Fluctuation dynamics in coupled oscillator systems of spontaneously beating cultured cardiac myocytes

We report results of experimental and simulation studies on the fluctuation dynamics of interbeat intervals (IBIs) in aggregated systems of spontaneously beating cultured neonatal rat cardiac myocytes. The correlation properties of the IBI fluctuations vary depending on incubation time, which can be reproduced using Bonhoeffer-van der Pol coupled oscillator model with appropriate values of coupling strength among the oscillators.