Experiments on partially deneurotized nerves. I. Absence of branching of residual fibers

✍ Scribed by Edds, Mac V.

• Publisher: John Wiley and Sons
• Year: 1949
• Tongue: English
• Weight: 846 KB
• Volume: 111
• Category: Article
• ISSN: 0022-104X
• DOI: 10.1002/jez.1401110205

✦ Synopsis

FOVR FIGURES

The spontaneous recovery of partially denervated muscles, first reported by Welirmachcr and Hines ( '45), is now firmly established (Hines, Wehrmacher and Thomson, '45 ; van Harreveld, '45, '47 ; Weiss and Edds, '46 ; Frederick and Kosman, '48). Such muscles, rendered paretic by methods which inhibit regeneration of the severed nerve fibers, eventually regain part OF all of their lost weight and strength. Four possible explanations have been advanced to account for this recovery: ( a ) Muscle fibers which retain their innervation undergo hypertrophy. (b) Unattached terminal axon branches-present but functionally idle in normal muscle-take over denervated muscle fibers. (c) Newly formed branches of the intact, intramuscular axons spread to denervated muscle fibers. ( d ) Intact axons within the operated nerve break down at more proximal levels, regenerate with branching and enter denervated areas.

Although sporadic hypertrophy of the innervated muscle fibers ( a ) has been described in rabbits (van Harreveld, '45), it does not occur in rats (Weiss and Edds, '46) and, at least in the early stages, it appears to be a minor factor in recovery, There is still no critical evidence for the presence or absence of surplus, unconnected axon branches (b) in nornial Aided by a grant from TIIP National Foundation for Infantile Paralysis, Inc.