Center for Medical Sciences, Ibaraki Prefectural University of Health Sciences, 4669-2 Ami, Ibaraki, 300-0394, Japan.
J Physiol Sci. 2009 May;59(3):157-63. doi: 10.1007/s12576-009-0020-3. Epub 2009 Feb 6.
The pattern of respiratory activity in abdominal muscles was studied in anesthetized, spontaneously breathing, vagotomized neonatal rats at postnatal days 0-3. Anesthesia (2.0% isoflurane, 50% O(2)) depressed breathing and resulted in hypercapnia. Under this condition, abdominal muscles showed discharge late in the expiratory phase (E2 activity) in most rats. As the depth of anesthesia decreased, the amplitude of discharges in the diaphragm and abdominal muscles increased. A small additional burst frequently occurred in abdominal muscles just after the termination of diaphragmatic inspiratory activity (E1 or postinspiratory activity). Since this E1 activity is not often observed in adult rats, the abdominal respiratory pattern likely changes during postnatal development. Anoxia-induced gasping after periodic expiratory activity without inspiratory activity, and in most rats, abdominal expiratory activity disappeared before terminal apnea. These results suggest that a biphasic abdominal motor pattern (a combination of E2 and E1 activity) is a characteristic of vagotomized neonatal rats during normal respiration.
在出生后 0-3 天的麻醉、自主呼吸、迷走神经切断的新生大鼠中研究了腹部肌肉的呼吸活动模式。麻醉（2.0%异氟烷，50%O2）抑制呼吸并导致高碳酸血症。在这种情况下，大多数大鼠的腹部肌肉在呼气末期出现放电（E2 活动）。随着麻醉深度的降低，膈和腹部肌肉的放电幅度增加。在膈吸气活动结束后（E1 或吸气后活动），腹部肌肉经常会出现一个小的附加爆发。由于这种 E1 活动在成年大鼠中并不常见，因此腹部呼吸模式可能在出生后发育过程中发生变化。周期性呼气活动后缺氧引起的喘息，而没有吸气活动，并且在大多数大鼠中，腹部呼气活动在终末呼吸暂停之前消失。这些结果表明，双相腹部运动模式（E2 和 E1 活动的组合）是正常呼吸时迷走神经切断的新生大鼠的特征。
