TY - JOUR
T1 - Embryonic cord transplants in peripheral nerve restore skeletal muscle function
AU - Thomas, Christine K.
AU - Erb, Daniel E.
AU - Grumbles, Robert M.
AU - Bunge, Richard P.
N1 - Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2000
Y1 - 2000
N2 - The rapid atrophy of skeletal muscle after denervation severely compromises efforts to restore muscle function. We have transplanted embryonic day 14-15 (E14-E15) ventral spinal cord cells into adult Fischer rat tibial nerve stump to provide neurons for reinnervation. Our aim was to evaluate medial gastrocnemius reinnervation physiologically because this transplant strategy will only be effective if the reinnervated muscle contracts, generates sufficient force to induce joint movement, and is fatigue resistant enough to shorten repeatedly. Twelve weeks posttransplantation, brief duration electrical stimuli applied to the transplants induced medial gastrocnemius contractions that were strong enough to produce ankle movement in 4 of 12 rats (33%). The force of these four 'low-threshold' reinnervated muscles and control muscles declined only gradually during five hours of intermittent, supramaximal stimulation and without depression of EMG potential area, which is strong evidence of functional neuromuscular junctions and fatigue resistant muscles. Sectioning of the medial gastrocnemius nerves confirmed that these contractions were innervation dependent. Weakness in low-threshold reinnervated muscles (8% control force) related to incomplete reinnervation, reductions in muscle fiber size, specific tension, and/or the presence of nonfunctional neuromuscular junctions. Muscle reinnervation achieved using this novel transplantation strategy may salvage completely denervated muscle and may provide the potential to evoke limb movement when injury or disease precludes or delays peripheral axon regeneration.
AB - The rapid atrophy of skeletal muscle after denervation severely compromises efforts to restore muscle function. We have transplanted embryonic day 14-15 (E14-E15) ventral spinal cord cells into adult Fischer rat tibial nerve stump to provide neurons for reinnervation. Our aim was to evaluate medial gastrocnemius reinnervation physiologically because this transplant strategy will only be effective if the reinnervated muscle contracts, generates sufficient force to induce joint movement, and is fatigue resistant enough to shorten repeatedly. Twelve weeks posttransplantation, brief duration electrical stimuli applied to the transplants induced medial gastrocnemius contractions that were strong enough to produce ankle movement in 4 of 12 rats (33%). The force of these four 'low-threshold' reinnervated muscles and control muscles declined only gradually during five hours of intermittent, supramaximal stimulation and without depression of EMG potential area, which is strong evidence of functional neuromuscular junctions and fatigue resistant muscles. Sectioning of the medial gastrocnemius nerves confirmed that these contractions were innervation dependent. Weakness in low-threshold reinnervated muscles (8% control force) related to incomplete reinnervation, reductions in muscle fiber size, specific tension, and/or the presence of nonfunctional neuromuscular junctions. Muscle reinnervation achieved using this novel transplantation strategy may salvage completely denervated muscle and may provide the potential to evoke limb movement when injury or disease precludes or delays peripheral axon regeneration.
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U2 - 10.1152/jn.2000.84.1.591
DO - 10.1152/jn.2000.84.1.591
M3 - Article
C2 - 10899232
AN - SCOPUS:0033929772
VL - 84
SP - 591
EP - 595
JO - Journal of Neurophysiology
JF - Journal of Neurophysiology
SN - 0022-3077
IS - 1
ER -