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

项目总结/摘要 本研究的目的是阐明下丘脑后外侧区神经元细胞的作用 和电路在阿尔茨海默病（AD）的发病机制，使用尖端的转录组学和 连接组学分析。LPH由一系列相互关联的结构组成，包括横向 下丘脑区（LHA）和腹后下丘脑（VPH）是行为状态的关键调节器， 协调睡眠和觉醒、动机行为、神经内分泌功能和记忆处理。 越来越多的病理学证据表明，该区域的细胞类型易受AD变性的影响。为 例如，对AD患者死后大脑的检查显示，关键的睡眠-觉醒- 调节LPH中的细胞群。在LPH的更后部区域，临床和临床前证据 表明，在全脑记忆系统中的一个重要节点--乳头体（MB）也出现了 作为AD发病机制中的早期易感部位。在临床上，非认知和代谢紊乱一直是 在记忆力丧失和认知能力下降之前。这一集体证据指向LPH， 发生导致AD的神经病理学的风险/倾向的潜在早期指标。然而，底层 LPH的多种功能是高度异质的且特征不明显的神经元群体， 其亚群可能表现出不同的分子改变和/或导致特定的电路水平变化， 支持该区域内的早期AD相关病理。解决这些变化在一个细胞类型特异性 因此，电路特定的方式是对LPH的作用的机械理解的关键一步， 早期AD发病机制和早期生物标志物的鉴定。本补编是根据 亲本R 01（MH 112739）通过LPH的系统性分子、细胞和连接性分析， 具体解决与AD相关的特定于细胞类型和电路级的改变。我们会处理这个问题 通过结合尖端技术，包括单细胞转录组学，空间转录组学， 和连接组电路映射，在小鼠模型的AD（5XFAD）。在目标1中，我们将系统地收集 年轻和老年小鼠LPH的单细胞和空间转录组学谱，以确定LPH的变化。 以解剖学解析的方式与AD相关的转录组谱。在目标2中，我们将定量地 评估表现出病理改变的关键神经元群体的长程轴突投射， 将使用病毒追踪、膜片钳电生理学和光遗传学检查功能性突触连接。 这里提出的工作将产生一个有价值的细胞类型普查和连接组学分析的分子和 在AD神经变性的进展过程中，LPH内发生的细胞变化，并将形成 未来NIA应用的基础集中在特定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.