UMR 7179 CNRS (National Centre for Scientific Research), MNHN (National Museum of Natural History), Department of Ecology and Biodiversity Management, Brunoy, France.
J Biol Rhythms. 2012 Apr;27(2):164-71. doi: 10.1177/0748730411435223.
The endogenous circadian clock is entrained by external cues, mainly the light-dark cycle received by photopigments located in the retina. The authors investigated (1) the effect of aging on the synchronization of the rest-activity rhythm and (2) the physiological basis of light photoreception in the gray mouse lemur, a nocturnal Malagasy primate. Old individuals were tested at different irradiance levels under 3 different light wavelengths previously shown to trigger maximal response in young adults. Investigators analyzed animal activity and temperature waveforms and used 2 reference treatments, strong white light and continuous darkness. The investigation revealed manifold effects of aging picturing a general loss of responsiveness to light and age-related changes in activity and temperature. In addition, the investigation shows that photoentrainment is a continuous process. Short wavelengths (430 nm) are more efficient than longer wavelengths (470-540 nm) at low light levels at dawn and across all light levels at dusk. This suggests an implication of S-cones, differential at dawn and dusk. This results, surprising for several reasons, calls for further investigation. The study brings an interesting contribution to the understanding of the physiological processes underlying synchronization to light.
内源性生物钟受外部线索调节，主要是视网膜中光色素接收到的光暗周期。作者研究了（1）衰老对休息-活动节律同步的影响，以及（2）灰鼠狐猴光感光的生理基础，灰鼠狐猴是一种夜间生活在马达加斯加的灵长类动物。在 3 种先前被证明能在年轻人中引发最大反应的不同波长的光下，对老年个体进行了不同辐照度水平的测试。研究人员分析了动物的活动和温度波形，并使用了 2 种参考处理方法，强白光和连续黑暗。该研究揭示了衰老的多方面影响，描绘了对光的反应普遍丧失以及与年龄相关的活动和温度变化。此外，该研究表明，光生物节律调整是一个连续的过程。在黎明时，短波长（430nm）比长波长（470-540nm）在低光照水平下更有效，而在黄昏时，所有光照水平下都是如此。这表明 S-锥体在黎明和黄昏时存在差异，这一结果令人惊讶，需要进一步研究。该研究为理解光同步的生理过程提供了一个有趣的贡献。
