Entrainment in calorie-restricted mice: conflicting zeitgebers and free-running conditions
Entrainment in calorie-restricted mice: conflicting zeitgebers and free-running conditions
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DOI：
10.1152/ajpregu.1998.274.6.r1751
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发表时间：
1998-06-01
影响因子：
2.8
通讯作者：
Turek, FW
中科院分区：
文献类型：
--
作者：
Challet, E;Solberg, LC;Turek, FW
在小鼠暴露于12：12-h光-暗循环期间，研究了定时热量限制的相移效应。食物预期活动（FAA），一种食物可耐受的起搏器的输出，在进食时间之前表达，无论小鼠每天接受低热量食物（3.3 g食物/天）还是正常热量食物（5 g食物/天），在Zeitgeber时间（ZT）2（ZT 12 =熄灯）。随后，将小鼠置于恒定黑暗中并随意喂食。与正常热量喂养的对照组相比，热量限制的小鼠夜间自发活动的发作提前了1小时。当通过限制热量限制小鼠来阻止FAA时，相位提前仍然发生。在ZT 2、ZT 10、ZT 14或ZT 22期给予低热量食物分别使夜间活动模式提前1、3、1和1h。转移到恒定黑暗后，FAA自由运行与正常的夜间自发活动期平行。在早期主观夜间阶段的光脉冲延迟了这两个组件。这些结果表明：1）在光暗循环下定时的热量限制可以使可光激活的起搏器以相位依赖的幅度相位提前，2）FAA反馈对于所观察到的相位提前不是至关重要的，3）可光激活的起搏器可以控制随意喂养的小鼠中可食物激活的起搏器的周期。
Phase-shifting effects of timed calorie restriction were investigated in mice during exposure to a 12:12-h light-dark cycle. Food-anticipatory activity (FAA), the output of a food-entrainable pacemaker, was expressed before the time of feeding whether mice received daily hypocaloric food (3.3 g of chow/day) or normocaloric food (5 g of chow/day) at zeitgeber time (ZT) 2 (ZT12 = lights off). Subsequently, mice were placed in constant darkness and fed ad libitum. The onset of the nocturnal period of locomotor activity was phase advanced by 1 h in calorie-restricted mice compared with normocalorie-fed controls. The phase advance still occurred when FAA was prevented by restraining calorie-restricted mice. Giving hypocaloric food at ZT2, ZT10, ZT14, or ZT22 phase advanced the nocturnal pattern of activity by 1, 3, 1, and 1 h, respectively. After transfer to constant darkness, FAA free ran in parallel with the normal nocturnal period of locomotor activity. A light pulse during the early subjective night phase delayed both components. These results indicate that 1) timed calorie restriction under a light-dark cycle can phase advance the light-entrainable pacemaker with a phase-dependent magnitude, 2) FAA feedback is not crucial for the observed phase advance, and 3) the light-entrainable pacemaker may control the period of the food-entrainable pacemaker in mice fed ad libitum.