The respiratory control system rapidly develops during the perinatal period in mammalian species. Therefore, premature birth prevents the completion of important neurological maturation processes, which can cause periodic breathing and apneas. The ventilatory response to hypoxia (HVR) is among the test that have been used to study the immature respiratory control system in human and animal subjects (Carroll 2003; Cohen and Katz-Salamon 2005). This response is biphasic because the early increase in the HVR of newborn mammals is not sustained as in adults but decreases to below baseline values (Bissonnette 2000; Cohen and Katz-Salamon 2005; Niane and Bairam 2011). In a preliminary report, we have suggested that rats at postnatal days 1, 4, 7 and 12 (P1, P4, P7 and P12) may be selected to represent the postnatal changes in the biphasic HVR pattern (peak and steady state) and apnea frequency (Niane and Bairam 2011). To better understand the relationship between the maturation of respiratory control and the decreased apnea frequency with age (Niane and Bairam 2011), we re-analyzed our data in P1-, P4-, P7-, P12-, P21- and P90-day-old rats. The following two parameters were studied as an index of respiratory stability during development: the coefficient of variation of minute ventilation and the apnea types (spontaneous vs. post-sigh). The correlation between apnea types and the coefficient of variation of minute ventilation under baseline and steady-state conditions of HVR were assessed.
Respiratory instability Newborn rat
This is a preview of subscription content, log in to check access.
This study was partially supported by the CIHR operating grant MOP-81101 to A. Bairam. We thank Mrs. Melanie Pelletier and Sylvie Viger for animal care.
Al-Hathlol K et al (2000) A study of breathing pattern and ventilation in newborn infants and adult subjects. Acta Paediatr 89(12):1420–1425PubMedCrossRefGoogle Scholar
Al-Matary A et al (2004) Increased peripheral chemoreceptor activity may be critical in destabilizing breathing in neonates. Semin Perinatol 28(4):264–272PubMedCrossRefGoogle Scholar
Bissonnette JM (2000) Mechanisms regulating hypoxic respiratory depression during fetal and postnatal life. Am J Physiol Regul Integr Comp Physiol 278(6):R1391–R1400PubMedGoogle Scholar
Cardot V et al (2007) Ventilatory response to a hyperoxic test is related to the frequency of short apneic episodes in late preterm neonates. Pediatr Res 62(5):591–596PubMedCrossRefGoogle Scholar
Cohen G, Katz-Salamon M (2005) Development of chemoreceptor responses in infants. Respir Physiol Neurobiol 149(1–3):233–242PubMedCrossRefGoogle Scholar
Horne RS et al (2005) Postnatal development of ventilatory and arousal responses to hypoxia in human infants. Respir Physiol Neurobiol 149(1–3):257–271PubMedCrossRefGoogle Scholar
Julien CA et al (2010) Carotid sinus nerve stimulation, but not intermittent hypoxia, induces respiratory LTF in adult rats exposed to neonatal intermittent hypoxia. Am J Physiol Regul Integr Comp Physiol 299(1):R192–R205PubMedCrossRefGoogle Scholar
Julien CA et al (2011) Alteration of carotid body chemoreflexes after neonatal intermittent hypoxia and caffeine in rat pups. Respir Physiol Neurobiol 177(3):301–312Google Scholar
Mendelson WB et al (1988) Periodic cessation of respiratory effort during sleep in adult rats. Physiol Behav 43(2):229–234PubMedCrossRefGoogle Scholar
Niane LM, Bairam A (2011). Selecting representative ages for developmental changes of respiratory irregularities and hypoxic ventilatory response in rats. Open J Mol Integr Physiol 1:1–7 (Website: http://www.scirp.org/journal/OJMIPGoogle Scholar
Niane LM et al (2010) Ventilatory and carotid body chemoreceptor responses to purinergic P2X receptor antagonists in newborn rats. J Appl Physiol 110:83–94PubMedCrossRefGoogle Scholar
Nock ML et al (2004) Relationship of the ventilatory response to hypoxia with neonatal apnea in preterm infants. J Pediatr 144(3):291–295PubMedCrossRefGoogle Scholar
Rigatto H, Brady JP (1972a) Periodic breathing and apnea in preterm infants. I. Evidence for hypoventilation possibly due to central respiratory depression. Pediatrics 50(2):202–218PubMedGoogle Scholar
Rigatto H, Brady JP (1972b) Periodic breathing and apnea in preterm infants. II. Hypoxia as a primary event. Pediatrics 50(2):219–228PubMedGoogle Scholar