Day-length encoding through tonic photic effects in the retinorecipient SCN region.
Day-length encoding through tonic photic effects in the retinorecipient SCN region.
复制标题
DOI：
10.1111/j.1460-9568.2008.06493.x
复制
发表时间：
2008-11
期刊：
影响因子：
--
通讯作者：
Silver R
中科院分区：
文献类型：
--
作者：
Yan L;Silver R
视交叉上核（SCN）中的昼夜节律钟通过感知环境光周期在季节过程中起着关键作用。为了探索它如何测量日照长度，我们使用神经元活动标记物（c-FOS）和时钟蛋白（PER 1）评估了长日照（LD，16：8小时光照：黑暗）与短日照（SD，8：16小时光照：黑暗）叙利亚仓鼠SCN振荡器的状态。在SD期间，在整个核的喙尾侧范围内没有可检测到的相位分散。相反，在LD期间，尾侧SCN相的节律分别领先于中间和喙侧SCN的节律4-8 h和8-12 h。重要的是，视网膜受体核心SCN中的一些神经元的独特之处在于，它们在LD的暗期呈FOS阳性，而在SD中则不然。LD动物转移到恒定的黑暗或骨骼光周期显示，暗相FOS的表达依赖于补光曝光，而不是内在的时钟特性。通过将动物从SD转移到LD，我们接下来发现有两个独立的SCN细胞群，一个对急性光暴露有反应，另一个对补光暴露有反应。结果表明，SCN的季节性编码的一天的长度需要重组的组成振荡器的SCN核心的一个亚组的神经元，响应紧张性光的线索。
The circadian clock in the suprachiasmatic nucleus (SCN) plays a critical role in seasonal processes by sensing ambient photoperiod. To explore how it measures daylength, we assessed the state of SCN oscillators using markers for neuronal activity (c-FOS) and the clock protein (PER1) in Syrian hamsters housed in long (LD, 16:8hr light:dark) versus short days (SD, 8:16hr light:dark). During SD, there was no detectable phase dispersion across the rostro-caudal extent of the nucleus. In contrast, during LD, rhythms in the caudal SCN phase led those in the mid- and rostral SCN by 4–8 h and 8–12 h, respectively. Importantly, some neurons in the retinorecipient core SCN were unique in that they were FOS-positive during the dark phase in LD, but not SD. Transfer of LD animals to constant darkness or skeleton photoperiod revealed that dark phase FOS expression depends on tonic light exposure rather than on intrinsic clock properties. By transferring animals from SD to LD, we next discovered that there are two separate populations of SCN cells one responding to acute and the other to tonic light exposure. The results suggest that the SCN’s seasonal encoding of day-length entails reorganization of its constituent oscillators by a subgroup of neurons in the SCN core that respond to tonic photic cues.
登录
查看更多内容
DOI：
10.1007/s00359-003-0486-z
发表时间：
2004-02-01
影响因子：
2.1
作者：
Burgoon, PW;Lindberg, PT;Gillette, MU
通讯作者：
Gillette, MU
影响因子：
3.5
作者：
FINLEY, CM;GORMAN, MR;ZUCKER, I
通讯作者：
ZUCKER, I
影响因子：
16.2
作者：
KORNHAUSER, JM;NELSON, DE;TAKAHASHI, JS
通讯作者：
TAKAHASHI, JS
影响因子：
9.2
作者：
de la Iglesia, HO;Cambras, T;Díez-Noguera, A
通讯作者：
Díez-Noguera, A
影响因子：
3.4
作者：
Jobst, EE;Allen, CN
通讯作者：
Allen, CN