2010 NSF-CMACS Workshop on Cellular Signaling Pathways

Workshop Dates: January 6, 2010 - January 26, 2010

Workshop Location: Carman Room 118, Lehman College

The theme of the 2011 CMACS Workshop on Atrial Fibrillation will be understanding emergent behaviors of cardiac cells in order to improve understanding of both normal and abnormal cardiac rhythms. Better understanding of emergent behaviors in cardiac tissue will support better health care for victims of heart disease, in particular atrial fibrillation, which affects about one in five people who reach the age of 80.

Participants will learn important electrophysiological dynamics of cardiac cells that have been discovered experimentally; how these characteristics are modeled; some mathematical techniques for analyzing models, and limitations of the techniques; and how to build and use simulations based on such models to discover and understand emergent properties of cardiac cells. An emergent behavior of particular interest is the development of spiral waves as a precursor to atrial fibrillation.

The approach taken in the workshop will be participatory, inquiry-based, and team-oriented, culminating in a project in which participants use simulations to discover and test emergent behaviors in cardiac tissue. The first week of the workshop will be based on lecture and guided exercises, the second week will develop practice with mathematical and simulation tools, and the final week will focus on team-oriented student projects. There will also be invited keynote talks on special topics.

Participants will be provided with scaffolding (based on existing code) for their simulations. This is not a class, there will be no tests or grades, but to benefit from the workshop participants should expect to study and try out the techniques presented.

Distinguished visitor Flavio Fenton of Cornell will present the basics of cardiac cell function, as understood from experiment, and discuss how experiments are constructed. He will introduce two historically important models, the Hodgkin-Huxley and Fitzhugh-Nagumo models of action potentials in cells. These models describe the behavior of action potentials in individual cells. Action potentials are important to the understanding of both cardiac cells and neurons, because they cause neurons to fire and drive the contractions of cardiac cells. Dr. Fenton will discuss how action potentials propagate in tissue to form waves and how disruptions to propagation can produce spiral waves, which are precursors to atrial fibrillation, as well as introduce mathematical and simulation techniques for studying cardiac behavior.

Participants will learn and apply standard mathematical techniques for analyzing models such as Hodgkin-Huxley and Fitzhugh-Nagumo. Since these models and other important models of cardiac cells are based on partial differential equations, techniques for mathematical and numerical analysis of pde’s will be discussed along with their limitations.

There are many more models of cardiac behavior, some developed to simplify analysis and others to model specific aspects of behavior in more detail. Participants in this workshop will work with “minimal” three- and four-variable models of cardiac cells developed by Flavio Fenton and Elizabeth Cherry, which were designed to combine accuracy of the model with simulation speed.

This work was supported by the NSF under grant number 0926200.

Nancy Griffeth

nancy.griffeth@lehman.cuny.edu