Landaw Julian, Garfinkel Alan, Weiss James N, Qu Zhilin
Department of Medicine (Cardiology), University of California, Los Angeles, California 90095, USA.
Department of Biomathematics, University of California, Los Angeles, California 90095, USA.
Phys Rev Lett. 2017 Mar 31;118(13):138101. doi: 10.1103/PhysRevLett.118.138101. Epub 2017 Mar 28.
Excitable systems display memory, but how memory affects the excitation dynamics of such systems remains to be elucidated. Here we use computer simulation of cardiac action potential models to demonstrate that memory can cause dynamical instabilities that result in complex excitation dynamics and chaos. We develop an iterated map model that correctly describes these dynamics and show that memory converts a monotonic first return map of action potential duration into a nonmonotonic one, resulting in a period-doubling bifurcation route to chaos.
可兴奋系统表现出记忆特性，但其如何影响此类系统的兴奋动力学仍有待阐明。在此，我们利用心脏动作电位模型的计算机模拟来证明，记忆可引发动态不稳定性，进而导致复杂的兴奋动力学和混沌现象。我们开发了一个迭代映射模型，该模型能正确描述这些动力学，并表明记忆将动作电位持续时间的单调首次返回映射转换为非单调映射，从而导致通向混沌的倍周期分岔路径。
