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

项目摘要 慢性大量饮酒和压力与认知灵活性受损有关，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影响的神经基础的理解 通过将离体切片电生理学研究与非侵入性磁共振波谱学相结合 (MRS)在实验过程中对小鼠和非人灵长类动物（NHP）受试者的测量 INIA-Stress联盟中常见的饮酒程序。脑切片的电生理记录 已经证明，习惯性行为的建立，包括大量饮酒，涉及并增加 小鼠中棘神经元（MSNs）神经输入的兴奋性与抑制性音调（E/I比值） 背外侧纹状体（DLS），在灵长类动物中称为壳核。专业的MRS技术， 通过对特定大脑区域内的γ-氨基丁酸（GABA）和谷氨酸进行定量， 我建议谷氨酸/GABA比率反映E/I，在慢性应激的背景下，然而MRS 这种方法还有待与电生理记录进行直接比较来验证。在目标1和2中， 我们建议使用电生理学和MRS来研究经历慢性间歇性乙醇暴露的小鼠， 联合强迫游泳应激（CIE-FSS小鼠）。我们的实验将扩大我们对纹状体的理解 使用化学遗传和重组小鼠对应激和乙醇暴露的神经回路适应 菌株，以表征皮质（兴奋性）和小清蛋白表达中间神经元（抑制性）的变化 输入到DLS MSN。在相同的小鼠中，将用动态MRS方法表征代谢变稳态 监测大脑葡萄糖代谢和神经递质合成以估计神经三羧酸 真实的时间内的酸循环速率（VTCA），以提供用于解释谷氨酸/GABA比率的生物化学背景， 这也将在这些小鼠中进行测量。在目标3中，平行的化学遗传操作和 将在NHP受试者中进行电生理记录， 开放式饮酒这些测量将直接与谷氨酸/GABA的MRS测定进行比较 以及壳核内的VTCA总之，这些结果将支持非侵入性策略的发展， 测量压力和乙醇诱导的纹状体神经回路的变化， 酗酒行为。跨物种办法将有助于得出可靠的结论， 并增强这项工作在人类受试者中未来应用的可翻译性。

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.