ATAC-ing dopaminergic cell identity with single-cell resolution

多巴胺神经元是大脑奖赏通路的关键组成部分。从历史上看，多巴胺神经元 被认为是一个相对同质的群体，介导了来自 食物、水和生殖，同时受到感官刺激。然而，最近的研究表明，这些 神经元形成具有不同生理特征、神经投射和生物功能的亚群。 这些不同的亚群在成瘾周期的进程中也扮演着不同的角色，从使用到使用 虐待、禁欲和故态复萌。这项应用的目标是设计出新的基因工具，使 精确操纵不同亚群的多巴胺回路，特异性低至单对 神经元。为此，我们将首先应用一种新技术，单细胞atac-seq，以确定所有开放 果蝇~250个多巴胺神经元的染色质/可及DNA增强子元件 大脑。其次，我们将确定哪些开放的增强子片段或其组合将是唯一的 识别单个多巴胺细胞/细胞类型。第三，在这个分析的基础上，我们将设计出无数新的 并测试它们在体内的有效性和特异性。虽然这些目标是线性的和完全的 相互依存的是，赠款总体上应用了非常新的技术--单细胞ATAC-SEQ来“突破新的 地面“和”加快发现步伐，以推进成瘾研究“。该提案实质上是对 假设这种无偏见的全基因组方法可以被利用来产生新的工具 精准干预。因为该方法本身可以扩展，可以应用于任何单元格类型，也可以转换为 哺乳动物，这一应用完全符合尖端基础研究奖的精神 (CEBRA)机制，将“支持高风险、高影响的研究”(PAR-18-437)。

Dopamine neurons are a critical component of reward pathways in the brain. Historically, dopamine neurons were considered a relatively homogeneous population mediating association of reinforcement signals from food, water, and reproduction with coinciding sensory stimuli. However, recent studies have shown that these neurons form subpopulations with distinct physiological profiles, neural projections, and biological functions. These distinct subpopulations also have different roles in the progression of the addiction cycle, from use to abuse, abstinence and relapse. The goal of this application is to engineer novel genetic tools that will allow precise manipulation of distinct subpopulations of dopamine circuits, with specificity down to single pairs of neurons. To this end we will first apply a new technique, single-cell ATAC-seq, to determine all open chromatin/accessible DNA enhancer elements of every one of the ~250 dopamine neurons in the Drosophila brain. Second, we will determine which open enhancer fragments, or combinations thereof, will uniquely identify single dopamine cells/cell-types. And third, based on this analysis, we will engineer numerous new genetic tools and test them for their in vivo efficacy and specificity. While these Aims are linear and fully interdependent, the grant overall applies the very new technique of single-cell ATAC-seq to “break new ground” and “accelerate the pace of discoveries to advance addiction research”. The proposal essentially tests the hypothesis that this unbiased, genome-wide approach can be harnessed to generate new tools for precision intervention. Because the approach itself can be scaled, applied to any cell type, and translated to mammals, this application is fully consistent with the spirit of the Cutting-Edge Basic Research Awards (CEBRA) mechanism, which will “support high-risk, high impact research” (PAR-18-437).