Araujo J F, Marques N
Departamento de Fisiologia e Biofísica, Universidade de São Paulo, Brasil.
Braz J Med Biol Res. 1996 Oct;29(10):1369-72.
The objective of the present study was to investigate the circadian and the ultradian rhythms of drinking behavior in Wistar rats maintained under conditions of constant darkness. Six mature male rats (weighing 270-350 g) were exposed to light-dark 12:12-h cycles (LD 12:12, light on at 12:00 h) for 35 days and then switched to constant darkness (DD) conditions for at least 2 weeks. Drinking behavior was monitored continuously with a standard drinkometer circuit and the data was stored in 5-min bins. A modification of Enright's periodogram technique was used to evaluate the free-running drinking behavior circadian rhythm. Ultradian rhythms in drinking behavior were estimated by the Fast Fourier Transform (FFT) technique. Two of the animals (rats 4 and 6) showed no statistically significant circadian or ultradian rhythms and the other four showed free-running drinking circadian rhythm behavior shorter than 24 h (ranging from 23.333 to 23.967 h). Ultradian rhythms of drinking behavior of 12- and 8-h periods were detected in 4 (rats 1, 2, 3 and 5) and 2 (rats 1 and 5) animals, respectively. The relation of the compound structure of the circadian and ultradian rhythms is discussed demonstrating that drinking behavior is a good marker for studies of physiology of temporal organization.
本研究的目的是调查在持续黑暗条件下饲养的Wistar大鼠饮水行为的昼夜节律和超日节律。六只成年雄性大鼠（体重270 - 350克）先暴露于12:12小时的明暗循环（LD 12:12，12:00开灯）35天，然后切换到持续黑暗（DD）条件下至少2周。用标准的饮水计电路持续监测饮水行为，数据以5分钟的时段存储。采用Enright周期图技术的改进方法来评估自由运行的饮水行为昼夜节律。通过快速傅里叶变换（FFT）技术估计饮水行为的超日节律。其中两只动物（大鼠4和6）未表现出统计学上显著的昼夜节律或超日节律，另外四只表现出自由运行的饮水昼夜节律行为，周期短于24小时（范围从23.333至23.967小时）。分别在4只动物（大鼠1、2、3和5）和2只动物（大鼠1和5）中检测到12小时和8小时周期的饮水行为超日节律。讨论了昼夜节律和超日节律复合结构的关系，表明饮水行为是时间组织生理学研究的一个良好标志物。
