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，使尼古丁的致命性大约是阿片类药物的10倍。在……里面 此外，在美国，与吸烟相关的疾病每年花费超过3000亿美元。无论是遗传因素还是 社会环境对吸烟行为有较强的fl影响。至少26项人类全基因组关联研究 到目前为止，已经开展了关于吸烟的全球环境卫生组织(GWAS)。只有11个基因座，每个座位解释了0.2%-0.99%的方差 一些自我报告的表型已经被复制。我们已经开发了一种尼古丁自我给药模型 捕捉到社会学习在促进尼古丁摄取中的作用的青春期大鼠。这种可操作的舔舔模式提供了 静脉注射尼古丁和附带的口服fl味道(即，味道和气味)提示。我们发现社交学习促进了 消除条件性尼古丁厌恶，促进尼古丁摄取。在之前的资助期，我们几乎有 fi利用该模型对1,600只青春期异种雄性和雌性大鼠进行了表型分析。我们还测量了 这些大鼠的几种社交、寻求新奇和类焦虑行为。我们的回归分析表明，社交 而类似情绪的行为可以解释尼古丁摄入量变化的大约30%。我们还测序了 来自幼稚大鼠的440个样本的转录组。我们的遗传分析已经确定了许多数量性状基因座(fi) 行为表型和基因表达表型。人类GWAS研究表明，样本大小呈指数级增加 增加符号fi铁路超高关联的数量。同样，我们已经完成了关于体重和相关的GWA 使用了近3,200只老鼠的特征。通过检查我们在只有1600只老鼠的情况下会发现的情况，我们显示了 QTL在1600~3200之间呈指数型，而不是线性型。因此，在这次续期申请中，我们建议 通过增加1,600只大鼠的表型来扩展我们的研究，这将使我们的fiNAL样本量达到3,200只。我们期待着 这项联合研究将确定与尼古丁成瘾的不同方面有关的基因，如奖赏和 尼古丁的厌恶作用、尼古丁摄取的进展和复发等。我们计划维持 上一个资助期的实验设计，因为它运行良好，并确保3200只大鼠的全部队列 是尽可能同质的。但是，我们将添加一项新的社交测试，在该测试中，我们将分析 用我们实验室开发的一种基于艺术智能的分析方法，对两只自由活动的大鼠的行为进行了研究。 在目标1中，我们将对青春期异种大鼠进行表型。饲养员将从核心B(HS育种核心)获得， 我们将用它在1-4年内每年生产400只青春期大鼠。这些大鼠将首先被fi分型为他们的 社交、寻求新奇和类似焦虑的行为。然后，他们将被植入颈静脉导管。尼古丁静脉注射 将从出生后第38天开始。在目标2中，我们将使用回归和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，以确定遗传的多效性效应。 在这个项目中发现了fi的变种。在目标3中，我们将获得解剖学上精确的脑组织，从幼鼠到 扩展我们的转录数据库。这些数据将为获得的行为关联提供机械性的见解 来自项目1-3，并由项目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.