Slow shift of dead zone after an abrupt shift of the light-dark cycle
Slow shift of dead zone after an abrupt shift of the light-dark cycle
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DOI：
10.1016/j.brainres.2019.02.014
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发表时间：
2019-07-01
期刊：
影响因子：
2.9
通讯作者：
Shigeyoshi, Yasufumi
中科院分区：
文献类型：
--
作者：
Nagano, Mamoru;Ikegami, Keisuke;Shigeyoshi, Yasufumi
视交叉上核（SCN）是哺乳动物昼夜节律系统的中枢。环境光信号改变SCN中的昼夜节律的相位，除了在死区期间，当光信号在从视网膜到SCN中的神经元的途中的某处被门控时。在这里，我们研究了死区的相位后，突然延迟的LD周期数天，通过观察的me-Fos诱导SCN的光脉冲。在LD周期突然移位后，死区显示出缓慢的相移，每天约两小时，这与静息-活动周期的缓慢相移很好地对应。在我们以前的研究中，我们证明了，LD周期的突然转变后，SCN壳和核心区域之间的瞬时内源性去钙化，分别表现出缓慢和快速的昼夜节律转变。因此，目前的研究结果后，LD周期移位的死区的相移表明，死区的相位控制的定时信号从壳区的SCN。
The suprachiasmatic nucleus (SCN) is the center of the mammalian circadian system. Environmental photic signals shifts the phase of the circadian rhythm in the SCN except during the dead zone, when the photic signal is gated somewhere on the way from the retina to the neurons in the SCN. Here we examined the phase of the dead zone after an abrupt delay of the LD cycles for several days by observing the me-Fos induction in the SCN by light pulses. After an abrupt shift of the LD cycles, the dead zone showed a slow phase shift, about two hours per day, which was well corresponded with the slow phase shift of the rest-activity cycles. In our previous study we demonstrated that, after an abrupt shift of the LD cycles, the SCN showed transient endogenous desynchronization between shell and core regions that showed a slow and a rapid shift of the circadian rhythms, respectively. Therefore, the present findings on the phase shift of the dead zone after the LD cycles shift suggest that the phase of the dead zone is under the control of the timing signals from the shell region of the SCN.