Noradrenergic arousal and systems consolidation: maintaining memory specificity?

去甲肾上腺素能唤醒和系统整合：保持记忆特异性？

• 批准号: 403479502
• 负责人: Professor Dr. Lars Schwabe
• 金额: --
• 依托单位: Centre for Cognitive Neuroimaging
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/403479502?language=en
• 关键词: Noradrenergic; arousal; systems; consolidation; maintaining

With time, memory is thought to undergo a neural reorganization, referred to as systems consolidation, during which memories are, at least partly, transferred from hippocampus to neocortical networks. This systems consolidation is highly dynamic and accompanied by a transformation from detailed, specific to more semantic, gist-like memory. Whether systems consolidation can be modulated is largely unknown. Emotional arousal-induced noradrenaline is known to be a powerful modulator of initial memory formation, leading via increased amygdala activity to increased memory strength and vividness as well as to enhanced hippocampal involvement in memory. Although it is well-established that noradrenaline may strengthen the initial consolidation of memory, its impact on systems consolidation processes and the time-dependent change in the specificity of memory is largely unknown. Based on recent rodent data, we hypothesize that post-encoding noradrenergic stimulation may change systems consolidation processes and maintain remote memories hippocampus dependent and specific. To test this hypothesis, healthy participants will be administered a placebo or the α2-adrenoceptor antagonist yohimbine, leading to increased noradrenergic stimulation, after they encode a series of neutral and emotionally arousing pictures. Memory will be tested in a recognition test, either 1 day or 28 days after encoding. To assess memory specificity, the recognition test will include, in addition to old and entirely novel items, lures carrying the gist of the initially encoded pictures as well as perceptually similar lures carrying a different gist. In order to assess the postulated systems consolidation and the neural underpinnings of post-encoding noradrenergic arousal on memory transformation, participants will be scanned with functional magnetic resonance imaging at 3T both during encoding and retention testing. Beyond their crucial relevance for our understanding of human memory in general and the long-term vividness of emotional memory in particular, the findings of this project might have implications for mental disorders in which aberrant emotional memory processing is prominent.

随着时间的推移，记忆被认为经历了一次神经重组，称为系统整合，在此期间，记忆至少部分地从海马体转移到新皮层网络。这种系统整合是高度动态的，并伴随着从详细的、具体的记忆到更语义化的、类似记忆的转变。系统整合是否可以调整，在很大程度上是未知的。已知情绪唤醒诱导的去甲肾上腺素是初始记忆形成的强有力调节剂，通过增加杏仁核活性导致记忆强度和生动性增加以及海马参与记忆的增强。虽然它是公认的，去甲肾上腺素可能会加强记忆的初始巩固，其对系统的巩固过程和记忆的特异性随时间变化的影响在很大程度上是未知的。基于最近的啮齿动物数据，我们假设编码后去甲肾上腺素能刺激可能会改变系统的巩固过程，并维持海马依赖性和特异性的远程记忆。为了验证这一假设，健康的参与者将被给予安慰剂或α2-肾上腺素受体拮抗剂育亨宾，导致增加去甲肾上腺素能刺激后，他们编码了一系列中性和情绪激动的图片。在编码后1天或28天，将在识别测试中测试记忆。为了评估记忆特异性，识别测试将包括，除了旧的和全新的项目，诱饵携带的主旨最初编码的图片以及感知相似的诱饵携带不同的主旨。为了评估假设的系统巩固和编码后去甲肾上腺素能觉醒对记忆转化的神经基础，将在编码和保持测试期间在3 T下对参与者进行功能性磁共振成像扫描。除了对我们理解人类记忆，特别是情感记忆的长期生动性至关重要之外，这个项目的发现可能对异常情感记忆处理突出的精神障碍有影响。