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（由申请人提供）：越来越多的证据表明，与疾病相关的脑电路中突触传播的异常可能有助于神经精神疾病的病因。因此，基本问题：如何指定和维护电路级突触性能？分子，突触细胞粘附分子（骗局）是主要候选物，因为它们通常跨越前和突触后膜，物理上末端并启动细胞内信号级联，以募集钥匙突触分子与突触。此外，基因组研究在许多与精神病有关的分子中都有突变。 Neurexin-3（NRXN3）是一种必需的突触前骗局，与人类的精神分裂症（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，并具有由于腹侧下调（VSUB） - 伏隔核（NAC）壳壳电路而导致多巴胺失调的常见病理生理基础。该电路的多动症可能是由于VSUB-NAC投影电路中突触传播的变化或腹侧下局部电路的变化。尽管VSUB-NAC壳电路显而易见，但仍缺乏对该电路的分子和突触理解。因此，在此提案中，将测试Neurexin-3的假说对多巴胺调节所必需的批判性，细胞类型的特异性和非冗余功能，以塑造投影和局部的亚微电路。 AIM 1将研究如何通过在NAC壳中支配D1R或D2R的两种类型的VSUB投影神经元使用NRXN3。对VSUB和NAC壳之间的细胞类型特异性连通性以及NRXN3如何塑造这些兴奋性突触特性的基本了解；因此，在该疾病回路内的细胞类型特异性前和突触后功能的解剖可能会为治疗策略开辟新的途径。 AIM 2将基于在K99训练阶段产生的初步RNA-seq数据，该训练阶段揭示了NRXN3同工型表达在两个不同的海马Gabaergic Interurons中的不同子集中受到强烈差异调节。我们将剖析较低的细胞类型特异性局部回路，以及如何利用离散的NRXN3基因产物来塑造细胞型特异性突触传播。 AIM 3将使用单细胞RNA-seq方法来表征亚致中电生理上不同锥体神经元的转录谱。这种无偏的方法将允许鉴定差异，细胞类型的特定疾病与疾病相关的骗局表达，并为未来的研究以及生成遗传工具的产生以促进亚基的解剖。 NRXN3在局部和投影下回路中对NRXN3的分子询问将为Neurexin-3的疾病 - 相关性提供首次见解，并将进一步了解我们对神经素功能的理解，并将为未来的研究奠定基础。