【托福培训-阅读】托福阅读材料：Out for the count

托福阅读的关键是在于多看多练，为了帮助广大考生更好的复习，小编为大家整理提供托福阅读材料:Out for the count.以供各位考生复习参考，生活中有很多事情需要大家细心观察和发现，阅读文章不仅可以锻炼能力还能了解各方面的知识。在托福阅读练习中大家要多找些托福文章练习，小编也会经常找些文章让大家参考的，下面开始今天的托福阅读吧。

　　麻醉，是各种手术中不可缺少的环节。麻醉被广泛应用了很多年，但目前为止，为什么药物能在人体内工作并让人在一段时间内失去知觉仍是神经科学中的未解之谜。

　　If you've ever had major surgery, you probably remember lying down and waking up--but nothing in between. Learn about anesthetics on this Moment of Science.

　　If you’ve ever had major surgery, you probably remember lying down and waking up–but nothing in between. Thanks to the anesthesiologist, during the actual surgery you were out of it: immobilized and insensitive to pain. But until recently scientists had little understanding of how anesthetics actually work on the cellular level.

　　That’s changed thanks to recent experiments performed by researchers at the University of Zurich, in Switzerland. They knew that anesthetics caused pain receptors in the brain to turn off by acting like most drugs do: anesthetizing drugs attach to particular sites on nerve cells and turn them off. The question was, where on nerve cells do these drugs attach?

　　Nerve cell membranes(细胞膜) have receptors for different kinds of chemicals produced by the brain. Gamma-amino butyric acid(γ-氨基丁酸), or GABA(伽马氨基丁酸), for example, is a chemical that shuts down nerve cells. The hypothesis was that general anesthesia works by binding to GABA receptors on a nerve cell, thereby activating the receptor and instructing the cell to shut down. So it made sense for the Zurich researchers to focus on GABA receptors.

　　To do this they worked with mice that had been genetically engineered to have nerve cells with GABA receptors that wouldn’t respond to anesthetics. And sure enough, when such mice were given anesthetic drugs they weren’t nearly as immune to pain as regular mice that had also been given pain-blocking drugs. Clearly, GABA receptor sites on nerve cells are part of what allows anesthetics to do their job.

　　以上就是今天的托福阅读材料，每天做几篇阅读，坚持下来，一定会有不小的进步，阅读的同时不要忘记，积累陌生词汇与优秀的句子，以便考试的时候能派上用场，英语不是一朝一夕的事，所以大家一定要勤加练习。