Abstract
Sarcopenia has been linked to a host of health problems including osteoporosis, accidental falls, and type II diabetes. Denervation may precipitate the loss in muscle size and change in fiber type distribution characterizing sarcopenia. This study aimed to determine whether remodeling of the neuromuscular junction (NMJ) preceded alterations in myofiber profile commonly observed with aging. Ten young (5 mo) and 10 moderately aged (22 mo) Fischer 344 rats were killed and plantaris muscles were removed, and frozen until analysis. To visualize NMJs, longitudinal muscle sections were doubly stained with rhodamine conjugated α‐bungarotoxin and fluorescein labeled RT‐97 antibody, which bind to postsynaptic acetylcholine receptors and presynaptic nerve terminal branches, respectively. Myofiber profiles were assessed with histochemical staining for mATPase activity of muscle cross‐sections. Compared to NMJs of young rats, those of moderately aged ones displayed significant (P<0.05) remodeling including greater nerve terminal branch length and complexity of arborization, along with amplified perimeter length and area of staining at post‐synaptic endplates. In contrast, myofibers of aged rats showed no evidence of atrophy or changes in fiber type composition. These data show that age‐related alterations of the neuromuscular system are observed sooner in NMJs than in myofibers.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
