship between changes in the velocity of neurofilament transport and alterations in the composition of the cytoskeleton that occur as the axon grows in caliber during postnatal development.

• Research Organization: Neuropathology Laboratory, Johns Hopkins University School of Medicine, Baltimore, Maryland
• OSTI ID: 5605340
• Journal Information: J. Neurosci.; (United States), Journal Name: J. Neurosci.; (United States) Vol. 3:8; ISSN JNRSD
• Country of Publication: United States
• Language: English

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59 BASIC BIOLOGICAL SCIENCES
AGE DEPENDENCE
AMINO ACIDS
ANIMAL CELLS
ANIMALS
CARBOXYLIC ACIDS
ELECTROPHORESIS
EMISSION SPECTROSCOPY
FILAMENTS
FLUORESCENCE SPECTROSCOPY
GROWTH
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LEUCINE
LYSINE
MAMMALS
NERVE CELLS
NERVES
NERVOUS SYSTEM
ORGANIC ACIDS
ORGANIC COMPOUNDS
PROTEINS
RATS
RODENTS
SCIATIC NERVE
SOMATIC CELLS
SPECTROSCOPY
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES