Substrates of selective neuronal vulnerability in aging: neocortical pyramidal neurons and their surrounding neuropil environment in visual versus frontal cortex of young and aged rhesus monkeys

衰老过程中选择性神经元脆弱性的基础：年轻和老年恒河猴视觉与额叶皮层中的新皮质锥体神经元及其周围神经元环境

• 批准号: 10194943
• 负责人: JENNIFER I LUEBKE
• 金额: $ 32.18万
• 依托单位: BOSTON UNIVERSITY MEDICAL CAMPUS
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-05-01 至 2023-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10194943
• 关键词: Action Potentials; Age-associated memory impairment; Aging; Anatomy; Area; Astrocytes; Behavioral; Brain; Cell physiology; Cells; Cognitive; Data; Databases; Dendritic Spines; Dependence; Dyes; Electrophysiology (science); Environment; Funding; Future; Goals; Immunofluorescence Immunologic; Immunohistochemistry; Impaired cognition; In Situ; In Vitro; Individual; Inflammation; Inflammatory; Laser Scanning Confocal Microscopy; Macaca mulatta; Maps; Mediating; Membrane; Microglia; Monkeys; Morphology; Myelin; Neuroglia; Neurons; Neuropil; Oligodendroglia; Outcome; Oxidative Stress; Paraffin; Pathway interactions; Pattern; Performance; Physical shape; Physiological; Population; Predisposition; Prefrontal Cortex; Primates; Process; Property; Proteins; Resolution; Sensory; Series; Short-Term Memory; Slice; Specific qualifier value; Structure; Synapses; Testing; Therapeutic; Tissue Sample; United States National Institutes of Health; Vertebral column; Visual; Work; age effect; age group; age related; aged; aging population; animal tissue; area striata; biocytin; brain dysfunction; cell type; cognitive function; cognitive performance; cytokine; density; design; frontal lobe; hippocampal pyramidal neuron; interest; middle age; molecular phenotype; neocortical; neuron loss; normal aging; novel; patch clamp; postsynaptic; white matter

Normal aging in primates often leads to impaired cognitive function, particularly in working memory, which begins to decline in middle-age. Our group and others have established that age-related cognitive impairment is not due to overt death of neurons but rather is associated with a constellation of sublethal changes to neurons particularly in layer (L3), such as spine, synapse and myelin loss and consequent alterations to synaptic and intrinsic electrophysiological properties. Importantly these structural and functional changes have been abundantly observed with aging in neurons and white matter pathways in the prefrontal cortex (PFC), a brain area that is a key player in working memory. By contrast, the properties of primary visual cortex (V1) pyramidal neurons are largely spared during normal aging. We currently lack a mechanistic understanding of why pyramidal neurons in these two brain areas are differentially vulnerable in normal aging or how age- related changes at the single-cell and pathway level in PFC impact network function and thus working memory performance. The overall hypothesis of this project is that selective vulnerability of neurons and associated networks in LPFC compared to V1 during aging is due to key differences in both the intrinsic properties and the neuropil context of neurons in the two areas, and a greater susceptibility of neurons in LPFC to increases in oxidative stress and inflammation. We propose a novel experimental approach -multiplexed immunohistochemistry combined with high resolution structural analyses of physiologically characterized individual neurons- to compare the properties of individual LPFC and V1 pyramidal neurons in the context of their surrounding neuropil in young and aged rhesus monkeys. These monkeys will also have been assessed for cognitive status, pathway integrity, and CSF pro-inflammatory cytokine levels as part of other existing NIH- funded projects. This project has two aims: 1) To assess the morphological properties of physiologically characterized L3 pyramidal neurons in LPFC and V1 of young and aged monkeys. We will assess dendritic topology and the number and density of dendritic spine subtypes and correlate these data with existing data on 30 different physiological properties of these same cells. 2) To characterize the normative properties and effects of aging on the same L3 pyramidal neurons studied in Aim 1 in the context of the neuropil. We will perform in situ immunofluorescence multiplexing of ~20 protein targets on the same tissue sample to determine the molecular phenotype of biocytin-filled layer 3 pyramidal neurons. A major outcome of this project will be the ability to quantitatively specify those parameters that differ between L3 pyramidal neurons in two highly distinct brain areas and which combination of parameters best predict cognitive impairment in aging. This study will form the basis of future series of larger studies to investigate relationships and co-dependence of age-related cellular changes in a variety of cell types, laminae and cortical areas during normal aging that can be correlated with cognitive performance in rhesus monkeys.

灵长类动物的正常老化通常会导致认知功能受损，尤其是在工作记忆中， 中年开始下降。我们的小组和其他人已经确定了与年龄相关的认知障碍 不是由于神经元的公开死亡，而是与一系列圣灵的变化有关 神经元特别在（L3）中，例如脊柱，突触和髓磷脂损失，因此改变了 突触和内在电生理特性。重要的是，这些结构性和功能变化具有 在神经元和白质途径的衰老中大量观察到前额叶皮层（PFC），A 大脑区域是工作记忆中的关键参与者。相比之下，主要视觉皮层（V1）的特性 在正常衰老期间，锥体神经元在很大程度上幸免。我们目前缺乏对 为什么这两个大脑区域中的锥体神经元在正常衰老中差异很大，或者年龄如何 PFC冲击网络功能中的单细胞和路径级别的相关更改，从而工作记忆 表现。该项目的总体假设是神经元和相关的选择性脆弱性 LPFC与衰老期间V1相比的网络是由于内在特性和 神经元在这两个区域的神经元背景，LPFC中神经元的敏感性更大 氧化应激和炎症。我们提出了一种新型的实验方法 - 多重的 免疫组织化学结合了高分辨率的生理表征结构分析 单个神经元 - 比较单个LPFC和V1锥体神经元的特性 他们周围的神经胶质在年轻和老化的恒河猴中。这些猴子也将被评估 作为认知状况，途径完整性和CSF促炎细胞因子水平，作为其他现有NIH-的一部分 资助的项目。该项目有两个目标：1）评估生理学的形态特性 在LPFC和年轻猴子的V1中表征了L3锥体神经元。我们将评估树突状 拓扑以及树突状脊柱亚型的数量和密度，并将这些数据与现有数据相关联 30这些相同细胞的不同生理特性。 2）表征规范性能和 衰老对在神经胶质背景下在AIM 1中研究的相同L3锥体神经元的影响。我们将 在同一组织样品上进行〜20个蛋白靶标的原位免疫荧光多路复用 确定3层锥体神经元的生物细胞填充的分子表型。该项目的主要结果 将可以定量指定两个l3锥体神经元之间不同的参数 高度不同的大脑区域以及哪种参数结合最能预测衰老的认知障碍。 这项研究将构成未来大型研究的基础，以研究关系和共同依赖性 在正常衰老期间，各种细胞类型，薄片和皮质区域的年龄相关细胞变化 可以与恒河猴的认知表现相关。