文章来源:未知 文章作者:enread 发布时间:2011-07-10 05:24 字体: [ ]  进入论坛

Oh, the challenges of being a neuron, responsible for essential things like muscle contraction1, gland2 secretion3(分泌物) and sensitivity to touch, sound and light, yet constantly bombarded with signals from here, there and everywhere. How on earth are busy nerve cells supposed to pick out and respond to relevant signals amidst all that information overload4?

Somehow neurons do manage to accomplish the daunting5(使人畏缩的) task, and they do it with more finesse6(策略,纤细) than anyone ever realized, new research by University of Michigan mathematician7 Daniel Forger8 and coauthors demonstrates. Their findings---which not only add to basic knowledge about how neurons work, but also suggest ways of better designing the brain implants10 used to treat diseases such as Parkinson's disease---were published July 7 in the online, open-access journal PLoS Computational Biology.

Forger and coauthors David Paydarfar at the University of Massachusetts Medical School and John Clay at the National Institute of Neurological Disorders11 and Stroke studied neuronal excitation using mathematical models and experiments with that most famous of neuroscience study subjects, the squid giant axon(轴突) ---a long arm of a nerve cell that controls part of the water jet propulsion system in squid.

Among the key findings: Neurons are quite adept12 at their job. "They can pick out a signal from hundreds of other, similar signals," said Forger, an associate professor of mathematics in the College of Literature, Science and the Arts and a research assistant professor of computational medicine and bioinformatics at the U-M Medical School.

Neurons discriminate13 among signals based on the signals' "shape," (how a signal changes over time), and Forger and coauthors found that, contrary to prior belief, a neuron's preference(偏向,倾向) depends on context. Neurons are often compared to transistors14 on a computer, which search for and respond to one specific pattern, but it turns out that neurons are more complex than that. They can search for more than one signal at the same time, and their choice of signal depends on what else is competing for their attention.

"We found that a neuron can prefer one signal---call it signal A---when compared with a certain group of signals, and a different signal---call it signal B---when compared with another group of signals," Forger said. This is true even when signal A and signal B aren't at all alike.

The findings could contribute in two main ways to the design and use of brain implants in treating neurological disorders.

"First, our results determine the optimal15 signals to stimulate16 a neuron," Forger said. "These signals are much more effective and require less battery power than what is currently used." Such efficiency would translate into less frequent surgery to replace batteries in patients with brain implants.

"Second, we found that the optimal(最佳的) stimulus17 is context-dependent," he said, "so the best signal will differ, depending on the part of the brain where the implant9 is placed."


1 contraction sn6yO     
  • The contraction of this muscle raises the lower arm.肌肉的收缩使前臂抬起。
  • The forces of expansion are balanced by forces of contraction.扩张力和收缩力相互平衡。
2 gland qeGzu     
  • This is a snake's poison gland.这就是蛇的毒腺。
  • Her mother has an underactive adrenal gland.她的母亲肾上腺机能不全。
3 secretion QDozG     
  • Is there much secretion from your eyes?你眼里的分泌物多吗?
  • In addition,excessive secretion of oil,water scarcity are also major factors.除此之外,油脂分泌过盛、缺水也都是主要因素。
4 overload RmHz40     
  • Don't overload the boat or it will sink.别超载,否则船会沉。
  • Large meals overload the digestive system.吃得太饱会加重消化系统的负担。
5 daunting daunting     
  • They were faced with the daunting task of restoring the house.他们面临着修复房子的艰巨任务。
  • Starting a new job can be a daunting prospect.开始一项新工作有时会让人望而却步。
6 finesse 3kaxV     
  • It was a disappointing performance which lacked finesse.那场演出缺乏技巧,令人失望。
  • Lillian Hellman's plays are marked by insight and finesse.莉莲.赫尔曼的巨作以富有洞察力和写作技巧著称。
7 mathematician aoPz2p     
  • The man with his back to the camera is a mathematician.背对着照相机的人是位数学家。
  • The mathematician analyzed his figures again.这位数学家再次分析研究了他的这些数字。
8 forger ji1xg     
  • He admitted seven charges including forging passports.他承认了7项罪名,其中包括伪造护照。
  • She alleged that Taylor had forged her signature on the form.她声称泰勒在表格上伪造了她的签名。
9 implant YaBxT     
  • A good teacher should implant high ideals in children.好教师应该把高尚理想灌输给孩子们。
  • The operation to implant the artificial heart took two hours.人工心脏植入手术花费了两小时。
10 implants c10b91e33a66c4b5cba3b091fcdfe0ac     
n.(植入身体中的)移植物( implant的名词复数 )
  • Hormone implants are used as growth boosters. 激素植入物被用作生长辅助剂。 来自《简明英汉词典》
  • Perhaps the most far-reaching project is an initiative called Living Implants From Engineering (LIFE). 也许最具深远意义的项目,是刚刚启动的建造活体移植工程 (LIFE)。 来自英汉非文学 - 生命科学 - 医学的第四次革命
11 disorders 6e49dcafe3638183c823d3aa5b12b010     
n.混乱( disorder的名词复数 );凌乱;骚乱;(身心、机能)失调
  • 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》
12 adept EJIyO     
  • When it comes to photography,I'm not an adept.要说照相,我不是内行。
  • He was highly adept at avoiding trouble.他十分善于避开麻烦。
13 discriminate NuhxX     
  • You must learn to discriminate between facts and opinions.你必须学会把事实和看法区分出来。
  • They can discriminate hundreds of colours.他们能分辨上百种颜色。
14 transistors ff750796e6ff1fb40d6a8248a6485dc3     
晶体管( transistor的名词复数 ); 晶体管收音机,半导体收音机
  • In semiconductor receivers transistors take the place of vacuum tubes. 在半导体收音机中晶体管代替了真空管。
  • We often turn to this handbook for information on transistors. 我们常从这本手册查阅有关晶体管的资料。
15 optimal zmDzhM     
  • What is the optimal mix of private and public property rights in natural resources?私人和国家的自然资源产权的最适宜的组合是什么?
  • Optimal path planning is a key link for the sailing contest.帆船最优行驶路径规划是帆船比赛取胜的关键环节。
16 stimulate wuSwL     
  • Your encouragement will stimulate me to further efforts.你的鼓励会激发我进一步努力。
  • Success will stimulate the people for fresh efforts.成功能鼓舞人们去作新的努力。
17 stimulus 3huyO     
  • Regard each failure as a stimulus to further efforts.把每次失利看成对进一步努力的激励。
  • Light is a stimulus to growth in plants.光是促进植物生长的一个因素。
TAG标签: cells nerve neuron