諾貝爾醫學獎揭曉 挪威夫妻上榜"夫妻檔"

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】

據諾貝爾獎官網消息，英國倫敦大學學院教授約翰·奧基夫、挪威科技大學教授梅·布里特·莫澤及其丈夫愛德華·莫澤因發現“大腦中的GPS”——組成大腦定位系統的細胞，而獲得今年諾貝爾生理學或醫學獎。莫澤夫婦也成爲第五對獲諾貝爾獎的夫婦。

諾貝爾獎評選委員會在聲明中介紹，“我們如何知道我們身處何方？我們怎麼找到從一個地方到另一個地方的路徑？我們如何存儲這些信息，從而能夠在下一次立即找到這條路？”三位獲獎科學家的研究爲我們解答了這些疑問。儘管三位科學家研究所處的時空並不相同，但是他們的研究都和大腦定位系統的細胞有關，揭示了大腦中的“GPS”定位和導航系統是如何工作的。

1971年，奧基夫就發現了構成這一體系的第一個組成部分。他發現，大腦的海馬體裏有一種特殊的神經細胞，每當老鼠身處屋子的特定位置時，這種細胞的一部分就會被激活。而當老鼠到了房間內的其他位置時，另外一些細胞則被激活。奧基夫認爲，這些“位置細胞”構成了房間位置的一幅地圖。

34年之後的2005年，莫澤夫婦發現了大腦定位機制的另外一項關鍵組成部分。據諾貝爾獎官網稱，他們確認了另外一種神經細胞，將其稱爲“網格細胞”。這種細胞能夠產生一種座標系統，從而使得精確定位與路徑搜尋成爲可能。二人的後續研究則揭示了位置和網格細胞是如何令定位和導航成爲可能的。