Real-Time Measurements of Neurotransmission in Drosphilia melanogaster

项目总结 神经元信号如何控制行为？神经学家通过映射神经元来回答这个问题 电路，研究动作电位放电，或监测由此产生的神经化学物质的释放。果蝇是一种 用于绘制神经回路和研究先天行为(如进食)过程中的细胞放电的模型系统。直接 需要测量神经调节剂来了解行为调节，因为释放是高度 异质性和可塑性；即相同的放电模式在不同的脑内引起不同的神经调节剂释放 由于复杂的监管而导致的情况。了解神经调节如何调节行为或编码 记忆，我们需要工具来检查整个电路中的多个神经调节器。这个项目的目标是 开发研究果蝇喂糖过程中神经调节剂相互作用的新型复合工具。这个 中心假说是，多巴胺、章鱼胺和谷氨酸的神经调节只会发生在离散的 神经传导功能随喂糖频率的不同而不同，当糖与气味配对时，神经传导功能增强。这项研究 意义重大，因为它将开发工具来映射整个 电路，并使用这些工具来展示电路中的神经调节器如何相互作用控制食欲记忆 在喂糖的过程中形成。在目标1中，我们将开发新的纳米电极来同时检测章鱼和 用快速扫描循环伏安法(FSCV)测定蘑菇体(MB)G5中的多巴胺 喂糖过程中的隔室。章鱼胺对多巴胺的调节作用将通过选择性激活来测试 或者抑制特定的八胺能神经元。在目标2中，目标是了解多巴胺的神经调节 在跨MB隔间喂糖时。一种基因编码的多巴胺传感器(GRABDA)将是 选择性地在MB多巴胺神经元或前脑前内侧(PAM)投射中表达 在喂糖和嗅觉调节过程中记录到的神经元和多巴胺。在目标3中，神经调节将 通过测量G5中的多巴胺和章鱼胺来调节糖奖赏的整个回路 蘑菇体的隔室和蘑菇体输出神经元的谷氨酸信号转导(IGluSnFR) 在内侧前脑的上端。这些实验将是第一次将口蹄疫病毒和基因 编码传感器以了解蘑菇体内的多巴胺/章鱼胺调节如何控制输出 在电路中向下游发送信号。这项工作的预期结果是绘制神经调节剂的图谱 成年果蝇在进食和嗅觉调节过程中环路的相互作用。积极的影响 将是进行未来遗传学研究所必需的先进方法和基础知识， 行为或疾病会改变神经调节剂的释放。这里研究的神经调节剂与精神疾病有关 健康障碍，如精神分裂症、强迫进食或成瘾，这项工作促进了使用 果蝇作为研究神经系统疾病中神经调节的模式生物。

PROJECT SUMMARY How does neuronal signaling control behavior? Neuroscientists answer this question by mapping neuronal circuits, studying action potential firing, or monitoring the resultant neurochemicals released. Drosophila is a model system used to map neural circuits and study cell firing during innate behaviors, such as feeding. Direct measurements of neuromodulators are required to understand behavioral regulation because release is highly heterogeneous and plastic; i.e. the same firing patterns elicit different neuromodulator release in different circumstances due to complex regulation. To understand how neuromodulation regulates behavior or encodes memories, we need tools to examine multiple neuromodulators throughout a circuit. The goal of this project is to develop new multiplexed tools to study neuromodulator interactions in Drosophila during sugar feeding. The central hypothesis is that dopamine, octopamine, and glutamate neuromodulation will occur only in discrete neuropil, vary with frequency of sugar feeding, and be enhanced when sugar is paired with odors. This research is significant because it will develop tools to map real-time signaling of multiple neuromodulators throughout a circuit and use these tools to show how neuromodulator interactions in a circuit control appetitive memory formation during sugar feeding. In Aim 1, we will develop new nanoelectrodes to co-detect octopamine and dopamine using fast-scan cyclic voltammetry (FSCV) and measure them in the mushroom body (MB) g5 compartment during sugar feeding. Octopamine modulation of dopamine will be tested by selectively activating or suppressing a specific octopaminergic neuron. In Aim 2, the goal is to understand dopamine neuromodulation during sugar feeding across compartments of the MB. A genetically-encoded dopamine sensor (GRABDA) will be selectively expressed in either MB dopamine neurons or the protocerebral anterior medial (PAM) projection neurons and dopamine recorded during sugar feeding and olfactory conditioning. In Aim 3, neuromodulation will be mapped throughout a circuit that regulates sugar reward by measuring dopamine and octopamine in the g5 compartment of the mushroom body and glutamate signaling (iGluSnFR) from a mushroom body output neuron in the superior medial protocerebrum. These experiments will be the first to multiplex FSCV and genetically encoded sensors to understand how dopamine/octopamine regulation in the mushroom body controls output signaling downstream in a circuit. The expected outcomes of this work are mapping of neuromodulator interactions throughout a circuit in adult Drosophila during feeding and olfactory conditioning. The positive impact will be advanced methods and foundational knowledge necessary to perform future studies of how genetics, behavior, or disease alter neuromodulator release. The neuromodulators studied here are implicated in mental health disorders, such as schizophrenia, compulsive eating, or addiction, and this work facilitates using Drosophila as a model organism for studying neuromodulation in neurological diseases.