Hypothalamic spatial transcriptomics and connectomics in a mouse model of Alzheimers disease

项目摘要/摘要 这项建议的目的是阐明下丘脑外侧后部(LPH)神经元细胞的作用 和电路在阿尔茨海默病(AD)发病机制中的应用 连通分析。LPH包括一组相互关联的结构，包括侧向 下丘脑区(LHA)和下丘脑腹后部(VPH)是行为状态的关键调节器， 协调睡眠和清醒、动机行为、神经内分泌功能和记忆处理。 越来越多的病理证据表明，该区域的细胞类型在AD时容易变性。为 例如，对AD患者身体大脑的检查显示，关键的睡眠-觉醒功能急剧丧失-- 调节LPH中的细胞数量。在LPH的更多后部，临床和临床前证据 这表明，整个大脑记忆系统中的一个重要节点--乳房小体(MB)也出现了 作为阿尔茨海默病发病机制的早期脆弱部位。临床上，非认知和新陈代谢障碍 显示在记忆力丧失和认知衰退的开始之前。这一集体证据表明，LPH是 一种潜在的早期风险/倾向指标，可发展为导致AD的神经病理。然而，潜在的 LPH的不同功能是一个高度异质性和特征不佳的神经元群体， 它们的子集可能表现出明显的分子变化和/或促成特定的电路级变化， 这是该地区早期AD相关病理的基础。解决特定于单元格类型的 因此，特定于电路的方式是通向机械地理解LPH在 阿尔茨海默病的早期发病机制和早期生物标志物的识别。本补编是根据以下内容编写的 亲本R01(MH112739)通过系统的分子、细胞和连接性分析 具体解决与AD相关的单元类型特定和电路级更改。我们将着手解决这一问题 通过结合尖端技术，包括单细胞转录组，空间转录组， 在AD(5XFAD)小鼠模型上进行连接回路标测。在目标1中，我们将系统地收集 从幼年和老年小鼠LPH的单细胞和空间转录图谱，以确定变化 以解剖解析的方式与AD相关的转录组图谱。在目标2中，我们将从数量上 评估表现出病理改变的关键神经元群体的长期轴突投射和 将使用病毒追踪、膜片钳电生理学和光遗传学来检查功能性突触连接。 这里提出的工作将产生有价值的细胞类型普查和分子和连接分析 在AD神经退行性变的进展过程中，LPH内发生的细胞变化，将形成 未来NIA应用的基础，重点是特定的下丘脑细胞和回路在AD中的作用 发病机制。

PROJECT SUMMARY/ABSTRACT The goal of this proposal is to elucidate the role of lateroposterior hypothalamic (LPH) neuronal cells and circuits in the pathogenesis of Alzheimer’s disease (AD) using cutting-edge transcriptomic and connectomic analyses. The LPH comprises a collection of interrelated structures, including the lateral hypothalamic area (LHA) and ventral posterior hypothalamus (VPH) that are key modulators of behavioral state, orchestrating sleep and wakefulness, motivated behavior, neuroendocrine function and memory processing. Mounting pathological evidence suggests that cell types in this region are vulnerable to degeneration in AD. For example, examination of post-mortem brains from AD patients shows a dramatic loss of key sleep-wake- regulating cell populations in the LPH. In more posterior regions of the LPH, both clinical and preclinical evidence suggests that the mammillarybodies (MB), an important node in a brain-wide memorysystem,has also emerged as a site of early vulnerability in AD pathogenesis. Clinically, non-cognitive and metabolic disruptions have been shown to precede the onset of memory loss and cognitive decline. This collective evidence points to the LPH as a potential early indicator of risk/propensity to develop neuropathology that leads to AD. However, underlying the diverse functions of the LPH is a highly heterogenous and poorly characterized population of neurons, subsets of which may exhibit distinct molecular alterations and/or contribute to specific circuit-level changes that underpin the early AD-associated pathology within this region. Resolving these alterations in a cell-type-specific and circuit-specific manner is thus the crucial step towards a mechanistic understanding of the LPH’s role in early AD pathogenesis and the identification of early-stage biomarkers. The present supplement builds upon the parent R01 (MH112739) through a systematic molecular, cellular and connectivity analysis of the LPH to specifically address the cell type-specific and circuit-level alterations associated with AD. We will approach this through a combination of cutting-edge techniques including single-cell transcriptomics, spatial transcriptomics, and connectomic circuit mapping, in a mouse model of AD (5XFAD). In Aim 1, we will systematically collect single-cell and spatial transcriptomic profiles from young and aged mouse LPH, to identify the changes in transcriptome profiles associated with AD in an anatomically resolved manner. In Aim 2, we will quantitatively assess the long-range axonal projections of key populations of neurons that exhibit pathological alterations and will examine functional synaptic connectivity using viral tracing, patch-clamp electrophysiology and optogenetics. The work proposed here will yield a valuable cell type census and connectomic analysis of the molecular and cellular changes occurring within the LPH during the progression of AD neurodegeneration, and will form the basis for future NIA applications focused on the role of specific hypothalamic cells and circuits in AD pathogenesis.