Multiphoton Monoamine Imaging of Serotonin Neuron Function

描述（由申请人提供）：中缝核的5-羟色胺神经元控制情绪，对滥用药物如苯丙胺MDMA（3，4-亚甲二氧基甲基苯丙胺，Ecketamine）和可卡因敏感。由于轴突衍生的静脉曲张，细胞体和树突的5-羟色胺释放不能直接在完整的组织中进行测定和比较，每个细胞隔室的贡献，释放诱发的电活动和药物尚未被量化。同样地，中缝背核5-羟色胺神经元附近的释放位点的性质，从该神经元产生的，从同一核中的相邻神经元和从其他中缝核的投射尚未确定与当前的方法。因此，我们一直在开发一种新的光学技术来研究脑切片中的5-羟色胺神经元。多光子单胺成像（MMI）利用荧光5-羟色胺类似物，其由来自钛：蓝宝石激光器的725 nm脉冲红外光激发。我们已经证明，MMI检测中缝背核脑切片中5-羟色胺神经元细胞体和静脉曲张的摄取和去极化诱发的释放。在这里，实验建立MMI的效用研究释放在脑切片诱导的相关刺激（动作电位和MDMA）在确定的车厢（轴突终末，树突和细胞体）的5-羟色胺神经元。这一进一步的发展将确保MMI将能够解决有关滥用药物对5-羟色胺神经元影响的基本问题。公共卫生相关性：药物滥用仍然是一个主要的公共卫生问题。已知神经递质5-羟色胺影响情绪（例如抑郁、焦虑）和涉及成瘾的多巴胺能奖励系统。该CEBRA应用将进一步开发一种称为多光子单胺成像的新光学方法，用于研究5-羟色胺神经元的递质释放。

DESCRIPTION (provided by applicant): Serotonin neurons of the raphe nuclei control mood and are sensitive to drugs of abuse such as the amphetamine MDMA (3,4-Methylenedioxymethamphetamine, Ecstasy) and cocaine. Because serotonin release by axon-derived varicosities, cell bodies and dendrites cannot be assayed and compared directly in intact tissue, the contribution of each cellular compartment to release evoked by electrical activity and drugs has not been quantified. Likewise, the properties of release sites near a dorsal raphe nucleus serotonin neuron that arise from that neuron, from neighboring neurons in the same nucleus and projections from other raphe nuclei have not been determined with current methods. Therefore, we have been developing a new optical technique for studying serotonin neurons in brain slices. Multiphoton monoamine imaging (MMI) utilizes a fluorescent serotonin analog that is excited by 725 nm pulsed infrared light from Ti:sapphire laser. We have demonstrated that MMI detects uptake and depolarization-evoked release from serotonin neuron cell bodies and varicosities in dorsal raphe nucleus brain slices. Here, experiments are presented to establish the utility of MMI for studying release in brain slices induced by relevant stimuli (action potentials and MDMA) at identified compartments (axonal boutons, dendrites and cell bodies) of serotonin neurons. This further development will ensure that MMI will be able to address fundamental questions concerning the effects of abused drugs on serotonin neurons. PUBLIC HEALTH RELEVANCE: Drug abuse continues to be a major public health problem. It is known that the neurotransmitter serotonin affects mood (e.g. depression, anxiety) and dopaminergic reward systems involved in addiction. This CEBRA application will further develop a new optical method called Multiphoton Monoamine Imaging for studying transmitter release by serotonin neurons.