Laryngeal effects and respiration in the suckling opossum.
Electromyogram (EMG) activity of the posterior cricoarytenoid (PCA muscles were active, but was otherwise closed. Larynx closure may contribute to the end-inspiratory pauses often observed in the intact animal. During inhalation of an asphyxiant test gas in place of room air, PCA and diaphragm activity generally increased; and increases in anesthesia decreased the EMG activity of both muscles. Water on the larynx transiently abolished both PCA and diaphragm discharge; but EMG activity returned to the PCA muscles before the diaphragm. Further, reactivation of the diaphragm was not always accompanied by a synchronized burst of PCA activity. Therefore, it is possible under some conditions to dissociate the motor outputs from the PCA muscles and diaphragm in this immature mammal.
D000200:Action Potentials; D000828:Animal Population Groups / Q000502:physiology*; D000818:Animals; D000833:Animals, Suckling / Q000502:physiology*; D003964:Diaphragm / Q000502:physiology; D004576:Electromyography; D007830:Larynx / Q000502:physiology*; D009130:Muscle, Smooth / Q000502:physiology; D009893:Opossums / Q000502:physiology*; D012119:Respiration