Neuroscience Bulletin ：发现疑似抑郁易感基因

近日，我国科学家成功发现一个可能的焦虑或抑郁易感基因。相关研究成果作为封面文章日前发表在《神经科学通报》（Neuroscience Bulletin ）上。

情感障碍（例如焦虑和抑郁）在全球范围内具有较高的发病率，往往给病人造成心理和生活上的诸多困扰和障碍，严重者更会表现出自杀倾向。此前研究发现，在高加索人（也称白种人）中，编码5-羟色胺转运体蛋白的5-HTTLPR基因对焦虑和抑郁的发生至关重要。5-HTTLPR短等位基因的存在，对于白种人而言，往往暗示着发生焦虑和抑郁的较大可能性。然而，在亚洲人群中这种关联是否存在仍是个谜。

中科院自动化研究所教授蒋田仔和天津医科大学总医院教授于春水带领团队通过对233位健康的中国汉族受试者运用功能磁共振成像（fMRI）和磁共振弥散张量成像（DTI），比较了5-HTTLPR长、短等位基因携带者大脑中脑区间的功能与结构连接的变化。他们意外发现，5-HTTLPR长等位基因携带者较短纯合子携带者具有更高的焦虑分值，并且静息状态下前额叶皮层—杏仁核的功能和结构连接显著减弱。

相关系数检验显示，这两个脑区间的功能连接与焦虑程度呈显著负相关，并且结构连接与抑郁程度也呈显著负相关。这些结果表明，与白种人不同，在中国汉族人群中，5-HTTLPR的长等位基因可能是焦虑或抑郁的易感基因。

据悉，该杂志同期还为此刊发了“亮点评述”。中国医科大学教授徐克和美国耶鲁大学教授王菲表示，这项研究成果对于认识神经网络处理情感信息的结构和功能基础具有长远而积极的意义，同时也增加了人们对焦虑和抑郁病理机制的认识。更为重要的是，这些发现明确了基因对于神经信号处理的重要性以及研究精神紊乱时考虑种族背景的重要性。 

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The long rather than the short allele of 5-HTTLPR predisposes Han Chinese to anxiety and reduced connectivity between prefrontal cortex and amygdala

Haixia Long1,*, Bing Liu1,*, Bing Hou1, Chao Wang2, Jin Li1, Wen Qin3, Dawei Wang3, Yuan Zhou4, Keith M. Kendrick2, Chunshui Yu3, Tianzi Jiang1,2,5

The short allele of the serotonin-transporter gene is associated with higher risk for anxiety and depression in Caucasians, but this association is still unclear in Asians. Here, we addressed this issue using behavioral and multi-modal MRI approaches in a large group of healthy Han Chinese participants (n = 233). In contrast to findings in Caucasians, we found that long-allele (L) carriers had higher anxiety scores. In another group (n = 64) experiencing significant levels of depression or anxiety, the L-allele frequency was also significantly higher. In healthy participants, L-carriers had reduced functional and anatomical connectivity between the amygdala and prefrontal cortex (PFC), which was correlated with anxiety or depression scores. Our findings demonstrated that in Chinese Han participants, in contrast to Caucasians, the L-allele confers vulnerability to anxiety or depression and weakens top-down emotional control between the PFC and amygdala. Therefore, ethnic background should be taken into account in generelated studies and their potential clinical applications。