RUI: Role of the Intergeniculate Leaflet in Circadian Rhythms

昼夜节律是哺乳动物的基本生物过程，它将生物体的激素、代谢和生理活动同步到24小时的周期中。主要的昼夜节律起搏器，也被称为生物钟，在位于大脑下丘脑底部的视交叉上核的神经元集合中被发现。这种起搏器接收来自眼睛的输入，以传达关于太阳日的明/暗周期的信息，该信息用于设置时钟的时间，但起搏器也接收来自功能不清楚的其他大脑区域的输入。这个项目的目的是确定这些输入之一，来自丘脑的膝间小叶，对仓鼠生物钟的计时特性的作用。本项目将使用行为学和解剖学方法来研究膝间小叶在昼夜活动节律中的作用。这个项目有望证明从膝间小叶到时钟的输入在夜间是音调抑制的，当这一输入被阻断时，起搏器能够更快地重新设置时间，以响应白天的变化。该项目还将展示生物体如何能够防止来自恒星和月球的低水平光改变起搏器的时间。这个项目的结果对于我们理解生物体如何适应其环境中的季节性日光变化非常重要。最后，该项目将为本科生和研究生提供关键的科学培训，他们中的许多人将是女性和代表性不足的少数民族。

Circadian rhythms are fundamental biological processes in mammals that synchronize the hormonal, metabolic and physiological activities of the organism into a twenty-four hour cycle. The primary circadian pacemaker, also called the biological clock, is found in a collection of neurons located in the suprachiasmatic nuclei at the base of the hypothalamus in the brain. This pacemaker receives input from the eye to convey information about the light/dark cycle of a solar day that is used to set the time of the clock, but the pacemaker also receives input from other brain regions whose function is unclear. This project aims to determine the role of one of these inputs, from the intergeniculate leaflet of the thalamus, on the timekeeping properties of the biological clock in hamsters. This project will use behavioral and anatomical approaches to study the role of the intergeniculate leaflet in circadian activity rhythms. This project is expected to demonstrate that the input from the intergeniculate leaflet to the clock is tonically inhibitory at night, and that when this input is blocked, the pacemaker is capable of a much more rapid resetting of time in response to changes in daylength. This project will also demonstrate how organisms are able to prevent low levels of light from stars and the moon from shifting the timing of the pacemaker. The results of this project are very important for our understanding of how organisms adapt to seasonal daylight changes in their environment. Finally, this project will provide crucial training in the sciences to undergraduate and graduate students, many of whom will be female and underrepresented minorities.