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许多人都希望自己能变成更聪明。这也是各种健脑、补脑药品和营养品大行其道的原因。普林斯顿的一位神经生物学家Joseph Z. Tsien则宣称找到了开启智慧之门的钥匙——基因。
Many people dream of having a smarter brain. Princeton neurobiologist Joseph Z. Tsien found the key. In September he announced that he’d built a better mouse by altering a gene1 that affects learning and memory. A similar process of gene manipulation might conceivably be used one day to boost intelligence in humans.
The secret lies in a feature of brain cells called the nmda receptor, which Tsien likens to a cylindrical2 tube or window that mediates3 the flow of information. When the window is open, chemicals called neurotransmitters flow through easily and memory is registered and stored. But as organisms mature, the window begins to close. (This may explain why children lose their facility for learning new languages when they reach sexual maturity4 and why some people suffer memory loss as they age.)
Tsien noticed that the receptor worked more efficiently5 when teamed with the gene NR2B, so he introduced extra NR2B genes6 into a batch7 of fertilized8 mouse eggs. In a normal mouse, the memory window is open for just 150-thousandths of a second. In Tsien’s specially9 engineered mice, the window opens for 250-thousandths of a second, long enough to make a remarkable10 difference in memory retention11. When he pitted his mice against common mice, they won paws down. Ordinary mice could recognize a Lego block for 12 hours, but smart mice could remember the block for up to three days. "That’s a profound enhancement," Tsien says.
Can it be done with humans? Maybe, but genetic12 engineering will have to make some extraordinary advances first. And some thorny13 ethical14 issues will have to be resolved. Meanwhile, Tsien promises to keep his furry15 little geniuses locked up in a lab, far from your larder16. "Otherwise," he says, "you might need a smart cat or a smart mousetrap to catch them."
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1 gene | |
n.遗传因子,基因 | |
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2 cylindrical | |
adj.圆筒形的 | |
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3 mediates | |
调停,调解,斡旋( mediate的第三人称单数 ); 居间促成; 影响…的发生; 使…可能发生 | |
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4 maturity | |
n.成熟;完成;(支票、债券等)到期 | |
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5 efficiently | |
adv.高效率地,有能力地 | |
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6 genes | |
n.基因( gene的名词复数 ) | |
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7 batch | |
n.一批(组,群);一批生产量 | |
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8 Fertilized | |
v.施肥( fertilize的过去式和过去分词 ) | |
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9 specially | |
adv.特定地;特殊地;明确地 | |
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10 remarkable | |
adj.显著的,异常的,非凡的,值得注意的 | |
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11 retention | |
n.保留,保持,保持力,记忆力 | |
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12 genetic | |
adj.遗传的,遗传学的 | |
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13 thorny | |
adj.多刺的,棘手的 | |
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14 ethical | |
adj.伦理的,道德的,合乎道德的 | |
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15 furry | |
adj.毛皮的;似毛皮的;毛皮制的 | |
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16 larder | |
n.食物贮藏室,食品橱 | |
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