文章来源:未知 文章作者:meng 发布时间:2010-06-18 02:46 字体: [ ]  进入论坛

Are we born with an innate1(先天的,固有的) sense of direction, or is it learned? Research from the Norwegian University of Science and Technology's Kavli Institute for Systems Neuroscience(神经系统科学) suggests that the brain comes hard-wired with working navigational(航行的) neurons. While these neurons – head direction cells, place cells and grid2 cells – mature over time, they appear to function in rodents3(啮齿动物) as soon as they make their first exploratory steps outside the nest. Researchers Rosamund Langston and colleagues wanted to know how the brain mapped place and space when an animal navigates5 for the first time ever. The research team implanted miniature(微型的) sensors6 in rat pups before their eyes had opened (and thus before they were mobile). That enabled the researchers to record neural7(神经的) activity when the rat pups left the nest for the first time to explore a new environment.

The researchers were not only able to see that the rats had working navigational neurons right from the beginning, but they were also able to see the order in which the cells matured.

The first to mature were head direction cells. These neurons are exactly what they sound like – they tell the animal which direction it is heading, and are thought to enable an internal inertia8(惯性,惰性) -based navigation system, like a compass. "These cells were almost adult-like right from the beginning," Langston says.

The next cells to mature were the place cells, which are found in the hippocampus(海马) . These cells represent a specific place in the environment, and in addition provide contextual(上下文的,前后关系的) information — perhaps even a memory — that might be associated with the place. Last to mature were grid cells, which provide the brain with a geometric(几何学的) coordinate9 system that enables the animal to figure out exactly where it is in space and how far it has travelled. Grid cells essentially10 anchor the other cell types to the outside world so that the animal can reliably reproduce the mental map that was made last time it was there.

Baby rats open their eyes and begin exploring by about 15 days after birth. At this point, researchers could already see head direction cells fully11 developed, and the rudiments12(入门,初步) of the other two cell types in place. By the time they were 30 days old, or on the threshold(极限,门槛) of rat adolescence13(青春期) , virtually all of the different navigational cell types had matured.

Langston says the findings are a partial answer to the age-old question of whether or not you are born with the innate ability to find your way around. Her answer? "It really seems that this is hard-wired," she says, "You do have a basic foundation that is there as soon as you can explore – there are strong building blocks for a system that you can use to navigate4. " Langston says experience could also play a role, which makes this topic an important theme for further research.

The researchers found no difference in navigational skills between male and female rat pups, which implies that both sexes have the same building blocks with which to construct representations of space. Perhaps the age-old question of whether males or females have a better sense of direction could be a case of how we choose to build our map, rather than the materials we start with.


1 innate xbxzC     
  • You obviously have an innate talent for music.你显然有天生的音乐才能。
  • Correct ideas are not innate in the mind.人的正确思想不是自己头脑中固有的。
2 grid 5rPzpK     
  • In this application,the carrier is used to encapsulate the grid.在这种情况下,要用载体把格栅密封起来。
  • Modern gauges consist of metal foil in the form of a grid.现代应变仪则由网格形式的金属片组成。
3 rodents 1ff5f0f12f2930e77fb620b1471a2124     
n.啮齿目动物( rodent的名词复数 )
  • Rodents carry diseases and are generally regarded as pests. 啮齿目动物传播疾病,常被当作害虫对待。 来自《简明英汉词典》
  • Some wild rodents in Africa also harbor the virus. 在非洲,有些野生啮齿动物也是储毒者。 来自辞典例句
4 navigate 4Gyxu     
  • He was the first man to navigate the Atlantic by air.他是第一个飞越大西洋的人。
  • Such boats can navigate on the Nile.这种船可以在尼罗河上航行。
5 navigates 958df1f5bfaf5943d4890ea6c3cd4bd4     
v.给(船舶、飞机等)引航,导航( navigate的第三人称单数 );(从海上、空中等)横越;横渡;飞跃
  • Dolpins also navigates by some kind of echo system. 原来海豚也是借助某种回声系统寻向的。 来自辞典例句
  • Navigates in menus, lists, choice screens and into edited texts. 可以操纵菜单、列表、屏幕选项和进入编辑文本。 来自互联网
6 sensors 029aee483db9ae244d7a5cb353e74602     
n.传感器,灵敏元件( sensor的名词复数 )
  • There were more than 2000 sensors here. 这里装有两千多个灵敏元件。 来自《简明英汉词典》
  • Significant changes have been noted where sensors were exposed to trichloride. 当传感器暴露在三氯化物中时,有很大变化。 来自辞典例句
7 neural DnXzFt     
  • The neural network can preferably solve the non- linear problem.利用神经网络建模可以较好地解决非线性问题。
  • The information transmission in neural system depends on neurotransmitters.信息传递的神经途径有赖于神经递质。
8 inertia sbGzg     
  • We had a feeling of inertia in the afternoon.下午我们感觉很懒。
  • Inertia carried the plane onto the ground.飞机靠惯性着陆。
9 coordinate oohzt     
  • You must coordinate what you said with what you did.你必须使你的言行一致。
  • Maybe we can coordinate the relation of them.或许我们可以调和他们之间的关系。
10 essentially nntxw     
  • Really great men are essentially modest.真正的伟人大都很谦虚。
  • She is an essentially selfish person.她本质上是个自私自利的人。
11 fully Gfuzd     
  • The doctor asked me to breathe in,then to breathe out fully.医生让我先吸气,然后全部呼出。
  • They soon became fully integrated into the local community.他们很快就完全融入了当地人的圈子。
12 rudiments GjBzbg     
  • He has just learned the rudiments of Chinese. 他学汉语刚刚入门。
  • You do not seem to know the first rudiments of agriculture. 你似乎连农业上的一点最起码的常识也没有。
13 adolescence CyXzY     
  • Adolescence is the process of going from childhood to maturity.青春期是从少年到成年的过渡期。
  • The film is about the trials and tribulations of adolescence.这部电影讲述了青春期的麻烦和苦恼。
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