Development of Fluorescent False Neurotransmitters

 描述(申请人提供)：单胺类神经递质(多巴胺、去甲肾上腺素和5-羟色胺)通过激活相应的受体，在调节兴奋性和抑制性神经传递强度方面发挥重要作用。单胺神经元在整个大脑中投射轴突，调节不同的大脑功能，包括唤醒、压力、情绪、奖励、学习和认知。在细胞水平上，单胺调节靶细胞和突触的反应。单胺类神经传递的异常与许多神经和神经精神疾病有关，包括帕金森氏症、精神分裂症、多动症、药物成瘾、抑郁和焦虑。然而，由于方法学的限制，单胺类神经传递的研究仅限于大型单胺类突触的整体水平。目前还没有实验工具来检测单个突触前突触的单胺释放特性，这是一个基本的生理参数。Dalibor Smes博士(PI-1)和David Sulzer博士(PI-2)建立了一个跨学科的研究计划，专注于解决这一挑战。具体地说，被称为“荧光假神经递质”(FFN)的光学探针被设计为多巴胺的示踪剂。这一新的应用旨在将FFN概念的范围扩大到整个单胺系统、许多不同的大脑区域和活的啮齿动物。我们建议开发选择性地检测去甲肾上腺素和5-羟色胺突触的FFN探针，以及适用于活体啮齿动物的显微成像方法。拟议的新成像方法将首次实现在体内几个大脑区域(纹状体、体感皮质、海马体感觉皮质)特定神经化学类型的单个突触前终末的突触内容释放的可视化。这些新的探针和相关的成像方法将揭开解决许多长期存在的问题的可能性，这些问题涉及单个突触的释放特性及其在啮齿动物疾病模型中的生理调节和解除调节。FFN探头与现有的钙和电压传感器兼容，因此这些工具将联合提供更完整的突触功能和完整电路中的可塑性读数。

 DESCRIPTION (provided by applicant): Monoamine neurotransmitters (dopamine, norepinephrine, and serotonin) play important roles in modulating the strength of both excitatory and inhibitory neurotransmission via activation of the corresponding receptors. Monoamine neurons project their axons throughout the brain and regulate diverse brain functions including arousal, stress, emotion, reward, learning, and cognition. On a cellular level, monoamines modulate responsiveness of the target cells and synapses. Aberrations in monoamine neurotransmission have been implicated in numerous neurological and neuropsychiatric disorders including Parkinson's disease, schizophrenia, ADHD, drug addiction, depression, and anxiety. However, due to methodological limitations, monoamine neurotransmission have only been studied on the bulk level of large ensembles of monoaminergic synapses. There have been no experimental tools to examine the monoamine release characteristics of individual presynaptic boutons, a fundamental physiological parameter. Drs. Dalibor Sames (PI-1) and David Sulzer (PI-2) established an interdisciplinary research program focused on addressing this challenge. Specifically, optical probes termed "Fluorescent False Neurotransmitters" (FFNs) were designed as tracers of dopamine. This new application aims to expand the scope of the FFN concept to the entire monoamine system, many different brain areas, and living rodents. We propose to develop FFN probes selective for norepinephrine and serotonin synapses, and in vivo microscopic imaging methods applicable in living rodents. The proposed new imaging methods will enable, for the first time, visualization of synaptic content release at individual presynaptic terminals of specific neurochemical types in vivo in several brain areas (striatum, somatosensory cortex, hippocampus). These new probes and associated imaging methods will unlock the possibility of addressing many long-standing questions about release properties of single synapses and their physiological regulation and deregulation in rodent disease models. The FFN probes are compatible with the existing calcium and voltage sensors and thus jointly these tools will provide a more complete readout of synaptic function and plasticity in intact circuitry.