精神分裂症可导致脑神经连接受损
文章来源:未知 文章作者:meng 发布时间:2010-04-01 02:54 字体: [ ]  进入论坛
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The strongest known recurrent(周期性的,复发的) genetic1 cause of schizophrenia(精神分裂症) impairs2 communications between the brain's decision-making and memory hubs(枢纽,中心) , resulting in working memory deficits4, according to a study in mice. "For the first time, we have a powerful animal model that shows us how genetics affects brain circuitry(电路,线路) , at the level of single neurons(神经原,神经细胞) , to produce a learning and memory deficit3 linked to schizophrenia," explained Thomas R. Insel, M.D., director of the National Institute of Mental Health (NIMH), part of the National Institutes of Health. "This new research tool holds promise for ultimately unraveling(解开,阐明) the underlying5 anatomical(解剖的,结构上的) connections and specific genes6 involved."

NIMH grantees Joshua Gordon, M.D., Ph.D., Joseph Gogos, M.D., Ph.D., Maria Karayiorgou, M.D., and Columbia University colleagues, report on their discovery in genetically7 engineered mice in the April 1, 2010 issue of the journal Nature.

"Our findings pinpoint8(查明) a specific circuit and mechanism9 by which a mutation10 produces a core feature of the disorder11," said Gordon, who led the research.

Researchers have suspected such a brain connectivity disturbance12 in schizophrenia for more than a century, and the NIH has launched a new initiative(主动权,首创精神) on the brain's functional13 circuitry, or connectome(连接体) . Although the disorder is thought to be 70 percent heritable(可继承的) , its genetics are dauntingly14(令人生畏地,吓人地) complex, except in certain rare cases, such as those traced to the mutation in question.

Prior to this study, neuroimaging(神经成像) studies in schizophrenia patients had found abnormal connections between the brain's prefrontal(前额的) cortex(皮质,树皮) , the executive hub, and the hippocampus(海马体) , the memory hub, linked to impaired15 working memory. It was also known that a mutation in the suspect site on chromosome16 22, called 22q11.2, boosts schizophrenia risk 30-fold and also causes other abnormalities). Although accounting17 for only a small portion of cases, this tiny missing section of genetic material, called a microdeletion(缺失) , has repeatedly turned up in genetic studies of schizophrenia and is an indisputable(明白的) risk factor for the illness.

Still, the mutation's link to the disturbed connectivity and working memory deficit eluded18(逃避,躲避) detection until now.

To explore the mutation's effects on brain circuitry, Gogos, Karayiorgou and colleagues engineered a line of mice expressing the same missing segment of genetic material as the patients. Strikingly, like their human counterparts with schizophrenia, these animals turned out to have difficulty with working memory tasks – holding information in mind from moment to moment.

Successful performance of such tasks depends on good connections in a circuit linking the prefrontal cortex and the hippocampus. To measure such functional connections, Gordon and colleagues monitored signals emitted by single neurons implanted in the two distant brain structures while mice performed a working memory task in a T-maze.

The more in-sync the neurons from the two areas fired, the better the functional connections between the two structures – and the better the mice performed the task. Moreover, the better the synchrony to start with, the quicker the animals learned the task. The more synchrony(同步) improved, the better they performed.

As suspected, the mice with the chromosome(染色体) 22 mutation faltered19 on all counts -- showing much worse synchrony, learning and performance levels than control mice.

"Our results extend beyond those in patients by showing how an undeniable genetic risk factor for schizophrenia can disrupt connectivity at the level of single neurons," explained Gordon.

The researchers plan to follow up with studies into how the mutation affects brain anatomical and molecular20 connections and the workings of affected21 genes.



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1 genetic PgIxp     
adj.遗传的,遗传学的
参考例句:
  • It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
  • Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。
2 impairs 866bc0da43dd90e04b6073750ff1e87c     
v.损害,削弱( impair的第三人称单数 )
参考例句:
  • Smoking impairs our health. 吸烟会损害我们的健康。 来自《简明英汉词典》
  • Almost anything that impairs liver function can cause hepatitis. 任何有损于肝功能的因素,几乎都会引起肝炎。 来自辞典例句
3 deficit tmAzu     
n.亏空,亏损;赤字,逆差
参考例句:
  • The directors have reported a deficit of 2.5 million dollars.董事们报告赤字为250万美元。
  • We have a great deficit this year.我们今年有很大亏损。
4 deficits 08e04c986818dbc337627eabec5b794e     
n.不足额( deficit的名词复数 );赤字;亏空;亏损
参考例句:
  • The Ministry of Finance consistently overestimated its budget deficits. 财政部一贯高估预算赤字。 来自《简明英汉词典》
  • Many of the world's farmers are also incurring economic deficits. 世界上许多农民还在遭受经济上的亏损。 来自辞典例句
5 underlying 5fyz8c     
adj.在下面的,含蓄的,潜在的
参考例句:
  • The underlying theme of the novel is very serious.小说隐含的主题是十分严肃的。
  • This word has its underlying meaning.这个单词有它潜在的含义。
6 genes 01914f8eac35d7e14afa065217edd8c0     
n.基因( gene的名词复数 )
参考例句:
  • You have good genes from your parents, so you should live a long time. 你从父母那儿获得优良的基因,所以能够活得很长。 来自《简明英汉词典》
  • Differences will help to reveal the functions of the genes. 它们间的差异将会帮助我们揭开基因多种功能。 来自英汉非文学 - 生命科学 - 生物技术的世纪
7 genetically Lgixo     
adv.遗传上
参考例句:
  • All the bees in the colony are genetically related. 同一群体的蜜蜂都有亲缘关系。
  • Genetically modified foods have already arrived on American dinner tables. 经基因改造加工过的食物已端上了美国人的餐桌。 来自英汉非文学 - 生命科学 - 基因与食物
8 pinpoint xNExL     
vt.准确地确定;用针标出…的精确位置
参考例句:
  • It is difficult to pinpoint when water problems of the modern age began.很难准确地指出,现代用水的问题是什么时候出现的。
  • I could pinpoint his precise location on a map.我能在地图上指明他的准确位置。
9 mechanism zCWxr     
n.机械装置;机构,结构
参考例句:
  • The bones and muscles are parts of the mechanism of the body.骨骼和肌肉是人体的组成部件。
  • The mechanism of the machine is very complicated.这台机器的结构是非常复杂的。
10 mutation t1PyM     
n.变化,变异,转变
参考例句:
  • People who have this mutation need less sleep than others.有这种突变的人需要的睡眠比其他人少。
  • So far the discussion has centered entirely around mutation in the strict sense.到目前为止,严格来讲,讨论完全集中于围绕突变问题上。
11 disorder Et1x4     
n.紊乱,混乱;骚动,骚乱;疾病,失调
参考例句:
  • When returning back,he discovered the room to be in disorder.回家后,他发现屋子里乱七八糟。
  • It contained a vast number of letters in great disorder.里面七零八落地装着许多信件。
12 disturbance BsNxk     
n.动乱,骚动;打扰,干扰;(身心)失调
参考例句:
  • He is suffering an emotional disturbance.他的情绪受到了困扰。
  • You can work in here without any disturbance.在这儿你可不受任何干扰地工作。
13 functional 5hMxa     
adj.为实用而设计的,具备功能的,起作用的
参考例句:
  • The telephone was out of order,but is functional now.电话刚才坏了,但现在可以用了。
  • The furniture is not fancy,just functional.这些家具不是摆着好看的,只是为了实用。
14 dauntingly 40d8002313ec2fcefad2feb55d7944c3     
参考例句:
  • She is dauntingly articulate. 她的能言善辩令人敬畏。 来自柯林斯例句
15 impaired sqtzdr     
adj.受损的;出毛病的;有(身体或智力)缺陷的v.损害,削弱( impair的过去式和过去分词 )
参考例句:
  • Much reading has impaired his vision. 大量读书损害了他的视力。 来自《现代汉英综合大词典》
  • His hearing is somewhat impaired. 他的听觉已受到一定程度的损害。 来自《现代汉英综合大词典》
16 chromosome 7rUzX     
n.染色体
参考例句:
  • Chromosome material with exhibits of such behaviour is called heterochromatin.表现这种现象的染色体物质叫做异染色质。
  • A segment of the chromosome may become lost,resulting in a deletion.染色体的一个片段可能会丢失,结果产生染色体的缺失。
17 accounting nzSzsY     
n.会计,会计学,借贷对照表
参考例句:
  • A job fell vacant in the accounting department.财会部出现了一个空缺。
  • There's an accounting error in this entry.这笔账目里有差错。
18 eluded 8afea5b7a29fab905a2d34ae6f94a05f     
v.(尤指机敏地)避开( elude的过去式和过去分词 );逃避;躲避;使达不到
参考例句:
  • The sly fox nimbly eluded the dogs. 那只狡猾的狐狸灵活地躲避开那群狗。 来自《现代汉英综合大词典》
  • The criminal eluded the police. 那个罪犯甩掉了警察的追捕。 来自《现代英汉综合大词典》
19 faltered d034d50ce5a8004ff403ab402f79ec8d     
(嗓音)颤抖( falter的过去式和过去分词 ); 支吾其词; 蹒跚; 摇晃
参考例句:
  • He faltered out a few words. 他支吾地说出了几句。
  • "Er - but he has such a longhead!" the man faltered. 他不好意思似的嚅嗫着:“这孩子脑袋真长。”
20 molecular mE9xh     
adj.分子的;克分子的
参考例句:
  • The research will provide direct insight into molecular mechanisms.这项研究将使人能够直接地了解分子的机理。
  • For the pressure to become zero, molecular bombardment must cease.当压强趋近于零时,分子的碰撞就停止了。
21 affected TzUzg0     
adj.不自然的,假装的
参考例句:
  • She showed an affected interest in our subject.她假装对我们的课题感到兴趣。
  • His manners are affected.他的态度不自然。
TAG标签: genetic brain memory
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