VOA标准英语2010年-Fruit Flies Could Unlock Mystery of Al

At Scripps Research Institute in Jupiter, Florida, scientists are working to find clues about how the human brain processes memories. Their laboratory test animal is not a chimp¹ or a dog or a rat — animals that we know can remember things — it is the common fruit fly.

"They're relatively² simple," Ron Davis says, explaining why the fruit fly's brain has some ideal properties for human brain research. "The brain of the fruit fly has about 100,000 neurons. The brain of a human has about 100 billion neurons, and that's an enormous network of interconnected neurons in the human brain, if one thinks about it. We literally³ can't wrap our brains around the human brain yet."

Fruit fly training regimen

Davis chairs the Department of Neuroscience at Scripps Florida. He's designed an experiment in which fruit flies are trained to remember an odor associated with an unpleasant electrical shock.

Dr. Ron Davis says fruit flies have essentially⁴ the same genes⁶ as humans do, just fewer of them.

It involves a series of Plexiglas tubes which have an electrifiable copper⁷ grid⁸ on their surfaces. "One puts the fly in these tubes first, passes an odor through the tube," Davis says. "Odor A shocks the animal, mild electric shock." After fresh air has been blown through the tubes to remove any trace of the first odor, a second scent⁹ is pumped in.

"Odor B passes through the tube and the animals are not shocked. That's the training where we're hoping the animals will develop an association. They'll learn that one odor is bad because it's been punished in the presence of that odor. And the other odor is okay."

Then, the flies are tested to see how well they remember which odor is which. Davis says about 90 percent do, and avoid the electric shock. The ones that don't are isolated¹¹, so their genes can be studied.

The human-fruit fly connection

Researchers can remove a fly's brain and place it — still functioning — under a microscope. They can isolate¹⁰ neurons that have different functions and watch them fire -or send signals- to other neurons when stimulated¹².

 

A research associate at Davis' lab prepares the series of tubes for the flies' olfactory¹³ memory training.

Once they identify which neurons are firing differently in the normal flies that have learned to identify the difference, they examine the mutants that don't remember the shocking odor to see how genes control the firing process.

Fruit flies have essentially the same genes as we do, just fewer of them. Davis says that correlation¹⁴ is what makes his research so promising¹⁵.

"If we find a gene⁵ in flies that's important for a process like memory formation, that sequence of that gene is generally conserved¹⁶ [across species]. We can use that gene to identify a similar gene in a mouse or in humans, because they have a very, very high sequence similarity. The bases that make up the gene are very similar." He explains that is how researchers are able to identify with a very high probability in humans the vast majority of genes that exist in fruit flies.

"We're actually quite similar to a fruit fly, believe it or not," he adds with a laugh.

Each vial in the storeroom can hold more than 150 flies.

Generations of flies in one room

Fruit flies have a very short lifespan compared to other laboratory animals like the mouse or rat. So, with the flies mating and reproducing every two weeks, many generations of flies can be studied in a year, allowing researchers to do genetic¹⁷ studies quickly. And since the flies are small, hundreds of thousands of them can be stored easily and inexpensively in plastic vials.

Davis shows off a small room at the Institute, filled with vials of fruit flies — all to be used in the search for answers to how our memories are made and stored.

"If one examines the vast majority of neurological diseases — Alzheimer's, Parkinson's and so forth¹⁸, and psychiatric diseases — schizophrenia, bipolar disorder¹⁹, ADHD, autism, all of these have a commonality in that they have learning disorders²⁰, in general, or memory formation seems to be an underlying²¹ feature of the vast majority of neurological and psychiatric diseases."

Davis and his team of researchers hope their work will lead to a drug that will help the brain fight learning- and memory-related diseases. He says gaining a fundamental understanding of how the learning process works could be the key to treating — and perhaps curing — them.

 

1 chimp   

n.黑猩猩

参考例句：

• In fact,the color of gorilla and chimp are light-color.其实大猩猩和黑猩猩的肤色是较为浅的。
• The chimp is the champ.猩猩是冠军。

2 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。

3 literally   

adv.照字面意义，逐字地；确实

参考例句：

• He translated the passage literally.他逐字逐句地翻译这段文字。
• Sometimes she would not sit down till she was literally faint.有时候，她不走到真正要昏厥了，决不肯坐下来。

4 essentially   

adv.本质上，实质上，基本上

参考例句：

• 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。

5 gene   

n.遗传因子，基因

参考例句：

• A single gene may have many effects.单一基因可能具有很多种效应。
• The targeting of gene therapy has been paid close attention.其中基因治疗的靶向性是值得密切关注的问题之一。

6 genes   

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 copper   

n.铜；铜币；铜器；adj.铜(制)的；(紫)铜色的

参考例句：

• The students are asked to prove the purity of copper.要求学生们检验铜的纯度。
• Copper is a good medium for the conduction of heat and electricity.铜是热和电的良导体。

8 grid   

n.高压输电线路网；地图坐标方格；格栅

参考例句：

• 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。

9 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。

10 isolate   

vt.使孤立，隔离

参考例句：

• Do not isolate yourself from others.不要把自己孤立起来。
• We should never isolate ourselves from the masses.我们永远不能脱离群众。

11 isolated   

adj.与世隔绝的

参考例句：

• His bad behaviour was just an isolated incident. 他的不良行为只是个别事件。
• Patients with the disease should be isolated. 这种病的患者应予以隔离。

12 stimulated   

a.刺激的

参考例句：

• The exhibition has stimulated interest in her work. 展览增进了人们对她作品的兴趣。
• The award has stimulated her into working still harder. 奖金促使她更加努力地工作。

13 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。

14 correlation   

n.相互关系，相关，关连

参考例句：

• The second group of measurements had a high correlation with the first.第二组测量数据与第一组高度相关。
• A high correlation exists in America between education and economic position.教育和经济地位在美国有极密切的关系。

15 promising   

adj.有希望的，有前途的

参考例句：

• The results of the experiments are very promising.实验的结果充满了希望。
• We're trying to bring along one or two promising young swimmers.我们正设法培养出一两名有前途的年轻游泳选手。

16 conserved   

v.保护，保藏，保存( conserve的过去式和过去分词 )

参考例句：

• He conserved his energy for the game. 他为比赛而养精蓄锐。 来自《简明英汉词典》
• Under these conditions, the total mechanical energy remains constant, or is conserved. 在这种条件下，总机械能保持不变或机械能保存。 来自辞典例句

17 genetic   

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。

18 forth   

adv.向前；向外，往外

参考例句：

• The wind moved the trees gently back and forth.风吹得树轻轻地来回摇晃。
• He gave forth a series of works in rapid succession.他很快连续发表了一系列的作品。

19 disorder   

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。

20 disorders   

n.混乱( disorder的名词复数 )；凌乱；骚乱；（身心、机能）失调

参考例句：

• Reports of anorexia and other eating disorders are on the increase. 据报告，厌食症和其他饮食方面的功能紊乱发生率正在不断增长。 来自《简明英汉词典》
• The announcement led to violent civil disorders. 这项宣布引起剧烈的骚乱。 来自《简明英汉词典》

21 underlying   

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。