Open Access Open Access  Restricted Access Subscription or Fee Access

Effects of Gap Junction Conductance in Synchronizing Cardiac Oscillators

T.S. Murugesh, J. Krishnan, R. Malathi


The auto-rhythmic cells in the Rabbit heart beat at a wide range of frequencies (330-80 beats per minute) in culture, but in the whole heart they beat at a common frequency set by the normal sinus rhythm. For such a varied range of intrinsic frequencies in a large network of oscillators synchronization becomes much more difficult. Keeping this in mind, an attempt has been made with the help of electro physiology model of cardiac pacemaker cells to analyze the synchronization issue in the syncytium of the cardiac system. A single cell model of a rabbit sinoatrial node was simulated using Matlab package and it was found that the simulated results matched with the experimental findings. Being a sinoatrial nodal cell there exist a parameter for varying the frequency of the generated action potential. After a thorough study of the single cell model, cells were coupled via a coupling element that resembles Gap Junction conductance in real electrophysiology, thus a pair of cell is developed. The intrinsic frequencies of the cells were varied to all possible extents and it was observed that the cells were oscillating in a new frequency and thereby failed to synchronize. The significant role of gap junctions in establishing synchronization was carried out. These investigations emphasized the role of gap junction conductance in their role in synchronization.


Action Potential, Cardiac Pacemaker Cell, Gap Junction Conductance, Intrinsic Frequency, Sinoatrial Node

Full Text:



Guyton AC and Hall JE. “Textbook of Medical Physiology,” WB Saunders Company, Tenth Edition, 2000.

Trautwein W, Uchizono K. “Electron microscopic and electrophysiologic study of the pacemaker in the sinoatrial node of the rabbit heart,” Z Zellforsch 1963; 61:96–109.

Denyer JC and Brown HF, “Rabbit sinoatrial node cells: isolation and electrophysiological properties,” J Physiol (Lond) 428:405–424, 1990.

Strogatz SH. “Nonlinear Dynamics and Chaos: With Applications in Physics, Biology, Chemistry, and Engineering (Studies in Nonlinearity),” Addison Wesley, 1994.

Panifilov AV and Holden AV. “Computational Biology of the Heart,” John Wiley, 1997.

Winslow RL, Kimball A, Varghese A and Noble D. “Simulating cardiac sinus and atrial network dynamics on the Connection Machine,” Physica D: Nonlinear Phenomena 1993; 64: 281–98.

S.S. Demir, J.W. Clark, C.R. Murphey, and W.R. Giles, “Modeling in Physiology, A mathematical model of a rabbit sinoatrial node cell,” The American Physiological Society, 0193-1849/94, 1994.

Difrancesco D, Ferroni A, Mazzanti M, and Tromba C, “Properties of the hyperpolarizing-activated current (If) in cells isolated from the rabbit sinoatrial node,” J Physiol (Lond) 377:61–88, 1986.

Bleeker WK, Mackaay AJC, Masson-Pe´vet M, Bouman LN, and Becker AE “Functional and morphological organization of the rabbit sinus node,” Circ Res 46: 11–22, 1980.

Wilders R, Jongsma HJ, and van Ginneken ACG, “Pacemaker activity of the rabbit sinoatrial node: a comparison of mathematical models,” Biophys J 60: 1202–1216, 1991.

Michaels DC, Matyas EP, and Jalife J, “Mechanisms of pacemaker synchronization: a new hypothesis,” Circ Res 61: 704–714, 1987.

Dongming Cai, Raimond L. Winslow, and Denis Noble, “Effects of Gap Junction Conductance on Dynamics of Sinoatrial Node Cells: Two-Cell and Large-scale Network Models,” IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING, VOL. 41, NO. 3, MARCH 1994.

Stefan Dhein, “Cardiac Gap Junctions-Physiology, Regulation, Pathophysiology and Pharmacology,” S. Karger AG, 1998, P.O. Box, CH–4009 Basel (Switzerland).

Sander Verheule, Marjan J. A. van Kempen, Sjoerd Postma, Martin B. Rook and Habo J. Jongsma, “Gap junctions in the rabbit sinoatrial node” Am J Physiol Heart Circ Physiol 280: H2103-H2115, 2001.

Yang Qu and Gerhard Dahl, “Function of the voltage gate of gap junction channels: Selective exclusion of molecules,” Department of Physiology and Biophysics, University of Miami, School of Medicine, Miami, FL 33101, PNAS _ January 22, 2002 _ vol. 99 _ no. 2 _ 697–702.

Alexopoulos H, Bottger A, Fischer S, Levin A, Wolf A, Fujisawa T, Hayakawa S, Gojobori T, Davies JA, David CN, et al. 2004. “Evolution of gap junctions: The missing link?” CurrBiol 14: R879–R880.

Daniel A. Goodenough and David L. Paul, “Gap Junctions,” Cold Spring Harb Perspect Biol, 2009.

Arora RC, Cardinal R, Smith FM, Ardell JL, Dell‟Italia LJ, and Armour JA, “Intrinsic cardiac nervous system in tachycardia induced heart failure,” Am J Physiol Regul Integr Comp Physiol 285: R1212–R1223, 2003.

Armour J A “Cardiac neuronal hierarchy in health and disease”, Am J Physiol Regul Interg Comp Physiol 2004; 287: R 262- R271.

J.Krishnan, V.S. Chakravathy, S. Radhakrishnan, V. Nayak, Solomon Victor, “Neural Influence is essential for synchronizing cardiac oscillators: A computational model,” IJTCVS, 2005, 21, 262-268.


  • There are currently no refbacks.

Creative Commons License
This work is licensed under a Creative Commons Attribution 3.0 License.