Regulation of expiratory muscles during postnatal development in anesthetized piglets.

  title={Regulation of expiratory muscles during postnatal development in anesthetized piglets.},
  author={Ita Litmanovitz and R. J. Martin and Musa A. Haxhiu and Luigi Cattarossi and B Haxhiu-Poskurica and Waldemar A. Carlo},
  journal={Journal of applied physiology},
  volume={74 6},
We compared maturation of the responses of the rib cage [triangularis sterni (TS)] and abdominal [transversus abdominis (TA)] expiratory muscles with each other and with the responses of the diaphragm (DIA) during hypercarbic and hypoxic stimulation. Studies were performed in anesthetized (urethan and chloralose) piglets of two age groups (< 6 days, n = 10; 14-21 days, n = 11) before and after bilateral cervical vagotomy. Hypercarbia (7% CO2-93% O2) was associated with comparable sustained… 
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Differential effects of hypercapnia on expiratory phases of respiration in the piglet.
It is demonstrated that, in early postnatal life, a hypercapnia induced increase in respiratory drive is associated with centrally mediated prolongation of both phases of expiration, a greater prolongationOf TE-1, and an increase in laryngeal resistance during post-inspiration, which serves to optimize gas exchange by reducing large fluctuations in functional residual capacity.
Diaphragmatic activity during biphasic ventilatory response to hypoxia in rats.
The results suggest that the increased end-expiratory activity of the diaphragm limits its phasic inspiratory activation and thus contributes to the biphasic character of the ventilatory response to sustained hypoxia; and vagal input does not play a major role in this phenomenon.
CO2-induced prolongation of expiratory time during early development.
It is demonstrated for the first time that in early postnatal life, hypercapnia induced increase in phrenic activity is associated with centrally mediated prolongation of expiratory duration and the results suggest that brainstem GABAergic mechanisms play an important role in CO2-induced prolongations of expIRatory time during early development.
Control of abdominal muscles
  • S. Iscoe
  • Medicine
    Progress in Neurobiology
  • 1998
Studies of the multifunctional roles of the abdominal muscles, on the basis of recent work, hold considerable promise for improving understanding of their control.
Influence of hypercapnic acidosis and hypoxia on abdominal expiratory nerve activity in the rat
Both hypercapnic acidosis and hypoxia activate abdominal muscle motoneurons in the absence of phasic afferent inputs, and both enhance abdominal motor activity transiently and cause a sustained increase in activity.
Control of Breathing and Neonatal Apnea
The ventral surface of the medulla and adjacent areas play a key integrative function for central CO2 chemosensitivity and modulation of afferent inputs from peripheral chemoreceptors and laryngeal afferents.