Influence of non-neuronal cells on regeneration of the rat sciatic nerve.
The ability of the rat sciatic nerve to regenerate into a previously frozen distal nerve segment was studied and compared to regeneration after a crush lesion. The regeneration rate in the frozen segment was 1.9 mm/day, which was approximately half of that observed after a crush lesion (3.3 mm/day). If an unfrozen nerve segment was left intact beyond the frozen section, the rate of regeneration increased to 3.2 mm/day. However, a fresh nerve segment sutured along the frozen segment did not significantly affect the rate of regeneration. Incorporation of [3H]thymidine in the regenerating nerve, analyzed after 1, 3 and 6 days, showed an increased labelling in the frozen segment. This increase spread from the proximal nerve segment into the frozen section. In nerves where a segment was left intact beyond the frozen section, [3H]thymidine incorporation was seen to enter the frozen section from both sides. The spreading of [3H]thymidine incorporation appeared to correlate with the rate of regeneration. However, the same pattern of incorporation could be observed in nerves where regeneration was detained by a transection. The results suggest that Schwann and/or other cells which invade the frozen nerve segment affect the rate of axonal elongation, and that the migration of these cells occurs independently of regenerating fibers.
Sjöberg
J
J
Department of Zoophysiology, University of Lund, Sweden.
Kanje
M
M
Edström
A
A
D000818:Animals; D001369:Axons / Q000502:physiology*; D002455:Cell Division; D005260:Female; D005615:Freezing; D009416:Nerve Regeneration; D051381:Rats; D011919:Rats, Inbred Strains; D012584:Sciatic Nerve / Q000166:cytology / Q000502:physiology*; D013936:Thymidine; D013997:Time Factors
D013936:Thymidine