Circadian dynamics of cytosolic and nuclear Ca2+ in single suprachiasmatic nucleus neurons
Circadian dynamics of cytosolic and nuclear Ca2+ in single suprachiasmatic nucleus neurons
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DOI：
10.1016/s0896-6273(03)00164-8
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发表时间：
2003-04-24
期刊：
影响因子：
16.2
通讯作者：
Allen, CN
中科院分区：
文献类型：
--
作者：
Ikeda, M;Sugiyama, T;Allen, CN
细胞内游离钙离子调节多种细胞过程，包括膜电位、神经递质释放和基因表达。为了研究昼夜节律产生的细胞机制，将编码钙离子敏感的荧光蛋白(Cameleon)的核靶向和非靶向cDNA导入到主要的昼夜节律调节器--小鼠视交叉上核(SCN)的器官培养物中。SCN神经元胞浆内钙离子浓度有昼夜节律，但胞核内钙离子浓度无昼夜节律。细胞内钙节律周期与用多电极阵列监测的昼夜多单位活动(MUA)节律周期相匹配，平均提前4小时。河豚毒素阻断MUA节律，但不阻断钙节律，兰尼定抑制钙节律和MUA节律。这些结果表明，SCN神经元的胞浆钙节律受兰尼定敏感储存区钙离子释放的调节。
Intracellular free Ca2+ regulates diverse cellular processes, including membrane potential, neurotransmitter release, and gene expression. To examine the cellular mechanisms underlying the generation of circadian rhythms, nucleus-targeted and untargeted cDNAs encoding a Ca2+-sensitive fluorescent protein (cameleon) were transfected into organotypic cultures of mouse suprachiasmatic nucleus (SCN), the primary circadian pacemaker. Circadian rhythms in cytosolic but not nuclear Ca2+ concentration were observed in SCN neurons. The cytosolic Ca2+ rhythm period matched the circadian multiple-unit-activity (MUA)-rhythm period monitored using a multiple-electrode array, with a mean advance in phase of 4 hr. Tetrodotoxin blocked MUA, but not Ca2+ rhythms, while ryanodine damped both Ca2+ and MUA rhythms. These results demonstrate cytosolic Ca2+ rhythms regulated by the release of Ca2+ from ryanodine-sensitive stores in SCN neurons.