Get Smart
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 gene 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[1] to a cylindrical tube or window that mediates[2] 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 maturity and why some people suffer memory loss as they age.)
Tsien noticed that the receptor worked more efficiently when teamed[3] with the gene NR2B, so he introduced extra NR2B genes into a batch of fertilized mouse eggs. In a normal mouse, the memory window is open for just 150-thousandths of a second. In Tsien's specially engineered mice, the window opens for 250-thousandths of a second, long enough to make a remarkable difference in memory retention. When he pitted[4] 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 genetic engineering will have to make some extraordinary advances first. And some thorny ethical issues will have to be resolved. Meanwhile, Tsien promises to keep his furry little geniuses locked up in a lab, far from your larder. "Otherwise," he says, "you might need a smart cat or a smart mousetrap to catch them."
許多人都希望自己能變成更聰明。普林斯頓神經(jīng)生物學(xué)家Joseph Z. Tsien就找到了這把開啟智慧之門的鑰匙：他于九月宣布，通過改變影響學(xué)習(xí)和記憶能力的基因培養(yǎng)出了一只聰明的老鼠。類似的基因處理技術(shù)有望在未來日子里運(yùn)用到人腦，以推動(dòng)人類智慧的飛躍。
該技術(shù)的奧秘就在于名為nmda感受器的腦細(xì)胞的功能。Tsien將其比作一個(gè)傳遞信息流的圓柱通道或窗口。當(dāng)窗口開放時(shí)，某種稱為神經(jīng)傳遞素的化學(xué)物質(zhì)就能輕易流過，記憶因此登記并存儲(chǔ)了下來。然而，當(dāng)器官成熟時(shí)，這扇窗口就開始關(guān)閉。（這也能解釋為何兒童長大后（性器官成熟之時(shí)）會(huì)失去掌握新語言的能力，以及為何某些人年老時(shí)會(huì)患失憶）。
Tsien注意到，當(dāng)感受器與名為NR2B的基因協(xié)作時(shí)效率會(huì)更高。因此，他將NR2B基因植入一批老鼠的受精卵中。一只普通老鼠的記憶之窗僅開放千分之150秒。而經(jīng)Tsien植入基因的老鼠，記憶之窗能開放千分之250秒，這已經(jīng)能夠使其記憶力發(fā)生驚人的改變。當(dāng)他讓自己的老鼠與普通老鼠互斗時(shí)，它們竟能輕而易舉地取勝。普通老鼠能夠保留關(guān)于Lego block的記憶12小時(shí)，而聰明的老鼠居然能將記憶保持三天?！斑@可是一個(gè)意義深遠(yuǎn)的進(jìn)步?！盩sien這樣說。
那么，人類也能接受這種基因移植嗎？ 或許可以，但前提是基因工程得首先做出非凡的成就，還必須解決一系列棘手的倫理問題。Tsien保證他一定會(huì)將那些披著毛皮的小天才鎖入實(shí)驗(yàn)室，遠(yuǎn)離人們的食品柜?！胺駝t，”他說，“為了捉住他們，人們就不得不去尋找更聰明的貓或者功能更強(qiáng)的捕鼠器了?！?BR>
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 gene 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[1] to a cylindrical tube or window that mediates[2] 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 maturity and why some people suffer memory loss as they age.)
Tsien noticed that the receptor worked more efficiently when teamed[3] with the gene NR2B, so he introduced extra NR2B genes into a batch of fertilized mouse eggs. In a normal mouse, the memory window is open for just 150-thousandths of a second. In Tsien's specially engineered mice, the window opens for 250-thousandths of a second, long enough to make a remarkable difference in memory retention. When he pitted[4] 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 genetic engineering will have to make some extraordinary advances first. And some thorny ethical issues will have to be resolved. Meanwhile, Tsien promises to keep his furry little geniuses locked up in a lab, far from your larder. "Otherwise," he says, "you might need a smart cat or a smart mousetrap to catch them."
許多人都希望自己能變成更聰明。普林斯頓神經(jīng)生物學(xué)家Joseph Z. Tsien就找到了這把開啟智慧之門的鑰匙：他于九月宣布，通過改變影響學(xué)習(xí)和記憶能力的基因培養(yǎng)出了一只聰明的老鼠。類似的基因處理技術(shù)有望在未來日子里運(yùn)用到人腦，以推動(dòng)人類智慧的飛躍。
該技術(shù)的奧秘就在于名為nmda感受器的腦細(xì)胞的功能。Tsien將其比作一個(gè)傳遞信息流的圓柱通道或窗口。當(dāng)窗口開放時(shí)，某種稱為神經(jīng)傳遞素的化學(xué)物質(zhì)就能輕易流過，記憶因此登記并存儲(chǔ)了下來。然而，當(dāng)器官成熟時(shí)，這扇窗口就開始關(guān)閉。（這也能解釋為何兒童長大后（性器官成熟之時(shí)）會(huì)失去掌握新語言的能力，以及為何某些人年老時(shí)會(huì)患失憶）。
Tsien注意到，當(dāng)感受器與名為NR2B的基因協(xié)作時(shí)效率會(huì)更高。因此，他將NR2B基因植入一批老鼠的受精卵中。一只普通老鼠的記憶之窗僅開放千分之150秒。而經(jīng)Tsien植入基因的老鼠，記憶之窗能開放千分之250秒，這已經(jīng)能夠使其記憶力發(fā)生驚人的改變。當(dāng)他讓自己的老鼠與普通老鼠互斗時(shí)，它們竟能輕而易舉地取勝。普通老鼠能夠保留關(guān)于Lego block的記憶12小時(shí)，而聰明的老鼠居然能將記憶保持三天?！斑@可是一個(gè)意義深遠(yuǎn)的進(jìn)步?！盩sien這樣說。
那么，人類也能接受這種基因移植嗎？ 或許可以，但前提是基因工程得首先做出非凡的成就，還必須解決一系列棘手的倫理問題。Tsien保證他一定會(huì)將那些披著毛皮的小天才鎖入實(shí)驗(yàn)室，遠(yuǎn)離人們的食品柜?！胺駝t，”他說，“為了捉住他們，人們就不得不去尋找更聰明的貓或者功能更強(qiáng)的捕鼠器了?！?BR>