Nicholson Emma L, Bryant Richard A, Felmingham Kim L
School of Psychology, University of Tasmania, Australia.
School of Psychology, University of New South Wales, Australia.
Neurobiol Learn Mem. 2014 Jul;112:204-11. doi: 10.1016/j.nlm.2013.11.018. Epub 2013 Dec 1.
Recent evidence suggests that an interaction of noradrenaline (NE) and cortisol (CORT) during encoding leads to greater consolidation of emotional memories. Convergent models of posttraumatic stress disorder (PTSD) suggest the release of CORT and NE lead to greater intrusive memories in PTSD. This study examined the effect of NE and CORT during encoding on recall and intrusive memories in PTSD. Fifty-eight participants (18 participants with PTSD, 20 trauma-exposed controls, and 20 non-trauma exposed controls) provided saliva samples of NE (indexed by salivary alpha amylase; sAA) and CORT at (a) baseline and (b) after viewing negative emotional stimuli. Delayed memory recall and number of intrusive memories of negative, neutral and positive stimuli were recorded two days after this initial testing session. The PTSD group had greater NE levels to negative stimuli and reported greater numbers of intrusive memories of negative stimuli than controls. Regression analyses revealed that the interaction of CORT and NE significantly predicted negative intrusive memories in the PTSD group. The trauma-exposed group reported significantly greater recall of negative images compared to controls, but did not differ significantly from the PTSD group. The PTSD group reported greater levels of suppression of negative images during encoding compared to the other groups. Our results confirm that the interaction of NE and CORT significantly predicts greater negative intrusive memories, but this occurs specifically in the PTSD group. This suggests that a level of heightened arousal is required for the relationship between stress hormones and emotional memory to manifest in PTSD.
近期证据表明，编码过程中去甲肾上腺素（NE）与皮质醇（CORT）的相互作用会使情绪记忆得到更好的巩固。创伤后应激障碍（PTSD）的趋同模型表明，CORT和NE的释放会导致PTSD患者出现更多侵入性记忆。本研究考察了编码过程中NE和CORT对PTSD患者记忆回忆及侵入性记忆的影响。58名参与者（18名PTSD患者、20名有创伤暴露经历的对照者和20名无创伤暴露经历的对照者）在（a）基线期以及（b）观看负面情绪刺激后提供了NE（以唾液α淀粉酶；sAA为指标）和CORT的唾液样本。在这一初始测试 session 两天后，记录对负面、中性和正面刺激的延迟记忆回忆以及侵入性记忆的数量。与对照者相比，PTSD组对负面刺激的NE水平更高，且报告的负面刺激侵入性记忆数量更多。回归分析显示，CORT和NE的相互作用显著预测了PTSD组的负面侵入性记忆。与对照者相比，有创伤暴露经历的组报告对负面图像的回忆显著更多，但与PTSD组无显著差异。与其他组相比，PTSD组在编码过程中对负面图像的抑制水平更高。我们的结果证实，NE和CORT的相互作用显著预测了更多的负面侵入性记忆，但这一情况仅在PTSD组中出现。这表明，应激激素与情绪记忆之间的关系要在PTSD中表现出来，需要一定程度的唤醒增强。
