Fast Online Microdialysis/Liquid Chromatography for Monoamine Neurotransmitters

描述(申请人提供)：微透析提供了一个了解大脑的窗口。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。它被广泛用于疾病和创伤的动物模型的研究，甚至在遭受创伤的人类身上也得到了广泛的应用。尽管这项技术功能强大，但它有一个主要限制--它无法测量与传播去极化和行为等现象相关的快速变化。科学家可以在亚分钟到五分钟的范围内测量神经递质多巴胺(几个纳摩尔基础水平)和5-羟色胺(亚纳摩尔基础水平)的细胞外浓度，在时间范围内存在很大差距。作为一种补充技术，快速扫描循环伏安法测量亚秒到几秒的时间范围内浓度的变化。基于我们合理的理论见解和技术改进，我们建议改进微透析的时间刻度，以涵盖这一重要范围。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5-羟色胺振荡是否是由于扩散的去极化？(2)在动物在应激情况下做出决定的过程中，与应激/焦虑相关的神经递质5-羟色胺(5-羟色胺)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与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?