000176823 001__ 176823
000176823 005__ 20181203022708.0
000176823 0247_ $$2doi$$a10.1371/journal.pcbi.1002419
000176823 022__ $$a1553-734X
000176823 02470 $$2ISI$$a000302244000027
000176823 037__ $$aARTICLE
000176823 245__ $$aEffect of Network Architecture on Synchronization and Entrainment Properties of the Circadian Oscillations in the Suprachiasmatic Nucleus
000176823 260__ $$bPublic Library of Science$$c2012
000176823 269__ $$a2012
000176823 336__ $$aJournal Articles
000176823 520__ $$aIn mammals, the suprachiasmatic nucleus (SCN) of the hypothalamus constitutes the central circadian pacemaker. The SCN receives light signals from the retina and controls peripheral circadian clocks (located in the cortex, the pineal gland, the liver, the kidney, the heart, etc.). This hierarchical organization of the circadian system ensures the proper timing of physiological processes. In each SCN neuron, interconnected transcriptional and translational feedback loops enable the circadian expression of the clock genes. Although all the neurons have the same genotype, the oscillations of individual cells are highly heterogeneous in dispersed cell culture: many cells present damped oscillations and the period of the oscillations varies from cell to cell. In addition, the neurotransmitters that ensure the intercellular coupling, and thereby the synchronization of the cellular rhythms, differ between the two main regions of the SCN. In this work, a mathematical model that accounts for this heterogeneous organization of the SCN is presented and used to study the implication of the SCN network topology on synchronization and entrainment properties. The results show that oscillations with larger amplitude can be obtained with scale-free networks, in contrast to random and local connections. Networks with the small-world property such as the scale-free networks used in this work can adapt faster to a delay or advance in the light/dark cycle (jet lag). Interestingly a certain level of cellular heterogeneity is not detrimental to synchronization performances, but on the contrary helps resynchronization after jet lag. When coupling two networks with different topologies that mimic the two regions of the SCN, efficient filtering of pulse-like perturbations in the entrainment pattern is observed. These results suggest that the complex and heterogeneous architecture of the SCN decreases the sensitivity of the network to short entrainment perturbations while, at the same time, improving its adaptation abilities to long term changes.
000176823 6531_ $$aSmall-World Networks
000176823 6531_ $$aRhythm Generation
000176823 6531_ $$aCell Autonomy
000176823 6531_ $$aJet-Lag
000176823 6531_ $$aClock
000176823 6531_ $$aNeurons
000176823 6531_ $$aModel
000176823 6531_ $$aOrganization
000176823 6531_ $$aRobustness
000176823 6531_ $$aSystems
000176823 700__ $$0242831$$g137075$$aHafner, Marc
000176823 700__ $$aKoeppl, Heinz
000176823 700__ $$aGonze, Didier
000176823 773__ $$j8$$tPlos Computational Biology$$q-
000176823 909C0 $$xU10425$$0252097$$pLANOS
000176823 909CO $$pIC$$particle$$ooai:infoscience.tind.io:176823
000176823 917Z8 $$x105368
000176823 937__ $$aEPFL-ARTICLE-176823
000176823 973__ $$rREVIEWED$$sPUBLISHED$$aEPFL
000176823 980__ $$aARTICLE