Keywords: physiology, biophysics, bioelectricity, computer modeling, signal processing, action potential, cardiac cells, cardiac arrhythmias, heart
Institute of Physiology
Background:
Cardiac arrhythmias are prevalent causes of morbidity and mortality. The goal of our research is to understand the biophysical phenomena that determine how the electrical excitation (action potential) propagates through cardiac tissue. Our interdisciplinary approach involves mathematical modeling (computer simulations of the action potential) and experiments (with cardiac cells).
Research project:
Action potential propagation depends on ion channels in cell membranes, especially sodium (Na+) channels, which are organized in elaborate nanodomains. In the conventional paradigm, the action potential propagates due to currents passing through intercellular gap junctional channels. However, another mechanistic hypothesis (called ephaptic coupling) proposes that the current produced by the Na+ channels of a given cell produces a substantial electrical potential and significant ion concentration changes in the narrow intercellular cleft, which influences the function of the Na+ channels in the next cell. We will investigate ephaptic coupling in computer simulations using state-of-the-art finite element models of cardiac intercellular junctions that we are refining in the context of international collaborations. In parallel, we will conduct experiments with cardiac cells to demonstrate the existence of the new phenomena identified by the simulations. The study is expected to further our understanding of the function of cardiac Na+ channels at the nanoscale level, with implications for both physiology and pathophysiology.
The project is supported by the Swiss National Science Foundation.
Further details can be found on http://www.physio.unibe.ch/~kucera/group/index.aspx