Related Experiment Videos
A specific force deficit exists in skeletal muscle after partial denervation.
Loree K Kalliainen1, Sameer S Jejurikar, Lawrence W Liang
1Department of Surgery, Division of Plastic Surgery, Ohio State University, Columbus, Ohio, USA.
Muscle & Nerve
|December 26, 2001
Summary
Partial denervation of skeletal muscle causes a specific force deficit. Denervated muscle fibers explain over half of this deficit, but other unknown factors also contribute to muscle contractile dysfunction.
Area of Science:
- Muscle physiology
- Neuroscience
- Skeletal muscle research
Background:
- Skeletal muscle exhibits a specific force deficit following nerve injury, muscle transfer, and aging.
- Muscle atrophy alone does not explain these force deficits, suggesting unknown mechanisms of contractile dysfunction.
Purpose of the Study:
- To investigate the role of denervated muscle fibers in the specific force deficit after partial peripheral nerve denervation.
- To test the hypothesis that a subpopulation of denervated fibers is responsible for contractile dysfunction.
Main Methods:
- Partial denervation (80% transection) of the rat extensor digitorum longus (EDL) nerve.
- Measurement of maximal isometric force (F(0)) and specific force (sF(0)) in situ.
- Immunohistochemical labeling for neural cell adhesion molecule (NCAM) to identify denervated fibers and calculate innervated fiber cross-sectional area (CSA(inn)).
Main Results:
- Partial denervation significantly reduced muscle mass, F(0), and sF(0).
- 49% of EDL muscle fibers showed denervation (NCAM expression) post-partial denervation.
- A 62.7% specific force deficit was observed, with denervated fibers accounting for 59.3% of this deficit.
Conclusions:
- Denervated muscle fibers partially explain the specific force deficit in partially denervated rat EDL muscles.
- A significant portion of the specific force deficit remains unexplained, indicating other contributing factors to muscle contractile dysfunction.