title: Differences in laryngeal neurotrophic factor gene expression after recurrent laryngeal nerve and vagus nerve injuries.
abstract: OBJECTIVE
  Recurrent laryngeal nerve (RLN) and vagus nerve (VN) injuries characteristically are followed by differing degrees of spontaneous reinnervation, yet laryngeal muscle neurotrophic factor (NF) expression profiles after RLN and VN injuries have not been well elucidated. This study's objective was to determine the relative changes in gene expression of 5 well-characterized NFs from laryngeal muscle after RLN or VN injuries in a time-dependent fashion, and demonstrate how these changes correspond with electromyography-assessed innervation status.
  
  
  METHODS
  Thirty-six male rats underwent left RLN transection (12 rats), left VN transection (12 rats), or a sham procedure (12 rats). The primary outcomes included electromyographic assessment and laryngeal muscle NF expression quantification with reverse transcription polymerase chain reaction at 3 days and at 1 month.
  
  
  RESULTS
  Electromyography at 3 days demonstrated electrical silence in the VN injury group, normal activity in the sham group, and nascent units with decreased recruitment in the RLN injury group. Reverse transcription polymerase chain reaction demonstrated that changes in NF gene expression from laryngeal muscles varied depending on the type of nerve injury (RLN or VN) and the specific laryngeal muscle (posterior cricoarytenoid or adductor) assessed.
  
  
  CONCLUSIONS
  Laryngeal muscle NF expression profiles after cranial nerve X injury depend both upon the level of nerve injury and upon the muscles involved.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Indiana University School of Medicine, Indianapolis, Indiana, USA.
authors.forename: Stacey L
authors.initials: SL
authors.lastname: Halum
authors.forename: Khadijeh
authors.initials: K
authors.lastname: Bijangi-Vishehsaraei
authors.forename: M Reza
authors.initials: MR
authors.lastname: Saadatzadeh
authors.forename: Bryan R
authors.initials: BR
authors.lastname: McRae
mesh_terms: D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics; D020934:Ciliary Neurotrophic Factor / Q000235:genetics; D004576:Electromyography; D015870:Gene Expression; D051100:Glial Cell Line-Derived Neurotrophic Factor / Q000235:genetics; D007334:Insulin-Like Growth Factor I / Q000235:genetics; D007821:Laryngeal Muscles / Q000502:physiology; D008297:Male; D009414:Nerve Growth Factors / Q000235:genetics*; D056325:Neuronal Tract-Tracers; D051381:Rats; D011916:Rats, Inbred F344; D061226:Recurrent Laryngeal Nerve Injuries / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D061223:Vagus Nerve Injuries / Q000235:genetics*; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D020934:Ciliary Neurotrophic Factor; D051100:Glial Cell Line-Derived Neurotrophic Factor; D009414:Nerve Growth Factors; D056325:Neuronal Tract-Tracers; D042461:Vascular Endothelial Growth Factor A; D007334:Insulin-Like Growth Factor I