Behavioral, molecular and genetic studies of VIP in the SCN

描述（由申请人提供）：下丘脑的视交叉上核（SCN）由大约20,000个神经元组成，这些神经元共同作用，产生哺乳动物的先天生物钟。这个时钟由昼夜节律基因表达的转录和翻译反馈回路维持，包括周期1 （Per1）。SCN节律由包括血管活性肠肽（vasoactive intestinal peptide， VIP）在内的光信号通路设定并与外部环境同步，VIP在光刺激下上调Per1的表达。生物钟紊乱与人类各种形式的抑郁和睡眠障碍有关，并在动物模型中显示出显著的行为后果。本提案将试图回答以下关于VIP在SCN中的作用的具体问题：首先，在VIP和Vipr2 （VIP的受体）敲除小鼠中，SCN是如何组织的，这种组织如何解释行为输出？第二，跑轮对这些动物的行为特征有什么影响？我们将在VIP和vipr2缺失小鼠中采用滚轮跑步和红外运动检测来研究VIP的行为作用。一个mPer1::GFP（绿色荧光蛋白）转基因报告系将被用于在VIP-和vipr2缺陷小鼠的SCN中通过共聚焦显微镜进行实时昼夜节律基因表达分析。这些都是在我们的实验室和合作者一起使用的新颖而非常成功的方法。生物钟紊乱会严重影响人体健康。例如，季节性情感障碍（SAD）发生在人体时钟在冬季的几个月里光线输入减少时，每年影响多达3%的美国人口。这种疾病的治疗方法是光疗法和选择性血清素再摄取抑制剂（SSRI）——两种哺乳动物VIP的调节剂。VIP在光携带中的重要作用表明该肽作为一个基因申请者可能在很大程度上导致昼夜节律障碍。敲除小鼠模型是最极端的证据，表明如果VIP或Vipr2基因被突变或多态性改变会发生什么。这一证据表明，vip能信号对人类健康很重要，对小鼠模型的研究可以为人类时钟及其在与昼夜节律相关的疾病中功能障碍的能力提供有价值的见解。

DESCRIPTION (provided by applicant): The suprachiasmatic nuclei (SCN) of the hypothalamus consists of about 20,000 neurons that function together to produce an innate biological clock in mammals. This clock is maintained by transcriptional and translational feedback loops of circadian gene expression including Period 1 (Per1). SCN rhythms are set by and synchronized with the external environment by light signaling pathways including vasoactive intestinal peptide (VIP), which upregulates the expression of Per1 upon stimulation by light. Dysfunction in the circadian clock has been linked to various forms of depression and sleep disorders in humans, and has been shown to have dramatic behavioral consequences in animal models. This proposal will attempt to answer the following specific questions regarding the role of VIP in the SCN: First, how is the SCN organized in VIP and Vipr2 (VIP's receptor) knockout mice, and how does this organization account for the behavioral output? Second, what influence does wheel-running have on the behavioral characteristics of these animals? The behavioral role of VIP will be investigated using wheel-running and infrared motion detection in VIP- and Vipr2-deficient mice. A mPer1::GFP (green fluorescent protein) transgenic reporter line will be used to perform real-time circadian gene expression analyses by confocal microscopy in the SCN of VIP- and Vipr2-deficient mice. These are novel and highly successful approaches used in our laboratory and in conjunction with collaborators. Circadian clock dysfunction can dramatically affect human health. Seasonal Affective Disorder (SAD), for example, occurs when the human clock gets less light input during the winter months and affects up to 3% of the United States population every year. The disease is treated with light therapy and selective serotonin reuptake inhibitors (SSRI)-two modulators of VIP in mammals. VIP's essential role in photic entrainment implicates the peptide as a genetic applicant that could contribute greatly to circadian dysfunction. The knockout mouse models are the most extreme evidence of what could happen if the VIP or Vipr2 genes are altered by mutation or polymorphism. This evidence suggests that VIP-ergic signaling is important to human health, and that the study of the mouse model can grant valuable insight into the human clock and its capacity for dysfunction in circadian-linked disease.