Molecular Mechanisms of Inhibitory Circuit Development

抑制电路发展的分子机制

基本信息

批准号：
8821673
负责人：
Patricia F Maness
金额：
$ 38万
依托单位：
UNIV OF NORTH CAROLINA CHAPEL HILL
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：
2014-04-01 至 2019-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8821673
关键词：
Area Autistic Disorder Behavior Behavior assessment Binding Binding Sites Brain Brain Diseases Cell Adhesion Molecules Cell surface Cells Cerebral cortex Cognitive deficits Complex Cues Development Disease Endocytosis Equilibrium Etiology Extracellular Domain Functional disorder Goals Health Image Immunoglobulins Inherited Inhibitory Synapse Interneurons Learning Life Maps Measures Mediator of activation protein Metalloproteases Microscopy Mission Molecular Mus Mutant Strains Mice Myoepithelial cell NCAM1 gene Neural Cell Adhesion Molecules Neurodevelopmental Disorder Outcome Study Output Performance Phosphotransferases Prefrontal Cortex Presynaptic Receptors Protein Tyrosine Kinase Public Health Pyramidal Cells Receptor Protein-Tyrosine Kinases Regulation Research Resolution Role Sampling Schizophrenia Short-Term Memory Signal Transduction Slice Synapses Synaptic plasticity Technology Testing Time United States National Institutes of Health Work autism spectrum disorder base cognitive function equilibration disorder genetic association hippocampal pyramidal neuron information processing innovation mutant nerve supply neurodevelopment neuropsychiatry novel optogenetics postsynaptic presynaptic promoter receptor synaptic function two-photon

项目摘要

DESCRIPTION (provided by applicant): There is a fundamental gap in understanding how an appropriate balance of excitatory and inhibitory (E/I) connectivity is achieved during development of cortical networks and adjusted through synaptic plasticity for normal functioning of the cerebral cortex. Until this gap is filled, understanding neuropsychiatric disorders with GABAergic inhibitory connection deficits, such as schizophrenia and autism, will remain a mystery. The long term goal is to identify the molecular mechanisms that establish E/I balance in the prefrontal cortex, which may identify new targets for disorders where this balance is altered. The objective is to define a novel mechanism for limiting inhibitory connections between basket interneurons and the perisomatic region of pyramidal neurons in developing prefrontal cortex. The central hypothesis is that neural cell adhesion molecule NCAM, tyrosine kinase EphA3, and ADAM10 metalloprotease comprise a presynaptic receptor complex for postsynaptic ephrinA5 that promotes elimination of perisomatic synapses critical for proper prefrontal network organization and functioning, such as in working memory. Aim 1. To identify a novel molecular mechanism for limiting perisomatic basket cell innervation in the developing mouse prefrontal cortex through NCAM-dependent ephrinA5/EphA3 signaling We will identify NCAM/EphA3 binding sites, assess the ability of NCAM to stabilize EphA3 on the cell surface by inhibiting endocytosis and promoting ephrinA5-induced EphA3 kinase signaling, and define the developmental and activity-dependent regulation of ephrinA5 in mouse prefrontal cortex. Aim 2. To define presynaptic and postsynaptic functions of NCAM, ephrinA5/EphA3, and ADAM10 metalloprotease in perisomatic inhibitory synapse regulation Analysis of new conditional NCAM and ADAM10 mutant mice and cell-specific expression in brain slices will distinguish pre- versus post-synaptic functions for NCAM, ephrinA5/EphA3, and ADAM10, and test causal roles for their interactions in perisomatic synapse regulation. Dynamics of inhibitory synapse elimination will be analyzed by time-lapse two-photon microscopy in cortical slice cultures. Aim 3. To delineate the contribution of NCAM to prefrontal cortical network organization and function using optogenetic mapping and behavioral assessment of working memory. Optogenetic mapping will be performed in brain slices from NCAM null and conditional mutant mice expressing channelrhodopsin-2 from the VGAT promoter in interneurons. Working memory performance will be measured in live mice by the delayed non-match-to-sample T-maze task. The outcome of these studies is expected to have a sustained, positive impact, because it will illuminate novel molecular mechanisms of interneuronal connectivity that control cognitive function, while innovative optogenetic technology will elucidate cortical networks targeted in neurodevelopmental disorders.

描述（由申请人提供）：了解在开发皮质网络期间如何实现兴奋性和抑制性（E/I）的适当平衡的基本差距，并通过突触可塑性进行调整以使大脑皮层的正常功能调整。在填补这一差距之前，了解具有GABA能抑制性连接缺陷的神经精神疾病，例如精神分裂症和自闭症，将仍然是一个谜。长期目标是确定在前额叶皮层中建立E/I平衡的分子机制，该机制可能会确定改变这种平衡的新目标。目的是定义一种新的机制，用于限制篮子中间神经元与锥体神经元的围核区域之间的抑制性连接，以发展前额叶皮层。中心假设是，神经细胞粘附分子NCAM，酪氨酸激酶EPHA3和ADAM10金属蛋白酶构成了突触后ephrina的突触前受体复合物，可促进消除对适当的前胎儿网络组织和功能（例如在工作中的工作中）至关重要的periastomation themotical蛋白酶。目的1。确定一种新型的分子机制，用于通过NCAM依赖性ephrina5/epha3信号来限制发育中的小鼠前额叶皮层中的周期性篮细胞支配，我们将确定NCAM/EPHA3结合位点，评估NCAM通过抑制EPHAS稳定EPHA3的能力，并抑制EPHA3的能力。并定义小鼠前额叶皮层中埃菲琳娜5的发育依赖性调节。目的2。定义NCAM，Ephrina5/epha3和ADAM10金属蛋白酶在周性抑制性突触调节中的新条件NCAM和ADAM10突变体和细胞特异性表达中的NCAM和ADAM10金属蛋白酶在大脑slices中的新抑制突触调节分析中，将在脑slice中和S-synaps pre-ncaM的EDAM，EDAM和EDAM，EDAM和EDAM的EPHRINAS，测试因果作用，以使其在perisation骨突触调节中的相互作用。抑制性突触消除的动力学将通过皮质切片培养物中的延时两光子显微镜来分析。目的3。使用光遗传学映射和工作记忆行为评估，描绘NCAM对前额叶皮层网络组织的贡献和功能。光遗传学映射将在NCAM无效的大脑切片中进行，并从中间神经元中的VGAT启动子表达通道Ropopsin-2的条件突变小鼠。工作记忆性能将通过延迟的非匹配样本T-Maze任务在活小鼠中测量。这些研究的结果有望产生持续的积极影响，因为它将阐明控制认知功能的新型分子机制，而创新的光遗传学技术将阐明针对神经发育障碍的皮质网络。