一组来自瑞士和德国的科学家最近发现了一段可以增强情感记忆的基因序列,而这种情感记忆的维持通常与创伤后应激综合征(PTSD)关系密切。研究团队通过对大样本随机人群进行情感记忆测试,并将此与一组来自1994年卢旺达大屠杀中的幸存者进行比对,他们发现了情感记忆与PTSD的遗传关系。
为了证实PRKCA基因突变的个体可能会拥有更强烈的情感记忆,研究团队征募了700名志愿者进行了该测试。参与者首先进行DNA测序,然后观看一组情感事件的图片并在数分钟后描述他们所看到的内容细节。结果显示拥有2个PRKCA突变拷贝的人群可唤起更多的细节,另一组拥有1对G片段的人群则表现的不是很理想,而同时拥有1个PRKCA突变片段与1个G片段的人群则变现适中。
为了得到更精确的结果,研究团队征募了另外394名志愿者进行了相同的测试,但是这次志愿者被要求在fMRI的检测中完成测试,整个过程研究者可以观察到志愿者的脑部磁共振变化。与预估的结果相同,研究者发现在所有的参与者脑中负责记忆的区域在测试过程中特别活跃。那些拥有一对突变基因序列的志愿者显示较一对G序列的拥有更高的活性,与此前相同,各拥有1个基因的志愿者结果适中。
证实了他们的设想后,研究组测试了347个卢旺达大屠杀的幸存者。他们发现仍然被PTSD折磨的幸存者中拥有1对突变基因的占了绝大部分,而且这些人发生PTSD的概率大概是没有或者只有1个突变基因的2倍。
研究团队从这些结果中得出结论,PRKCA突变基因位点和情感记忆存在紧密的联系,这为以后研究创伤后应激综合征开拓了新的方向。(生物谷:Bioon.com)
doi: 10.1073/pnas.1200857109
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PKCα is genetically linked to memory capacity in healthy subjects and to risk for posttraumatic stress disorder in genocide survivors
Dominique J.-F. de Quervain,Iris-Tatjana Kolassad, Sandra Ackermanne, Amanda Aernia, et al.
Strong memory of a traumatic event is thought to contribute to the development and symptoms of posttraumatic stress disorder (PTSD). Therefore, a genetic predisposition to build strong memories could lead to increased risk for PTSD after a traumatic event. Here we show that genetic variability of the gene encoding PKCα (PRKCA) was associated with memory capacity—including aversive memory—in nontraumatized subjects of European descent. This finding was replicated in an independent sample of nontraumatized subjects, who additionally underwent functional magnetic resonance imaging (fMRI). fMRI analysis revealed PRKCA genotype-dependent brain activation differences during successful encoding of aversive information. Further, the identified genetic variant was also related to traumatic memory and to the risk for PTSD in heavily traumatized survivors of the Rwandan genocide. Our results indicate a role for PKCα in memory and suggest a genetic link between memory and the risk for PTSD.