Novel Model to Assess Laryngeal Function, Innervation, and Reinnervation

Abstract

A reliable, accurate model for the characterization of laryngeal function, routes of innervation, and sources of spontaneous reinnervation following recurrent laryngeal nerve resection has been developed. This stable and reproducible model can serve as a dependable tool in future investigations of laryngeal nerve injury and recovery.

Spontaneous laryngeal reinnervation following chronic recurrent laryngeal nerve injury

“…General anesthesia with spontaneous respiration and microlaryngoscopy was performed as previously described . In brief, intraperitoneal ketamine (50 mg/kg) and xylazine (5 mg/kg) with inhaled 1.8% isoflurane were used to induce anesthesia for endoscopy to document vocal fold mobility.…”

“…In those rats that were to undergo denervation, 5 mm of the right RLN was resected. Retrograde labeling procedures were performed according to Figures and using techniques previously published . Briefly, FG was injected into the right TA muscle of designated animals using endoscopic guidance.…”

“…Rats that underwent FG labeling procedures were euthanized and harvested on postoperative day 6 following tracer application, and brainstems, DRG, SCG, and NOD ganglia were immediately dissected and processed as previously described . ProLong Gold antifade reagent with DAPI (Life Technologies, Grand Island, New York) was used to quantify FG positive cells, which were counted and recorded according to side (left, right) and precise rostral/caudal position in relation to the obex.…”

“…Development of the experimental model utilized in the current study and data for control animals were previously published . In the previous study, methods for rat suspension microlaryngoscopy and endoscopic thyroarytenoid (TA) muscle injection with the retrograde tracer FluoroGold (FG; Fluorochrome, LLC, Denver, Colorado) were developed.…”

Immunohistologic analysis of spontaneous recurrent laryngeal nerve reinnervation in a rat model

“…The study was performed with the approval of the University of Michigan Committee on Use and Care of Animals. Twelve male Sprague‐Dawley rats, age 60 days, underwent RLN resection using procedures previously described in a rat model of chronic RLN injury . Briefly, intraperitoneal ketamine (50 mg/kg) and xylazine (5 mg/kg) with inhaled 1.8% isofluorane were used to induce anesthesia with spontaneous respiration for microlaryngoscopy to document vocal fold mobility.…”