TY - JOUR
T1 - Response of laryngeal motoneurons to hyperventilation induced apnea in the rat
AU - Sun, Qi Jian
AU - Berkowitz, Robert G.
AU - Pilowsky, Paul M.
PY - 2005/4/15
Y1 - 2005/4/15
N2 - Central apnea is common in the premature newborn. To explain the upper airway findings in different clinical conditions characterized by central apnea, we made single unit recordings from laryngeal motoneurons during normal and hyperventilation. Posterior cricoarytenoid (n = 4) and cricothyroid (n = 4) motoneurons displayed an inspiratory pattern during normal ventilation and remained synchronous with phrenic nerve discharge (PND) during hyperventilation. Laryngeal constrictor motoneurons (LCon) displayed a post-inspiratory pattern during normal ventilation, but lost phasic activity during early hyperventilation (the period after the onset of hyperventilation but before cessation of PND; n = 12). There was a nearly linear relationship between the post-inspiratory activity and strength of PND. Six LCon motoneurons remained silent throughout hyperventilation, while the other six developed a tonic activity during cessation of PND. Further analysis suggested that the silent and tonic LCon motoneurons are likely to share a similar mechanism in their post-inspiratory pattern generation, but differ from each other in their responses to CO2 inputs. In addition, strong inhibition of the LCon tonic activity by the early return of PND could be an important factor in recovery following a period of apnea. Failure of this inspiratory inhibition to occur might explain certain clinical situations, where obstructive apnea supervenes following a period of central apnea. Crown
AB - Central apnea is common in the premature newborn. To explain the upper airway findings in different clinical conditions characterized by central apnea, we made single unit recordings from laryngeal motoneurons during normal and hyperventilation. Posterior cricoarytenoid (n = 4) and cricothyroid (n = 4) motoneurons displayed an inspiratory pattern during normal ventilation and remained synchronous with phrenic nerve discharge (PND) during hyperventilation. Laryngeal constrictor motoneurons (LCon) displayed a post-inspiratory pattern during normal ventilation, but lost phasic activity during early hyperventilation (the period after the onset of hyperventilation but before cessation of PND; n = 12). There was a nearly linear relationship between the post-inspiratory activity and strength of PND. Six LCon motoneurons remained silent throughout hyperventilation, while the other six developed a tonic activity during cessation of PND. Further analysis suggested that the silent and tonic LCon motoneurons are likely to share a similar mechanism in their post-inspiratory pattern generation, but differ from each other in their responses to CO2 inputs. In addition, strong inhibition of the LCon tonic activity by the early return of PND could be an important factor in recovery following a period of apnea. Failure of this inspiratory inhibition to occur might explain certain clinical situations, where obstructive apnea supervenes following a period of central apnea. Crown
UR - http://www.scopus.com/inward/record.url?scp=14844337119&partnerID=8YFLogxK
U2 - 10.1016/j.resp.2004.12.006
DO - 10.1016/j.resp.2004.12.006
M3 - Article
C2 - 15766904
AN - SCOPUS:14844337119
SN - 1569-9048
VL - 146
SP - 155
EP - 163
JO - Respiratory Physiology and Neurobiology
JF - Respiratory Physiology and Neurobiology
IS - 2-3
ER -