Adhesion GPCR Cirl as a novel regulator of dopamine neurotransmission

粘附 GPCR Cirl 作为多巴胺神经传递的新型调节剂

基本信息

批准号：
10401313
负责人：
Lilian Coie
金额：
$ 4.68万
依托单位：
COLUMBIA UNIVERSITY HEALTH SCIENCES
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-07-01 至 2023-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10401313
关键词：
Acute Adhesions Adult Aggressive behavior Arousal Attention deficit hyperactivity disorder Back Basal Ganglia Behavior Biological Assay Biological Models Biosensor Brain CRISPR/Cas technology Cations Cocaine Complement Complex Corpus striatum structure Data Dependence Development Disease Disease model Dopamine Drosophila genus Early-life trauma Exposure to Financial compensation Fluorescence Functional disorder G-Protein-Coupled Receptors Genes Genetic Polymorphism Goals Homologous Gene Hyperactivity Knockout Mice Ligands Light Link Locomotion Measures Mediating Motor Motor Activity Mus Neurons Phenocopy Phenotype Population Predisposition Prosencephalon Protein Fragment Rattus Regulation Research Risk Role Signal Transduction Single Nucleotide Polymorphism Stimulant Substance Use Disorder Synapses Temperature Testing Therapeutic Zebrafish calcium indicator comorbidity confocal imaging density dopamine transporter dopaminergic neuron fluorescence imaging fly imaging study in vivo in vivo imaging interest knock-down locomotor control mutant neuropsychiatric disorder neurotransmission new therapeutic target novel novel therapeutics null mutation optogenetics postsynaptic postsynaptic neurons receptor relating to nervous system response selective expression sensor synaptic function transmission process trauma exposure two-photon

项目摘要

PROJECT ABSTRACT/SUMARY Adhesion G-protein coupled receptors (GPCRs) are the second largest class of GPCRs yet their functions and ligands remain predominantly unidentified. Polymorphisms in the gene encoding the adhesion GPCR ADGRL3 have been associated with an increased risk for substance use disorder and attention deficit hyperactivity disorder in various linkage and association studies. Disrupting the function of the ADGRL3 homologs leads to hyperactivity in four different model systems – zebrafish, fruit flies, mice, and rats. In addition to hyperactivity, ADGRL3 knockout mice have higher dopamine levels in forebrain motor regions as well as increased sensitivity to the stimulant cocaine, which acts on the dopamine transporter. Together with dopamine’s established role in mediating locomotion, these findings suggest that ADGRL3 contributes to behavior by modulating dopamine signaling; however, a mechanistic link has yet to be established. The goal of this proposed research is to investigate the synaptic mechanisms that underlie ADGRL3 function in dopaminergic circuits using Drosophila as a model system. I have replicated the hyperactive phenotype in fruit flies that carry a null mutation for the ADGRL3 homolog, Cirl. To directly assay the role of Cirl in neurotransmission, I activated dopamine neurons acutely and found that Cirl null flies were much more sensitive to dopamine neurotransmission. Intriguingly, activating dopamine neurons in Cirl null flies throughout development rescued Cirl null hyperactivity to control levels, indicating that tonic dopamine neurotransmission during development may compensate for lack of Cirl function. To test whether Cirl functions in dopamine neurons to modulate activity, I reintroduced Cirl expression in dopamine neurons in the Cirl null background and instead found that this exacerbated the hyperactive phenotype. Thus, the hyperactivity seen in Cirl null mutants is likely not mediated by its absence from dopamine neurons, but rather in a separate population of neurons in which Cirl normally acts to reduce activity. My imaging studies have revealed that Cirl is expressed post-synaptically throughout the brain, and additionally localizes to the central complex which is involved in locomotion and motor planning and receives dense dopaminergic input. This proposal aims to first identify the dopamine neuron or group of neurons that induces hyperactivity when acutely activated, and identify their synaptic contacts in the central complex. Once I have identified this circuit, I will use optogenetics, in combination with in vivo 2-photon imaging of fluorescent biosensors to delineate the pre and postsynaptic changes in this circuit responsible for the hyperactive response to dopamine neuron activation during adulthood, as well as the reversal of this phenotype in Cirl null flies subjected to continuous dopamine neuron activation throughout development. These results will delineate how an adhesion GPCR modulates dopamine neurotransmission in vivo, and identify a novel therapeutic target for disorders caused by dysregulation of dopaminergic activity such as substance use disorder.

项目摘要/Sumary 粘附G蛋白偶联受体（GPCR）是第二大GPCR类，但它们的功能和配体仍然主要是身份不明的。编码粘合剂GPCR ADGRL3的基因中的多态性与药物使用障碍和注意力不足多动症的风险增加有关各种联系和关联研究中的疾病。破坏ADGRL3同源物的功能导致四种不同模型系统的多动症 - 斑马鱼，果蝇，小鼠和大鼠。除了多动症之外 ADGRL3敲除小鼠在前脑运动区域中具有较高的多巴胺水平，并提高了灵敏度刺激可卡因，该可卡因作用于多巴胺转运蛋白。以及多巴胺在这些发现介导运动，表明ADGRL3通过调节多巴胺有助于行为信号传导；但是，机械链接尚未建立。这项拟议研究的目的是研究使用ADGRL3在多巴胺能回路中起作用的突触机制果蝇作为模型系统。我已经复制了携带无效的水果蝇中的多动活跃表型 adgrl3同源物的突变，cirl。为了直接主张cirl在神经传递中的作用，我激活了多巴胺神经元敏锐地发现cirl null Flies对多巴胺更为敏感神经传递。有趣的是，在整个发育过程中激活cirl null蝇中的多巴胺神经元恢复对控制水平的无效无效，表明在发育过程中有多巴胺神经传递可能会弥补缺乏cirl功能。为了测试cirl是否在多巴胺神经元中起作用以调节活性，我在cirl null背景中重新引入了多巴胺神经元中的cirl表达，而是发现这是加剧了多活跃表型。那就是cirl null突变体中看到的多动症可能未介导由于它缺乏多巴胺神经元，而是在单独的神经元中，在这种神经元中通常是cirl 动作减少活动。我的影像学研究表明，cirl在整个过程中以后表达大脑，并在与运动和运动计划有关的中央建筑群中本地化以及接收致密的多巴胺能输入。该建议旨在首先识别多巴胺神经元或神经元组当急性激活时，这会影响多动症，并确定其在中央复合物中的突触接触。一旦确定了该电路，我将使用光遗传学，并结合体内2光片成像荧光生物传感器描绘该电路中的前和突触后变化负责对成年期多巴胺神经元激活的多动反应，以及这种表型的逆转在整个发育过程中受到连续多巴胺神经元激活的cirl零蝇。这些结果将会描述粘附GPCR如何在体内调节多巴胺神经传递，并识别一种新颖由多巴胺能活性失调（例如药物使用障碍）引起的疾病的治疗靶标。