英语听力文摘 English Digest 595、恐惧闻起来像糖！

 　　Fear Smells Like Sugar

 

　　Scientists have suspected for many years that fish might give off a chemical signal to warn other fish about the presence of predators¹. When a fish in a school is injured, for example, the rest of the school will panic and swim away in response.

 

　　Scientists dubbed² this unknown chemical “Schreckstoff,” or “scary stuff” in German, but they didn’t know what it was composed of until recently.

 

　　A major component³ in fish skin, chondroitin sulfate, appears to be the mystery chemical. When a fish is wounded, this substance is converted by enzymes⁴ into sugary molecules⁵ that are then shed into the water.

 

　　Scientists tested one of those molecules, glycosaminoglycan chondroitin or GAG for short, on zebra fish. They found that the sugary warning is detected by special crypt cells in the brain’s scent⁶ processing olfactory⁷ bulb. This region is directly connected with higher areas of the brain and could initiate⁸ a quick flight response in fish.

 

　　Scientists have also found that closely-related species sometimes respond to each other’s warning signals, but unrelated species do not. This suggests that there may be a variety of sugary-smelling molecules, with each species producing their own version.

 

　　Because the zebra fish brain is relatively⁹ simple, this research is allowing scientists to investigate at the cellular¹⁰ level what happens in the brain when an organism detects danger. It will allow them to see how groups of neurons regulate behavior and emotional responses.

 

　　Fortunately, fear doesn’t smell sweet for humans. We can enjoy all the apple pie, ice cream, candy and cookies that we want.

 

 

 

 

　　恐惧闻起来像糖

 

　　多年来科学家们一直都在怀疑鱼会释放一种化学信号来警告其他鱼类捕食者的出现。比如说，当鱼群中的一条鱼受到伤害时，鱼群中的其它鱼将会感到恐慌并且四散游开。

 

　　科学家将这种未知的化学物质命名为“Schreckstoff”，德语译为“令人恐惧的东西”。但是直到最近他们才知道这种物质的组成。

 

　　鱼的表皮中有一种叫硫酸软骨素的主要成分，似乎就是那种神秘的化学物质。当有一条鱼受伤时，这种物质就会通过酶的作用转化成含糖分子释放到水中。

 

　　科学家们测试了用斑马鱼释放出来的分子中的其中一个，可称为葡糖胺聚糖硫酸软骨素或简称为GAG。他们发现这种含糖的警告可以被特殊的隐窝细胞检测到，而隐窝细胞存在于大脑处理气味的嗅球中。这一区域和大脑更高级的区域相连，可以刺激鱼快速逃跑。

 

　　科学家们还发现亲缘关系很近的物种有时也对彼此的警报信号有反应，但是不同的物种就不会有反应。这告诉我们可能会有各种各样闻起来像糖一样的分子，每个物种会产生它们自己的版本。

 

　　因为斑马鱼的大脑构造比较简单，这项研究让科学家们可以在细胞水平上研究当生物遇到危险时大脑的反应机制。也可以研究神经组织是如何控制行为和情感反应的。

 

　　幸运的是，人类的恐惧闻起来不像糖。我们可以尽情的吃我们想吃的苹果派，冰激凌，糖果和饼干。

1 predators   

n.食肉动物( predator的名词复数 )；奴役他人者（尤指在财务或性关系方面）

参考例句：

• birds and their earthbound predators 鸟和地面上捕食它们的动物
• The eyes of predators are highly sensitive to the slightest movement. 捕食性动物的眼睛能感觉到最细小的动静。 来自《简明英汉词典》

2 dubbed   

v.给…起绰号( dub的过去式和过去分词 )；把…称为；配音；复制

参考例句：

• Mathematics was once dubbed the handmaiden of the sciences. 数学曾一度被视为各门科学的基础。
• Is the movie dubbed or does it have subtitles? 这部电影是配音的还是打字幕的？ 来自《简明英汉词典》

3 component   

n.组成部分，成分，元件；adj.组成的，合成的

参考例句：

• Each component is carefully checked before assembly.每个零件在装配前都经过仔细检查。
• Blade and handle are the component parts of a knife.刀身和刀柄是一把刀的组成部分。

4 enzymes   

n. 酶，酵素

参考例句：

• It was said that washing powders containing enzymes remove stains more efficiently. 据说加酶洗衣粉除污更有效。
• Among the enzymes which are particularly effective are pepsin, papain. 在酶当中特别有效的是胃朊酶、木瓜酶。

5 molecules   

分子( molecule的名词复数 )

参考例句：

• The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。
• Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里，大分子裂变为小分子。

6 scent   

n.气味，香味，香水，线索，嗅觉；v.嗅，发觉

参考例句：

• The air was filled with the scent of lilac.空气中弥漫着丁香花的芬芳。
• The flowers give off a heady scent at night.这些花晚上散发出醉人的芳香。

7 olfactory   

adj.嗅觉的

参考例句：

• He is to develop a sensor to substitute for the olfactory abilities of dogs.克罗克将研制一种传感器用以代替狗的嗅觉功能。
• Based on these findings, Keller suspects that each person has an olfactory blind spot.根据这些发现，凯勒推断，每个人都有一个嗅觉盲区。

8 initiate   

vt.开始，创始，发动；启蒙，使入门；引入

参考例句：

• A language teacher should initiate pupils into the elements of grammar.语言老师应该把基本语法教给学生。
• They wanted to initiate a discussion on economics.他们想启动一次经济学讨论。

9 relatively   

adv.比较...地，相对地

参考例句：

• The rabbit is a relatively recent introduction in Australia.兔子是相对较新引入澳大利亚的物种。
• The operation was relatively painless.手术相对来说不痛。

10 cellular   

adj.移动的；细胞的，由细胞组成的

参考例句：

• She has a cellular telephone in her car.她的汽车里有一部无线通讯电话机。
• Many people use cellular materials as sensitive elements in hygrometers.很多人用蜂窝状的材料作为测量温度的传感元件。