美国科学60秒 SSS 2013-02-13
时间：2019-01-20 作者：英语课 分类：Scientific American(二)月
英语课
Too little salt makes for(导致) a bland(温和的；乏味的) meal. But too much is offensively briny 1(海水的；咸的). Now, scientists have discovered why too much tastes bad. The work is in journal Nature.
As the previous podcast noted 2, the cells that process taste send a unique signal to the brain for each kind of flavor. The signals for sweet and umami make animals crave 3 more, while sour and bitter are often rejected. But saltiness is appealing in low doses and aversive at high levels. The researchers found out why: too much salt activates 4 the cells that sense sourness and bitterness, sending unpleasant signals to the brain and transforming a tasty bite into a turn-off(使厌烦).
The study used mice unable to taste sourness, bitterness, or both. Animals that could still sense one of the flavors rejected overly salty water. But mice unable to taste sour and bitter were happy to lick up liquid that was far too briny for normal animals.
With salt being a variable flavor, our bodies can better keep its levels within a healthful range. And leave a good taste in the mouth.
adj.盐水的；很咸的；n.海洋
- The briny water is not good for the growth of the trees.海水不利于这种树木的生长。
- The briny air gave a foretaste of the nearby sea.咸空气是快近海的前兆。
adj.著名的，知名的
- 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。
vt.渴望得到，迫切需要，恳求，请求
- Many young children crave attention.许多小孩子渴望得到关心。
- You may be craving for some fresh air.你可能很想呼吸呼吸新鲜空气。