锌调节着脑细胞之间的交流

时间：2011-09-22 05:48:25

（单词翻译:单击）

Zinc1 has been found to play a critical role in regulating communication between cells in the brain, possibly governing the formation of memories and controlling the occurrence of epileptic seizures2（癫痫发作） . A collaborative project between Duke University Medical Center researchers and chemists at the Massachusetts Institute of Technology has been able to watch zinc in action as it regulates communication between neurons in the hippocampus（海马） , where learning and memory processes occur -- and where disrupted communication may contribute to epilepsy.

 
"We discovered that zinc is essential to control the efficiency of communication between two critical populations of nerve cells in the hippocampus," said James McNamara, M.D., senior author and chair of the Department of Neurobiology at Duke. "This addresses a longstanding controversy3 in the field."
 
The study appeared in Neuron Journal online on Sept. 21.
 
McNamara noted4 that zinc supplements are commonly sold over the counter to treat several different brain disorders5, including depression. It isn't clear whether these supplements modify zinc content in the brain, or modify the efficiency of communication between these nerve cells. He emphasized that people taking zinc supplements should be cautious, pending6 needed information on the desired zinc concentrations and how oral supplements affect them.
 
More than 50 years ago scientists discovered that high concentrations of zinc are contained in a specialized7 compartment8 of nerve cells, called vesicles（囊泡） , that package the transmitters which enable nerve cells to communicate. The highest concentrations of brain zinc were found among the neurons of the hippocampus, the center of learning and memory.
 
Zinc's presence in these vesicles suggested that zinc played some role in communication between nerve cells, but whether it actually did so remained controversial.
 
To address this controversy, McNamara and his colleagues at Duke teamed up with Dr. Steve Lippard and colleagues in the Department of Chemistry at the Massachusetts Institute of Technology.
 
The Lippard team synthesized a novel chemical that bound zinc far more rapidly and selectively than previously9 available compounds. Use of this chemical let the Duke team rapidly bind10 the zinc released by nerve cells, taking it out of circulation and preventing enhanced communication.
 
The Duke team went on to confirm that eliminating zinc from the vesicles of mutant mice also prevented enhanced communication. They also found that increases in the transmitter glutamate（谷氨酸盐） seemed to increase zinc-mediated enhancement of communication.
 
Interestingly, the nerve cells in which the high concentrations of zinc reside are critical for a particular type of memory formation. Excessive enhancement of communication by the zinc-containing nerve cells occurs in epileptic animals and may worsen the severity of the epilepsy.
 
"Carefully controlling zinc's regulation of communication between these nerve cells is critical to both formation of memories and perhaps to occurrence of epileptic seizures," McNamara said.
 
McNamara also noted that the scientific collaboration11 between the Duke and MIT scientists was critical to the success of this work. The availability of the novel chemical provided a critical tool that allowed the neuroscientists to unravel12 the puzzle.

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1 zinc DfxwX     
n.锌；vt.在...上镀锌
参考例句：
  • Brass is formed by the fusion of copper and zinc.黄铜是通过铜和锌的熔合而成的。
  • Zinc is used to protect other metals from corrosion.锌被用来保护其他金属不受腐蚀。
2 seizures d68658a6ccfd246a0e750fdc12689d94     
n.起获( seizure的名词复数 )；没收；充公；起获的赃物
参考例句：
  • Seizures of illicit drugs have increased by 30% this year. 今年违禁药品的扣押增长了30%。 来自《简明英汉词典》
  • Other causes of unconsciousness predisposing to aspiration lung abscess are convulsive seizures. 造成吸入性肺脓肿昏迷的其他原因，有惊厥发作。 来自辞典例句
3 controversy 6Z9y0     
n.争论，辩论，争吵
参考例句：
  • That is a fact beyond controversy.那是一个无可争论的事实。
  • We ran the risk of becoming the butt of every controversy.我们要冒使自己在所有的纷争中都成为众矢之的的风险。
4 noted 5n4zXc     
adj.著名的，知名的
参考例句：
  • The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
  • Jim is noted for arriving late for work.吉姆上班迟到出了名。
5 disorders 6e49dcafe3638183c823d3aa5b12b010     
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》
6 pending uMFxw     
prep.直到，等待…期间；adj.待定的；迫近的
参考例句：
  • The lawsuit is still pending in the state court.这案子仍在州法庭等待定夺。
  • He knew my examination was pending.他知道我就要考试了。
7 specialized Chuzwe     
adj.专门的，专业化的
参考例句：
  • There are many specialized agencies in the United Nations.联合国有许多专门机构。
  • These tools are very specialized.这些是专用工具。
8 compartment dOFz6     
n.卧车包房，隔间；分隔的空间
参考例句：
  • We were glad to have the whole compartment to ourselves.真高兴，整个客车隔间由我们独享。
  • The batteries are safely enclosed in a watertight compartment.电池被安全地置于一个防水的隔间里。
9 previously bkzzzC     
adv.以前，先前（地）
参考例句：
  • The bicycle tyre blew out at a previously damaged point.自行车胎在以前损坏过的地方又爆开了。
  • Let me digress for a moment and explain what had happened previously.让我岔开一会儿，解释原先发生了什么。
10 bind Vt8zi     
vt.捆，包扎；装订；约束；使凝固；vi.变硬
参考例句：
  • I will let the waiter bind up the parcel for you.我让服务生帮你把包裹包起来。
  • He wants a shirt that does not bind him.他要一件不使他觉得过紧的衬衫。
11 collaboration bW7yD     
n.合作，协作；勾结
参考例句：
  • The two companies are working in close collaboration each other.这两家公司密切合作。
  • He was shot for collaboration with the enemy.他因通敌而被枪毙了。
12 unravel Ajzwo     
v.弄清楚（秘密）；拆开，解开，松开
参考例句：
  • He was good with his hands and could unravel a knot or untangle yarn that others wouldn't even attempt.他的手很灵巧，其他人甚至都不敢尝试的一些难解的绳结或缠在一起的纱线，他都能解开。
  • This is the attitude that led him to unravel a mystery that long puzzled Chinese historians.正是这种态度使他解决了长期以来使中国历史学家们大惑不解的谜。

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