飞翔的龙血沸腾小说:5-羟色胺：人类怒火的主宰

记者：凯特·凯兰德   编辑：保罗·凯斯凯托

发稿地：伦敦

发稿时间：2011年9月15日

(Reuters) - Fluctuating levels of the brain chemical serotonin, often brought on when someone hasn't eaten or is stressed, affect brain regions that enable people to regulate anger, scientists said Thursday.

路透社报道：周四，科学家发表研究结果称，当人在忍受饥饿或经受压力时，人脑中的化学物质5-羟色胺浓度会发生波动，而这一物质的浓度水平会影响到人用来控制愤怒情绪的脑部活动区域。

In a study using healthy volunteers, researchers from Britain's Cambridge University found that when serotonin levels are low, it may be more difficult for the brain to control emotional responses to anger.

英国剑桥大学的科研小组在研究中针对健康人群志愿者进行了研究，他们发现，当5-羟色胺浓度降低时，人脑控制愤怒情绪可能变得更为困难。

Although reduced serotonin levels have previously been linked to aggression, this is the first study to show how this chemical helps regulate behavior in the brain as well as why some individuals may be more prone to aggression.

尽管过去就有研究将5-羟色胺浓度降低与暴力倾向联系在一起，但这仍是一项新研究来展示这种化学物质是如何帮助大脑活动并揭示为什么某些个体更倾向暴力行为。

The researchers behind the work, which was published in the journal Biological Psychiatry, hope their findings could help in the search for new treatments for psychiatric disorders where violence and aggression are common symptoms.

    已将这一研究成果发表在《生物精神病学》杂志上的这些科学家们希望，他们的发现能够对找寻到躁狂型精神病新的治疗方案有所帮助。

For the study, healthy volunteers' serotonin levels were altered by manipulating their diet. On the serotonin depletion day, they were given a mixture of amino acids that lacked tryptophan, the building block for serotonin. On the placebo day, they were given the same mixture but with a normal amount of tryptophan.

    研究中，志愿者的5-羟色胺浓度靠饮食来调节。在5-羟色胺水平低下的实验日，志愿者食用的氨基酸混合物中清除了色氨酸，色氨酸正是5-羟色胺的储存体。而在对照日中，他们食用的混合物中存有正常含量的色氨酸。

The researchers then scanned the volunteers' brains using functional magnetic resonance imaging (fMRI) as they viewed faces with angry, sad, and neutral expressions. They were able to measure how different brain regions reacted and communicated with one another when the volunteers saw angry faces, as opposed to sad or neutral faces.

科学家于是利用磁共振成像对志愿者的大脑进行扫描，分别于其面部表情呈现愤怒、悲伤及正常时进行。这样，科学家就能够测量大脑内不同区域是如何活动、并不同区域间是如何进行交流的；并将其面部表情呈现愤怒时的大脑活动与呈现悲伤及正常时的做出对比。

The results showed that low brain serotonin made communications between specific brain regions of the emotional limbic system of the brain -- a structure called the amygdala -- and the frontal lobes weaker compared to when serotonin levels are normal.

结果显示，低5-羟色胺浓度与正常浓度比较，低浓度时大脑中控制情绪的大脑边缘系统区域——杏仁核——与大脑前庭间的交流变得更为微弱。

Using a personality questionnaire, the researchers also analysed which of the volunteers had a natural tendency to behave aggressively. In these people, the communications between the amygdala and the prefrontal cortex was even weaker following serotonin depletion.

科学家们同时利用人格问卷来分析出些志愿者的人格特征，他们有中等水平的暴力倾向。在这些人中，当5-羟色胺浓度低下时，其大脑杏仁核与前额皮质间的交流甚至更为微弱。

"Although these results came from healthy volunteers, they are also relevant for a broad range of psychiatric disorders," said Luca Passamonti, who worked on the research with colleagues at the Cognition and Brain Sciences Unit of the Medical Research Council in Cambridge.

剑桥医疗研究中心的大脑与认知研究室的科学家 卢卡·帕斯蒙迪说：“尽管研究成果是基于健康志愿者得出的，但它仍与大范围的精神异常很有相关性。”

For example, Passamonti said, patients with an condition known as intermittent explosive disorder (IED) typically can have intense, uncontrollable outbursts of violence which may be triggered by cues such as a facial expression of anger."We are hopeful that our research will lead to improved diagnostics as well as better treatments for this and other conditions."

帕斯蒙迪举例说，患有间歇性暴力异常的的病人，当他们哪怕只看到一个发怒的表情，就会引发其暴力冲动，并无法控制其暴力行为的发生。“我们希望我们的研究能够改进对这种疾病的诊断并找到更好的治疗方案。”