Bright daytime light enhances circadian amplitude in a diurnal mammal.
Bright daytime light enhances circadian amplitude in a diurnal mammal.
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明亮的白天光线增强昼行性哺乳动物的昼夜节律振幅。
DOI：
10.1073/pnas.2100094118
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发表时间：
2021-06-01
影响因子：
11.1
通讯作者：
Lucas RJ
中科院分区：
文献类型：
--
作者：
Bano-Otalora B;Martial F;Harding C;Bechtold DA;Allen AE;Brown TM;Belle MDC;Lucas RJ
光是内源性生物钟的重要调节因子。有规律的明暗周期设定昼夜节律，以确保与外部时间同步，而不规则或不适当的光照会破坏昼夜节律。我们在这里问光是否也可以影响昼夜节律的另一个关键参数，它们的振幅，在稳定夹带的条件下。使用一个昼夜啮齿动物物种和仔细校准的光刺激，我们表明，增加白天的光强度增强了再现性和鲁棒性的行为和生理节律，并增加了昼夜节律的幅度在中枢脑起搏器的电活动。这些发现揭示了光对昼夜节律振幅的影响，并强调了白天光照对昼夜节律健康的潜在重要性。哺乳动物的昼夜节律是由下丘脑视交叉上核（SCN）中的主起搏器协调的，该主起搏器从视网膜接收关于24小时光暗周期的信息。这种光信号的公认功能是重置昼夜节律相位，以确保与天体日的适当同步。在这里，我们要问的是，光是否也会影响昼夜节律振荡的另一个关键特性--振幅。为此，我们测量了昼夜节律的行为活动，体温，SCN电生理活动在白天的啮齿类动物短杆鼠稳定夹带到12：12光暗周期在四个不同的白天强度（范围从18到1,900 lx黑视等效日光照度）。R. pumilio表现出强烈的昼夜活动和体温节律在所有条件下，但节奏鲁棒性的措施正相关，白天的辐照下夹带和随后的自由运行。在离体SCN的电生理活动的全细胞和细胞外记录显示，在昏暗和明亮的光条件下的电生理活动的实质性差异。在较低的白天辐照度，SCN自发放电率和膜去极化的白天峰值大幅压低，导致整体显着减少自发活动的昼夜节律的幅度。我们的数据揭示了白天光照强度对SCN生理和昼夜节律振幅的影响，并强调了白天光照对昼夜健康的潜在重要性。
Light is an important regulator of endogenous circadian clocks. Regular light–dark cycles set circadian phase to ensure synchrony with external time, while irregular or inappropriate light exposure can disrupt circadian rhythms. We ask here whether light can also impact another key parameter of circadian rhythms, their amplitude, under conditions of stable entrainment. Using a diurnal rodent species and carefully calibrated light stimuli, we show that increasing the intensity of daytime light enhances the reproducibility and robustness of behavioral and physiological rhythms and increases the amplitude of circadian rhythms in electrical activity in the central brain pacemaker. These findings reveal an impact of light on circadian amplitude and highlight the potential importance of daytime light exposure for circadian health. Mammalian circadian rhythms are orchestrated by a master pacemaker in the hypothalamic suprachiasmatic nuclei (SCN), which receives information about the 24 h light–dark cycle from the retina. The accepted function of this light signal is to reset circadian phase in order to ensure appropriate synchronization with the celestial day. Here, we ask whether light also impacts another key property of the circadian oscillation, its amplitude. To this end, we measured circadian rhythms in behavioral activity, body temperature, and SCN electrophysiological activity in the diurnal murid rodent Rhabdomys pumilio following stable entrainment to 12:12 light–dark cycles at four different daytime intensities (ranging from 18 to 1,900 lx melanopic equivalent daylight illuminance). R. pumilio showed strongly diurnal activity and body temperature rhythms in all conditions, but measures of rhythm robustness were positively correlated with daytime irradiance under both entrainment and subsequent free run. Whole-cell and extracellular recordings of electrophysiological activity in ex vivo SCN revealed substantial differences in electrophysiological activity between dim and bright light conditions. At lower daytime irradiance, daytime peaks in SCN spontaneous firing rate and membrane depolarization were substantially depressed, leading to an overall marked reduction in the amplitude of circadian rhythms in spontaneous activity. Our data reveal a previously unappreciated impact of daytime light intensity on SCN physiology and the amplitude of circadian rhythms and highlight the potential importance of daytime light exposure for circadian health.
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影响因子：
2.8
作者：
Duffy, Jeanne F;Czeisler, Charles A
通讯作者：
Czeisler, Charles A
DOI：
10.1073/pnas.1319820111
发表时间：
2014-07-01
影响因子：
11.1
作者：
Farajnia, Sahar;van Westering, Tirsa L. E.;Michel, Stephan
通讯作者：
Michel, Stephan
影响因子：
5.5
作者：
Brown, Timothy M.;Wynne, Jonathan;Lucas, Robert J.
通讯作者：
Lucas, Robert J.
影响因子：
3.1
作者：
Ancoli-Israel, Sonia;Gehrman, Philip;Levi, Leah
通讯作者：
Levi, Leah
影响因子：
3.7
作者：
Buijink MR;Almog A;Wit CB;Roethler O;Olde Engberink AH;Meijer JH;Garlaschelli D;Rohling JH;Michel S
通讯作者：
Michel S