当前位置: X-MOL 学术J. Biol. Rhythms › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Distinct Components of Photoperiodic Light Are Differentially Encoded by the Mammalian Circadian Clock.
Journal of Biological Rhythms ( IF 3.5 ) Pub Date : 2020-06-11 , DOI: 10.1177/0748730420929217
Michael C Tackenberg 1 , Jacob J Hughey 2, 3 , Douglas G McMahon 1, 2
Affiliation  

Seasonal light cycles influence multiple physiological functions and are mediated through photoperiodic encoding by the circadian system. Despite our knowledge of the strong connection between seasonal light input and downstream circadian changes, less is known about the specific components of seasonal light cycles that are encoded and induce persistent changes in the circadian system. Using combinations of 3 T cycles (23, 24, 26 h) and 2 photoperiods per T cycle (long and short, with duty cycles scaled to each T cycle), we investigate the after-effects of entrainment to these 6 light cycles. We measure locomotor behavior duration (α), period (τ), and entrained phase angle (ψ) in vivo and SCN phase distribution (σφ), τ, and ψ ex vivo to refine our understanding of critical light components for influencing particular circadian properties. We find that both photoperiod and T-cycle length drive determination of in vivo ψ but differentially influence after-effects in α and τ, with photoperiod driving changes in α and photoperiod length and T-cycle length combining to influence τ. Using skeleton photoperiods, we demonstrate that in vivo ψ is determined by both parametric and nonparametric components, while changes in α are driven nonparametrically. Within the ex vivo SCN, we find that ψ and σφ of the PER2∷LUCIFERASE rhythm follow closely with their likely behavioral counterparts (ψ and α of the locomotor activity rhythm) while also confirming previous reports of τ after-effects of gene expression rhythms showing negative correlations with behavioral τ after-effects in response to T cycles. We demonstrate that within-SCN σφ changes, thought to underlie α changes in vivo, are induced primarily nonparametrically. Taken together, our results demonstrate that distinct components of seasonal light input differentially influence ψ, α, and τ and suggest the possibility of separate mechanisms driving the persistent changes in circadian behaviors mediated by seasonal light.



中文翻译:

哺乳动物昼夜节律时钟对光周期光的不同成分进行了差分编码。

季节性光周期会影响多种生理功能,并由昼夜节律系统通过光周期编码介导。尽管我们知道季节性光照输入和下游昼夜节律变化之间有很强的联系,但人们对季节性光照周期的特定成分知之甚少,这些特定成分被编码并诱发昼夜节律系统中的持续变化。使用3个T周期(23、24、26小时)和每个T周期2个光周期(长和短,占空比按每个T周期缩放)的组合,我们研究了这6个光周期的夹带后效应。我们测量运动行为的持续时间(α),周期(τ),和体内夹带的相位角(ψ)和SCN相位分布(σ φ),τ和ψ,以进一步完善我们对影响特定昼夜节律特性的关键光分量的理解。我们发现光周期和T周期长度都驱动体内ψ的测定,但对α和τ的后效应有不同的影响,α的光周期驱动变化和光周期长度以及T周期长度共同影响τ。使用骨架的光周期,我们证明了体内ψ由参数和非参数分量决定,而α的变化是非参数驱动的。在体外SCN,我们发现,ψ和σ φPER2∷LUCIFERASE节律的变化与它们可能的行为对应关系(运动活动节律的ψ和α)密切相关,同时也证实了先前的基因表达节律的τ后效应与T反应后的行为τ后效应呈负相关的报道。周期。我们证明,内-SCNσ φ的变化,认为是背后α改变在体内,主要非参数方式诱导。两者合计,我们的结果表明,季节性光输入的不同成分会分别影响ψ,α和τ,并暗示了单独的机制可能会驱动季节性光介导的生物节律行为的持续变化。

更新日期:2020-06-11
down
wechat
bug