HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Free Full Text (PDF) Free All Versions of this Article: 101/4/1097    most recent 00378.2006v1 Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (3) Citing Articles via Google Scholar Google Scholar Articles by Davis, S. E. Articles by Forster, H. V. Search for Related Content PubMed PubMed Citation Articles by Davis, S. E. Articles by Forster, H. V.

Postnatal developmental changes in CO₂ sensitivity in rats

Department of Physiology, Medical College of Wisconsin and Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin

Submitted 29 March 2006 ; accepted in final form 15 June 2006

Ventilatory sensitivity to CO₂ in awake adult Brown Norway (BN) rats is 50–75% lower than in adult Sprague-Dawley (SD) and salt-sensitive Dahl S (SS) rats. The purpose of the present study was to test the hypothesis that this difference would be apparent during the development of CO₂ sensitivity. Four litters of each strain were divided into four groups such that rats were exposed to 7% inspired CO₂ for 5 min in a plethysmograph every third day from postnatal day (P) 0 to P21 and again on P29 and P30. From P0 to P14, CO₂ exposure increased pulmonary ventilation (E) by 25–50% in the BN and SD strains and between 25 to over 200% in the SS strain. In all strains beginning around P15, the response to CO₂ increased progressively reaching a peak at P19–21 when E during hypercapnia was 175–225% above eucapnia. There were minimal changes in CO₂ sensitivity between P21 and P30, and at both ages there were minimal between-strain differences. At P30, the response to CO₂ in the SS and SD strains was near the adult response, but the response in the BN rats was 100% greater at P30 than in adults. We conclude that 1) CO₂-sensing mechanisms, and/or mechanisms downstream from the chemoreceptors, change dramatically at the age in rats when other physiological systems are also maturing (P15), and 2) there is a high degree of age-dependent plasticity in CO₂ sensitivity in rats, which differs between strains.

neural control of breathing; consomics; hypercapnia

This article has been cited by other articles:

				P. G. Guyenet The 2008 Carl Ludwig Lecture: retrotrapezoid nucleus, CO2 homeostasis, and breathing automaticity J Appl Physiol, August 1, 2008; 105(2): 404 - 416. [Abstract] [Full Text] [PDF]

				K. J. Cummings, C. Willie, and R. J. A. Wilson Pituitary adenylate cyclase-activating polypeptide maintains neonatal breathing but not metabolism during mild reductions in ambient temperature Am J Physiol Regulatory Integrative Comp Physiol, March 1, 2008; 294(3): R956 - R965. [Abstract] [Full Text] [PDF]

				L. Xia, J. C. Leiter, and D. Bartlett Jr. Laryngeal apnea in rat pups: effects of age and body temperature J Appl Physiol, January 1, 2008; 104(1): 269 - 274. [Abstract] [Full Text] [PDF]