Photonic Bioimaging Section, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
Department of Chronomedicine, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
Sci Rep. 2017 Aug 15;7(1):8210. doi: 10.1038/s41598-017-08186-5.
The circadian pacemaker in the suprachiasmatic nucleus (SCN) yields photoperiodic response to transfer seasonal information to physiology and behavior. To identify the precise location involved in photoperiodic response in the SCN, we analyzed circadian Period1 and PERIOD2 rhythms in horizontally sectioned SCN of mice exposed to a long or short day. Statistical analyses of bioluminescence images with respective luciferase reporters on pixel level enabled us to identify the distinct localization of three oscillating regions; a large open-ring-shape region, the region at the posterior end and a sharply demarcated oval region at the center of the SCN. The first two regions are the respective sites for the so-called evening and morning oscillators, and the third region is possibly a site for mediating photic signals to the former oscillators. In these regions, there are two classes of oscillating cells in which Per1 and Per2 could play differential roles in photoperiodic responses.
视交叉上核（SCN）中的生物钟起搏器对光周期产生反应，将季节信息传递给生理和行为。为了确定 SCN 中参与光周期反应的确切位置，我们分析了暴露于长日或短日条件下的小鼠 SCN 水平切片中的 circadian Period1 和 PERIOD2 节律。利用各自的荧光素酶报告基因对生物发光图像进行像素级别的统计分析，使我们能够识别三个振荡区域的独特定位；一个大的开环形状区域、后端区域和 SCN 中心的一个明显界定的椭圆形区域。前两个区域是所谓的傍晚和清晨振荡器的各自部位，第三个区域可能是将光信号传递给前振荡器的部位。在这些区域中，存在两类振荡细胞，其中 Per1 和 Per2 可能在光周期反应中发挥不同的作用。
