The discovery of cells in the brain that act as the body's internal global positioning system, which won three scientists the Nobel Prize for medicine on Monday, opens an intriguing new window onto dementia.

Since these spatial cells are among the first to be hit in Alzheimer's and other forms of dementia -- explaining why sufferers often lose their way -- understanding how they are degraded should shed important light on the disease process.
That is the belief of British-American researcher John O'Keefe, winner of the 2014 prize alongside Norwegians May-Britt and Edvard Moser, who plans to take his research to the next level as director of a new brain institute in London.

"We're now setting up to do much more high-tech studies where we hope to follow the progression of disease over time," he told reporters after hearing he would share the 8 million Swedish crowns ($1.1 million) prize.

"This will give us the first handle as to when and where the disease starts and how we can attack it at a the molecular and cellular level."

The battle against Alzheimer's has been long and frustrating. Global cases of dementia are expected to treble by 2050, yet scientists are still struggling to understand its basic biology and drug development is littered with failures.

The work by O'Keefe and the Mosers will not lead to immediate breakthroughs but by explaining how cells function -- and then fail to function -- in two very specific regions of the brain it is seen as vital for unpicking how Alzheimer's develops.

Dementia, of which Alzheimer's is the most common form, already affects 44 million people worldwide and that number is set to reach 135 million by 2050, according to Alzheimer's Disease International, a non-profit campaign group.

"Understanding how the healthy brain functions, especially areas of the brain crucial to learning and memory, is incredibly important in understanding what changes occur during conditions such as Alzheimer's disease," said Doug Brown, director of research and development at Britain's Alzheimer's Society.

The Nobel Prize winners' work on the brain's navigation system stretches back more than 40 years, but more recently scientists have developed powerful new tools for studying brain circuits that O'Keefe plans to put to work at the new London research institute where his is director.

The first of more than 150 scientists will start work at the Sainsbury Wellcome Centre for Neural Circuits and Behaviour at University College London next year, using state-of-the-art lasers, molecular biology and computational modelling to explore the brain's intricate wiring.

"It's a very exciting time," O'Keefe said.

The Group of Eight leading industrial countries set a goal last December of finding a cure or effective treatment for dementia by 2025.

It is a decade since the last drug was approved to treat Alzheimer's, and there is still no treatment that can slow the progression of the disease, with current drugs only easing some of the symptoms of the disorder.

"We all know there is a time bomb there," O'Keefe said. "We are starting to get a handle on it but that doesn't mean it is going to turn into a cure in the immediate future."

【新聞快訊】

據(jù)諾貝爾獎(jiǎng)官網(wǎng)消息,英國倫敦大學(xué)學(xué)院教授約翰·奧基夫、挪威科技大學(xué)教授梅·布里特·莫澤及其丈夫愛德華·莫澤因發(fā)現(xiàn)“大腦中的GPS”——組成大腦定位系統(tǒng)的細(xì)胞,而獲得今年諾貝爾生理學(xué)或醫(yī)學(xué)獎(jiǎng)。莫澤夫婦也成為第五對(duì)獲諾貝爾獎(jiǎng)的夫婦。

諾貝爾獎(jiǎng)評(píng)選委員會(huì)在聲明中介紹,“我們?nèi)绾沃牢覀兩硖幒畏??我們?cè)趺凑业綇囊粋€(gè)地方到另一個(gè)地方的路徑?我們?nèi)绾未鎯?chǔ)這些信息,從而能夠在下一次立即找到這條路?”三位獲獎(jiǎng)科學(xué)家的研究為我們解答了這些疑問。盡管三位科學(xué)家研究所處的時(shí)空并不相同,但是他們的研究都和大腦定位系統(tǒng)的細(xì)胞有關(guān),揭示了大腦中的“GPS”定位和導(dǎo)航系統(tǒng)是如何工作的。

1971年,奧基夫就發(fā)現(xiàn)了構(gòu)成這一體系的第一個(gè)組成部分。他發(fā)現(xiàn),大腦的海馬體里有一種特殊的神經(jīng)細(xì)胞,每當(dāng)老鼠身處屋子的特定位置時(shí),這種細(xì)胞的一部分就會(huì)被激活。而當(dāng)老鼠到了房間內(nèi)的其他位置時(shí),另外一些細(xì)胞則被激活。奧基夫認(rèn)為,這些“位置細(xì)胞”構(gòu)成了房間位置的一幅地圖。

34年之后的2005年,莫澤夫婦發(fā)現(xiàn)了大腦定位機(jī)制的另外一項(xiàng)關(guān)鍵組成部分。據(jù)諾貝爾獎(jiǎng)官網(wǎng)稱,他們確認(rèn)了另外一種神經(jīng)細(xì)胞,將其稱為“網(wǎng)格細(xì)胞”。這種細(xì)胞能夠產(chǎn)生一種坐標(biāo)系統(tǒng),從而使得精確定位與路徑搜尋成為可能。二人的后續(xù)研究則揭示了位置和網(wǎng)格細(xì)胞是如何令定位和導(dǎo)航成為可能的。