Role of CaMKII in memory storage

CaMKII 在记忆存储中的作用

• 批准号: 9376238
• 负责人: Leslie C Griffith
• 金额: $ 34.51万
• 依托单位: BRANDEIS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-01 至 2022-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9376238
• 关键词: Aging; Alzheimer' s Disease; Animals; Behavioral; Binding; Binding Proteins; Brain-Derived Neurotrophic Factor; Cell Death; Complex; Cytoplasm; Development; Dominant-Negative Mutation; Epilepsy; Fluorescence Resonance Energy Transfer; Goals; Healthcare; Hippocampus (Brain); Hour; In Vitro; Learning; Maintenance; Memory; Memory Loss; Methods; Modification; Molecular; Mutation; N-Methylaspartate; Nature; Neurologic Dysfunctions; Optical Methods; Pathologic Processes; Peptides; Phosphotransferases; Process; Property; Protein Synthesis Inhibitors; Proteins; Reaction; Role; Specificity; Stroke; Synapses; Synaptic Transmission; Synaptic plasticity; Testing; Vertebral column; Viral; Weight; Work; addiction; base; calmodulin-dependent protein kinase II; densin-180; enhancing factor; experimental study; in vivo; inhibitor/antagonist; memory process; nervous system disorder; novel; painful neuropathy; prevent

Project Summary/Abstract Activity-dependent synaptic modifications (LTP/LTD) are a major candidate for the mechanism of memory. LTP involves induction, maintenance, and expression processes. This proposal seeks to elucidate the molecular basis of the maintenance process, the process that underlies the engram. The critical test of any hypothesis regarding maintenance is the “erasure test” in which an inhibitor is applied after LTP/memory is established. If this blocks LTP/memory and the effect persists after the inhibitor is removed, the inhibitor must have erased a maintenance process. We have conducted the erasure test using an inhibitor of CaMKII (CN-peptide). We found that application of this peptide after LTP induction produced erasure of saturated LTP. We now propose two experiments that test the role of CaMKIIα in memory maintenance at the behavioral level. In the first, we ask whether a dominant-negative form of CaMKIIα can erase conditioned place avoidance. We present strong preliminary evidence that it does. The second test is the “occlusion test.” It has been shown that activated kinase (CaMKIIα*) enhances synaptic transmission that occludes synaptically induced LTP. We will virally express CaMKIIα* and test two predictions: that because this maximally increases all synaptic weights it should destroy memory function, and furthermore, that learning under these conditions should not be possible. Preliminary evidence supporting these predictions is presented. Other experiments in this proposal are aimed at understanding the nature of the CaMKIIα complex that stores the engram. There are strong reasons to suspect that what maintains LTP is actually the complex of CaMKIIα with NMDAR (and perhaps also densin- 180). Studies of the binding of proteins to CaMKII have relied on in vitro work, and there has been no previous method for studying the complexes formed during actual LTP induction. Thus, crucial information regarding the complex formation and persistence is lacking. We have developed and validated a novel optical method based on FLIM-FRET. Our preliminary evidence demonstrates that LTP induction produces complex of CaMKIIα with GluN2B in spines and that the formation is synapse specific. We will determine the duration of the complex under conditions that either induce short-lasting LTP (early LTP) or produce both early and late LTP. We will also examine how the duration of the complex depends on factors that enhance (e.g., BDNF) or prevent (e.g., protein synthesis inhibitors) late LTP. This approach will be extended to study the interaction of CaMKIIα with densin-180. Having identified properties of the complex that underlies LTP, in vivo experiments will be conducted to test whether disruption of protein interactions within the complex can disrupt maintenance of the engram.

项目总结/摘要 活动依赖性突触修饰（LTP/LTD）是记忆机制的主要候选者。LTP 包括诱导、维持和表达过程。这一建议旨在阐明分子 这是维持过程的基础，也是记忆印记的基础。任何假设的关键检验 关于维护的是“擦除测试”，在该测试中，在LTP/记忆建立之后应用抑制剂。如果 这会阻止LTP/记忆，并且在去除抑制剂后效果仍然存在，抑制剂必须擦除 维护过程。我们使用CaMKII抑制剂（CN-肽）进行了擦除试验。我们 发现在LTP诱导后应用这种肽产生饱和LTP的消除。我们现建议 两个实验测试了CaMKIIα在行为水平的记忆维持中的作用。第一，我们 问一个显性负性形式的CaMKIIα是否可以消除条件性位置回避。我们提供强大的 初步证据表明，它。第二个测试是“闭塞测试”。研究表明，激活 激酶（CaMKIIα*）增强突触传递，阻断突触诱导的LTP。我们将病毒式地 表达CaMKIIα* 并测试两个预测：因为这最大限度地增加了所有突触权重， 应该会破坏记忆功能，而且在这种情况下学习是不可能的。 支持这些预测的初步证据。该提案中的其他实验旨在 了解储存记忆印迹的CaMKIIα复合物的性质。我们有充分的理由 我怀疑维持LTP的实际上是CaMKIIα与NMDAR的复合物（也许还有致密蛋白- 180）。蛋白质与CaMKII结合的研究依赖于体外工作，以前没有 用于研究在实际LTP诱导期间形成的复合物的方法。因此，关于 缺乏复杂的形成和持久性。我们已经开发并验证了一种新的光学方法， 在FLIM-FRET上。我们的初步证据表明，LTP诱导产生CaMK Ⅱ α与 GluN 2B在脊柱和形成是突触特异性。我们将决定综合体的持续时间 在诱导短暂LTP（早期LTP）或产生早期和晚期LTP的条件下。我们将 还检查复合物的持续时间如何取决于增强的因素（例如，BDNF）或预防（例如， 蛋白质合成抑制剂）晚期LTP。这种方法将被扩展到研究CaMKIIα与 密度蛋白-180。在确定了LTP基础的复合物的特性之后，将进行体内实验。 进行，以测试复合物内蛋白质相互作用的破坏是否会破坏复合物的维持。 记忆痕迹