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，记忆被认为会经历神经重组，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质网络。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的、类似要点的记忆的转变。系统整合是否可以调整很大程度上还是未知数。众所周知，情绪唤醒诱导的去甲肾上腺素是初始记忆形成的强大调节剂，通过增加杏仁核活动来增加记忆强度和生动性，并增强海马对记忆的参与。尽管众所周知，去甲肾上腺素可以增强记忆的初始巩固，但其对系统巩固过程和记忆特异性随时间变化的影响在很大程度上尚不清楚。根据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整合过程并维持海马体依赖性和特异性的远程记忆。为了检验这一假设，健康参与者在编码一系列中性且情绪激动的图片后，将服用安慰剂或α2-肾上腺素受体拮抗剂育亨宾，从而增加去甲肾上腺素能刺激。编码后 1 天或 28 天将在识别测试中测试记忆力。为了评估记忆特异性，除了旧的和完全新颖的项目之外，识别测试还将包括带有最初编码图片要点的诱饵以及带有不同要点的感知相似的诱饵。为了评估假设的系统整合和编码后去甲肾上腺素能唤醒对记忆转化的神经基础，在编码和保留测试期间，将使用 3T 功能磁共振成像对参与者进行扫描。除了对我们对人类记忆的一般理解，特别是情绪记忆的长期生动性的理解至关重要之外，该项目的研究结果可能对异常情绪记忆处理突出的精神障碍产生影响。