Model number


Single Cell action potential of rabbit sinoatrial node modulated by acetyl choline by Demir, Clark, Giles 1999 from CellML source


Demir99 fig1

NOTA BENE: The model parameter and variable units were revised
so that the model could be compiled with "unit conversion on;"

   (ABSTRACT) We have extended our compartmental model [Am. J.
Physiol. 266 (Cell Physiol. 35): C832–C852, 1994] of the
single rabbit sinoatrial node (SAN) cell so that it can simulate
cellular responses to bath applications of ACh and isoprenaline
as well as the effects of neuronally released ACh. The
model employs three different types of muscarinic receptors
to explain the variety of responses observed in mammalian
cardiac pacemaking cells subjected to vagal stimulation. The
response of greatest interest is the ACh-sensitive change in
cycle length that is not accompanied by a change in action
potential duration or repolarization or hyperpolarization of
the maximum diastolic potential. In this case, an AChsensitiveK
! current is not involved.Membrane hyperpolarization
occurs in response to much higher levels of vagal
stimulation, and this response is also mimicked by the model.
Here, an ACh-sensitive K+ current is involved. The wellknown
phase-resetting response of the SAN cell to single and
periodically applied vagal bursts of impulses is also simulated
in the presence and absence of the "beta-agonist isoprenaline.
Finally, the responses of the SAN cell to longer continuous
trains of periodic vagal stimulation are simulated, and this
can result in the complete cessation of pacemaking. Therefore,
thismodel is 1) applicable over the full range of intensity
and pattern of vagal input and 2) can offer biophysically
based explanations for many of the phenomena associated
with the autonomic control of cardiac pacemaking.


The equations for this model may be viewed by running the JSim model applet and clicking on the Source tab at the bottom left of JSim's Run Time graphical user interface. The equations are written in JSim's Mathematical Modeling Language (MML). See the Introduction to MML and the MML Reference Manual. Additional documentation for MML can be found by using the search option at the Physiome home page.

Download JSim model project file


Help running a JSim model.


Key terms
action potential simulation
muscarinic receptors
junctional receptor
extrajunctional receptor
phase sensitivity
phase-response curve
steady-state entrainment
cardiac pacemaker cell
whole cell voltage clamp
Hodgkin-Huxley model

Please cite in any publication for which this software is used and send one reprint to the address given below:
The National Simulation Resource, Director J. B. Bassingthwaighte, Department of Bioengineering, University of Washington, Seattle WA 98195-5061.

Model development and archiving support at provided by the following grants: NIH U01HL122199 Analyzing the Cardiac Power Grid, 09/15/2015 - 05/31/2020, NIH/NIBIB BE08407 Software Integration, JSim and SBW 6/1/09-5/31/13; NIH/NHLBI T15 HL88516-01 Modeling for Heart, Lung and Blood: From Cell to Organ, 4/1/07-3/31/11; NSF BES-0506477 Adaptive Multi-Scale Model Simulation, 8/15/05-7/31/08; NIH/NHLBI R01 HL073598 Core 3: 3D Imaging and Computer Modeling of the Respiratory Tract, 9/1/04-8/31/09; as well as prior support from NIH/NCRR P41 RR01243 Simulation Resource in Circulatory Mass Transport and Exchange, 12/1/1980-11/30/01 and NIH/NIBIB R01 EB001973 JSim: A Simulation Analysis Platform, 3/1/02-2/28/07.