Premium
Acetylcholine receptor distribution and synapse elimination at the developing neuromuscular junction of mdx mice
Author(s) -
Minatel Elaine,
Neto Humberto Santo,
Marques Maria Julia
Publication year - 2003
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.10416
Subject(s) - neuromuscular junction , postsynaptic potential , acetylcholine receptor , dystrophin , synapse , biology , mdx mouse , neurofilament , microbiology and biotechnology , anatomy , duchenne muscular dystrophy , neuroscience , endocrinology , medicine , receptor , immunology , skeletal muscle , immunohistochemistry , biochemistry , genetics
Abstract The pattern of innervation of the vertebrate neuromuscular junction is established during early development, when junctions go from multiple to single innervation in the phenomenon of synapse elimination, suggesting that changes at the molecular level in the postsynaptic cell lead to the removal of nerve terminals. The mdx mouse is deficient in dystrophin and associated proteins that are part of the postsynaptic cytoskeleton. We used rhodamine‐α‐bungarotoxin and anti‐neurofilament IgG–FITC to stain acetylcholine receptors and nerve terminals of the sternomastoid muscle during postnatal development in mdx and control C57BL/10 mice. Using fluorescence confocal microscopy, we observed that, 7 days after birth, 86.7% of the endplates of mdx mice were monoinnervated ( n = 200) compared with 41.4% in control mice ( n = 200). By the end of the second postnatal week, all endplates were innervated singly (100% mdx and 94.7% controls, n = 200 per group). These results show that dystrophic fibers achieve single innervation earlier, perhaps because dystrophin or a normal cytoskeletal complex is implicated in this phenomenon. Muscle Nerve 28: 561–569, 2003