Effect of Recurrent Laryngeal Nerve Section on the Laryngeal Muscles of Adult Rabbits
Presented at the Annual Meeting of the Academy of Otolaryngology–Head and Neck Surgery, Los Angeles, CA, September 25-28, 2005.
Objective
To examine the effect of recurrent laryngeal nerve section on myonuclear addition and myofiber remodeling in adult rabbit laryngeal muscles.
Study design and setting
Unilateral section of the recurrent laryngeal nerve was performed on adult rabbits. Rabbits were labeled with bromodeoxyuridine, euthanized, and the laryngeal muscles were examined for bromodeoxyuridine (brdU) and neonatal myosin heavy chain (MyHC) expression.
Results
One week after nerve section, brdU-positive myonuclei were significantly increased on the denervated and contralateral sides. Neonatal MyHC expression significantly increased. By 24 weeks, the upregulation of myonuclear addition returned to control levels.
Conclusion
Laryngeal muscle denervation results in significant upregulation of myonuclear addition. Denervation also resulted in a significant upregulation of neonatal MyHC expression.
Significance
Laryngeal muscles can be successfully reinnervated after long periods of denervation. This significant and maintained increase in myonuclear addition may contribute to the ability of laryngeal muscles to survive for extended periods following interruption of the recurrent laryngeal nerve.
aDepartment of Otolaryngology, University of Minnesota, Minneapolis, MN
bDepartment of Ophthalmology and Neuroscience, University of Minnesota, Minneapolis, MN
Reprint requests: Linda McLoon, PhD, Department of Ophthalmology, University of Minnesota, Room 374, Lions Research Building, 2001 6th Street SE, Minneapolis, MN 55455
Supported by EY13979 and EY11375 from the National Institutes of Health (LKM) and American Academy of Otolaryngology–Head and Neck Surgery Foundation, Inc. Resident grant (MS), Minnesota Lions Foundation.
ABSTRACT