Morphological approach to mechanisms of light input and synchronization to the circadian oscillator

本研究探讨了视交叉上核（SCN）的光输入和同步化机制。使用rPer 2启动子：：荧光素酶大鼠，我们已经发现SCN分为两个区域，与周期长度相关。其中一个显示SCN的内侧区域包含周期小于24小时的振荡器（SPR）和周期大于24小时的振荡器（LPR）。我们发现SPR和LPR之间的同步可能是通过cAMP信号实现的。然后，我们观察了当环境LD周期（12：12-h）突然改变以解离背内侧SCN（DMSCN）和腹外侧SCN（VLSCN）时，光诱导SCN中Per 1和cFos的表达。其结果是，门的相移与DMSCN的相移对应良好。这一发现表明DMSCN决定了门的相位。

We investigated the mechanisms of light input and synchronization in the suprachiasmatic nucleus (SCN). Using rPer2 promoter::Luciferase rat, we have found that the SCN is divided into two regions in relevance to period length. One of which showed medial region of the SCN containing oscillators with a period shorter than 24 hours (SPR) and lateral region with a period longer than 24 hours (LPR). And we have found that synchrony between SPR and LPR is possibly attained by cAMP signaling. Then, We observed Per1 and cFos induction in the SCN by light when the environmental LD cycle (12:12-h) was abruptly changed to dissociate the dorsomedial SCN (DMSCN) and ventrolateral SCN (VLSCN). As a result, the phase shifting of the gate corresponded well with that of the DMSCN. The finding suggested that the DMSCN determines the phase of the gate.