Modulation of nerve fibers in the rat thyroarytenoid muscle following recurrent laryngeal nerve injury.
CONCLUSIONS
Regeneration of nerve fibers in the thyroarytenoid (TA) muscle occurred actively after damage on the recurrent laryngeal nerve (RLN) compared with the vagus nerve (VN). However, remyelination did not occur after damage on the RLN.


OBJECTIVE
To determine the regeneration process of nerve fibers in the TA muscle following transection and immediate anastomosis of the RLN or VN.


METHODS
Three types of animal model were prepared: an RLN anastomosis model (RLNa), a VN anastomosis model (VNa), and a peroneal nerve anastomosis model (PNa). Animals were sacrificed at five time points following the procedure. The modulation of axons, myelin sheaths, Schwann cells (SCs), nerve terminals (NTs), and acetylcholine receptors (AchRs) in the TA or tibialis anterior muscles was examined by immunohistochemical analysis. The ratios of the expression areas in axons, myelin sheaths, and SCs, and the number of NTs and AchRs in the treated (T) and untreated (U) sides (T/U) were evaluated.


RESULTS
At 18 weeks, the T/U ratios of expression in RLNa, VNa, and PNa were 68.5, 0, and 100.4%, respectively, in axons; 0, 0, and 97.6% in myelin sheaths; 53.7, 0, and 93.6% in SCs; 61.0, 0, and 96.4% in NTs; and 99.4, 67.0, and 101.2% in AchRs.
Department of Otolaryngology-Head and Neck Surgery, Kumamoto University, Graduate School of Medicine, Japan. toya-yutaka@fc.kuh.kumamoto-u.ac.jp
Yutaka
Y
Toya
Yoshihiko
Y
Kumai
Ryosei
R
Minoda
Eiji
E
Yumoto
D000714:Anastomosis, Surgical; D000818:Animals; D001369:Axons / Q000473:pathology / Q000502:physiology; D005260:Female; D007150:Immunohistochemistry; D007821:Laryngeal Muscles / Q000294:innervation*; D009045:Motor Endplate / Q000473:pathology; D004676:Myelin Basic Protein / Q000378:metabolism; D009416:Nerve Regeneration; D010543:Peroneal Nerve / Q000293:injuries / Q000378:metabolism / Q000503:physiopathology / Q000601:surgery; D051381:Rats; D017208:Rats, Wistar; D011950:Receptors, Cholinergic / Q000378:metabolism; D012009:Recurrent Laryngeal Nerve / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D061226:Recurrent Laryngeal Nerve Injuries / Q000473:pathology / Q000503:physiopathology*; D009418:S100 Proteins / Q000378:metabolism; D012583:Schwann Cells / Q000473:pathology; D014630:Vagus Nerve / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology / Q000601:surgery
D004676:Myelin Basic Protein; D011950:Receptors, Cholinergic; D009418:S100 Proteins