title: Entrainment range of nonidentical circadian oscillators by a light-dark cycle.
abstract: The suprachiasmatic nucleus (SCN) is a principal circadian clock in mammals, which controls physiological and behavioral daily rhythms. The SCN has two main features: Maintaining a rhythmic cycle of approximately 24 h in the absence of a light-dark cycle (free-running period) and the ability to entrain to external light-dark cycles. Both free-running period and range of entrainment vary from one species to another. To understand this phenomenon, we investigated the diversity of a free-running period by the distribution of coupling strengths in our previous work [Phys. Rev. E 80, 030904(R) (2009)]. In this paper we numerically found that the dispersion of intrinsic periods among SCN neurons influence the entrainment range of the SCN, but has little influence on the free-running periods under constant darkness. This indicates that the dispersion of coupling strengths determines the diversity in free-running periods, while the dispersion of intrinsic periods determines the diversity in the entrainment range. A theoretical analysis based on two coupled neurons is presented to explain the results of numerical simulations.
authors.affiliation: Department of Molecular Cell Biology, Laboratory for Neurophysiology, Leiden University Medical Center, Leiden, 2300 RC, The Netherlands.
authors.forename: Changgui
authors.initials: C
authors.lastname: Gu
authors.forename: Jinshan
authors.initials: J
authors.lastname: Xu
authors.forename: Zonghua
authors.initials: Z
authors.lastname: Liu
authors.forename: Jos H T
authors.initials: JH
authors.lastname: Rohling
mesh_terms: D057906:Circadian Clocks / Q000528:radiation effects*; D003624:Darkness; D008954:Models, Biological; D013493:Suprachiasmatic Nucleus / Q000502:physiology* / Q000528:radiation effects*