Development of Visual Connections

视觉联系的发展

基本信息

批准号：
9477657
负责人：
Carla J Shatz
金额：
$ 41.28万
依托单位：
STANFORD UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
1979
资助国家：
美国
起止时间：
1979-01-01 至 2021-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9477657
关键词：
APP-PS1 Adolescent Adult Affinity Age Aging Alleles Alzheimer&apos s Disease Alzheimer&apos s disease model Amaze Amblyopia Amino Acids Amyloid beta-Protein Anatomy Animal Model Appearance Binding Blindness Brain Cells Cerebral cortex Child Clinical Dendritic Spines Development Disease Electroporation Engineering Epitopes Expression Profiling Functional disorder Genotype Goals Growth Hippocampus (Brain)Histocompatibility Human Image Immune Immunoglobulins Knock-out Knockout Mice Knowledge Laboratories Learning Life Ligand Binding Ligands Measures Memory Memory Loss Methods Molecular Mus Natural regeneration Neurodegenerative Disorders Neurons Ocular Dominance Outcomes Research Pathogenicity Peptides Photons Physiological Process Prosencephalon Protein Engineering Proteins Reagent Recombinant Proteins Recombinants Recovery Regulation Research Research Proposals RiboTag Ribosomal Proteins Role Savings Signal Pathway Signal Transduction Sum Synapses Synaptic plasticity Techniques Testing Training Transcript Transgenic Mice Vertebral column Visual Cortex Visual system structure Work Yeasts abeta oligomer brain repair candidate identification cell type clinically relevant cofilin cognitive enhancement congenital cataract critical developmental period critical period density design experience experimental study functional restoration hippocampal pyramidal neuron in utero in vivo imaging mRNA Expression mouse model neural circuit new therapeutic target novel novel therapeutics prevent public health research receptor repaired restoration transcriptome transcriptome sequencing vision development visual deprivation

项目摘要

7. Project Summary What enables a baby's brain to learn so rapidly during early developmental critical periods? Is it possible to re- engage in adult the enhanced learning capacity present in the child's brain for repair or restoration of function? We have discovered that a neuronal receptor called PirB (Paired Immunoglobulin-like receptor B; human LilrB2/3) regulates synapse pruning and plasticity in cerebral cortex. Blocking PirB function in visual cortex rapidly leads to new dendritic spines and functional synapses even in adult. These observations have clinical relevance. A hallmark of Alzheimer's disease (AD) is loss of plasticity and excessive synapse pruning. But when PirB is knocked out in a mouse model of AD, mice are protected from memory loss. Moreover, new synapses generated by PirB blockade can be captured to facilitate recovery from severe vision loss in Amblyopia. A major goal of this research proposal is to save or regenerate synapses by understanding cell and molecular mechanisms of how PirB regulates synapse pruning. Three specific aims are proposed. 1) Assess effects of PirB deletion on dendritic spine density and stability in visual cortex. We have generated mice with a conditional allele of PirB (PirB flox/flox). We have also made a soluble PirB function- blocking recombinant protein: sPirB. These mice and reagents permit cell-type specific and temporal disruption of PirB and will be used in 2 photon imaging and physiological studies of synapse pruning and spine turnover in cortical pyramidal neurons. Results from these experiments should illuminate further how PirB regulates plasticity and synapse pruning in juvenile and adult visual cortex. 2) Investigate how PirB functions by using expression profiling to identify PirB signaling pathways. Preliminary experiments suggest that cofilin signaling contributes to PirB dependent regulation of dendritic spine density, and is hyperactivated in a mouse model of AD. Here an unbiased approach to identify PirB-driven alterations in mRNA expression is proposed. RiboTag mice will be used to isolate neuronal transcripts from PirB+/+ vs PirB-/- visual cortex. Using microarrays and RNAseq, the transcriptomes of the 2 genotypes will be analyzed and compared. This approach should facilitate identification of candidate signaling pathways regulated by PirB. 3) PirB and Alzheimer's disease- Engineer high affinity, specific blockers of the PirB-Abeta interaction. We have measured a direct interaction between PirB and soluble oligomers of beta amyloid (Abeta), the pathogenic 42 amino acid peptide in AD. The PirB-Abeta interaction represents a novel and potentially pivotal signaling axis. Protein engineering techniques including yeast display and affinity maturation will be used to create molecular entities able to block the Abeta-PirB (or Abeta-LilrB2 in human) interaction, potentially yielding new drug targets to treat AD. In sum, this proposal seeks to extend understanding of PirB function and dysfunction towards the ultimate goal of designing novel therapies that can regenerate lost synapses, thereby restoring function to neural circuits whose connections have been altered by abnormal experience or disease.

七、项目概要是什么让婴儿的大脑在早期发育关键期能够如此快速地学习？是否可以重新成人大脑中存在的增强学习能力可以修复或恢复功能吗？我们发现了一种称为 PirB（配对免疫球蛋白样受体 B；人类 LilrB2/3) 调节大脑皮层的突触修剪和可塑性。阻断视觉皮层中的 PirB 功能即使在成人中，也会迅速产生新的树突棘和功能性突触。这些观察结果具有临床意义关联。阿尔茨海默病 (AD) 的一个标志是可塑性丧失和突触过度修剪。但当 AD 小鼠模型中 PirB 被敲除时，小鼠的记忆力就不会丧失。此外，新可以捕获 PirB 阻断产生的突触，以促进严重视力丧失的恢复弱视。该研究计划的一个主要目标是通过了解细胞和突触来保存或再生突触。 PirB 如何调节突触修剪的分子机制。提出了三个具体目标。 1）评估 PirB 缺失对视皮层树突棘密度和稳定性的影响。我们已经生成了具有 PirB 的条件等位基因（PirB flox/flox）。我们还制备了可溶性 PirB 功能阻断重组体蛋白质：sPirB。这些小鼠和试剂允许对 PirB 进行细胞类型特异性和暂时性破坏，并将用于皮质锥体突触修剪和脊柱周转的 2 光子成像和生理学研究神经元。这些实验的结果应该进一步阐明 PirB 如何调节可塑性和突触青少年和成人视觉皮层的修剪。 2) 通过使用表达分析来研究 PirB 的功能识别 PirB 信号通路。初步实验表明 cofilin 信号传导有助于 PirB 树突棘密度的依赖性调节，并且在 AD 小鼠模型中过度激活。这里有一个提出了一种公正的方法来识别 PirB 驱动的 mRNA 表达变化。 RiboTag 小鼠将用于从 PirB+/+ 与 PirB-/- 视觉皮层分离神经元转录本。使用微阵列和 RNAseq，将分析和比较两种基因型的转录组。这种方法应该有助于识别 PirB 调节的候选信号通路。 3) PirB 和阿尔茨海默病 - 设计高亲和力， PirB-Abeta 相互作用的特异性阻断剂。我们测量了 PirB 和 β 淀粉样蛋白 (Abeta) 的可溶性低聚物，AD 中的致病性 42 个氨基酸肽。 PirB-阿贝塔相互作用代表了一种新颖且潜在关键的信号轴。蛋白质工程技术包括酵母展示和亲和力成熟将用于创建能够阻断 Abeta-PirB（或 Abeta-LilrB2 在人类中的相互作用，可能产生治疗 AD 的新药物靶点。总而言之，这个提案旨在扩展对 PirB 功能和功能障碍的理解，以实现设计新颖的最终目标可以再生丢失的突触的疗法，从而恢复其连接的神经回路的功能因异常经历或疾病而改变。