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
医学
Scientists used to believe adult brains did not grow any new neurons, but it has emerged that new neurons can sprout in the brai
Scientists used to believe adult brains did not grow any new neurons, but it has emerged that new neurons can sprout in the brai
admin
2013-11-14
22
问题
Scientists used to believe adult brains did not grow any new neurons, but it has emerged that new neurons can sprout in the brains of adult rats, birds and even humans. Understanding the process could be important, for finding ways to treat diseases such as Alzheimer’s in which neurons are destroyed.
Most neurons sprouting in adulthood seem to be in the hippocampus, a structure involved in learning and memory. But they rarely survive more than a few weeks. "We thought they were possibly dying because they were deprived of some sort of input," says Elizabeth Gould, a neuroscientist at Princeton. Because of the location, Gould and her colleagues suspect that learning itself might bolster the new neurons’ survival, and that only tasks involving the hippocampus would do the trick.
To test this, they injected adult male rats with a substance that labeled newborn neurons so that they could be tracked. Later, they gave some of the rats standard tasks. One involved using visual and spatial cues, such as posters on a well, to learn to find a platform hidden under murky water. In another, the rats learnt to associate a noise with a tiny shock half a second later. Both these tasks use the hippocampus — if this structure is damaged, rats can’t do them.
Meanwhile, the researchers gave other rats similar tasks that did not require the hippocampus finding a platform that was easily visible in water, for instance. Other members of the control group simply paddled in a tub of water or listened to noises.
The team reported in Nature Neuroscience that the animals given the tasks that activate the hippocampus kept twice as many of their new neurons alive as the others. "Learning opportunities increase the number of neurons," says Gould.
But Fred Gage and his colleagues at the Salk Institute for Biological Studies in La Jolla, California, dispute this. In the same issue of Nature Neuroscience, they reported that similar water maze experiments on mice did not help new neurons survive.
Gould thinks the difference arose because the groups labeled new neurons at different times. She gave the animals tasks two weeks after the neurons were labeled. When the new cells would normally be dying, she thinks the Salk group put their mice to work too early for new neurons to benefit. "By the time the cells were degenerating, the animals were not learning anything." she says.
Which of the following can clearly tell the two groups of rats from each other in the test?
选项
A、The water used.
B、The noises played.
C、The neurons newly born.
D、The hippocampus involved.
答案
D
解析
题干:在测试中,下列哪一个能清晰地将两组老鼠辨别开来?此题为细节定位题,原文中的第四段第一句话可以得出答案。
转载请注明原文地址:https://kaotiyun.com/show/DJU3777K
本试题收录于:
医学博士外语题库考研分类
0
医学博士外语
考研
相关试题推荐
Severalclassesofbittercitruscompoundhavelookedpromisingasanticanceragentsinlaboratorytests.Anewstudyindicates
Imagineadiseasespreadingacrosstheglobe,killingmostlymiddle-agedpeopleorleavingthemchronicallydisabled.Thenoned
Imagineadiseasespreadingacrosstheglobe,killingmostlymiddle-agedpeopleorleavingthemchronicallydisabled.Thenoned
Englishspeakerspickuppitchintherighthemispheresoftheirbrains,butspeakersofcertainotherlanguagesperceiveiton
Youfeelgenerallydepressedandunabletoconcentrate.Your【C1】______ofdailyactivitymaychange;youfindyourself【C2】______a
Sheisregardedasagoodnurseinthatsheattendstopatientswithoutanycomplaint.
Twoequallybrilliantscientistsapplyforaprestigiousresearchfellowshipawardedbyatopscientificorganization.Oneiswh
WhenwerecallastoryofidenticaloffspringofAdolfHitlerbeingraisedinordertofurtherhishorriblework,weareoutrage
A、Psychosocialeffectsofbreastsurgery.B、Lifecrisesofcancerpatients.C、Femaleself-imageinsociety.D、Awoman’spercept
Folkwisdomholdsthattheblindcanhearbetterthanpeoplewithsight.Scientistshaveanewreasontobelieveit.Researc
随机试题
在其他债券要素不变的情况下,如果一种债券的价格下降,其到期收益率必然()。
有机磷中毒时选用的洗胃液是()
等渗性缺水常常发生于
下列射线可致皮肤癌的是()。
赵余于2001年5月患病死亡,留有三子一女,长子赵定初、次子赵定次、三子赵定叁、幼女赵定肆。赵定初在其父病故后因悲痛过度,于同年6月去世,有妻胡梦娟、子赵无夷和赵无霞。赵定次与前妻有一子赵无澜,与李英美有一子赵无缺。赵定叁有妻卢颖琪;赵定肆于1999年4月
下列选项适合使用定额估价法计算分项工程人、料、机费用的是()。
国际货物运输合同按形式划分为:书面合同和()。
景区景点导游是导游服务的一个重要组成部分,包括()及名人故居等地的导游服务。
利用Photoshop调整图像大小,打开“图像大小”对话框后,如果选择“约束比例”(如图所示),那么其目的是()。
柏拉图曾经说过,“在一个国家中,法律永远是由强者的权力制定的。”此话蕴含的核心意义是
最新回复
(
0
)