Dissecting Mechanisms of Striatal Acetylcholine Transmission in the Vertebrate Brain

解析脊椎动物大脑中纹状体乙酰胆碱传输的机制

• 批准号: 10685277
• 负责人: Kathleen Allison Beeson
• 金额: $ 7.2万
• 依托单位: HARVARD MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10685277
• 关键词: Ablation; Acetylcholine; Affect; Area; Axon; Basal Ganglia; Behavior; Brain; Brain imaging; Calcium; Calcium Channel; Central Nervous System; Cholinergic Receptors; Complex; Corpus striatum structure; Data; Disease; Distant; Dopamine; Electrophysiology (science); Elements; Enzymes; Exocytosis; Functional Imaging; Genes; Genetic; Goals; Health; Interneurons; Learning; Locomotion; Measurement; Measures; Messenger RNA; Modeling; Molecular; Morphology; Motivation; Mus; Nerve; Nervous System Physiology; Neuromodulator; Neuromuscular Junction; Neurons; Nicotinic Receptors; Phase; Phospholipids; Proteins; Rewards; Signal Transduction; Site; Slice; Structure; Synapses; System; Testing; Tissue imaging; Tissues; Transcript; Transgenic Organisms; Varicosity; Vesicle; Work; brain volume; cholinergic; conditional knockout; esterase; fluorescence imaging; insight; mouse genetics; nano; neuroregulation; presynaptic; receptor; scaffold; secretory protein; sensor; social cognition; spatial relationship; superresolution microscopy; synaptotagmin I; tool; transmission process; vesicular release

PROJECT SUMMARY Acetylcholine critically controls complex neurological functions through its modulation of brain circuits. In contrast to the well-studied mechanisms of acetylcholine signaling at the neuromuscular junction, its transmission modes and mechanisms in the vertebrate central nervous system are not well understood. In the striatum, acetylcholine exerts rapid and powerful control over local dopaminergic activity. Together, these neuromodulators regulate a variety of important behaviors, including motivation and reward-related learning. Because acetylcholine is rapidly degraded after it is released in striatal tissues, the fidelity of acetylcholine to dopamine signaling must involve either tight spatial relationships between release sites and receptors, and/or fast transmission. However, neuromodulator signaling is classically modeled as occurring through volume transmission, involving dispersed, non-specific release as opposed to synaptic, point-to-point signaling – a concept that remains to be proven. Furthermore, the molecular mechanisms underlying striatal acetylcholine signaling remain elusive. I hypothesize that sparse cholinergic terminals require molecular elements for highly synchronous acetylcholine release. In this scenario, rapid and precise vesicle release could produce a synchronous wave of high-concentration acetylcholine, which might allow even distant receptors to sense this signal with potency. To test this hypothesis, I propose to examine the morphological and molecular substrate of striatal acetylcholine transmission in two aims. First, I will dissect the structure of acetylcholine to dopamine signaling in the striatum, including the presence of secretory machinery in acetylcholine nerve terminals and their apposition to acetylcholine receptors on dopamine axons, using superresolution microscopy. In a second aim, I will functionally test whether acetylcholine release onto dopamine axons requires secretory proteins that are predestined to generate fast and precise release, enabling phasic acetylcholine transmission. Additionally, I will determine how this transmission mode impacts subsequent dopamine signaling. To do this, I will use genetic tools paired with simultaneous imaging of fluorescent acetylcholine sensors and amperometric dopamine measurements in striatal slices. Together, these findings will inform our fundamental understanding of cholinergic to dopaminergic signaling in the striatum, including the identification of important genes that regulate acetylcholine transmission. This molecular-level understanding will ultimately be important to better understand brain function and disease.

项目摘要 乙酰胆碱通过调节脑电路严格控制复杂的神经功能。在 与神经肌肉连接处乙酰胆碱信号传导的良好研究机制形成对比， 脊椎动物中枢神经系统中的传播模式和机制尚不清楚。在 纹状体，乙酰胆碱对局部多巴胺能活性产生快速而有力的控制。在一起，这些 神经调节剂调节各种重要行为，包括动机和与奖励相关的学习。 因为乙酰胆碱在纹状体组织中释放后迅速降解，所以乙酰胆碱的保真度 多巴胺信号必须涉及释放站点和接收器之间的紧密空间关系，和/或 快速传输。然而，神经调节剂信号传导经典建模为通过体积发生 传输，涉及分散的，非特异性释放，而不是突触，点对点信号 - A 尚待证明的概念。此外，纹状体乙酰胆碱的分子机制 信号仍然难以捉摸。我假设稀疏的胆碱能末端需要分子元素才能高度 同步乙酰胆碱释放。在这种情况下，快速而精确的囊泡释放可能会产生 高浓度乙酰胆碱的同步波，这可能允许遥远的接收器感知到这一点 信号具有效力。 为了检验该假设，我建议检查纹状体的形态和分子底物 乙酰胆碱在两个目标中的传播。首先，我将剖析乙酰胆碱的结构对多巴胺信号传导 在纹状体中，包括乙酰胆碱神经末端中的秘密机械及其 使用上分辨率显微镜在多巴胺轴突上使用乙酰胆碱受体的方法。在第二个目标中，我 将在功能上测试乙酰胆碱是否释放到多巴胺轴突上需要秘书蛋白 注定要生成快速，精确的释放，从而实现阶段乙酰胆碱的传播。另外，我会的 确定这种传输模式如何影响随后的多巴胺信号传导。为此，我将使用通用 工具与荧光乙酰胆碱传感器和安培多巴胺的简单成像配对 纹状体切片的测量。这些发现将共同了解我们对 纹状体中的胆碱能与多巴胺能信号传导，包括鉴定重要基因 调节乙酰胆碱的传播。这种分子水平的理解最终对于更好的 了解大脑功能和疾病。