Developmental gene networks of 5HT neurons in addiction, aggression, and anxiety

成瘾、攻击性和焦虑中 5HT 神经元的发育基因网络

基本信息

批准号：
8836993
负责人：
Susan M. Dymecki
金额：
$ 59.27万
依托单位：
HARVARD MEDICAL SCHOOL
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-04-15 至 2019-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8836993
关键词：
Action Potentials Adolescence Adult Adverse effects Affect Affective Age Aggressive behavior Alleles Anxiety Axon Behavior Behavioral Biological Assay Brain Brain region Cells Childhood Cognitive Development Developmental Gene Disease Dopamine Dopamine D1 Receptor Dopamine D2 Receptor Electrophysiology (science)Emotional Functional disorder Gene Expression Profile Genes Genetic Genetic Predisposition to Disease Goals Grant Health Human Impulsivity Individual Ion Channel Label Link Longevity Maps Methods Molecular Molecular Profiling Mood Disorders Motivation Mus Nervous System Physiology Neurobiology Neurons Pathway interactions Pattern Pharmacogenetics Phenotype Presynaptic Terminals Property Prosencephalon RNA Research Resolution Rewards Sensorimotor functions Serotonergic System Serotonin Shapes Slice Social Behavior Social Interaction Sorting - Cell Movement Stress Substance abuse problem Synapses System Techniques Testing Therapeutic Tracer Transgenes Ursidae Family Viral Whole-Cell Recordings Work addiction age related base behavior test brain cell cell type critical period differential expression emotional behavior improved in vivo innovation male motivated behavior nerve supply neural circuit neurochemistry neuronal cell body new technology novel postsynaptic postsynaptic neurons receptor receptor expression response social therapeutic target tool transcription factor transcriptome sequencing

项目摘要

DESCRIPTION (provided by applicant): The proposed research brings cutting-edge genetic tools to bear on understanding the neural circuitry under- lying aggression and motivated behavior. Our recent progress reveals that these behaviors in mice are regulated by two molecularly distinct, small subsets of brain serotonergic (5-HT) neurons: one subset, ~3,000 neurons, uniquely defined among 5-HT neurons by expression of the D1 dopamine (DA) receptor (Drd1a gene), and the other, ~1,000 neurons, by the D2 DA receptor (Drd2 gene). These results combined with the enabling genetic tools, like a powerfully sharpened wedge, can now be used to "break open" and access the circuitry, cellular properties, and molecular pathways underlying these consequential behaviors. Here we propose applying this "wedge" in the form of four aims to answer: What cellular and molecular properties are unique to these behavior-critical 5-HT neurons? As suggested by receptor expression, are these 5-HT neurons responsive to DA - a neurochemical commonly associated with the reward system of the brain? Through what forebrain circuitry do these subtypes modulate aggression and motivation? Do these parameters change across the life span, perhaps bearing on human age-related propensity for impulsivity, aggression, and substance abuse? In Aim 1, we will identify functional properties of the Drd1a and Drd2 5-HT neuron subtypes by transcriptional profiling (RNA-seq) and electrophysiological recording. This work is enabled through novel genetic tools for neuron subtype-specific marking, suitable for neuron subtype sorting and molecular profiling, and for whole-cell recording. These same genetic tools not only offer access to the soma of a 5-HT neuron subtype, but also to axons and terminals, thus allowing precise identification of target brain regions under neuron-subtype control - the goal of Aim 2. Functional postsynaptic connections will also be explored, with our intersectional genetic marking tools conferring unprecedented resolution to classic tract- tracing techniques as well as to cutting-edge viral approaches that involve trans-synaptic tracers. Thus, Aim 2 will define, label, and allow for molecular characterization of "aggression-relevant" postsynaptic neurons downstream in these circuits. In Aim 3, we will explore more deeply the behavioral facets modulated by these two 5-HT neuron subtypes and if their contributions vary across life span. Similar subtype-specific silencing methods will be employed as in the foundational aggression studies, but now additional social behaviors and neurological functions will be queried. In Aim 4, we will use pharmacogenetics (DREADDs) to transiently silence each Drd 5-HT neuron subtype during "childhood," asking if lasting changes occur that predispose to hyperaggression and altered social motivation in adulthood, as predicted by human studies that associate genetic predisposition via the 5-HT system, childhood stress, and adult pathological aggression. Our approaches are technically and conceptually innovative, and are foundational for discovering new, potentially behavior-selective, age-suitable therapeutics. Results compel a redefinition of 5-HT system organization.

描述（由申请人提供）：拟议的研究带来了尖端的遗传工具，有助于理解攻击性和动机行为背后的神经回路。我们最近的进展表明，小鼠的这些行为受到大脑血清素能 (5-HT) 神经元的两个分子上不同的小亚群的调节：其中一个亚群约 3,000 个神经元，通过 D1 多巴胺 (DA) 的表达在 5-HT 神经元中唯一定义。 ) 受体（Drd1a 基因），另一个约 1,000 个神经元，由 D2 DA 受体（Drd2 基因）控制。这些结果与有利的遗传工具（如强力锐利的楔子）相结合，现在可用于“打开”并访问这些后果性行为背后的电路、细胞特性和分子途径。在这里，我们建议以四个目标的形式应用这个“楔子”来回答：这些行为关键的 5-HT 神经元有哪些独特的细胞和分子特性？正如受体表达所示，这些 5-HT 神经元是否对 DA（一种通常与大脑奖励系统相关的神经化学物质）有反应？这些亚型通过什么前脑回路调节攻击性和动机？这些参数在整个生命周期中是否会发生变化，是否可能与人类与年龄相关的冲动、攻击性和药物滥用倾向有关？在目标 1 中，我们将通过转录分析 (RNA-seq) 和电生理记录来识别 Drd1a 和 Drd2 5-HT 神经元亚型的功能特性。这项工作是通过用于神经元亚型特异性标记的新型遗传工具实现的，适用于神经元亚型分类和分子分析以及全细胞记录。这些相同的遗传工具不仅可以访问 5-HT 神经元亚型的体细胞，还可以访问轴突和末梢，从而可以精确识别神经元亚型控制下的目标大脑区域 - 这是目标 2 的目标。功能性突触后连接将还可以探索，我们的交叉遗传标记工具为经典的纤维束追踪技术以及涉及跨突触示踪剂的尖端病毒方法提供了前所未有的分辨率。因此，目标 2 将定义、标记并允许对这些回路下游的“攻击相关”突触后神经元进行分子表征。在目标 3 中，我们将更深入地探讨这两种 5-HT 神经元亚型调节的行为方面，以及它们的贡献在整个生命周期中是否有所不同。将采用与基础攻击性研究类似的特定亚型沉默方法，但现在将询问额外的社会行为和神经功能。在目标 4 中，我们将使用药物遗传学 (DREADD) 在“童年”期间暂时沉默每个 Drd 5-HT 神经元亚型，询问是否会发生持久的变化，这些变化容易导致成年期的过度攻击性和社会动机的改变，正如与遗传相关的人类研究所预测的那样。通过 5-HT 系统、童年压力和成人病理性攻击行为产生的易感性。我们的方法在技术和概念上都是创新的，是发现新的、潜在的行为选择性、适合年龄的疗法的基础。结果迫使我们重新定义 5-HT 系统组织。