Project 7/8: INIA Stress and Chronic Alcohol Interactions: Cross-species studies of metabolic allostasis and altered striatal circuitry

项目总结 长期大量饮酒和压力与认知灵活性受损有关，这反映在习惯性 和强迫性饮酒。这项建议旨在提高我们对这些效应的神经基础的理解。 通过将体外切片电生理研究与无创磁共振波谱相结合 实验过程中对小鼠和非人灵长类动物(NHP)的(MRS)测量 饮酒程序在INIA-Stress财团中很常见。脑片的电生理记录 已经证明，习惯行为的建立，包括酗酒，涉及并增加 小鼠中棘神经元(MSN)神经传入兴奋抑制音(E/I比) 背外侧纹状体(DLS)，在灵长类动物中称为壳核。专门的磁共振波谱技术 对特定大脑区域中-氨基丁酸和谷氨酸的定量研究使研究人员 提出谷氨酸/氨基丁酸比值反映E/I，在慢性应激的背景下，而MRS 该方法尚未通过与电生理记录的直接比较来验证。在目标1和目标2中， 我们建议使用电生理学和MRS来研究慢性间歇性酒精暴露的小鼠， 强迫游泳应激(CIE-FSS小鼠)。我们的实验将扩大我们对纹状体的理解 利用化学遗传和重组小鼠对应激和酒精暴露的神经回路适应 表征皮层(兴奋性)和小白蛋白表达中间神经元(抑制性)变化的菌株 输入到DLS MSN。在同一小鼠中，代谢异位症将用动态MRS方法来表征。 监测大脑葡萄糖代谢和神经递质合成以估计神经三羧酸 实时酸循环速率(VTCA)，以提供用于解释谷氨酸/GABA比率的生化环境， 这也将在这些小鼠身上进行测量。在目标3中，并行化学发生操作和 NHP受试者的电生理记录将在计划诱导的多饮和 开放式饮酒。这些方法将直接与谷氨酸/GABA的MRS测定进行比较。 和壳核内的VTCA。总而言之，这些结果将支持开发非侵入性策略来 测量应激和酒精诱导的纹状体神经回路的变化与建立 酗酒行为。跨物种方法将有助于将得出的结论的可靠性， 并增强了这项工作的可译性，以供将来在人类受试者中应用。

PROJECT SUMMARY Chronic heavy ethanol drinking and stress are associated with impaired cognitive flexibility, reflected in habitual and compulsive drinking. This proposal seeks to improve our understanding of the neural basis of these effects by combining ex vivo slice electrophysiological studies with non-invasive magnetic resonance spectroscopy (MRS) measurements on mouse and nonhuman primate (NHP) subjects over the course of experimental drinking procedures common across the INIA-Stress consortium. Electrophysiological recordings of brain slices have demonstrated that establishment of habitual behaviors, including heavy drinking, involve and increase in the excitatory to inhibitory tone of neural input (the E/I ratio) to medium spiny neurons (MSNs) of the mouse dorsolateral striatum (DLS), which in primates is termed the putamen. Specialized MRS techniques for quantifying -aminobutyric acid (GABA) and glutamate within specific brain regions have led researchers to propose that the glutamate/GABA ratio reflects E/I, in the context of chronic stress, however the MRS approach has yet to be validated with direct comparisons to electrophysiological recordings. In Aims 1 and 2, we propose to use electrophysiology and MRS to study mice undergoing chronic intermittent ethanol exposure, combined with forced swim stress (CIE-FSS mice). Our experiments will expand our understanding of striatal neurocircuit adaptations to stress and ethanol exposure by using chemogenetic and recombinant mouse strains to characterize changes in cortical (excitatory) and parvalbumin-expressing interneuron (inhibitory) input to DLS MSNs. In the same mice, metabolic allostasis will be characterized with dynamic MRS methods that monitor cerebral glucose metabolism and neurotransmitter synthesis to estimate the neural tricarboxcylic acid cycle rate (VTCA) in real time, to provide a biochemical context for interpreting glutamate/GABA ratios, which will also be measured in these mice. In Aim 3, parallel chemogenetic manipulations and electrophysiological recordings will be performed in NHP subjects following schedule-induced polydipsia and open-access drinking. These measures will be directly compared to MRS determinations of glutamate/GABA and VTCA within the putamen. Together, these results will support the development of non-invasive strategies to measure stress and ethanol-induced changes in striatal neurocircuitry associated with the establishment of heavy drinking behaviors. The cross-species approach will contribute reliability to the conclusions to be drawn, and enhance the translatability of this work to future application in human subjects.