Europhys. Lett, 43 (4), pp. 363-368 (1998)

Stochastic feedback and the regulation
of biological rhythms

P. Ch. Ivanov ¹, L. A. Nunes Amaral ^1,2, A. L. Goldberger ³ and H. E. Stanley ¹

¹ Center for Polymer Studies and Department of Physics, Boston University
Boston, MA 02215, USA
² Department of Physics, Massachusetts Institute of Technology
Cambridge, MA 02139, USA
³ Cardiovascular Division, Harvard Medical School
Beth Israel Hospital, Boston, MA 02215, USA

(received 12 May 1998; accepted in final form 26 June 1998)

PACS. 02.50Ey - Stochastic processes.
PACS. 05.40 - Fluctuation phenomena, random processes, and Brownian motion.
PACS. 05.45 - Theory and models of chaotic systems.

Abstract:

We propose a general approach to the question of how biological rhythms spontaneously self-regulate, based on the concept of "stochastic feedback''. We illustrate this approach by considering at a coarse-grained level the neuroautonomic regulation of the heart rate. The model generates complex dynamics and successfully accounts for key characteristics of cardiac variability, including the 1/f power spectrum, the functional form and scaling of the distribution of variations, and correlations in the Fourier phases indicating nonlinear dynamics.

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