Evans Jennifer A, Elliott Jeffrey A, Gorman Michael R
Department of Psychology, University of California.
Department of Psychiatry, University of California.
Behav Neurosci. 2010 Feb;124(1):87-96. doi: 10.1037/a0018088.
Within the mammalian suprachiasmatic nucleus, multiple oscillators interact to coordinate circadian rhythms in behavior and physiology. We have developed a behavioral assay that disassociates central oscillators and allows rigorous study of their formal properties and interactions. Rodents held under 24h light:dark:light:dark (LDLD) cycles display "split" activity rhythms that reflect the reorganization of the central pacemaker into two oscillator groups cycling ~12h apart. After transfer to constant conditions, the two activity components rejoin through a series of transients lasting 2-7 days. Here we analyze fusion dynamics, characterize the underlying oscillator interactions, and assess two influencing factors: phase of transfer and lighting conditions upon transfer. Syrian hamsters were split under LDLD with dimly lit nights and then transferred to constant dim illumination or complete darkness during one of the two daily scotophases. Fusion was influenced by phase of transfer, suggesting that the oscillators split under LDLD exert an asymmetric influence over one another. Transfer to constant dim and dark conditions produced similar overall patterns of fusion, but nevertheless differed in the rejoined state of the system. The present results are discussed within a model wherein oscillators influence one another in a phase-dependent manner.
在哺乳动物的视交叉上核内，多个振荡器相互作用以协调行为和生理中的昼夜节律。我们开发了一种行为测定法，可分离中央振荡器，并允许对其形式特性和相互作用进行严格研究。处于24小时光照：黑暗：光照：黑暗（LDLD）周期下的啮齿动物表现出“分裂”的活动节律，这反映了中央起搏器重新组织为两个振荡器组，其周期约为12小时。转移到恒定条件后，两个活动成分通过持续2 - 7天的一系列瞬变重新合并。在这里，我们分析融合动态，表征潜在的振荡器相互作用，并评估两个影响因素：转移阶段和转移时的光照条件。叙利亚仓鼠在LDLD条件下，夜间光照昏暗时被分开，然后在两个每日暗期之一期间转移到恒定的昏暗光照或完全黑暗环境中。融合受转移阶段的影响，这表明在LDLD条件下分开的振荡器对彼此施加不对称影响。转移到恒定的昏暗和黑暗条件下产生了相似的总体融合模式，但系统的重新合并状态仍有所不同。本文的结果在一个模型中进行了讨论，在该模型中振荡器以相位依赖的方式相互影响。
