捷克和美國研究人員發(fā)現(xiàn),，壓力能夠提高小鼠與此壓力環(huán)境無關(guān)的記憶。研究人員認(rèn)為,，這項發(fā)現(xiàn)有助了解創(chuàng)傷后應(yīng)激障礙（PTSD）病癥,，尋找更加有效的治療方法。
走迷宮
捷克科學(xué)院,、美國紐約州立大學(xué)唐斯泰特醫(yī)學(xué)中心和美國洛克菲勒大學(xué)研究人員用實驗室小鼠進(jìn)行一系列實驗,，發(fā)現(xiàn)壓力環(huán)境確實有助小鼠更好地回想起先前所學(xué)信息。
研究人員將小鼠放置在一個Ｔ型迷宮中,，讓它們了解左轉(zhuǎn)和右轉(zhuǎn)的不同結(jié)果,。第二天，研究人員把一半小鼠放入一大桶水中,，迫使小鼠奮力游泳才不致溺死,；把另一半小鼠放入淺水中，它們不必游泳也不會溺死,。
隨后,，研究人員將所有小鼠放入迷宮。結(jié)果發(fā)現(xiàn),，與那些在淺水中的小鼠相比,，被迫游泳的小鼠能夠更好地記憶起從哪個方向走出迷宮。
增記憶
研究人員又進(jìn)行一系列實驗,，觀察迷宮出路記憶是受游泳壓力影響還是其他外因影響,。結(jié)果發(fā)現(xiàn)，學(xué)習(xí)迷宮本身并沒有對小鼠造成壓力,，而游泳產(chǎn)生的壓力與迷宮出路記憶能力間存在明顯聯(lián)系,。
美國每日科學(xué)網(wǎng)站21日援引研究負(fù)責(zé)人、紐約大學(xué)神經(jīng)學(xué)中心教授安德里·芬頓的話報道：“我們的結(jié)果顯示，壓力能夠刺激記憶,，即便這一記憶與承受壓力經(jīng)歷無關(guān),。”芬頓曾是捷克科學(xué)院研究科學(xué)家和紐約州立大學(xué)唐斯泰特醫(yī)學(xué)中心生理學(xué)和藥理學(xué)副教授。
研究結(jié)果由美國《科學(xué)公共圖書館生物卷》月刊發(fā)表,。
助了解
研究人員說,，游泳促使小鼠單側(cè)記憶在大腦兩半球之間傳遞，顯示壓力環(huán)境能夠刺激小鼠與這一環(huán)境不相關(guān)的固有記憶,。
研究人員由此假設(shè),，對人類而言，創(chuàng)傷造成的壓力可能激活與創(chuàng)傷無關(guān)的記憶,，進(jìn)而聯(lián)系到創(chuàng)傷記憶,，這有助了解創(chuàng)傷后應(yīng)激障礙與其他情緒紊亂的病理特征。
芬頓說,，壓力對記憶的影響效果可能有助了解創(chuàng)傷后應(yīng)激障礙和其他與壓力相關(guān)的情緒紊亂,，幫助醫(yī)生尋找更加有效的療法。
創(chuàng)傷后應(yīng)激障礙和各種情緒紊亂的一個共同特點就是由無害刺激或并不相關(guān)的中性環(huán)境聯(lián)想到負(fù)面記憶,。（生物谷Bioon.com）
生物谷推薦原文出處：
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.
