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Muscle reorganization after partial denervation and reinnervation
Author(s) -
Peyronnard JeanMarie,
Charron Louise
Publication year - 1980
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.880030608
Subject(s) - reinnervation , denervation , anatomy , sprouting , tibialis anterior muscle , muscle fibre , motor unit , biology , axon , spinal nerve , medicine , chemistry , skeletal muscle , dorsum , botany
The normal rat tibialis anterior (TA) muscle was found to be innervated by approximately 154 spinal motor cells of which 95 are alpha motoneurons. Most of these axons ran in the L4 root and connected with glycolytic type 2B muscle fibers. The L5 root supplied 8.4% to 14.7% of the motor axons of TA muscle and innervated type 1 and 2A muscle fibers rich in oxidative enzymes. Two months after section of the peroneal nerve, there was marked fiber‐type grouping and compact rearrangement of the L4 and L5 motor units. After section of the L4 radicular nerve, the TA muscle remained atrophic with no evidence of fiber‐type grouping until 3 months when the L4 regenerating axons reached the muscle. Similar results were obtained after ligation of the divided ends of the L4 radicular nerve, which delayed but did not prevent reinnervation. These data suggest that, after partial denervation, muscle reinnervation by collateral sprouting is a slowly developing process.