VOA慢速英语2009年-Health Report - Deficits Found in Brain's

This is the VOA Special English Health Report.

A.D.H.D. is attention deficit¹ hyperactivity disorder². Children with A.D.H.D. might have trouble paying attention. They might not seem to listen. They might forget things. They might not be able to stay seated or play quietly.

They might talk too much. And they might act and speak without thinking about the results of their behavior. These are among the signs listed on the Web site of the Centers for Disease Control and Prevention in the United States.
　
Barbara Eddy³ with daughters, Allegra, left, and Francesca. The mother from Pasadena, California, has A.D.H.D.

Doctors usually identify A.D.H.D. in children. But experts say the behaviors often last into adulthood⁴.

Researchers have been looking for the cause or causes of attention deficit hyperactivity disorder. Now, a brain-imaging study offers more evidence that could lead to new ways to treat it.

Researchers say they observed shortages in the brain's reward system in patients with A.D.H.D. The study found that levels of certain proteins were lower than normal.

Nora Volkow is director of the National Institute on Drug Abuse and the lead author of the study. She says the lack of attention and self-control that mark A.D.H.D. could be caused by problems in the flow of dopamine.

NORA VOLKOW: "Dopamine is considered a neurotransmitter that is crucial for our ability to perceive rewards and to be motivated in our behavior."

If people cannot sense a reward, she says, then they might have difficulty completing an activity.

Researchers compared the pathways that transmit dopamine in fifty-three adults with A.D.H.D. to those of forty-four adults without the disorder.

NORA VOLKOW: "There was a lower concentration of dopamine markers in the brain of individuals with A.D.H.D., specifically in the areas of the brain that are involved with reward and motivation."

Doctor Volkow says the dopamine levels were directly related to the severity of the patient's inattention.

The study used brain images taken at Brookhaven National Laboratory in New York State. Gene-Jack Wang is chairman of the Brookhaven medical department. He says the finding might also help explain why people with A.D.H.D. are more likely to abuse drugs or overeat. He says they might be trying to increase their dopamine levels to make up for the deficits⁵ in their reward system.

The Brookhaven Lab is part of the United States Department of Energy. The National Institutes of Health supported the research. The study appeared in the Journal of the American Medical Association.

And that's the VOA Special English Health Report, written by Caty Weaver⁶ with Carol Pearson. You can find transcripts⁷ and MP3s of our reports and share comments at voaspecialenglish.com. I'm Mario Ritter.

1 deficit   

n.亏空，亏损；赤字，逆差

参考例句：

• The directors have reported a deficit of 2.5 million dollars.董事们报告赤字为250万美元。
• We have a great deficit this year.我们今年有很大亏损。

2 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。

3 eddy   

n.漩涡，涡流

参考例句：

• The motor car disappeared in eddy of dust.汽车在一片扬尘的涡流中不见了。
• In Taylor's picture,the eddy is the basic element of turbulence.在泰勒的描述里，旋涡是湍流的基本要素。

4 adulthood   

n.成年，成人期

参考例句：

• Some infantile actions survive into adulthood.某些婴儿期的行为一直保持到成年期。
• Few people nowadays are able to maintain friendships into adulthood.如今很少有人能将友谊维持到成年。

5 deficits   

n.不足额( deficit的名词复数 )；赤字；亏空；亏损

参考例句：

• The Ministry of Finance consistently overestimated its budget deficits. 财政部一贯高估预算赤字。 来自《简明英汉词典》
• Many of the world's farmers are also incurring economic deficits. 世界上许多农民还在遭受经济上的亏损。 来自辞典例句

6 weaver   

n.织布工；编织者

参考例句：

• She was a fast weaver and the cloth was very good.她织布织得很快，而且布的质量很好。
• The eager weaver did not notice my confusion.热心的纺织工人没有注意到我的狼狈相。

7 transcripts   

n.抄本（ transcript的名词复数 ）；转写本；文字本；副本

参考例句：

• Like mRNA, both tRNA and rRNA are transcripts of chromosomal DNA. tRNA及rRNA同mRNA一样，都是染色体DNA的转录产物。 来自辞典例句
• You can't take the transfer students'exam without your transcripts. 没有成绩证明书，你就不能参加转学考试。 来自辞典例句