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

项目概要/摘要 该提案的目标是阐明下丘脑后部（LPH）神经元细胞的作用 使用尖端转录组学和方法研究阿尔茨海默氏病 (AD) 的发病机制 连接组学分析。 LPH 由一系列相互关联的结构组成，包括横向结构 下丘脑区（LHA）和下丘脑腹后区（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。 越来越多的病理证据表明，该区域的细胞类型在 AD 中很容易发生退化。对于 例如，对 AD 患者死后大脑的检查显示，关键的睡眠-觉醒功能显着丧失。 调节 LPH 中的细胞群。在 LPH 的更后部区域，临床和临床前证据 表明乳头体（MB），全脑记忆系统中的一个重要节点，也已经出现 作为 AD 发病机制的早期脆弱部位。临床上，非认知和代谢紊乱已被 显示在记忆丧失和认知能力下降之前。这些集体证据表明 LPH 是 发生导致 AD 的神经病理学风险/倾向的潜在早期指标。然而，底层 LPH 的多种功能是高度异质且特征不明的神经元群体， 其中的子集可能表现出不同的分子改变和/或导致特定的电路级变化 奠定了该区域早期 AD 相关病理的基础。解决细胞类型特异性的这些改变 因此，特定于电路的方式是机械理解 LPH 在 早期 AD 发病机制和早期生物标志物的鉴定。本补充建立在 母体 R01 (MH112739) 通过对 LPH 进行系统的分子、细胞和连接分析， 专门解决与 AD 相关的细胞类型特定和电路级改变。我们将接近这个 通过结合单细胞转录组学、空间转录组学等尖端技术， 以及 AD 小鼠模型（5XFAD）中的连接组电路图谱。在目标 1 中，我们将系统地收集 来自年轻和老年小鼠 LPH 的单细胞和空间转录组图谱，以确定 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 评估表现出病理改变的关键神经元群的长程轴突投射 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组学分析。 在 AD 神经变性的进展过程中，LPH 内发生细胞变化，并将形成 未来 NIA 应用的基础侧重于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.