Development of Fluorescent False Neurotransmitters

 描述（由申请人提供）：单胺神经递质（多巴胺、去甲肾上腺素和5-羟色胺）通过激活相应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。单胺神经元将其轴突投射到整个大脑，并调节各种大脑功能，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性。单胺神经传递的异常与许多神经和神经精神障碍有关，包括帕金森病、精神分裂症、ADHD、药物成瘾、抑郁症和焦虑症。然而，由于方法上的限制，单胺神经传递仅在单胺能突触的大集合体水平上进行了研究。目前还没有实验工具来研究单个突触前终扣的单胺释放特性，这是一个基本的生理参数。Dalibor Sames博士（PI-1）和大卫苏尔寿博士（PI-2）建立了一个跨学科的研究计划，专注于解决这一挑战。具体来说，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。这项新的应用旨在将FFN概念的范围扩展到整个单胺系统，许多不同的大脑区域和活体啮齿动物。我们建议开发FFN探针选择性去甲肾上腺素和5-羟色胺突触，并在活体显微成像方法适用于活的啮齿动物。提出的新的成像方法将使，第一次，在体内的几个脑区（纹状体，体感皮层，海马）的特定神经化学类型的单个突触前终端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解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去调节。FFN探针与现有的钙和电压传感器兼容，因此这些工具将共同提供完整电路中突触功能和可塑性的更完整读数。

 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.