Abstract
Both intracellular and surface electrodes were employed to record electrical activity from embryonic chick hearts between the ages of 3 and 20 days. Cells from the sinus venosus, sinoatrial (SA) valves, atrium, atrioventricular (AV) ring, and ventricle were localized and characterized on the basis of shape, amplitude, rise time, and duration of transmembrane potentials. The differences in transmembrane potentials from these various regions provided the basis for a hypothesis concerned with the distribution of pacemaker potentiality and one related to the origin of the His-Purkinje system. Action potentials recorded along the entire embryonic AV ring were comparable to those of the adult rabbit AV nodal cells in both configuration and sequence of activation and were thus categorized into three functional regions (AN, N, NH). Histological sections of 7 and 14 day hearts demonstrated muscular continuity between the right atrium and ventricle across the muscular AV valve.
Full Text
The Full Text of this article is available as a PDF (897.2 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- BOUCEK R. J., MURPHY W. P., Jr, PAFF G. H. Electrical and mechanical properties of chick embryo heart chambers. Circ Res. 1959 Sep;7:787–793. doi: 10.1161/01.res.7.5.787. [DOI] [PubMed] [Google Scholar]
- DE CARVALHO A. P., DE MELLO W. C., HOFFMAN B. F. Electrophysiological evidence for specialized fiber types in rabbit atrium. Am J Physiol. 1959 Mar;196(3):483–488. doi: 10.1152/ajplegacy.1959.196.3.483. [DOI] [PubMed] [Google Scholar]
- DEHAAN R. L. Differentiation of the atrioventricular conducting system of the heart. Circulation. 1961 Aug;24:458–470. doi: 10.1161/01.cir.24.2.458. [DOI] [PubMed] [Google Scholar]
- Davies F. The Conducting System of the Bird's Heart. J Anat. 1930 Jan;64(Pt 2):129–146.7. [PMC free article] [PubMed] [Google Scholar]
- FINGL E., WOODBURY L. A., HECHT H. H. Effects of innervation and drugs upon direct membrane potentials of embryonic chick myocardium. J Pharmacol Exp Ther. 1952 Jan;104(1):103–114. [PubMed] [Google Scholar]
- INOUE F. Slow potential and conduction delay at the atrioventricular region in frog's heart. J Cell Comp Physiol. 1959 Dec;54:231–235. doi: 10.1002/jcp.1030540304. [DOI] [PubMed] [Google Scholar]
- LEDOUARIN G., OBRECHT G., CORABOEUF E. ACTIVIT'E 'ELECTRIQUE TRANSMEMBRANAIRE DU COEUR EMBRYONNAIRE DE POULET EXPLANT'E EN CULTURE ORGANOTYPIQUE. C R Hebd Seances Acad Sci. 1964 Apr 13;258:3911–3914. [PubMed] [Google Scholar]
- LEHMKUHL D., SPERELAKIS N. TRANSMEMBRANE POTENTIALS OF TRYPSIN-DISPERSED CHICK HEART CELLS CULTURED IN VITRO. Am J Physiol. 1963 Dec;205:1213–1220. doi: 10.1152/ajplegacy.1963.205.6.1213. [DOI] [PubMed] [Google Scholar]
- Moore E. N. Experimental electrophysiological studies on avian hearts. Ann N Y Acad Sci. 1965 Sep 8;127(1):127–144. doi: 10.1111/j.1749-6632.1965.tb49397.x. [DOI] [PubMed] [Google Scholar]
- TRAUTWEIN W., KASSEBAUM D. G. On the mechanism of spontaneous impulse generation in the pacemaker of the heart. J Gen Physiol. 1961 Nov;45:317–330. doi: 10.1085/jgp.45.2.317. [DOI] [PMC free article] [PubMed] [Google Scholar]
- de CARVALHO A., de ALMEIDA D. Spread of activity through the atrioventricular node. Circ Res. 1960 Jul;8:801–809. doi: 10.1161/01.res.8.4.801. [DOI] [PubMed] [Google Scholar]