Ronnie055
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Researchers at Princeton University recently made a remarkable discovery about the brains of rats that exercise. Some of their neurons respond differently to stress than the neurons of slothful rats. Scientists have known for some time that exercise stimulates the creation of new brain cells (neurons) but not how, precisely, these neurons might be functionally different from other brain cells. In the experiment, preliminary results of which were presented last month at the annual meeting of the Society for Neuroscience in Chicago, scientists allowed one group of rats to run. Another set of rodents was not allowed to exercise. Then all of the rats swam in cold water, which they don’t like to do. Afterward, the scientists examined the animals’ brains. They found that the stress of the swimming activated neurons in all of the brains. (The researchers could tell which neurons were activated because the cells expressed specific genes in response to the stress.) But the youngest brain cells in the running rats, the cells that the scientists assumed were created by running, were less likely to express the genes. They generally remained quiet. The “cells born from running,” the researchers concluded, appeared to have been “specifically buffered from exposure to a stressful experience.” The rats had created, through running, a brain that seemed biochemically, molecularly, calm. For years, both in popular imagination and in scientific circles, it has been a given that exercise enhances mood. But how exercise, a physiological activity, might directly affect mood and anxiety — psychological states — was unclear. Now, thanks in no small part to improved research techniques and a growing understanding of the biochemistry and the genetics of thought itself, scientists are beginning to tease out how exercise remodels the brain, making it more resistant to stress. In work undertaken at the University of Colorado, Boulder, for instance, scientists have examined the role of serotonin, a neurotransmitter often considered to be the “h 阅读全文>> |
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T台上麻豆们光鲜照人的形象看得人心生崇拜，秀场外她们时髦惹眼同样令人嫉妒万分，对流行动向的先知先觉加上无可挑剔的好身材让穿衣搭配有了媲美时装秀的精彩度。下面，就和海报网编编一起来继续回顾2010春夏时装周超模们的街拍美图吧。
T台上麻豆们光鲜照人的形象看得人心生崇拜，秀场外她们时髦惹眼同样令人嫉妒万分，对流行动向的先知先觉加上无可挑剔的好身材让穿衣搭配有了媲美时装秀的精彩度。 下面，就和海报网编编一起来继续回顾2010春夏时装周超模们的街拍美图吧。 |
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住在国外，最怕的就是半夜铃声。那倒不是看了日本恐怖片《午夜凶铃》落下的后遗症，而是国内家人老忘了我这里的时差，常常是半夜三更铃声大作。本想睡觉前关掉电话，又怕万一家里真有啥急事。所以基本上我每周都给家里电话报平安，免得我妈妈又嘀咕我是不是只身在外受了啥委屈。 这些天，都在赶“功课”，常常是回到住处，已经很累了。今天只想美美睡一觉，明天不用“出操”呢！ 听！电话又在固执地响。 我睡梦中惊醒，心狂跳不已。 “哈啰！” 我摸索着接过床边的电话，对着话筒，我嗓音嘶哑。 “阿娃！张婶找你有急事。” 电话那头是我妈急促的声音。 “妈！啥事呀！我这里是凌晨2点多呢，你又忘了时差了！” “阿娃，是我，张婶，不好意思啊，吵醒了你。我家若兰已经几天几夜茶饭不思，跟任何人也不说话，你和她最要好，你知道她咋啦？” “若兰？！我上个星期还和她聊着呢！好像一切都还好呀。” “拜托了！阿娃！今天你就给她个电话，她不同我们身边的人说话，或许她会对你开口呢，开导开导她，有啥想不开的呢？” “好的！张婶，您放心，我呆会就给她电话。” “阿娃，医生说若兰得了什么抑郁症，这啥毛病啊，不严 |
