Early growth of regenerating neurites in acrylamide neuropathic mice: application of a film model.
Acrylamide intoxication markedly impairs neural regeneration following transection of a peripheral nerve. However, no neural inhibitory mechanism has yet been clarified. In the present study, the early growth of regeneration neurites in acrylamide neuropathic mice was analyzed using a film model: following transection of the common peroneal nerve, the proximal stump was sandwiched between two sheets of thin plastic film and kept in vivo for various intervals after axotomy. The regenerating axons grew for a significantly (P < 0.01) longer distance than those in the controls up to the 2nd day after axotomy (day 2), but thereafter the axons showed suppressed growth. Many disoriented neurofilaments were already accumulated in the axons on day 1, and their number progressively increased. The number of neurotubules was the same as that in the controls on day 1, but thereafter progressively decreased, and they had almost disappeared by day 5. Schwann cells began to migrate from the proximal stump of the transected nerve on day 3, showing their strong effect in promoting the axonal elongation. The initial acceleration of the growth seemed to be induced by the unusual mass of neurofilaments, and the suppression of growth at and after day 3 might be the result of both the decrease in the number of neurotubules and a refractory state of the axons to the stimuli from the migratory Schwann cells.
Torigoe
K
K
Department of Anatomy, Fukui Medical School, Japan.
Tanaka
H G
HG
Takahashi
A
A
Hashimoto
K
K
D020106:Acrylamide; D000178:Acrylamides / Q000633:toxicity*; D000818:Animals; D002465:Cell Movement / Q000502:physiology*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D008853:Microscopy / Q000379:methods; D008854:Microscopy, Electron; D009416:Nerve Regeneration / Q000502:physiology*; D016501:Neurites / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D016900:Neurofilament Proteins / Q000187:drug effects / Q000378:metabolism; D009498:Neurotoxins / Q000494:pharmacology; D010969:Plastics; D012583:Schwann Cells / Q000166:cytology / Q000187:drug effects* / Q000502:physiology
D000178:Acrylamides; D016900:Neurofilament Proteins; D009498:Neurotoxins; D010969:Plastics; D020106:Acrylamide