Circadian waves of cytosolic calcium concentration and long-range network connections in rat suprachiasmatic nucleus
Circadian waves of cytosolic calcium concentration and long-range network connections in rat suprachiasmatic nucleus
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DOI：
10.1111/j.1460-9568.2012.08069.x
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发表时间：
2012-05-01
影响因子：
3.4
通讯作者：
Lee, Kyoung J.
中科院分区：
文献类型：
--
作者：
Hong, Jin Hee;Jeong, Byeongha;Lee, Kyoung J.
视交叉上核（SCN）是哺乳动物体内控制日常生理和行为节律的主时钟。它由数千个时钟单元组成，它们的固有周期在很宽的范围内变化（2028 h）。尽管存在这种异质性，但完整的SCN通过一些细胞间偶联机制保持连贯的24小时周期性节律。本研究通过使用钙结合荧光蛋白cameleon监测时钟细胞的胞浆游离钙离子浓度（[Ca2+]c）来研究时钟细胞如何相互连接以及它们的相位如何在空间中组织。对SCN的18种不同器官型切片培养物的广泛分析表明，SCN钙动力学通过远程神经突的相位同步网络以及扩散传播的相位波来协调。网络出现相当广泛和深远的，它们连接的时钟细胞表现出不同的反应，在其振幅和周期的振荡河豚毒素治疗。总之，我们的研究表明，网络的远程蜂窝连接有一个重要的作用，SCN在实现其相位和周期的一致性。
The suprachiasmatic nucleus (SCN) is the master clock in mammals governing the daily physiological and behavioral rhythms. It is composed of thousands of clock cells with their own intrinsic periods varying over a wide range (2028 h). Despite this heterogeneity, an intact SCN maintains a coherent 24 h periodic rhythm through some cell-to-cell coupling mechanisms. This study examined how the clock cells are connected to each other and how their phases are organized in space by monitoring the cytosolic free calcium ion concentration ([Ca2+]c) of clock cells using the calcium-binding fluorescent protein, cameleon. Extensive analysis of 18 different organotypic slice cultures of the SCN showed that the SCN calcium dynamics is coordinated by phase-synchronizing networks of long-range neurites as well as by diffusively propagating phase waves. The networks appear quite extensive and far-reaching, and the clock cells connected by them exhibit heterogeneous responses in their amplitudes and periods of oscillation to tetrodotoxin treatments. Taken together, our study suggests that the network of long-range cellular connectivity has an important role for the SCN in achieving its phase and period coherence.