首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
考研
Researchers have both created and relieved symptoms of obsessive-compulsive disorder(OCD)in genetically modified mice using a te
Researchers have both created and relieved symptoms of obsessive-compulsive disorder(OCD)in genetically modified mice using a te
admin
2016-10-15
52
问题
Researchers have both created and relieved symptoms of obsessive-compulsive disorder(OCD)in genetically modified mice using a technique that turns brain cells on and off with light, known as optogenetics. The work, by two separate teams, confirms the neural circuits that contribute to the condition and points to treatment targets. It also provides insight into how quickly compulsive behaviors can develop—and how quickly they might be soothed.
Brain scanning in humans with OCD has pointed to two areas—the orbitofrontal cortex, just behind the eyes, and the striatum, a hub in the middle of the brain—as being involved in the condition’ s characteristic repetitive and compulsive behaviors. But "in people we have no way of testing cause and effect", says Susanne Ahmari, a psychiatrist and neuroscientist at Columbia University in New York who led one of the studies. It is not clear, for example, whether abnormal brain activity causes the compulsions, or whether the behavior simply results from the brain trying to hold symptoms at bay by compensating.
Ahmari’s team wanted to see if optogenetics could prompt repetitive grooming in mice. The team injected viruses into the orbitofrontal cortex carrying genes for light-sensitive proteins. The researchers then inserted an optical fiber to shine a light on these cells for a few minutes a day. It was only after a few days that they started to see the compulsive behavior.
In the second study, researchers at the Massachusetts Institute of Technology(MIT)in Cambridge used a mouse model of repetitive behavior in which the mice carried a mutation in a gene involved in creating neuronal connections. The researchers conditioned both mutant and control mice to groom when water was dripped on their foreheads. After a series of trials, the mutants began to groom even without a water drop.
The team then used optogenetics to stimulate neurons in the orbitofrontal cortex that feed into the striatum. This is a similar but not overlapping group of cells to the neural circuit studied by Ahmari’s team. "Within a matter of a second or two, a behavioral change occurs," says Ann Graybiel, who co-authored the MIT study. The abnormal grooming disappeared, leaving behind only the normal reaction to the water drop.
She was doubly surprised that the cortex—the area associated with executive, even conscious control of behavior—could be at the root of such an automatic response. "Everybody has thought that when we get these compulsive behaviors or really strong habits, then these behaviors
reel off
by themselves," she says. Instead, the orbitofrontal cortex can send a "stop" signal to other brain regions concerned with more automatic movements.
Such a rapid relief from symptoms contrasts with how long it took the Columbia team to create the symptoms in their mice. This could have been related to the fact that the types of mice used by the two teams were different, Ahmari says, and that they examined slightly different circuits, albeit within the same broad areas.
According to the passage, which one of the following is true of the second study—MIT team?
选项
A、The researchers injected viruses into the orbitofrontal cortex carrying genes for light-sensitive proteins.
B、The researchers inserted an optical fiber to shine a light on these cells for a few minutes a day.
C、The researchers used a mouse model of repetitive behavior in which the mice carried a mutation in a gene involved in creating neuronal connections.
D、The researchers conditioned both mutant and control mice to groom when water was dripped on their feet.
答案
C
解析
本题考查考生对文中所述两个实验研究的理解和把握。题目考查的是关于第二项实验研究哪一个说法是正确的。文章从第四段开始介绍第二项实验,第四段第一句就指出在第二项研究中,剑桥的麻省理工学院(MIT)的研究人员使用了重复行为的小鼠模型,这些小老鼠携带了参与生成神经元连接的变异基因。因此,[C]是正确选项。第四段接下来说道,研究人员设法使变异基因组和参照组的小鼠当水滴落到他们前额时作出梳理动作,而非脚上,因此[D]错误。[A]和[B]选项都出现在文章的第三段,都是关于第一项实验研完的描述,而非第二项,因此均不正确。
转载请注明原文地址:https://kaotiyun.com/show/pUoZ777K
0
考研英语一
相关试题推荐
Nowcustomhasnotbeencommonlyregardedasasubjectofanygreatimportance.Theinnerworkingsofourownbrainswefeelto
Nowcustomhasnotbeencommonlyregardedasasubjectofanygreatimportance.Theinnerworkingsofourownbrainswefeelto
Nowcustomhasnotbeencommonlyregardedasasubjectofanygreatimportance.Theinnerworkingsofourownbrainswefeelto
Nowcustomhasnotbeencommonlyregardedasasubjectofanygreatimportance.Theinnerworkingsofourownbrainswefeelto
Doctorshavetreatedthefirstreportedcaseof"Internetaddictiondisorder"broughtonbyexcessiveuseofGoogleGlass.I
Doctorshavetreatedthefirstreportedcaseof"Internetaddictiondisorder"broughtonbyexcessiveuseofGoogleGlass.I
Doctorshavetreatedthefirstreportedcaseof"Internetaddictiondisorder"broughtonbyexcessiveuseofGoogleGlass.I
随机试题
既能退虚热,又能截疟的药物是
A、开路粉碎B、闭塞粉碎C、干法粉碎D、循环粉碎E、自由粉碎连续把粉碎物料供给粉碎机的同时不断地从粉碎机中把已粉碎的细物料取出为()。
根据《行政处罚法》,下列表述正确的有()。
某电器公司经过分析和调查,消费者的生活方式正在发生变化,喜欢足不出户就能满足自己的需求,所以电器公司也开通了网上购物,实现了电商模式,该电器公司的消费细分属于()。
社会工作者为某打工子弟中学的新生设立了“大哥哥大姐姐”项目,其主要内容包括帮助新生适应学校生活,并在他们学习遇到困难的时候提供课业辅导,促进新老学生的交流。该项目属于()青少年社会工作。
分腿腾越练习时,保护者应站在()。
汇率目标区[中国人民银行2000研]
在一台Cisco路由器的g0/1端口上,用标准访问控制列表禁止源地址为10.0.0.0-10.255.255.255和172.16.0.0-172.31.255.255的数据包进出路由器。下列access-list配置,正确的是()。
Theideaofhelpingpeoplecomesnaturallytomostofus.Ifweseeablindpersongettingoffabus,wewatchtomakesurethat
LocalHospitaltoHaveBetterFacilitiesAKRON,Ohio,August14-TheMargaretLabonteMemorialHospitalwillsoonhaveimproved
最新回复
(
0
)