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

This Article Full Text Full Text (PDF) All Versions of this Article: 104/1/198    most recent 00843.2007v1 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 (1) Citing Articles via Google Scholar Google Scholar Articles by Bissonnette, J. M. Articles by Knopp, S. J. Search for Related Content PubMed PubMed Citation Articles by Bissonnette, J. M. Articles by Knopp, S. J.

Effect of inspired oxygen on periodic breathing in methy-CpG-binding protein 2 (Mecp2) deficient mice

¹Department of Obstetrics and Gynecology and ²Department of Cell and Development Biology, Oregon Health and Sciences University, Portland, Oregon

Submitted 6 August 2007 ; accepted in final form 12 November 2007

Rett syndrome (RTT) is a neurodevelopmental disorder caused by mutations in the X-linked gene methyl-CpG-binding protein 2 (Mecp2) that encodes a DNA binding protein involved in gene silencing. Periodic breathing (Cheyne-Stokes respiration) is commonly seen in RTT. Freely moving mice were studied with continuous recording of pleural pressure by telemetry. Episodes of periodic breathing in heterozygous Mecp2 deficient (Mecp2^+/–) female mice (9.4 ± 2.2 h^–1) exceeded those in wild-type (Mecp2^+/+) animals (2.5 ± 0.4 h^–1) (P = 0.010). Exposing Mecp2^+/– animals to 40% oxygen increased the amount of periodic breathing from 118 ± 25 s/30 min in air to 242 ± 57 s/30 min (P = 0.001), and 12% oxygen tended to decrease it (67 ± 29 s/30 min, P = 0.14). Relative hyperoxia and hypoxia did not affect the incidence of periodic breathing in Mecp2^+/+ animals. The ventilation/apnea ratio (V/A) was less at all levels of oxygen in heterozygous Mecp2^+/– females compare with wild type (P = 0.003 to P < 0.001), indicating that their loop gain is larger. V/A in Mecp2^+/– fell from 2.42 ± 0.18 in normoxia to 1.82 ± 0.17 in hyperoxia (P = 0.05) indicating an increase in loop gain with increased oxygen. Hyperoxia did not affect V/A in Mecp2^+/+ mice (3.73 ± 0.28 vs. 3.5 ± 0.28). These results show that periodic breathing in this mouse model of RTT is not dependent on enhanced peripheral chemoreceptor oxygen sensitivity. Rather, the breathing instability is of central origin.

control of respiration; Rett syndrome

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]