Spatiotemporal Heterogeneity in the Electrical Activity of Suprachiasmatic Nuclei Neurons and their Response to Photoperiod
Spatiotemporal Heterogeneity in the Electrical Activity of Suprachiasmatic Nuclei Neurons and their Response to Photoperiod
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DOI：
10.1177/0748730408327918
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发表时间：
2009-02-01
影响因子：
3.5
通讯作者：
Piggins, H. D.
中科院分区：
文献类型：
--
作者：
Brown, T. M.;Piggins, H. D.
视交叉上核（SCN）中数千个细胞振荡器的协调活动在时间上调节哺乳动物的生理机能，以预测季节性的日常环境变化。时钟基因表达的定相根据SCN中的解剖位置而变化，并且被认为编码光周期信息。然而，目前还不清楚SCN神经元的电活动是否发生类似的相位变化，这是对SCN内信号传导和时钟输出的测量。为了解决这个问题，我们记录了单单位和多单位活动（SUA/MUA）的背侧和腹侧亚区的中间水平的嘴尾轴的SCN冠状面脑切片从小鼠在不同的光周期下。我们证明，在对称（12小时光：12小时黑暗）的光周期，在背侧SCN的细胞是不太紧密同步比那些在腹侧SCN。从小鼠短（8小时光：16小时黑暗）或长（16小时光：8小时黑暗）光周期下的记录比较表明，腹侧，但不是背侧，SCN神经元的相位分布随着白天长度的增加而扩大。相反，持续时间，个别神经元活跃的增加，而不是腹侧，SCN下长的日子。这些数据表明，在腹侧SCN的光周期编码在网络水平，而这种编码发生在单个细胞的水平在背侧SCN。
The coordinated activity of thousands of cellular oscillators in the suprachiasmatic nuclei (SCN) temporally regulates mammalian physiology to anticipate daily environmental changes across the seasons. The phasing of clock gene expression varies according to anatomical location in the SCN and is thought to encode photoperiodic information. However, it is unclear whether similar variations in phase occur in the electrical activity of SCN neurons, a measure of both intraSCN signaling and clock output. To address this, we recorded single-unit and multiunit activity (SUA/MUA) from dorsal and ventral subregions of the middle level of the rostrocaudal axis of the SCN in coronal brain slices prepared from mice housed under different photoperiods. We demonstrate that under a symmetrical (12 h light: 12 h dark) photoperiod, cells in the dorsal SCN are less tightly synchronized than those in the ventral SCN. Comparison of recordings made from mice under short (8 h light: 16 h dark) or long (16 h light: 8 h dark) photoperiods shows that the phase distribution of ventral, but not dorsal, SCN neurons expands with increasing day length. Conversely, the duration that individual neurons are active increases in dorsal, but not ventral, SCN under long days. These data indicate that in the ventral SCN photoperiod is encoded at the network level, while this coding occurs at the level of individual cells in the dorsal SCN.