A resetting signal between Drosophila pacemakers synchronizes morning and evening activity
A resetting signal between Drosophila pacemakers synchronizes morning and evening activity
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DOI：
10.1038/nature04192
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发表时间：
2005-11-10
期刊：
影响因子：
64.8
通讯作者：
Rosbash, M
中科院分区：
文献类型：
--
作者：
Stoleru, D;Peng, Y;Rosbash, M
构成昼夜节律基础的生化机制在动物物种中是保守的，并驱动自我维持的分子振荡和功能，即使在单个异步组织培养细胞中也是如此（1-3）。然而，高等真核生物的产生节律的神经中心通常由相互连接的细胞网络组成，这有助于鲁棒性和同步性以及节律行为的其他复杂特征（4-7）。在哺乳动物中，人们对个体大脑振荡器是如何组织起来协调复杂的行为模式知之甚少。从这个角度来看，果蝇可以说是更先进的：我们和其他人最近已经表明，一组成年大脑时钟神经元表达神经肽PDF 8并控制早晨活动（小LNv细胞; M细胞），而另一组时钟神经元控制晚上活动（CRY+，PDF-细胞; E细胞）（6，9）。我们已经产生了在早晨和晚上细胞中具有不同昼夜节律周期的转基因嵌合体动物。在这里，我们通过行为和分子测定表明，六个典型的时钟神经元组（10）被组织成两个独立的神经元回路。其中一个对黑暗中的运动节律没有明显的影响，但在第二个回路中，晚上细胞的分子和行为时间是由早晨细胞的特性决定的。这是由于每天从早晨到晚上的重置信号，这些信号在连续信号之间以其遗传编程的速度运行。这种神经回路和兴奋器耦合机制确保了早晨和晚上自发活动的时间之间的适当关系。
The biochemical machinery that underlies circadian rhythms is conserved among animal species and drives self-sustained molecular oscillations and functions, even within individual asynchronous tissue-culture cells(1-3). Yet the rhythm- generating neural centres of higher eukaryotes are usually composed of interconnected cellular networks, which contribute to robustness and synchrony as well as other complex features of rhythmic behaviour(4-7). In mammals, little is known about how individual brain oscillators are organized to orchestrate a complex behavioural pattern. Drosophila is arguably more advanced from this point of view: we and others have recently shown that a group of adult brain clock neurons expresses the neuropeptide PDF8 and controls morning activity ( small LNv cells; M-cells), whereas another group of clock neurons controls evening activity (CRY+, PDF- cells; E-cells)(6,9). We have generated transgenic mosaic animals with different circadian periods in morning and evening cells. Here we show, by behavioural and molecular assays, that the six canonical groups of clock neurons(10) are organized into two separate neuronal circuits. One has no apparent effect on locomotor rhythmicity in darkness, but within the second circuit the molecular and behavioural timing of the evening cells is determined by morning-cell properties. This is due to a daily resetting signal from the morning to the evening cells, which run at their genetically programmed pace between consecutive signals. This neural circuit and oscillator-coupling mechanism ensures a proper relationship between the timing of morning and evening locomotor activity.