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科学美国人60秒 SSS 为什么痒痒就想挠

时间:2019-12-10 06:23:07

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(单词翻译)

 

This is Scientific American — 60-Second Science. I'm Karen Hopkin.

Everyone knows what it's like to itch1. And the sensation can drive you mad. Or, if you're Yan-Gang Sun of the Chinese Academy of Sciences, it can drive you to explore how the brain tells you it's time to scratch: "Our study is a??iming to understand the brain mechanism2 that promotes the itch-scratching cycle."

Itching3 can be caused by a number of irritants, from allergic4 reactions and abrasive5 textures6 to bug7 bites, skin conditions, infections or drugs. The usual solution is to simply scratch. But this cycle of itching and scratching, if it continues unabated, can actually damage tissue — like if you scratch yourself raw.

And Sun notes that: "Effective treatment for chronic8 itch is still lacking. This i???s largely due to our limited knowledge about the neuromechanism of itch."

Over the past 10 years, scientists have learned a lot about how the itch signal is carried from the skin to the spinal9 cord.

"In contrast, we know very little about how the itch information is processed in the brain, and how the brain can dynamically modulate10 the processing of itch."

Sun and his colleagues focused their attention on the periaqueductal gray...a brain region known to be involved in handling the closely related sensation of pain. They started by exposing mice to histamine or the antimalarial drug chloroquine, both of which trigger scratching.

And they found that this itch-inducing treatment activates11 a particular set of neurons within the periaqueductal gray: neurons that produce a neurochemical called Tac1.

When the researchers then eliminated this set of neurons, scratching was significantly diminished. And when they activated12 the neurons — even in the absence of a chemical irritant — the scratching resumed. Sun thus thinks of these Tac1-expressing neurons as the itch neurons in the brain. Getting these neurons firing makes animals itchy and gets them to scratch. His findings appear in the journal Neuron.

"These itch neurons in the brain can be a potential central therapeutic13 target for breaking the vicious itch-scratching cycle associated with chronic itch."

Which could be a big relief for many irritated people.

For Scientific American — 60-Second Science. I'm Karen Hopkin.


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1 itch 9aczc     
n.痒,渴望,疥癣;vi.发痒,渴望
参考例句:
  • Shylock has an itch for money.夏洛克渴望发财。
  • He had an itch on his back.他背部发痒。
2 mechanism zCWxr     
n.机械装置;机构,结构
参考例句:
  • The bones and muscles are parts of the mechanism of the body.骨骼和肌肉是人体的组成部件。
  • The mechanism of the machine is very complicated.这台机器的结构是非常复杂的。
3 itching wqnzVZ     
adj.贪得的,痒的,渴望的v.发痒( itch的现在分词 )
参考例句:
  • The itching was almost more than he could stand. 他痒得几乎忍不住了。 来自《现代汉英综合大词典》
  • My nose is itching. 我的鼻子发痒。 来自《简明英汉词典》
4 allergic 4xozJ     
adj.过敏的,变态的
参考例句:
  • Alice is allergic to the fur of cats.艾丽斯对猫的皮毛过敏。
  • Many people are allergic to airborne pollutants such as pollen.许多人对空气传播的污染物过敏,比如花粉。
5 abrasive 3yDz3     
adj.使表面磨损的;粗糙的;恼人的
参考例句:
  • His abrasive manner has won him an unenviable notoriety.他生硬粗暴的态度让他声名狼藉。
  • She had abrasions to her wrists where the abrasive rope had scraped her.她的手腕有多出磨伤,那是被粗糙的绳子擦伤的。
6 textures c5e62798e528da9080811018cbb27cd3     
n.手感( texture的名词复数 );质感;口感;(音乐或文学的)谐和统一感
参考例句:
  • I'm crazy about fabrics textures and colors and designs. 我喜欢各式各样的纺织物--对它的质地,色彩到花纹图案--简直是入了迷。 来自辞典例句
  • Let me clear up the point about the textures. 让我明确了一点有关的纹理。 来自互联网
7 bug 5skzf     
n.虫子;故障;窃听器;vt.纠缠;装窃听器
参考例句:
  • There is a bug in the system.系统出了故障。
  • The bird caught a bug on the fly.那鸟在飞行中捉住了一只昆虫。
8 chronic BO9zl     
adj.(疾病)长期未愈的,慢性的;极坏的
参考例句:
  • Famine differs from chronic malnutrition.饥荒不同于慢性营养不良。
  • Chronic poisoning may lead to death from inanition.慢性中毒也可能由虚弱导致死亡。
9 spinal KFczS     
adj.针的,尖刺的,尖刺状突起的;adj.脊骨的,脊髓的
参考例句:
  • After three days in Japan,the spinal column becomes extraordinarily flexible.在日本三天,就已经使脊椎骨变得富有弹性了。
  • Your spinal column is made up of 24 movable vertebrae.你的脊柱由24个活动的脊椎骨构成。
10 modulate IEOxl     
v.调整,调节(音的强弱);变调
参考例句:
  • Please modulate the sound on the TV.请调节一下电视的音量。
  • This system could modulate the voice signal effectively.这个系统可以对语音信号进行有效的调制。
11 activates 78ec2b8b23e0120508757d953f1013d1     
使活动,起动,触发( activate的第三人称单数 )
参考例句:
  • Activates the window and displays it in its current size and position. 激活窗口,保持当前的大小及位置不变。
  • Pulling out the alarm switch activates alarm and pushing it deactivates it. 闹钟的开和关是通过拔出和按入闹铃开关实现的。
12 activated c3905c37f4127686d512a7665206852e     
adj. 激活的 动词activate的过去式和过去分词
参考例句:
  • The canister is filled with activated charcoal.蒸气回收罐中充满了活性炭。
13 therapeutic sI8zL     
adj.治疗的,起治疗作用的;对身心健康有益的
参考例句:
  • Therapeutic measures were selected to fit the patient.选择治疗措施以适应病人的需要。
  • When I was sad,music had a therapeutic effect.我悲伤的时候,音乐有治疗效力。

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