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再分布有助于兴奋性长期 突触可塑性、学习和记忆。GABAA受体的类似再分布 GABAARs）已被证明存在于神经元培养物中，但其功能意义尚不清楚。 完整的脑回路中的过程仍不清楚。我们的目标是更好地理解 GABAA受体在海马体的突触可塑性中起作用，海马体是一个对大脑发育至关重要的区域。 学习和记忆。我们已经开发出光开关化学物质， 阻断GABAA受体，具有高度的空间和时间精确度以及绝对的特异性， 特定突变α亚基。在这里，我们专注于受体含有广泛的- 表达的α1-亚基，或富含α5-亚基的α5-亚基。启用照片控制 内源性受体，我们已经开发了基因敲入小鼠与光敏开关准备版本的α1 或α5取代它们的野生型对应物。使用这些小鼠和新的胞内抗体探针， 点亮或破坏GABAARs支架，我们将评估α1-和α5-GABAARs在 神经元，它们如何有助于突触功能，以及它们在突触中扮演什么角色。 可塑性目的1：定位两种GABAA在海马神经元中的分布。 这包括确定它们是否在近端到远端树突梯度中表达， 确定它们是在突触处聚集还是在突触外分散，以及 确定它们各自对来自不同神经元的抑制性突触传递的贡献。 识别抑制性中间神经元。目的2是研究神经元活动如何改变 GABAAR的分布。这包括使用光电开关作为稳定标签来评估 活性是否改变血浆上受体的寿命和横向移动性 膜的目的3：研究GABAARs如何改变兴奋性长时程突触的功能， 可塑性这包括调查GABAAR对诱导长期 增强和抑制以及NMDA受体信号传导。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 记忆障碍和其他神经系统疾病的治疗策略。 !