Model clamp and its application to synchronization of rabbit sinoatrial node cells. Wilders, Ronald, E. Etienne Verheijck, Rajiv Kumar, William N. Goolsby, Antoni C. G. Van Ginneken, Ronald W. Joyner, and Habo J. Jongsma. Department of Medical Physiology and Sports Medicine, Utrecht University, 3584 CG Utrecht, The Netherlands, Department of Physiology, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands, Todd Franklin Cardiac Research Laboratory, The Children's Heart Center, Department of Pediatrics, Emory University, Atlanta, GA 30322, USA
APStracts 3:0194H, 1996.
A method for coupling an isolated cardiac cell to a simulated cardiac cell, i.e., the real-time solution of a mathematical model of such cell, has been developed. With this "model clamp" technique, the real cell and the model cell are coupled by any desired value of intercellular coupling conductance, producing the effect of mutual interaction by electrical coupling through gap junctional channels. We implemented the model clamp technique with our previously published model of an isolated rabbit sinoatrial node cell. We used this model clamp system to study synchronization of sinoatrial node cells with regards to the critical value of intercellular coupling conductance required for frequency entrainment and the common interbeat interval during frequency entrainment. This common interbeat interval lay between the intrinsic intervals of the real cell and the model cell, but was closer to that of the intrinsically faster beating cell. Critical coupling conductance increased with increasing difference in intrinsic interbeat interval of the real cell and the model cell, and ranged between 50 and 300 pS in 11 hybrid cell pairs. 

Received 20 November 1995; accepted in final form 24 April 1996.
APS Manuscript Number H1091-5.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 8 May 96