INTERNAL TEMPORAL ORDER IN THE CIRCADIAN SYSTEM OF A DUAL-PHASING RODENT, THE OCTODON DEGUS
INTERNAL TEMPORAL ORDER IN THE CIRCADIAN SYSTEM OF A DUAL-PHASING RODENT, THE OCTODON DEGUS
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DOI：
10.3109/07420528.2010.503294
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发表时间：
2010-01-01
影响因子：
2.8
通讯作者：
Angeles Rol, Maria
中科院分区：
文献类型：
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作者：
Bano Otalora, Beatriz;Vivanco, Pablo;Angeles Rol, Maria
不同生化和血液学变量的日常节律已在昼间或夜间物种中被广泛描述，但迄今为止尚未在双相物种（例如八齿鼠）中进行这些变量节律的研究。八齿八齿鼠是一种啮齿动物，能够在实验室条件下根据轮子运行的情况从白天活动转变为夜间活动。该物种可以帮助我们发现完整的时间顺序反转是否与在该啮齿动物的活动模式中观察到的反转平行发生。本研究的目的是确定 26 个变量之间的相位关系，包括白天和晚上的行为、生理、生化和血液学变量，以及在受控实验室条件下通过车轮运行诱导的昼夜八齿鼠计时型。总共 39 只雄性八齿鼠被单独圈养在 12:12 的光暗 (LD) 循环中，并可以自由地轮式运行。在整个实验过程中记录轮跑活动（WRA）和体温（Tb）节律。通过每 6 小时采集一次血样（ZT1、ZT7、ZT13 和 ZT19）测定褪黑素、血液学和生化变量。尽管夜间和昼间八齿鼠的 WRA 和 Tb 节律存在很大差异，但在分析这两种时间型的大多数生物变量的时间模式中没有观察到这种差异。仅血浆尿素水平和淋巴细胞数量存在变化。还观察到褪黑激素节律的相位略有延迟。这项研究表明，双相哺乳动物的内部时间顺序并未根据其活动和体温模式显示出完全倒置；八齿鼠夜行性的开关机制似乎位于起搏器的下游。 （作者通讯：angerol@um.es）。
Daily rhythms in different biochemical and hematological variables have been widely described in either diurnal or nocturnal species, but so far no studies in the rhythms of these variables have been conducted in a dual-phasing species such as the degus. The Octodon degus is a rodent that has the ability to switch from diurnal to nocturnal activity under laboratory conditions in response to wheel-running availability. This species may help us discover whether a complete temporal order inversion occurs parallel to the inversion that has been observed in this rodent's activity pattern. The aim of the present study is to determine the phase relationships among 26 variables, including behavioral, physiological, biochemical, and hematological variables, during the day and at night, in diurnal and nocturnal degus chronotypes induced under controlled laboratory conditions through the availability of wheel running. A total of 39 male degus were individually housed under a 12: 12 light-dark (LD) cycle, with free wheel-running access. Wheel-running activity (WRA) and body temperature (Tb) rhythms were recorded throughout the experiment. Melatonin, hematological, and biochemical variables were determined by means of blood samples obtained every 6 h (ZT1, ZT7, ZT13, and ZT19). In spite of great differences in WRA and Tb rhythms between nocturnal and diurnal degus, no such differences were observed in the temporal patterns of most of the biological variables analyzed for the two chronotypes. Variation was only found in plasma urea level and lymphocyte number. A slight delay in the phase of the melatonin rhythm was also observed. This study shows the internal temporal order of a dual-phasing mammal does not show a complete inversion in accordance with its activity and body temperature pattern; it would appear that the switching mechanism involved in the degu's nocturnalism is located downstream from the pacemaker. (Author correspondence: angerol@um.es).