捷克和美国研究人员发现，压力能够提高小鼠与此压力环境无关的记忆。研究人员认为，这项发现有助了解创伤后应激障碍（PTSD）病症，寻找更加有效的治疗方法。
走迷宫
捷克科学院、美国纽约州立大学唐斯泰特医学中心和美国洛克菲勒大学研究人员用实验室小鼠进行一系列实验，发现压力环境确实有助小鼠更好地回想起先前所学信息。
研究人员将小鼠放置在一个Ｔ型迷宫中，让它们了解左转和右转的不同结果。第二天，研究人员把一半小鼠放入一大桶水中，迫使小鼠奋力游泳才不致溺死；把另一半小鼠放入浅水中，它们不必游泳也不会溺死。
随后，研究人员将所有小鼠放入迷宫。结果发现，与那些在浅水中的小鼠相比，被迫游泳的小鼠能够更好地记忆起从哪个方向走出迷宫。
增记忆
研究人员又进行一系列实验，观察迷宫出路记忆是受游泳压力影响还是其他外因影响。结果发现，学习迷宫本身并没有对小鼠造成压力，而游泳产生的压力与迷宫出路记忆能力间存在明显联系。
美国每日科学网站21日援引研究负责人、纽约大学神经学中心教授安德里·芬顿的话报道：“我们的结果显示，压力能够刺激记忆，即便这一记忆与承受压力经历无关。”芬顿曾是捷克科学院研究科学家和纽约州立大学唐斯泰特医学中心生理学和药理学副教授。
研究结果由美国《科学公共图书馆生物卷》月刊发表。
助了解
研究人员说，游泳促使小鼠单侧记忆在大脑两半球之间传递，显示压力环境能够刺激小鼠与这一环境不相关的固有记忆。
研究人员由此假设，对人类而言，创伤造成的压力可能激活与创伤无关的记忆，进而联系到创伤记忆，这有助了解创伤后应激障碍与其他情绪紊乱的病理特征。
芬顿说，压力对记忆的影响效果可能有助了解创伤后应激障碍和其他与压力相关的情绪紊乱，帮助医生寻找更加有效的疗法。
创伤后应激障碍和各种情绪紊乱的一个共同特点就是由无害刺激或并不相关的中性环境联想到负面记忆。（生物谷Bioon.com）
生物谷推荐原文出处：
PLoS Biol doi:10.1371/journal.pbio.1000570
Stress-Induced Out-of-Context Activation of Memory
Karel Je?ek1, Benjamin B. Lee2, Eduard Kelemen3, Katharine M. McCarthy4, Bruce S. McEwen4, André A. Fenton1,5,6*
1 Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic, 2 Graduate Program in Neural and behavioral Science, State University of New York, Downstate Medical Center, Brooklyn, New York, United States of America, 3 Department of Physiology and Pharmacology, State University of New York, Downstate Medical Center, Brooklyn, New York, United States of America, 4 Rockefeller University, New York, New York, United States of America, 5 The Robert F. Furchgott Center for Neural and Behavioral Science, State University of New York, Downstate Medical Center, Brooklyn, New York, United States of America, 6 Center for Neural Science, New York University, New York, New York, United States of America
Abstract
Inappropriate recollections and responses in stressful conditions are hallmarks of post-traumatic stress disorder and other anxiety and mood disorders, but how stress contributes to the disorders is unclear. Here we show that stress itself reactivates memories even if the memory is unrelated to the stressful experience. Forced-swim stress one day after learning enhanced memory recall. One-day post-learning amnestic treatments were ineffective unless administered soon after the swim, indicating that a stressful experience itself can reactivate unrelated consolidated memories. The swim also triggered inter-hemispheric transfer of a lateralized memory, confirming stress reactivates stable memories. These novel effects of stress on memory required the hippocampus although the memories themselves did not, indicating hippocampus-dependent modulation of extrahippocampal memories. These findings that a stressful experience itself can activate memory suggest the novel hypothesis that traumatic stress reactivates pre-trauma memories, linking them to memory for the trauma and pathological facilitation of post-traumatic recall.
Author Summary
This work identifies a powerful effect of stressful experiences on memories. We report that a single intensely stressful experience can activate memories in a situation that has essentially no physical or motivational relationship to the stressful experience. Using a forced-swim test as a stressor in rats, we find that this treatment was able to activate unrelated memories formed 24 hours earlier. We also find that the hippocampus of the brain is required for this effect of stress but that recall of the memories themselves does not. The ability of stress to activate memories that are unrelated to the stressful event may help to explain how memories can sometimes become pathological and uncontrollable following traumatic events, as in post-traumatic stress disorder. Our findings suggest the novel hypothesis that the stress of the traumatic event activates neutral, unrelated memories, which then become associated with the traumatic event. Subsequent normal recall of the neutral memories can more easily trigger inappropriate recall of the traumatic event, initiating another bout of stress and inappropriate associations of neutral and traumatic memories.
