Probing GABAa receptor function and plasticity with light

用光探测 GABAa 受体功能和可塑性

• 批准号: 9286699
• 负责人: RICHARD H KRAMER
• 金额: $ 48.84万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-04-15 至 2021-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9286699
• 关键词: Alcoholism; Alzheimer' s Disease; Anxiety; Bipolar Disorder; Brain; Brain Diseases; Brain region; Cell Culture Techniques; Cell membrane; Chemicals; Development; Disease; Distal; Ensure; Epilepsy; GABA Receptor; Genetic; Glutamate Receptor; Glutamates; Goals; Hippocampus (Brain); Hot Spot; Individual; Inhibitory Synapse; Interneurons; Intrabody; Knock-in Mouse; Knowledge; Label; Lateral; Learning; Learning Disorders; Light; Long-Term Depression; Long-Term Potentiation; Longevity; Maps; Measures; Mediating; Membrane; Memory; Memory Disorders; Mental Depression; Mus; N-Methyl-D-Aspartate Receptors; Neurons; Neurotransmitters; Photosensitivity; Photosensitization; Physiological; Play; Process; Protein Isoforms; Receptor Signaling; Role; Scaffolding Protein; Schizophrenia; Site; Sleeplessness; Specific qualifier value; Specificity; Stroke; Synapses; Synaptic Transmission; Synaptic plasticity; Time; Work; brain cell; cell type; chronic pain; gamma-Aminobutyric Acid; mutant; nervous system disorder; novel; receptor; receptor function; response; scaffold; synaptic function; tool; trafficking; treatment strategy; two-photon

GABA and glutamate are the main inhibitory and excitatory neurotransmitters in the brain. Activity-dependent redistribution of glutamate receptors contributes to excitatory long-term synaptic plasticity, learning and memory. A similar redistribution of GABAA receptors (GABAARs) has been shown to occur in neuronal culture, but the functional significance of this process in intact brain circuits remains unclear. Our goal is to better understand the role that GABAA receptors play in synaptic plasticity in the hippocampus, a brain region crucial for learning and memory. We have developed photoswitch chemicals that allow light to reversibly block GABAA receptors with high spatial and temporal precision and absolute specificity for a specified mutant α-subunit. Here we focus on receptors containing either the broadly- expressed α1-subunit, or the hippocampus-enriched α5-subunit. To enable photo-control of endogenous receptors, we have developed knock-in mice with photoswitch-ready version of α1 or α5 replacing their wild-type counterparts. Using these mice and novel intrabody probes that light-up or disrupt GABAARs scaffolds, we will evaluate where α1- and α5-GABAARs are in neurons, how they contribute to synaptic function, and what role they play in synaptic plasticity. Aim 1 is to map the distribution of the two GABAA types in hippocampal neurons. This includes determining whether they are expressed in proximal to distal dendritic gradients, determining whether they are aggregated at synapses or dispersed extrasynapatically, and determining their individual contributions to inhibitory synaptic transmission from different identified inhibitory interneurons. Aim 2 is to investigate how neuronal activity alters the distribution of GABAARs. This includes using the photoswitch as a stable tag to evaluate whether activity alters the lifespan and lateral mobility of the receptors on the plasma membrane. Aim 3 is to investigate how GABAARs alter excitatory long-term synaptic plasticity. This includes investigating the impact of the GABAARs on induction of long-term potentiation and depression and NMDA receptor signaling. The knowledge gained from this work will fill a gaping hole in our understanding of brain function and may reveal new treatment strategies for memory disorders and other neurological diseases. !

GABA和谷氨酸是大脑中的主要抑制性和兴奋性神经递质。 谷氨酸受体的活性依赖性重新分布有助于长期兴奋性 突触可塑性，学习和记忆。 GABAA接收器的类似重新分布 （Gabaars）已显示出在神经元培养中发生，但功能意义 完整的脑电路中的过程尚不清楚。我们的目标是更好地了解 GABAA接收器在海马中以突触可塑性发挥作用，这是一个至关重要的大脑区域 学习和记忆。我们开发了Photoswitch化学物质，使光可逆 阻断具有高空间和临时精度和绝对特异性的GABAA受体 指定的突变体α-亚基。在这里，我们专注于包含广泛的受体 表达α1-subunit或富含海马的α5-亚基。启用照片控制 内源性接收器，我们已经开发了使用Photoswitch Ready的α1的敲入小鼠 或α5取代其野生型对应物。使用这些小鼠和新颖的内部问题 点亮或破坏Gabaars脚手架，我们将评估α1和α5-Gabaar的位置 神经元，它们如何为突触功能做出贡献，以及它们在突触中的角色 可塑性。目的1是绘制海马神经元中两种GABAA类型的分布。 这包括确定它们是否在远端至远端树突状梯度中表达， 确定它们是在突触或分散外的汇总的，以及 确定他们对来自不同的抑制性突触传播的个人贡献 鉴定出抑制性中间神经元。目标2是研究神经元活动如何改变 加巴人的分布。这包括使用Photoswitch作为稳定标签来评估 活性是否会改变受体在血浆上的寿命和横向迁移率 膜。 AIM 3是研究Gabaars如何改变兴奋性长期突触 可塑性。这包括研究加巴人对诱导长期的影响 增强和抑郁以及NMDA受体信号传导。从中获得的知识 工作将在我们对大脑功能的理解中填补一个巨大的漏洞，并可能揭示新的 记忆障碍和其他神经系统疾病的治疗策略。 呢