Cardiac rhythms in chick embryos during hatching

Citation
H. Tazawa et al., Cardiac rhythms in chick embryos during hatching, COMP BIOC A, 124(4), 1999, pp. 511-521
Citations number
58
Categorie Soggetti
Animal Sciences",Physiology
Journal title
COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR AND INTEGRATIVE PHYSIOLOGY
ISSN journal
10956433 → ACNP
Volume
124
Issue
4
Year of publication
1999
Pages
511 - 521
Database
ISI
SICI code
1095-6433(199912)124:4<511:CRICED>2.0.ZU;2-L
Abstract
Avian embryos develop within a hard eggshell which permits the measurement of heart rate while maintaining an adequate gas exchange through the chorio allantoic membrane. Heart rate has been determined from cardiogenic signals detected either noninvasively, semi-invasively or invasively with various transducers. Firstly, we reviewed these previously-developed methods and ex perimental results on heart rate fluctuations in prenatal embryos. Secondly , we presented new findings;on the development of heart rate fluctuations d uring the last stages of incubation, with emphasis on the perinatal period, which remained-to be studied. Three patterns of acceleration of the instan taneous heart rate were unique to the external pipping period: irregular in termittent large accelerations, short-term repeated large accelerations and relatively long-lasting cyclic small accelerations. Besides these accelera tion patterns, respiratory arrhythmia, which comprized oscillating patterns with a period of 1-1.5 s, appeared during the external pipping period. Fur thermore, additional oscillating patterns with a period of 10-15 min were f ound in some externally pipped embryos. (C) 1999 Elsevier Science Inc. All rights reserved.