Synaptic Dissection of Cell Adhesion Molecule Function within Subicular Circuits

毛细血管内细胞粘附分子功能的突触解剖

• 批准号: 9171969
• 负责人: Jason Aoto
• 金额: $ 24.88万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-02-24 至 2018-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9171969
• 关键词: Acute; Adverse effects; Affect; Alternative Splicing; Behavior; Biological; Biological Assay; Brain; Cell Adhesion Molecules; Cells; Corpus striatum structure; DRD2 gene; Data; Development; Disease; Dissection; Dopamine; Dorsal; Drug Addiction; Economic Burden; Effectiveness; Electrophysiology (science); Etiology; Family; Foundations; Functional disorder; Future; Gene Expression Profiling; Generations; Genetic; Genome; Genomics; Goals; Grant; Health; Hippocampus (Brain); Human; Hyperactive behavior; Impaired cognition; Impulsivity; Individual; Infection; Interneurons; Label; Light; Link; Measures; Mediating; Mental Depression; Mental disorders; Mentors; Messenger RNA; Methods; Modeling; Molecular; Mus; Mutant Strains Mice; Mutation; Neurons; Nucleus Accumbens; Output; Patients; Phase; Play; Probability; Property; Protein Isoforms; RNA Splicing; Recruitment Activity; Regulation; Research; Rewards; Rhodopsin; Schizophrenia; Shapes; Signal Transduction; Site; Slice; Specific qualifier value; Stress; Structure; Synapses; Synaptic Membranes; Synaptic Transmission; Synaptic plasticity; Techniques; Technology; Testing; Training; Virus; base; cell type; differential expression; dopamine system; gene product; hippocampal pyramidal neuron; in vivo; insight; knock-down; mutant; neuropsychiatric disorder; novel; novel therapeutics; optogenetics; postsynaptic; presynaptic; recombinase; research study; screening; small hairpin RNA; social; synaptic function; tool; transcriptome sequencing; transcriptomics; transmission process; treatment strategy

DESCRIPTION (provided by applicant):Increasing evidence suggests that abnormalities in synaptic transmission in disease-relevant brain circuits likely contribute to the etiologies that underlie neuropsychiatric disorders. Thus, the essential question: how are circuit-level synaptic properties specified and maintained? Molecularly, synaptic cell adhesion molecules (SCAMs) are prime candidates because they often span the pre- and post-synaptic membrane, physically link both terminals and initiate intracellular signaling cascades to recruit key synaptic molecules to the synapse. Moreover, genomic studies have mutations in many of these molecules that are associated with psychiatric diseases. Mutations unique to neurexin-3 (Nrxn3), an essential presynaptic SCAM, have been linked to schizophrenia (SZ) and drug addiction in humans. These disorders are associated with an enormous social and economic burden and share a common pathophysiological basis of dopamine dysregulation due to hyperactivity in the ventral subiculum (vSub) - nucleus accumbens (NAc) shell circuit. Hyperactivity of this circuit can be caused by changes in synaptic transmission in the vSUB-NAc projection circuit or in the ventral subiculum local circuit. Despite the obvious importance of the vSUB-NAc shell circuit, a molecular and synaptic understanding of this circuit is lacking. Thus, the hypothesis that neurexin-3 plays critical, cell-type specific and nonredundant functions to shape projection and local subicular circuitry that are essential for dopamine regulation will be tested in this proposal. Aim 1 will investigate how Nrxn3 is utilized by the two types of vSUB projection neurons that innervate D1R or D2R expressing MSNs in the NAc shell. A fundamental understanding of the cell-type specific connectivity between the vSUB and NAc shell and how Nrxn3 shapes these excitatory synaptic properties is unexplored; thus, the dissection of cell-type specific pre- and post-synaptic functions of subicular neurons within this disease circuit may open new avenues for treatment strategies. Aim 2 will build on preliminary RNA-seq data generated during the K99 training phase that revealed Nrxn3 isoform expression is strongly differentially regulated in two distinct subsets of hippocampal GABAergic interneurons. We will dissect the poorly understood cell-type specific local circuit in the subiculum and how discrete Nrxn3 gene products are utilized to shape cell-type specific synaptic transmission. Aim 3 will characterize the transcriptional profiles of electrophysiologically distinct pyramidal neurons in the subiculum using a single-cell RNA-seq approach. This unbiased approach will allow for the identification of differential, cell-type specific disease-relevant SCAM expression for future study and for the generation of genetic tools to facilitate the dissection of the subiculum. The molecular interrogation of Nrxn3 in the local and projection subicular circuit will provide the first insight into the disease-relevance of neurexin-3 and will further our understanding of neurexin function in general and will lay the foundation for future studies.

描述(申请人提供)：越来越多的证据表明，与疾病相关的大脑回路中突触传递的异常可能是神经精神障碍的病因之一。因此，最基本的问题是：电路级突触的属性是如何指定和维持的？在分子水平上，突触细胞黏附分子(SCAM)是主要的候选分子，因为它们通常跨越突触前膜和突触后膜，在物理上连接两端，并启动细胞内信号级联，以招募关键突触分子到突触。此外，基因组研究发现，这些分子中有许多与精神疾病有关。NRXN3(NRXN3)是一种基本的突触前骗局，它的独特突变与人类精神分裂症(SZ)和药物成瘾有关。这些疾病与巨大的社会和经济负担有关，并且具有共同的病理生理学基础，即由于腹侧下丘(VSub)-伏核(Nac)外壳回路的过度活动而引起的多巴胺失调。VSuB-Nac投射回路或腹侧丘脑局部回路中突触传递的改变可引起该回路的过度活动。尽管vSUB-NAC壳层回路的重要性显而易见，但对该回路的分子和突触方面的了解还很缺乏。因此，关于neuresin-3发挥关键的、细胞类型特定的和非冗余的功能来塑造投射和局部亚核回路的假设将在这项提案中得到验证，这些功能对多巴胺的调节是必不可少的。目的1研究NAC壳中表达MSN的D1R和D2R的两种vSUB投射神经元如何利用NRXN3。对vSuB和NAC外壳之间的细胞类型特异性连接以及NRXN3如何塑造这些兴奋性突触属性的基本了解尚不清楚；因此，对这一疾病回路中亚神经元细胞类型特异性突触前和突触后功能的剖析可能为治疗策略开辟新的途径。目的2将建立在K99训练阶段产生的初步RNA-SEQ数据的基础上，该数据表明NRXN3异构体在海马GABA能中间神经元的两个不同亚群中的表达有很强的差异调节。我们将剖析在下丘脑中知之甚少的细胞型特异性局部电路，以及离散的NRXN3基因产物如何被用来塑造细胞型特异性突触传递。目的3将使用单细胞RNA-SEQ方法描述电生理上不同的下丘脑锥体神经元的转录图谱。这种不偏不倚的方法将允许识别差异的，细胞类型的特定疾病相关的骗局表达，用于未来的研究，并产生有助于解剖下丘的遗传工具。对NRXN3在局部和投射亚神经回路中的分子询问将为我们提供对neuresin-3与疾病相关性的第一个洞察力，并将加深我们对neuresin功能的总体理解，并为未来的研究奠定基础。