Photoreceptors Regulating Circadian Behavior: A Mouse Model

生命系统的一个中心属性是有节奏的周期性活动，特别是昼夜节律，也就是日常周期。目前尚不清楚是什么机制导致并调节了这些振荡的发生和时机。昼夜节律的主要环境信号是与黎明和黄昏相关的光强度的变化，但调节这些反应的“昼夜光感受器”仍然知之甚少。这个项目是一项试验性工作，试图通过使用一种新的标记技术来获取关于这一机制的信息，这种标记技术可以标记大脑中的路径。这一标记将允许可视化连接接收重要光刺激的细胞与大脑中调节昼夜节律的细胞的电路。一种特殊的突变小鼠被发现在眼睛中缺少关键的细胞元素，但仍然显示出光驱动的节律。这个突变体中的路径将与正常小鼠的路径进行比较，以阐明光信息是如何到达大脑的。如果这种新的标记技术能够很好地工作，结果将对视觉科学、时间生物学和整个神经科学非常重要。

A central property of living systems is rhythmic periodic activity, particularly circadian rhythms which are daily cycles. It is not yet clear what mechanisms entrain and regulate the occurrence and timing of these oscillations. The primary environmental signal for circadian rhythms is the change in light intensity associated with dawn and dusk, but the "circadian photoreceptors" that mediate these responses are still poorly understood. This project is pilot work to try to get information on this mechanism by using a new marking technique that labels pathways in the brain. This marker will allow visualizing the circuit that connects the cells that receive the important light stimulus to the cells in the brain that regulate the circadian rhythm. One particular strain of mutant mice has been found to be missing key cellular elements in the eye, yet still showing a photically driven rhythm. The pathway in this mutant will be compared to that in normal mice to clarify how the light information gets to the brain. If this novel marking technique can be made to work well, the results will be very important to visual science, chronobiology, and neuroscience in general.