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和谷氨酸是大脑中主要的抑制性和兴奋性神经递质。 谷氨酸受体活性依赖的重新分布有助于兴奋性的长期 突触可塑性、学习和记忆。GABAA受体的类似重新分布 (GABAARs)已被证明存在于神经元培养中，但其功能意义 完整的大脑回路中的过程仍不清楚。我们的目标是更好地理解 GABAA受体在海马区的突触可塑性中发挥作用，海马区是大脑中 学习和记忆。我们已经开发出一种光开关化学物质，可以使光可逆地 阻断GABAA受体具有高时空精确度和绝对特异性 指定的突变体α亚单位。在这里，我们将重点放在包含广泛的- 表达α1亚基，或海马区丰富的α5亚基。启用照片控制功能的步骤 内源性受体，我们已经用光开关就绪版本的α1建立了敲入小鼠 或者α5取代了野生型。使用这些小鼠和新的体内探测器 点亮或破坏GABAAR脚手架，我们将评估α1-和α5-GABAAR在哪里 神经元，它们如何对突触功能做出贡献，以及它们在突触中扮演什么角色 可塑性。目的1定位两种类型的GABAA在海马神经元中的分布。 这包括确定它们是否在远端树突状梯度的近端表达， 确定它们是聚集在突触处还是分散在突触外，以及 确定它们在抑制性突触传递中的个体贡献 鉴定出抑制性中间神经元。目标2是研究神经元活动是如何改变 伽巴尔的分布。这包括使用光开关作为稳定的标签来评估 活性是否改变了血浆受体的寿命和侧向迁移率 薄膜。目标3是研究GABA受体如何改变兴奋性长时程突触 可塑性。这包括调查GABAARs对诱导长期 增强和抑制与NMDA受体信号转导。从这一过程中获得的知识 研究将填补我们对大脑功能理解的一个空白，并可能揭示新的 记忆障碍和其他神经疾病的治疗策略。 好了！