Center for Genetic Studies of Drug Abuse in Outbred Rats

项目摘要 吸烟每年导致48万人死亡，尼古丁的致命性是阿片类药物的10倍。在 此外，美国每年因吸烟引起的疾病造成的损失超过3000亿美元。遗传因素和 社会环境对吸烟行为有很强的影响。至少26项人类全基因组关联研究 （GWAS）的研究。只有11个位点，每个位点的方差占总方差的0.2- 0.99 一些自我报告的表型已经被复制。我们开发了一种尼古丁自我给药模型， 青少年大鼠，捕捉社会学习在促进尼古丁摄入中的作用。这种操作性舔舔模式提供了 静脉内尼古丁与偶然的口服维生素A（即，味道和气味）提示。我们发现社会学习促进了 消除条件性尼古丁厌恶并促进尼古丁摄入。在上一个融资期，我们几乎 使用该模型完成了1，600只青春期异源雄性和雌性大鼠的表型分型。我们还测量 几个社会，新奇寻求和焦虑样行为在这些大鼠。我们的回归分析显示， 和类似情绪的行为解释了尼古丁摄入量大约30%的差异。我们还对 440份来自未处理大鼠的样本的转录组。我们的遗传分析已经确定了艾德许多数量性状位点（QTL）， 行为和基因表达表型。人类GWAS已经表明，样本量呈指数级增加 增加了重要关联的数量。同样，我们已经完成了体重和相关的GWAS 使用了近3,200只老鼠。通过研究我们在1,600只老鼠身上发现的东西，我们发现， 1600 ~ 3200之间的QTL是指数型的，而不是线性的。因此，在这次续期申请中，我们建议 通过对另外1，600只大鼠进行表型分析来扩展我们的研究，这将使我们的最终样本量达到3，200。我们预计 这项综合研究将确定涉及尼古丁成瘾不同方面的基因，如奖励和 尼古丁的厌恶作用、尼古丁摄入的进展和复发等。我们计划维持 实验设计，因为它运作良好，并确保整个队列的3,200只大鼠 尽可能均匀。然而，我们将添加一个新的社交互动测试，在那里我们将分析社交互动。 使用我们实验室开发的一种基于阿尔蒂官方智能的分析方法Yorodent对两只自由活动的大鼠进行行为分析。 在目标1中，我们将表型青春期异质大鼠。育种者将从核心B（HS育种核心）获得， 我们将用它在第1-4年每年生产400只青春期的老鼠。这些大鼠将首先进行表型分析， 社交、寻求新奇和焦虑行为。然后，他们将被植入颈静脉导管。尼古丁IVSA 从出生后第38天开始。在目标2中，我们将使用回归分析行为特征之间的关系， 遗传相关性我们还将进行一项全表型关联研究，以确定遗传因素的多效性效应。 在本项目中识别的变体艾德。在目标3中，我们将从幼稚大鼠中获得解剖学上精确的脑组织， 扩大我们的转录组数据库这些数据将为获得的行为关联提供机械的见解 从项目1-3和项目4用于网络分析。

Project Summary Cigarette smoking causes 480,000 deaths annually, making nicotine about 10 times more lethal than opioids. In addition, smoking-related illnesses in the United States cost more than $300 billion each year. Both genetic factors and social environment have a strong influence on smoking behavior. At least 26 human genome-wide association studies (GWAS) on smoking have been conducted to date. Only 11 loci, each accounting for 0.2–0.99% of the variances of a few self-reported phenotypes have been replicated. We have developed a model of nicotine self-administration in adolescent rats that captures the role of social learning in promoting nicotine intake. This operant licking model delivers intravenous nicotine with a contingent oral flavor (i.e., taste and odor) cue. We found social learning facilitated the extinction of conditioned nicotine aversion and promoted nicotine intake. In the prior funding period, we have almost finished phenotyping 1,600 adolescent heterogenous stock male and female rats using this model. We also measured several social, novelty-seeking and anxiety-like behaviors in these rats. Our regression analysis showed that social and emotional-like behaviors explain approximately 30% of the variance in nicotine intake. We also sequenced the transcriptome of 440 samples from naïve rats. Our genetic analysis has identified many quantitative trait loci (QTL) for both behavior and gene expression phenotypes. Human GWAS has shown that increasing sample size exponentially increases the number of significant associations. Similarly, we have completed a GWAS of body weight and related traits using almost 3,200 rats. By examining what we would have found with only 1,600 rats, we show the increase in QTL from 1,600 to 3,200 is exponential rather than linear. Therefore, in this renewal application, we are proposing to extend our study by phenotyping an additional 1,600 rats, which will bring our final sample size to 3,200. We anticipate the combined study will identify genes involved in different aspects of nicotine addiction, such as the rewarding and aversive effects of nicotine, progression of nicotine intake, and relapse, among many others. We plan to maintain the experimental design from the last funding period, because it worked well, and to assure that the full cohort of 3,200 rat is as homogeneous as possible. However, we will add a new social interaction test, where we will analyze the social behaviors of two freely moving rats using Yorodent, an artificial intelligence-based analysis method developed in our lab. In Aim 1, we will phenotype adolescent heterogeneous rats. Breeders will be obtained from Core B (HS Breeding Core), which we will use to generate 400 adolescent rats per year in years 1-4. These rats will first be phenotyped for their social, novelty-seeking and anxiety-like behaviors. They then will be implanted with a jugular catheter. Nicotine IVSA will start on postnatal day 38. In Aim 2, We will analyze the relationships between behavioral traits using regression and genetic correlations. We will also perform a phenome-wide associations study to identify pleiotropic effects of genetic variants identified in this project. In Aim 3, we will obtain brain tissues that are anatomically precise from naïve rats to expand our transcriptome database. These data will provide mechanistic insights for behavior associations obtained from Projects 1–3 and be used by Project 4 for network analysis.