NOBEL PRIZES
Physicists change the light bulb
NOBEL PRIZES
Brain’s GPS finds top honor “Place” and “grid” cells help explain how we navigate with O’Keefe: May-Britt Moser, now director of the Centre for Neural Computation in ere’s a valuable lesson for neuroTrondheim, Norway, and Edvard Moser, now scientists everywhere: Give your test director of the Kavli Institute for Systems subjects a little freedom to roam. Neuroscience in Trondheim. The husbandIn the 1970s, when neuroscientist wife team, who briefly worked in O’Keefe’s lab John O’Keefe was at McGill Univeras postdocs, also monitored the brain activity sity in Montreal, Canada, he recorded of roaming rodents, chemically inactivating rat brain activity in a region called the hipthe hippocampus to identify other brain repocampus as the animals meandered freely gions involved in spatial navigation. In 2005, about enclosures. He and colleagues they published their Nobelspotted a group of neurons that PHYSIOLOGY NOBEL winning finding: a set of “grid fired only when the animals passed “for their discoveries cells” in a brain region called the by a particular spot. Together, these of cells that constitute entorhinal cortex. Unlike place “place cells” acted as a mental GPS, a positioning system cells, which signal a specific in the brain” enabling the rats to create a mental point in the environment, indimap of their surroundings, O’Keefe John O’Keefe vidual grid cells fire in a roamsays. Now director of the Sainsbury ing rodent at multiple, regularly May-Britt Moser Wellcome Centre for Neural Cirspaced locations, which form a cuits and Behaviour at University Edvard Moser honeycomblike pattern. They College London, O’Keefe learned may provide a set of reference this week that his discovery won him one points for navigation, though more research half of the 2014 $1.1 million Nobel Prize in is needed to determine their precise role. physiology or medicine. Recently, researchers have begun to maPlace cells “set in motion an entire field” nipulate these navigational neurons. A team within neuroscience, says Loren Frank, a earlier this year altered the positive and neuroscientist at the University of Californegative associations that mice had formed nia, San Francisco. “Hundreds, if not thouwith specific locations, by triggering hipsands” of neuroscientists interested in how pocampal place cells with lasers while sithe brain perceives, remembers, and plans multaneously stimulating other brain cells. movement through space flocked to study And although grid and place cells remain the hippocampus’s role in spatial memory afa focus of fundamental neuroscience reter O’Keefe’s original find, adds Lynn Nadel, search, there are hints of clinical relevance: a neuroscientist at the University of Arizona The hippocampus and entorhinal cortex in Tucson, who collaborated with O’Keefe on are among the first brain regions dama 1978 book about place cells. aged in neurodegenerative diseases such as Among those drawn to the nascent field Alzheimer’s. There may yet be a place for was the couple who shared the Nobel Prize place and grid cells in medicine. ■ By Emily Underwood
ILLUSTRATION: MATTIAS KARLEN
H
SCIENCE sciencemag.org
Blue light-emitting diodes, critical to white LED lighting, win this year’s prize By Dennis Normile
I
n a choice that surprised Nobel watchers, this year’s physics prize is going to three Japanese scientists not for a basic discovery but rather for an invention: the blue light-emitting diode (LED). The Nobel Committee recognized three researchers as contributing equally to the breakthrough: Isamu Akasaki of Meijo University in Nagoya and Nagoya University; Hiroshi Amano of Nagoya University; and Shuji Nakamura, now of the University of California, Santa Barbara. LEDs appeared in commercial applications in the 1960s. But until the early 1990s they only came in such colors as red and green. They were used as indicator lights in electronic devices and in electronic displays and, later, in auto brake lights. But without a blue LED, there was no way to create the white light needed for generalpurpose lighting. The challenge was in the materials. LEDs are semiconductor constructions that rely on an applied voltage to drive electrons and positive carriers called holes through different layers of a crystal sandwich. When electrons and holes come together in the so-called active layer of the sandwich, they give off photons—light. The wavelength of the light, and thus the color, depends on the properties of the crystal and embedded impurities, called dopants. For years, major corporations tried to find the right combination of semiconductor materials and dopants to produce blue light, but they failed. This trio of Japanese researchers began experimenting with gallium nitride. Theoretically, gallium nitride had the right stuff to produce blue light, but it was notoriously finicky to work with. “People thought [a blue LED] wouldn’t be achieved during the 20th century,” Akasaki said during a 7 October press conference in Nagoya. “Other researchers gave up but I didn’t think of doing so—I was doing what I liked,” he said. 10 OCTOBER 2014 • VOL 346 ISSUE 6206
Published by AAAS
149
Downloaded from www.sciencemag.org on October 9, 2014
In a roaming rat, individual grid cells fire at regularly spaced intervals (top), forming a navigational grid; place cells fire whenever an animal enters a specific spot in the environment (bottom).
Physicists change the light bulb
NOBEL PRIZES
Brain’s GPS finds top honor “Place” and “grid” cells help explain how we navigate with O’Keefe: May-Britt Moser, now director of the Centre for Neural Computation in ere’s a valuable lesson for neuroTrondheim, Norway, and Edvard Moser, now scientists everywhere: Give your test director of the Kavli Institute for Systems subjects a little freedom to roam. Neuroscience in Trondheim. The husbandIn the 1970s, when neuroscientist wife team, who briefly worked in O’Keefe’s lab John O’Keefe was at McGill Univeras postdocs, also monitored the brain activity sity in Montreal, Canada, he recorded of roaming rodents, chemically inactivating rat brain activity in a region called the hipthe hippocampus to identify other brain repocampus as the animals meandered freely gions involved in spatial navigation. In 2005, about enclosures. He and colleagues they published their Nobelspotted a group of neurons that PHYSIOLOGY NOBEL winning finding: a set of “grid fired only when the animals passed “for their discoveries cells” in a brain region called the by a particular spot. Together, these of cells that constitute entorhinal cortex. Unlike place “place cells” acted as a mental GPS, a positioning system cells, which signal a specific in the brain” enabling the rats to create a mental point in the environment, indimap of their surroundings, O’Keefe John O’Keefe vidual grid cells fire in a roamsays. Now director of the Sainsbury ing rodent at multiple, regularly May-Britt Moser Wellcome Centre for Neural Cirspaced locations, which form a cuits and Behaviour at University Edvard Moser honeycomblike pattern. They College London, O’Keefe learned may provide a set of reference this week that his discovery won him one points for navigation, though more research half of the 2014 $1.1 million Nobel Prize in is needed to determine their precise role. physiology or medicine. Recently, researchers have begun to maPlace cells “set in motion an entire field” nipulate these navigational neurons. A team within neuroscience, says Loren Frank, a earlier this year altered the positive and neuroscientist at the University of Californegative associations that mice had formed nia, San Francisco. “Hundreds, if not thouwith specific locations, by triggering hipsands” of neuroscientists interested in how pocampal place cells with lasers while sithe brain perceives, remembers, and plans multaneously stimulating other brain cells. movement through space flocked to study And although grid and place cells remain the hippocampus’s role in spatial memory afa focus of fundamental neuroscience reter O’Keefe’s original find, adds Lynn Nadel, search, there are hints of clinical relevance: a neuroscientist at the University of Arizona The hippocampus and entorhinal cortex in Tucson, who collaborated with O’Keefe on are among the first brain regions dama 1978 book about place cells. aged in neurodegenerative diseases such as Among those drawn to the nascent field Alzheimer’s. There may yet be a place for was the couple who shared the Nobel Prize place and grid cells in medicine. ■ By Emily Underwood
ILLUSTRATION: MATTIAS KARLEN
H
SCIENCE sciencemag.org
Blue light-emitting diodes, critical to white LED lighting, win this year’s prize By Dennis Normile
I
n a choice that surprised Nobel watchers, this year’s physics prize is going to three Japanese scientists not for a basic discovery but rather for an invention: the blue light-emitting diode (LED). The Nobel Committee recognized three researchers as contributing equally to the breakthrough: Isamu Akasaki of Meijo University in Nagoya and Nagoya University; Hiroshi Amano of Nagoya University; and Shuji Nakamura, now of the University of California, Santa Barbara. LEDs appeared in commercial applications in the 1960s. But until the early 1990s they only came in such colors as red and green. They were used as indicator lights in electronic devices and in electronic displays and, later, in auto brake lights. But without a blue LED, there was no way to create the white light needed for generalpurpose lighting. The challenge was in the materials. LEDs are semiconductor constructions that rely on an applied voltage to drive electrons and positive carriers called holes through different layers of a crystal sandwich. When electrons and holes come together in the so-called active layer of the sandwich, they give off photons—light. The wavelength of the light, and thus the color, depends on the properties of the crystal and embedded impurities, called dopants. For years, major corporations tried to find the right combination of semiconductor materials and dopants to produce blue light, but they failed. This trio of Japanese researchers began experimenting with gallium nitride. Theoretically, gallium nitride had the right stuff to produce blue light, but it was notoriously finicky to work with. “People thought [a blue LED] wouldn’t be achieved during the 20th century,” Akasaki said during a 7 October press conference in Nagoya. “Other researchers gave up but I didn’t think of doing so—I was doing what I liked,” he said. 10 OCTOBER 2014 • VOL 346 ISSUE 6206
Published by AAAS
149
Downloaded from www.sciencemag.org on October 9, 2014
In a roaming rat, individual grid cells fire at regularly spaced intervals (top), forming a navigational grid; place cells fire whenever an animal enters a specific spot in the environment (bottom).
