Dynamics of sleep-wake cyclicity in developing rats
Dynamics of sleep-wake cyclicity in developing rats
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DOI：
10.1073/pnas.0506340102
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发表时间：
2005-10-11
影响因子：
11.1
通讯作者：
Karlsson, K&Aelig;
中科院分区：
文献类型：
--
作者：
Blumberg, MS;Seelke, AMH;Karlsson, K&Aelig;
成年哺乳动物在睡眠和清醒之间循环。人类和其他哺乳动物中这些循环的最新评估[Lo， c.c., Amaral, l.a.n., Havlin， S., Ivanov, p.c., Penzel， T., Peter， J.H. & Stanley, h.e.（2002）《欧洲物理》。leet, 57,625-631和Lo， c.c., Chou， T., Penzel， T., Scammell， T. E., Strecker， R. E., Stanley， H. E.和Ivanov， P. Ch. (2004) Proc. Natl。研究表明，睡眠持续时间呈指数分布，而清醒持续时间呈幂律分布。此外，研究还发现，在不同体型的哺乳动物中，觉醒期的分布表现出尺度不变性，而睡眠期的分布则没有。在这里，我们通过检查2至21日龄的幼鼠睡眠和觉醒时间的分布来检验这些发现的普遍性。与Lo等人的研究结果一致，我们发现睡眠持续时间在所有年龄段都呈指数分布。然而，与之相反的是，醒脑持续时间在年轻时也表现出指数分布，只有在老年时才出现明显的幂律分布。进一步的分析未能在数据中找到短期或长期相关性的实质性证据，因此表明当前睡眠和醒来的持续时间随着时间的推移而变化，而不记得之前的持续时间。这些发现进一步支持了睡眠和清醒是独立调节的观点。此外，最近有证据表明，睡眠和清醒发作的发育变化部分归因于前脑影响的增加，这些发现表明，有可能识别出在发育过程中调节睡眠和清醒动态变化复杂性的特定神经回路。
Adult mammals cycle between periods of sleep and wakefulness. Recent assessments of these cycles in humans and other mammals [Lo, C. C., Amaral, L. A. N., Havlin, S., Ivanov, P. Ch., Penzel, T., Peter, J.H. & Stanley, H. E. (2002) Europhys. Lett. 57,625-631 and Lo, C. C., Chou, T., Penzel, T., Scammell, T. E., Strecker, R. E., Stanley, H. E. & Ivanov, P. Ch. (2004) Proc. Natl. Acad. Sci. 101, 17545-17548] indicate that sleep bout durations exhibit an exponential distribution, whereas wake bout durations exhibit a power-law distribution. Moreover, it was found that wake bout distributions, but not sleep bout distributions, exhibit scale invariance across mammals of different body sizes. Here we test the generalizability of these findings by examining the distributions of sleep and wake bout durations in infant rats between 2 and 21 days of age. In agreement with Lo et al., we find that sleep bout durations exhibit exponential distributions at all ages examined. In contrast, however, wake bout durations also exhibit exponential distributions at the younger ages, with a clear power-law distribution only emerging at the older ages. Further analyses failed to find substantial evidence either of short- or long-term correlations in the data, thus suggesting that the durations of current sleep and wake bouts evolve through time without memory of the durations of preceding bouts. These findings further support the notion that bouts of sleep and wakefulness are regulated independently. Moreover, in light of recent evidence that developmental changes in sleep and wake bouts can be attributed in part to increasing forebrain influences, these findings suggest the possibility of identifying specific neural circuits that modulate the changing complexity of sleep and wake dynamics during development.