title: Noise Induces Oscillation and Synchronization of the Circadian Neurons.
abstract: The principle clock of mammals, named suprachiasmatic nucleus (SCN), coordinates the circadian rhythms of behavioral and physiological activity to the external 24 h light-dark cycle. In the absence of the daily cycle, the SCN acts as an endogenous clock that regulates the ~24 h rhythm of activity. Experimental and theoretical studies usually take the light-dark cycle as a main external influence, and often ignore light pollution as an external influence. However, in modern society, the light pollution such as induced by electrical lighting influences the circadian clock. In the present study, we examined the effect of external noise (light pollution) on the collective behavior of coupled circadian oscillators under constant darkness using a Goodwin model. We found that the external noise plays distinct roles in the network behavior of neurons for weak or strong coupling between the neurons. In the case of strong coupling, the noise reduces the synchronization and the period of the SCN network. Interestingly, in the case of weak coupling, the noise induces a circadian rhythm in the SCN network which is absent in noise-free condition. In addition, the noise increases the synchronization and decreases the period of the SCN network. Our findings may shed new light on the impact of the external noise on the collective behavior of SCN neurons.
authors.affiliation: Business School, University of Shanghai for Science and Technology, Shanghai, P. R. China.
authors.forename: Changgui
authors.initials: C
authors.lastname: Gu
authors.affiliation: College of Computer Science and Technology, Zhejiang University of Technology, Hangzhou, P. R. China.
authors.forename: Jinshan
authors.initials: J
authors.lastname: Xu
authors.affiliation: Department of Molecular Cell Biology, Laboratory for Neurophysiology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Jos
authors.initials: J
authors.lastname: Rohling
authors.affiliation: Business School, University of Shanghai for Science and Technology, Shanghai, P. R. China.
authors.forename: Huijie
authors.initials: H
authors.lastname: Yang
authors.affiliation: Department of Physics, East China Normal University, Shanghai, P. R. China.
authors.forename: Zonghua
authors.initials: Z
authors.lastname: Liu
mesh_terms: D000818:Animals; D057906:Circadian Clocks / Q000502:physiology; D002940:Circadian Rhythm / Q000502:physiology*; D003624:Darkness; D006801:Humans; D008027:Light / Q000009:adverse effects*; D008954:Models, Biological; D009474:Neurons / Q000502:physiology*; D013493:Suprachiasmatic Nucleus / Q000166:cytology* / Q000502:physiology