SSS 2008-03-27
时间：2018-12-24 作者：英语课 分类：Scientific American(三)月
This is Scientific American's 60-Second Science. I am Cynthia Graber. This will just take a minute.
Brains can register a food’s caloric value independent of our taste buds, say scientists from Duke University and from Portugal. First the scientists engineered mice without taste receptors for sweets. They compared the so-called sweet-blind mice to normal mice. Both were offered plain water or water with sucrose. And within about ten minutes, even the sweet-blind mice preferred the sugar water. The same test was repeated with sucrose, a calorie-free sweetener. The mice that could taste the sweetener preferred it, but the mice without the taste receptors never developed a preference for the fake stuff. Then the researchers looked at the brains of the sweet-blind mice. Sucrose turned on neurons in the brain’s food reward system. And the brain chemical dopamine was elevated. Dopamine is a crucial part of the brain’s reward circuitry. These changes show that the brain’s reward system can detect internal physiological 1 changes even independent of taste, maybe through the digestive system. The work appears in the March 27 issue of the journal Neuron. Scientists are calling this nutrient 2 awareness 3 the brain’s sixth sense for calories. They say teasing out these mechanisms 4 could have implications in understanding and combating obesity 5.
Thanks for the minute for Scientific American's 60-Second Science. I'm Cynthia Graber.
- He bought a physiological book.他买了一本生理学方面的书。
- Every individual has a physiological requirement for each nutrient.每个人对每种营养成分都有一种生理上的需要。
- Magnesium is the nutrient element in plant growth.镁是植物生长的营养要素。
- The roots transmit moisture and nutrient to the trunk and branches.根将水分和养料输送到干和枝。
- There is a general awareness that smoking is harmful.人们普遍认识到吸烟有害健康。
- Environmental awareness has increased over the years.这些年来人们的环境意识增强了。
- The research will provide direct insight into molecular mechanisms. 这项研究将使人能够直接地了解分子的机理。 来自《简明英汉词典》
- He explained how the two mechanisms worked. 他解释这两台机械装置是如何工作的。 来自《简明英汉词典》