PROJECT 4-NPTX2 and Adaptation to Cognitive Aging

项目 4-NPTX2 和认知衰老的适应

• 批准号: 10412005
• 负责人: PAUL F WORLEY
• 金额: $ 48.53万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-09-01 至 2026-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10412005
• 关键词: Adult; Age-associated memory impairment; Aging; Attention; Axon; Behavior; Biochemical; Biology; Brain; Cellular biology; Cognition; Cognitive; Cognitive aging; Collaborations; Confocal Microscopy; Dose; Equilibrium; Excitatory Synapse; Exocytosis; Extracellular Protein; Failure; Female; Genes; Hippocampus (Brain); Homeostasis; Image; Immediate-Early Genes; Impaired cognition; Impairment; Incidence; Injections; Interneurons; Interruption; Label; Lateral; Levetiracetam; Light; Long-Evans Rats; Maintenance; Measures; Mediating; Membrane; Memory; Messenger RNA; Methods; MicroRNAs; Microscopy; Modeling; Modification; Molecular; Neocortex; Neurons; Oligonucleotides; Parvalbumins; Peptide Hydrolases; Periodicity; Phase; Photons; Physiological Processes; Presynaptic Terminals; Process; Protein Analysis; Proteins; Rattus; Regulation; Resolution; Role; Schedule; Site; Sleep; Synapses; System; Testing; Therapeutic; Time; Transgenes; Vesicle; Virus; Work; age effect; age related; aged; base; calmodulin-dependent protein kinase II; cognitive performance; entorhinal cortex; experimental study; gain of function; hippocampal pyramidal neuron; in vivo; innovation; insight; intravenous administration; loss of function; mRNA Transcript Degradation; male; presynaptic; prevent; protein expression; protein function; resilience; success; synaptic function; tool; trafficking; transgene expression; translatable strategy; two-photon

Project 4 examines the role of NPTX2 and homeostatic scaling in age-related cognitive decline. NPTX2 is an immediate early gene expressed by pyramidal neurons and mediates activity-dependent homeostatic strengthening of inhibitory circuits by adaptively strengthening excitatory drive of parvalbumin interneurons (PV-IN). This PPG has examined the effect of aging on cognition using outbred Long-Evans rats and has documented increased pyramidal neuron excitability and reduced PV-IN circuit inhibition that are associated with cognitive decline. Preliminary studies further reveal reduced NPTX2 expression in Aged-Impaired rats and rescue of circuit deficits by NPTX2 transgene expression. Here, we build on these observations and examine the hypothesis that failure of NPTX2 homeostatic mechanisms contribute to age-related cognitive decline. Aim 1 will test the hypotheses that NPTX2 loss-of-function (LOF) accelerates age-related cognitive decline while NPTX2 gain-of-function (GOF) delays or prevents age-related cognitive decline. A conditional NPTX2 LOF model uses a newly developed NPTX2f/f rat together with virus-mediated delivery of Cre to delete NPTX2 at 11 m and together with Core B details the impact on cognitive behavior. In a reciprocal set of experiments, we create NPTX2 GOF models using two distinct approaches that include virus mediated NPTX2 transgene and oligonucleotide mediated NPTX2 mRNA stabilization. The impact of GOF on cognitive behavior is evaluated in collaboration with Core B. Aim 2 examines molecular and cellular mechanisms mediating dynamic targeting of NPTX2 to excitatory synapses. Studies use state-of-the-art proximity labeling methods to identify proteins involved in synaptic NPTX2 exocytosis and shedding. Aim 3 uses in vivo 2-photon imaging to examine the hypothesis that age-related cognitive deficits are associated with disruption of a critical phase of homeostatic scaling that mediates activity-dependent NPTX2 exocytosis and shedding. Analyses examine diurnal changes in synaptic NPTX2 in association with waking behaviors and sleep comparing Young, Aged-Impaired and Aged-Unimpaired rats. We also test the effect of levetiracetam in Aged-Impaired rats. Studies in Aims 1 and 3 include both male and female rats. The Aims are highly synergistic with other Projects and together will reveal fundamental mechanisms of aging, cognitive resilience and cognitive decline.

项目 4 研究了 NPTX2 和稳态缩放在与年龄相关的认知能力下降中的作用。 NPTX2 是 立即早期基因由锥体神经元表达并介导活动依赖性稳态 通过适应性加强小白蛋白中间神经元的兴奋性驱动来加强抑制回路 （PV-IN）。该 PPG 使用远交的 Long-Evans 大鼠检查了衰老对认知的影响，并得出了结论 记录了相关的锥体神经元兴奋性增加和 PV-IN 回路抑制减少 伴随认知能力下降。初步研究进一步揭示老年受损大鼠和大鼠中 NPTX2 表达降低 通过 NPTX2 转基因表达来挽救电路缺陷。在这里，我们以这些观察为基础并研究 NPTX2 稳态机制的失败导致与年龄相关的认知能力下降的假设。目的 1 将检验以下假设：NPTX2 功能丧失 (LOF) 会加速与年龄相关的认知能力下降，而 NPTX2 功能获得 (GOF) 可以延迟或预防与年龄相关的认知能力下降。有条件的 NPTX2 LOF 该模型使用新开发的 NPTX2f/f 大鼠以及病毒介导的 Cre 传递来删除 11 处的 NPTX2 m 并与核心 B 一起详细说明了对认知行为的影响。在一组相互的实验中，我们 使用两种不同的方法创建 NPTX2 GOF 模型，包括病毒介导的 NPTX2 转基因和 寡核苷酸介导的 NPTX2 mRNA 稳定性。 GOF 对认知行为的影响评估如下： 与 Core B 合作。Aim 2 检查介导动态靶向的分子和细胞机制 NPTX2 与兴奋性突触有关。研究使用最先进的邻近标记方法来识别蛋白质 参与突触 NPTX2 胞吐作用和脱落。 Aim 3 使用体内 2 光子成像来检查 假设与年龄相关的认知缺陷与稳态关键阶段的破坏有关 介导活性依赖性 NPTX2 胞吐作用和脱落的缩放。分析检查每日变化 比较年轻人、老年受损者和睡眠者的突触 NPTX2 与清醒行为和睡眠的关系 老年未受损大鼠。我们还测试了左乙拉西坦对老年受损大鼠的作用。目标 1 和 3 的研究 包括雄性和雌性大鼠。这些目标与其他项目高度协同，共同揭示 衰老、认知弹性和认知衰退的基本机制。