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。 谷氨酸受体的活动依赖性重新分布有助于长期兴奋 GABAA 受体的类似重新分布。 （GABAAR）已被证明存在于神经培养中，但其功能意义 完整大脑回路中的过程仍不清楚，我们的目标是更好地了解其作用。 GABAA 受体在海马体的突触可塑性中发挥作用，海马体是大脑的重要区域。 我们开发了光开关化学物质，可以让光可逆地传播。 以高空间和时间精度和绝对特异性阻断 GABAA 受体 在这里，我们重点关注含有广泛的突变α亚基的受体。 表达的α1-亚基，或海马体富集的α5-亚基，以实现光控制。 内源性受体，我们开发了具有光开关就绪版本 α1 的敲入小鼠 或 α5 取代其野生型磅 使用这些小鼠和新型体内探针 点亮或破坏 GABAAR 支架，我们将评估 α1- 和 α5-GABAAR 的位置 神经元，它们如何促进突触功能，以及它们在突触中发挥什么作用 目标 1 是绘制海马神经元中两种 GABAA 类型的分布图。 这包括确定它们是否以近端到远端树突梯度表达， 确定它们是聚集在突触处还是分散在突触外，以及 确定不同个体对抑制性突触传递的贡献 目标 2 是研究神经活动如何改变抑制性中间神经元。 GABAAR 的分布。这包括使用光开关作为稳定标签来评估。 活动是否会改变血浆上受体的寿命和横向移动性 目标 3 是研究 GABAAR 如何改变兴奋性长期突触。 这包括研究 GABAAR 对长期诱导的影响。 增强和抑制以及 NMDA 受体信号转导从中获得的知识。 这项工作将填补我们对大脑功能理解的一个空白，并可能揭示新的东西 记忆障碍和其他神经系统疾病的治疗策略。 ！