Indo US Center in Chronobiology, Department of Zoology, University of Delhi, Delhi, 110 007, India.
Indo US Center in Chronobiology, Department of Zoology, University of Delhi, Delhi, 110 007, India.
Physiol Behav. 2022 Sep 1;253:113866. doi: 10.1016/j.physbeh.2022.113866. Epub 2022 May 31.
We investigated whether nocturnal eating was causal to the impairment of metabolism and sleep disruption in diurnal animals exposed to illuminated nights. Adult zebra finches hatched and raised in 12 h light: 12 h darkness (LD) were exposed to 5-lux dim light at night (dLAN, two groups), with a control group maintained on LD. For the next 3 weeks, the food availability to one of the dLAN groups was restricted to the 12 h light period (dLAN -F); the other dLAN (dLAN +F) and LD groups were continued on ad lib feeding. In spite of similar food intakes, dLAN +F condition led to the fat accumulation and weight gain. These birds showed concurrent changes in hepatic expression of genes associated with carbohydrate and lipid metabolism, suggesting an enhanced gluconeogenesis and impaired fatty acids synthesis. Increased sirt1 mRNA levels indicated the activation of molecular mechanisms to counter-balance the metabolic damage under dLAN +F. Furthermore, reduced bout length and total duration of the nocturnal sleep suggested a poorer sleep in dLAN +F condition. Negative sleep effects of dLAN were supported by the lower hypothalamic expression of sleep promoting sik3 and camkii genes, and higher mRNA expression of awake promoting achm3 gene in dLAN +F, compared to the LD condition. Importantly, dLAN-induced negative effects in metabolism and sleep were alleviated in the dLAN -F group. These results suggest the role of timed feeding in alleviating the negative impact of illuminated nights in metabolism and sleep in diurnal zebra finches.
我们研究了在光照夜晚下，昼行性动物的夜间进食是否会导致代谢损伤和睡眠中断。在 12 小时光照：12 小时黑暗（LD）环境中孵化和饲养的成年斑胸草雀，夜间暴露于 5 勒克斯的暗光（dLAN，两组）中，对照组维持 LD 环境。在接下来的 3 周内，其中一组 dLAN（dLAN-F）的食物供应限制在光照期 12 小时内；另一组 dLAN（dLAN+F）和 LD 组继续自由进食。尽管摄入的食物量相似，但 dLAN+F 条件导致了脂肪积累和体重增加。这些鸟的肝脏中与碳水化合物和脂质代谢相关的基因表达发生了同时变化，表明糖异生增强和脂肪酸合成受损。sirt1 mRNA 水平的增加表明，分子机制的激活有助于抵消 dLAN+F 下的代谢损伤。此外，dLAN+F 条件下夜间睡眠的总时长和bout 长度减少，表明睡眠质量较差。dLAN 对睡眠的负面影响得到了支持，dLAN+F 组下丘脑中促进睡眠的 sik3 和 camkii 基因表达降低，以及促进觉醒的 achm3 基因表达升高，与 LD 条件相比。重要的是，dLAN-F 组缓解了 dLAN 诱导的代谢和睡眠的负面效应。这些结果表明，定时进食在缓解昼行性斑胸草雀代谢和睡眠在光照夜晚下的负面影响方面发挥了作用。
