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NEWS IN FOCUS than, say, macaques, which are commonly used A gene-editing method known as CRISPR now Kiyoto Kasai will lead the third group, which as animal models. permits precise DNA alterations1,2 and has been will collect information, such as brain scans, The marmoset brain is compact, too — just used to create transgenic monkeys3. from human patients. This will can be used to 8 grams, making it relatively easy to analyse. At the same time, geneticists have identi- find signatures of psychiatric, neurological and Yet the frontal lobe — a brain area involved in fied some of the key mutations that contrib- vascular disease to feed back to the marmoset human psychiatric disease — is more developed ute to human disorders such as schizophrenia researchers. in marmosets and more like the human version and autism. “This is a very important time to Japan’s rules regarding the use of primates in than the frontal lobes of other animals with be developing primate genetic models,” says such research are less stringent than European similarly small brains. Marmosets also share Robert Desimone, director of the McGovern or US regulations, but the project could still behavioural charac­teristics with humans that Institute for Brain face ethical hurdles over issues of cruelty to other monkeys, and even chimps, do not, such “I would love to Research at the Mas- animals. “It will be important for the Japanese as living in family units that resemble human see one single sachusetts Institute marmoset project to carefully examine the ones and making eye contact as a means of com- important of Technology in ethical issues that will inevitably arise up the munication, rather than as a form of aggression. disease studied Cambridge. road,” says Sejnowski. The monkeys are thus expected to be a in great depth.” Brain/MINDS will BRAIN/minds is technically ambitious. good model for studying conditions such as be divided into three Neuroscientist Afonso Silva at the National Parkinson’s disease and Alzheimer’s disease. groups. One, led by project co-leader Institute of Neurological Disorders and Stroke And learning what causes the breakdown of Hideyuki Okano at Keio University, will map in Bethesda, Maryland, who collaborates with social behaviours such as making eye contact brain function to structure using techniques Sasaki, points out that CRISPR has yet to be might help to clarify the mechanisms under- such as functional magnetic resonance imaging. shown to work in marmosets. He adds that lying autism, suggests Katsuki Nakamura, a The group will use transgenic models of disease the project’s researchers must resist the temp- neuroscientist­ at in Japan to link studies of macro-scale functions — long- tation to tackle too many conditions, so as not who works with marmosets. distance pathways across the brain — to micro- to spread themselves too thinly. “I would love Recent advances could also help researchers scale studies that identify and characterize to see one single important disease studied in to genetically marmosets more effi- specific neuronal features. The second group, great depth,” he says. “Validating the approach ciently. In 2009, a team led by transgenic-animal led by the project’s other co-leader, Atsushi on that one disease will then enable the project specialist Erika Sasaki at the Central Insti- Miyawaki at the RIKEN Brain Science Insti- to be repeated in other diseases.” ■ tute for Experimental Animals in Kawasaki, tute in Wako, and consisting of 17 independent 1. Cong, L. et al. Science 339, 819–823 (2013). Japan, was the first to introduce a gene into a teams, will develop technologies to support the 2. Mali, P. et al. Science 339, 823–826 (2013). primate that was passed on to viable offspring. mapping effort. And the University of Tokyo’s 3. Niu, Y. et al. Cell 156, 836–843 (2014).

NOBEL PRIZE Blue LED wins Nobel Invention revolutionized lighting and will reduce global electricity consumption.

BY ELIZABETH GIBNEY

ound in smartphones, computer screens and energy-efficient bulbs, blue light- emitting diodes (LEDs) are everywhere. FThat they have now earned three Japanese- JIJI PRESS/AFP/GETTY born inventors the 2014 in Physics is a rare example of the award being given for a practical invention. LEDs are devices that emit light when sub- jected to an electric current. Green and red versions have been around since the 1950s, but creating blue-emitters was a technical challenge that stumped industry efforts for decades. It was not until the 1990s that and , both at Japan’s University, in parallel with elec- , Hiroshi Amano and Isamu Akasaki (left to right) won the 2014 . trical engineer Shuji Nakamura, then working at Japanese chemicals firm , succeeded where missing electrons leave behind a positive target for making high-power blue LEDs, but in creating a blue LED. charge. When an electrical current is applied, they were faced with several technological LEDs are sandwiches of ­ the electrons and holes combine at the junctions hurdles. One was creating thin, high-quality materials. The layers are ‘doped’ with other ele- between the layers and emit light as a result. crystals of the material, which are notoriously ments, which provides some layers with extra From the 1980s, focused their difficult to grow. Another was doping gallium electrons and others with a surplus of ‘holes’, efforts on the material as a nitride such that it emitted light efficiently.

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Akasaki, Amano and Nakamura persisted NOBEL PRIZES with gallium nitride long after their com- petitors had moved on to other materials, says Wolfgang Schnick, a materials chem- ist at the Ludwig Maximilian University of Prize for place cells Munich in Germany. Their success in overcoming those hur- Discoverers of brain’s navigation system get physiology Nobel. dles has opened the door to white LEDs, which can have efficiencies nearly 20 times those of conventional bulbs. BY ALISON ABBOTT & EWEN CALLAWAY Almost all white LED-based lights consist of a blue LED chip combined with one or rain cells that make up the biological more luminescent materials, which convert equivalent of a satellite-navigation sys-

DAVID BISHOP/UCL DAVID part of the blue light to longer wavelengths. tem have garnered three scientists the “This has led to a revolution in the light- B2014 Nobel Prize in Physiology or Medicine. ing industry, and will have more and more The discovery of the cells sheds light on one of impact on the way people are lighting their neuroscience’s great mysteries — how we know homes,” says Dirk Poelman, a materials where we are in space. scientist at Ghent University in Belgium. John O’Keefe of University College London Schnick says that the development won half of the prize for his discovery in 1971 “cannot be estimated too highly”. “This will of ‘place’ cells in the hippocampus, a part of help to save up to 20% of the global electric- the brain associated with memory. Edvard and ity consumption,” he says. May-Britt Moser, who are married and jointly Schnick added that in future, blue LEDs run a lab at the Kavli Institute for Systems Neu- are likely to find uses in portable devices roscience in Trondheim, Norway, share the that can disinfect or sterilize water, and other half for their 2005 discovery of ‘grid’ cells perhaps in computer memories that use in an adjacent brain structure, the entorhinal light instead of electricity to store data. cortex. Along with other navigation cells, grid Blue lasers — also invented by Akasaki and and place cells allow animals to keep track of John O’Keefe, co-winner of a 2014 Nobel prize. Amano, and separately by Nakamura — are their position. Both cell types were discovered already used in Blu-ray Disc technology. in rats, but have since been found in humans. when rats pass the points of a hexagonal grid. The story is not without twists. Naka- “Understanding where we are in space is one They found out that the brain uses this pattern mura, who left Japan in 2000 to join the of the most fundamental issues for survival,” as a coordinate system for spatial navigation , Santa Barbara, says Tobias Bonhoeffer, director of the Max (T. Hafting et al. Nature 436, 801–806; 2005). sued Nichia in 2001 over the scant com- Planck Institute of Neurobiology in Martin- The pattern constitutes what is known as a pensation he received for inventing the sried, Germany. neural code. It is the only one known to be gen- blue LED technology while he worked The discoveries will also be key to answering erated entirely in the brain, marking a milestone there. The case was settled in January 2005, the broader question of how the brain makes for computational neuroscience (see page 154). when Nakamura accepted ¥840 million sense of the world, says neuro­scientist Botond Both place and grid cells have practical rel- (US$8.1 million at the time). “Nakamura Roska of the Friedrich Miescher Institute for evance. The early stages of Alzheimer’s disease was quite determined to show that gal- Biomedical Research in Basel, Switzerland. affect the entorhinal cortex, and one of the first lium nitride could be an effective LED “These are three deep-thinking people who symptoms is losing one’s way. The disease goes technology. He pushed it very hard — it have changed the way we think about the on to devastate the hippocampus, stripping was something they were not initially brain,” he says. sufferers of their memories. “It is a good exam- concentrating on,” says Martin Dawson, Most neuroscientists once doubted that brain ple of how very basic research can help us gain a photonics researcher at the University of activity could be linked with behaviour, but in the deeper understanding we need in such dev- Strathclyde in Glasgow, UK. the late 1960s, O’Keefe began to record signals astating diseases to move towards therapies,” Speaking on a crackling telephone line to from individual neurons in the brains of rats says Richard Morris, a memory researcher at journalists in on 7 October, Naka- moving freely in a box. He put electrodes in the the University of Edinburgh, UK. mura said that the feeling of winning the hippocampus and was surprised to find that May-Britt was presiding over a lab meeting prize was “unbelievable”. Staffan Normark, individual cells fired when the rats moved to when the call came from the Nobel committee permanent secretary of the Royal Swedish particular spots. He concluded that the memory in Stockholm. “I hesitated to answer it,” she told Academy of Sciences, told journalists that of an environment may be stored as a specific Nature, laughing. “But I did — and I couldn’t the trio had not been expecting the prize. combination of place-cell activities in the hippo­ believe it; I even cried.” Edvard’s excitement was “They had not been waiting all day and all campus (J. O’Keefe and J. Dostrovsky Brain Res. delayed: he was on a aeroplane to Munich, Ger- night for this call,” he said. 34, 171–175; 1971). “I realized that if you put many, when his wife got the call. O’Keefe heard Announcing the prize, Per Delsing, them all together, you could have something like the news while working on a grant revision at chairman of the academy’s Nobel Com- a map,” says O’Keefe. home. “I’m totally delighted and thrilled,” he mittee for Physics, said that the award Fast-forward to the 1990s, and his work said in front of a phalanx of television cameras cherished the tradition of its founder, the attracted the attention of the Mosers, then PhD at a London press conference. engineer and inventor Alfred Nobel. “I students at the University of Oslo. They joined The Mosers once described their time in really think that Alfred Nobel would have him in London as postdocs, but within months O’Keefe’s lab as “probably the most intense been happy about this prize,” he said. ■ they had moved to the Norwegian University learning experience in our lives”. O’Keefe has of Science and Technology in Trondheim to similar memories. “It was intense — because Additional reporting by Richard Van set up their own lab. There they discovered they’re intense. They’re absolutely superb Noorden. that some cells in the entorhinal cortex fire scientists.” ■

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