Fast Online Microdialysis/Liquid Chromatography for Monoamine Neurotransmitters

描述（由申请人提供）：微透析为大脑提供了一个窗口。它允许测量细胞外化学物质的浓度，这些化学物质的主要作用是细胞外功能，例如神经递质。它已被广泛应用于疾病和创伤的动物模型以及遭受创伤的人类的研究。这项技术虽然强大，但有一个主要的限制——它不能测量与扩散去极化和行为等现象相关的快速变化。科学家们可以测量神经递质多巴胺（几纳摩尔基础水平）和血清素（亚纳摩尔基础水平）在亚分钟到五分钟范围内的细胞外浓度，在时间制度上有很大的差距。一种补充技术，快速扫描循环伏安法测量亚秒到几秒时间范围内浓度的变化。基于我们良好的理论洞察力和技术改进，我们建议改善微透析的时间尺度以覆盖这一重要范围。我们将使用新功能处理三种类型的实验。(1)我们在前期工作中看到的血清素振荡是由于扩散去极化引起的吗？(2)应激/焦虑相关的神经递质血清素（5-羟色胺）在动物处于应激状态下做出决定时发生了什么变化？(3)微透析能否用于区分动物收到奖励时的多巴胺释放和动物收到与奖励相关的提示时的多巴胺释放？

DESCRIPTION (provided by applicant): Microdialysis provides a window on the brain. It permits measurements to be made of the extracellular concentration of chemicals whose primary role is an extracellular function, for example neurotransmitters. It has been widely adopted for investigations in animal models of disease and trauma and indeed in humans suffering trauma. The technique, as powerful as it is, has one major limitation - it cannot measure rapid changes that are relevant to phenomena such as spreading depolarization and behavior. There is a large gap in the time regime over which scientists can measure extracellular concentrations of the neurotransmitters dopamine (few nanomolar basal levels) and serotonin (sub-nanomolar basal levels) in the sub-minute to five minute range. A complementary technique, fast scan cyclic voltammetry measures changes in concentrations over the sub-second to several second timeframe. Based on our sound theoretical insight and technical improvements, we propose to improve the timescale of microdialysis to cover this important range. We will address three types of experiments with the new capability. (1) Are serotonin oscillations we have seen in preliminary work due to spreading depolarization? (2) What changes in the stress/anxiety-related neurotransmitter serotonin (5-hydroxytryptamine) are seen during the time an animal is making a decision in a stressful situation? (3) Can microdialysis be used to distinguish dopamine release upon an animal's receiving a reward from dopamine release upon the animal's receiving a cue associated with the reward?