title: Congenital bilateral vocal cord paralysis and the role of glycine.
abstract: OBJECTIVE
  We sought to modify normal laryngeal constrictor (LC) motoneuron activity to induce a pattern of aberrant LC muscle function that may serve as a model of congenital bilateral vocal cord paralysis.
  
  
  METHODS
  Single unit extracellular recordings of functionally identified LC motoneurons were made in anesthetized Sprague-Dawley rats, and the response to both intravenous and iontophoretic application of the glycine antagonist strychnine was studied.
  
  
  RESULTS
  The postinspiratory firing pattern of LC motoneurons became inspiratory after intravenous injection of strychnine (4 of 5 rats), but no change was recorded in response to strychnine iontophoresis (7 of 8 rats).
  
  
  CONCLUSIONS
  Blockade of glycinergic inhibitory neurotransmission by strychnine, acting above the level of the LC motoneuron, causes LC motoneurons to fire during inspiration rather than after inspiration. This observation suggests that impaired glycine neurotransmission may be an underlying mechanism that explains the clinical manifestations of congenital bilateral vocal cord paralysis.
authors.affiliation: Hypertension and Stroke Research Laboratories, Department of Physiology, University of Sydney, Sydney, Australia.
authors.forename: Robert G
authors.initials: RG
authors.lastname: Berkowitz
authors.forename: Qi-Jian
authors.initials: QJ
authors.lastname: Sun
authors.forename: Paul M
authors.initials: PM
authors.lastname: Pilowsky
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D018684:Glycine Agents / Q000494:pharmacology*; D007275:Injections, Intravenous; D007478:Iontophoresis; D007821:Laryngeal Muscles / Q000294:innervation; D009046:Motor Neurons / Q000187:drug effects* / Q000502:physiology; D010791:Phrenic Nerve / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013331:Strychnine / Q000494:pharmacology*; D014826:Vocal Cord Paralysis / Q000151:congenital* / Q000503:physiopathology
chemical_list: D018684:Glycine Agents; D013331:Strychnine