| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Department of Physiology, Faculty of Medicine and Health Science, University of Auckland, Auckland, New Zealand
We examined
developmental changes in breathing pattern and the ventilatory response
to hypoxia (7.4% O2) in unanesthetized Swiss CD-1 mice
ranging in age from postnatal day 0 to 42 (P0-P42) using head-out
plethysmography. The breathing pattern of
P0 mice was unstable. Apneas were frequent at
P0 (occupying 29 ± 6% of total time) but rare by
P3 (5 ± 2% of total time). Tidal volume increased in
proportion to body mass (~10-13 ml/kg), but increases in
respiratory frequency (f) (55 ± 7, 130 ± 13, and 207 ± 20 cycles/min for P0, P3, and
P42, respectively) were responsible for developmental increases in minute ventilation (690 ± 90, 1,530 ± 250, and 2,170 ± 430 ml · min
1 · kg1
for P0, P3, and P42, respectively).
Between P0 and P3, increases in f were mediated
by reductions in apnea and inspiratory and expiratory times; beyond
P3, increases were due to reductions in expiratory time.
Mice of all ages showed a biphasic hypoxic ventilatory response, which
differed in two respects from the response typical of most mammals.
First, the initial hyperpnea, which was greatest in mature animals,
decreased developmentally from a maximum, relative to control, of 2.58 ± 0.29 in P0 mice to 1.32 ± 0.09 in P42
mice. Second, whereas ventilation typically falls to or below control
in most neonatal mammals, ventilation remained elevated relative to
control throughout the hypoxic exposure in P0 (1.73 ± 0.31), P3 (1.64 ± 0.29), and P9 (1.34 ± 0.17) mice but not in P19 or P42 mice.
respiration; apnea; plethysmography; in vivo
This article has been cited by other articles:
|
|
 |
|
  C. Gaultier and J Gallego Neural control of breathing: insights from genetic mouse models J Appl Physiol, May 1, 2008; 104(5): 1522 - 1530. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. Matrot, E. Durand, S. Dauger, G. Vardon, C. Gaultier, and J. Gallego Automatic classification of activity and apneas using whole body plethysmography in newborn mice J Appl Physiol, January 1, 2005; 98(1): 365 - 370. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. J. Cummings, J. D. Pendlebury, N. M. Sherwood, and R. J. A. Wilson Sudden neonatal death in PACAP-deficient mice is associated with reduced respiratory chemoresponse and susceptibility to apnoea J. Physiol., February 15, 2004; 555(1): 15 - 26. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Durand, S. Dauger, G. Vardon, P. Gressens, C. Gaultier, S. de Schonen, and J. Gallego Plasticity in Respiratory Motor Control: Selected Contribution: Classical conditioning of breathing pattern after two acquisition trials in 2-day-old mice J Appl Physiol, February 1, 2003; 94(2): 812 - 818. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 W. Bernhard, S. Hoffmann, H. Dombrowsky, G. A. Rau, A. Kamlage, M. Kappler, J. J. Haitsma, J. Freihorst, H. von der Hardt, and C. F. Poets Phosphatidylcholine Molecular Species in Lung Surfactant . Composition in Relation to Respiratory Rate and Lung Development Am. J. Respir. Cell Mol. Biol., December 1, 2001; 25(6): 725 - 731. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Renolleau, S. Dauger, F. Autret, G. Vardon, C. Gaultier, and J. Gallego Maturation of baseline breathing and of hypercapnic and hypoxic ventilatory responses in newborn mice Am J Physiol Regulatory Integrative Comp Physiol, November 1, 2001; 281(5): R1746 - R1753. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
