Perret Martine, Gomez Doris, Barbosa Alexandra, Aujard Fabienne, Théry Marc
UMR 7179 Centre National de la Recherche Scientifique, Muséum National d'Histoire Naturelle, Département d'Ecologie et Gestion de la Biodiversité, Brunoy, France.
J Biol Rhythms. 2010 Jun;25(3):186-96. doi: 10.1177/0748730410368244.
The mammalian endogenous circadian clock, the suprachiasmatic nuclei, receives environmental inputs, namely the light-dark cycle, through photopigments located in the eye and from melanopsin-expressing retinal ganglion cells. The authors investigated the influence of light wavelength and intensity on the synchronization of the rest-activity rhythm of the gray mouse lemur, a nocturnal Malagasy primate. Animals were tested at different irradiance levels (320, 45, 13, and 6 nmol x m(-2) x s(- 1)) under several light wavelengths (from 400 to 610 nm). Several parameters including circadian period, activity, and body temperature waveforms were used to assess synchronization to a 12:12 light-dark cycle in comparison to control treatments (12:12 white light or continuous darkness). Entrainment of the circadian rest-activity cycle increased with light intensity. It was more efficient for mid wavelengths relative to shorter or longer wavelengths but not coincident with melanopsin maximal sensitivity, suggesting other photoreceptors are likely involved in lemurs' photoentrainment. The authors obtained a novel synchronization pattern characterized by a clear synchronization to lights-on only without phasing to lights-off. Changes in photo-responsiveness at dusk and dawn highlight differential responses of evening and morning oscillators in the circadian clock.
哺乳动物的内源性昼夜节律时钟——视交叉上核，通过眼睛中的光色素以及表达黑视蛋白的视网膜神经节细胞接收环境输入，即明暗周期。作者研究了光波长和强度对灰鼠狐猴（一种马达加斯加夜行性灵长类动物）休息 - 活动节律同步的影响。在几种光波长（400至610纳米）下，对动物在不同辐照度水平（320、45、13和6纳摩尔·米 -2·秒 -1）进行测试。与对照处理（12:12白光或持续黑暗）相比，使用包括昼夜周期、活动和体温波形在内的几个参数来评估对12:12明暗周期的同步情况。昼夜休息 - 活动周期的夹带随光强度增加。相对于较短或较长波长，中波长的夹带更有效，但与黑视蛋白的最大敏感性不一致，这表明其他光感受器可能参与狐猴的光诱导。作者获得了一种新的同步模式，其特征是仅对开灯有明显同步，而对关灯没有相位调整。黄昏和黎明时光反应性的变化突出了昼夜节律时钟中早晚振荡器的不同反应。
