Unpredictable feeding schedules unmask a system for daily resetting of behavioural and metabolic food entrainment
Unpredictable feeding schedules unmask a system for daily resetting of behavioural and metabolic food entrainment
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DOI：
10.1111/j.1460-9568.2007.05893.x
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发表时间：
2007-11-01
影响因子：
3.4
通讯作者：
Buijs, Ruud M.
中科院分区：
文献类型：
--
作者：
Escobar, Carolina;Martinez-Merlos, Ma Teresa;Buijs, Ruud M.
限制性进食时间表（RFS）是一种有效的Zeitgeber，它将外周组织中的日常代谢和时钟基因振荡与视交叉上核（SCN）分离，后者仍然被带入光暗周期。在RFS下，动物发展食物预期活动（FAA），其特征在于唤醒和增加运动。自然界中的食物供应并不精确，这表明动物需要每天调整与食物相关的活动。这项研究探讨了大鼠适应可变和不可预测的喂养时间表的能力。大鼠暴露于RFS与固定的每日膳食（RF）或可变的用餐时间（VAR）在光阶段。RF和VAR大鼠表现出由最后一餐事件驱动的每日代谢振荡;然而，VAR大鼠未能在预期的皮质酮峰值中表现出稳健的调整。VAR大鼠不能表现出FAA，但表现出与前一餐同步的每日激活模式。在这两组的背内侧核的下丘脑和弓状核，参与能量平衡，表现出增加c-Fos表达后24小时，最后一餐，而RF大鼠表现出低c-Fos表达的SCN。数据显示，代谢和行为的食物夹带的节奏可以重置每天的基础上，这两个条件引起了类似的下丘脑反应，而只有SCN被抑制在大鼠表现出预期的活动。可变的喂养策略揭示了一个快速（24小时的基础上）重置机制的新陈代谢和一般行为。
Restricted feeding schedules (RFS) are a potent Zeitgeber that uncouples daily metabolic and clock gene oscillations in peripheral tissues from the suprachiasmatic nucleus (SCN), which remains entrained to the light-dark cycle. Under RFS, animals develop food anticipatory activity (FAA), characterized by arousal and increased locomotion. Food availability in nature is not precise, which suggests that animals need to adjust their food-associated activity on a daily basis. This study explored the capacity of rats to adjust to variable and unpredictable feeding schedules. Rats were exposed either to RFS with fixed daily meal (RF) or to a variable meal time (VAR) during the light phase. RF and VAR rats exhibited daily metabolic oscillations driven by the last meal event; however, VAR rats were not able to show a robust adjustment in the anticipating corticosterone peak. VAR rats were unable to exhibit FAA but exhibited a daily activation pattern in phase with the previous meal. In both groups the dorsomedial nucleus of the hypothalamus and arcuate nucleus, involved in energy balance, exhibited increased c-Fos expression 24 h after the last meal, while only RF rats exhibited low c-Fos expression in the SCN. Data show that metabolic and behavioural food-entrained rhythms can be reset on a daily basis; the two conditions elicit a similar hypothalamic response, while only the SCN is inhibited in rats exhibiting anticipatory activity. The variable feeding strategy uncovered a rapid (24-h basis) resetting mechanism for metabolism and general behaviour.