Harrington Marcus O, Pennington Kyla, Durrant Simon J
School of Psychology, College of Social Science, University of Lincoln, Brayford Pool, Lincoln LN6 7TS, United Kingdom.
Neurobiol Learn Mem. 2017 Apr;140:43-51. doi: 10.1016/j.nlm.2017.02.003. Epub 2017 Feb 15.
Since the 1960's polysomnographic sleep research has demonstrated that depressive episodes are associated with REM sleep alterations. Some of these alterations, such as increased REM sleep density, have also been observed in first-degree relatives of patients and remitted patients, suggesting that they may be vulnerability markers of major depressive disorder (MDD), rather than mere epiphenomena of the disorder. Neuroimaging studies have revealed that depression is also associated with heightened amygdala reactivity to negative emotional stimuli, which may also be a vulnerability marker for MDD. Several models have been developed to explain the respective roles of REM sleep alterations and negatively-biased amygdala activity in the pathology of MDD, however the possible interaction between these two potential risk-factors remains uncharted. This paper reviews the roles of the amygdala and REM sleep in the encoding and consolidation of negative emotional memories, respectively. We present our 'affect tagging and consolidation' (ATaC) model, which argues that increased REM sleep density and negatively-biased amygdala activity are two separate, genetically influenced risk-factors for depression which interact to promote the development of negative memory bias - a well-known cognitive vulnerability marker for depression. Predictions of the ATaC model may motivate research aimed at improving our understanding of sleep dependent memory consolidation in depression aetiology.
自20世纪60年代以来，多导睡眠图睡眠研究表明，抑郁发作与快速眼动（REM）睡眠改变有关。其中一些改变，如REM睡眠密度增加，在患者的一级亲属和康复患者中也有观察到，这表明它们可能是重度抑郁症（MDD）的易感性标志物，而不仅仅是该疾病的附带现象。神经影像学研究表明，抑郁症还与杏仁核对负面情绪刺激的反应性增强有关，这也可能是MDD的易感性标志物。已经开发了几种模型来解释REM睡眠改变和杏仁核负性偏向活动在MDD病理中的各自作用，然而这两个潜在风险因素之间可能的相互作用仍不清楚。本文分别综述了杏仁核和REM睡眠在负性情绪记忆编码和巩固中的作用。我们提出了“情感标记与巩固”（ATaC）模型，该模型认为REM睡眠密度增加和杏仁核负性偏向活动是抑郁症两个独立的、受基因影响的风险因素，它们相互作用促进负性记忆偏向的发展——这是抑郁症一个众所周知的认知易感性标志物。ATaC模型的预测可能会推动旨在增进我们对抑郁症病因中睡眠依赖性记忆巩固理解的研究。
