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Ann Graybiel wins Kavli Prize in Neuroscience

Anne Trafton |

Three MIT researchers including Ann Graybiel  are among seven pioneering scientists worldwide named today as this year’s recipients of the Kavli Prizes.

These prizes recognize scientists for their seminal advances in astrophysics, nanoscience and neuroscience, and include a cash award of $1 million in each field. This year’s laureates were selected for their fundamental contributions to our understanding of the outer solar system; the differences in material properties at the nanoscale and at larger scales; and how the brain receives and responds to sensations such as sight, sound and touch.

The Kavli Prizes, awarded biennially since 2008, are a partnership between the Norwegian Academy of Science and Letters, the Kavli Foundation and the Norwegian Ministry of Education and Research. Today’s announcement was made by Nils Christian Stenseth, president of the Norwegian Academy of Science and Letters, and transmitted live at the opening event of the World Science Festival in New York.

King Harald of Norway will present the Kavli Prizes to the laureates at an award ceremony in Oslo on Sept. 4. The ceremony will be hosted by Ã…se Kleveland, former minister of culture for Norway, and Alan Alda, the actor, director, writer and longtime supporter of science.

The Kavli Prize in Astrophysics

The 2012 Kavli Prize in Astrophysics is shared by Jane X. Luu, a technical staff member at MIT’s Lincoln Laboratory, along with David C. Jewitt of the University of California at Los Angeles and Michael E. Brown of the California Institute of Technology. They received the prize “for discovering and characterizing the Kuiper Belt and its largest members, work that led to a major advance in the understanding of the history of our planetary system.”

In 1992, Luu and Jewitt spotted the first known object in the Kuiper Belt, a region beyond Neptune’s orbit that is more than 30 times Earth’s distance from the sun. Since then, they and others have identified more than 1,000 Kuiper Belt objects. Astronomers are particularly interested in these objects because their composition may resemble the primordial material that coalesced around the sun during the formation of our solar system.

Brown followed in Luu and Jewitt’s footsteps by searching the Kuiper Belt for planet-sized bodies. In 2005, he found Eris, an object about the same size as Pluto but with 27 percent more mass. As a result, astronomers revisited the definition of planets; Pluto was subsequently relegated to “dwarf planet” status.

The Kavli Prize in Nanoscience

The 2012 Kavli Prize in Nanoscience is given to Mildred S. Dresselhaus, Institute Professor Emerita of Physics and Computer Science and Engineering at MIT, “for her pioneering contributions to the study of phonons, electron-phonon interactions, and thermal transport in nanostructures.”

Over five decades, Dresselhaus has made multiple advances explaining how the nanoscale properties of materials can vary from those of the same materials at larger dimensions. Her early work on carbon fibers and on compounds made up of different chemical species sandwiched between graphite layers — known as graphite intercalation compounds — laid the groundwork for later discoveries concerning buckyballs, carbon nanotubes and graphene.

The Kavli Prize in Neuroscience

The Kavli Prize in Neuroscience is shared by Ann M. Graybiel, Institute Professor in MIT’s Department of Brain and Cognitive Science, along with Cornelia Isabella Bargmann of Rockefeller University and Winfried Denk of the Max Planck Institute for Medical Research. They received the prize “for elucidating basic neuronal mechanisms underlying perception and decision.”

Graybiel, of MIT’s McGovern Institute for Brain Research, has identified and traced neural loops connecting the outer layer of the brain to a region called the striatum, revealing that these form the basis for linking sensory cues to actions involved in habitual behaviors. Her work has provided a deeper understanding of human ability to make or break habits, and of what goes wrong in disorders involving movement and repetitive behaviors.

Bargmann has used nematode worms to provide insights into the molecular controls of animal behavior, yielding important advances including the discovery of the first evidence that odor response is governed by neurons; of the intracellular signaling pathways between odorant receptors and sensory neurons; and of specific neurons, receptors and neurotransmitters involved in behavior adaption following experience.

Two techniques developed by Denk have answered major questions about how information is transmitted from the eye to the brain: His invention of two-photon laser scanning fluorescence microscopy allowed imaging of living tissue at greater depths and with less unwanted background fluorescence, and his development of serial block-face electron microscopy allowed detailed 3-D imaging of minute structures within tissue.

About the Kavli Prizes

Kavli Prize recipients are chosen biennially by committees of distinguished international scientists recommended by the Chinese Academy of Sciences, the French Academy of Sciences, the Max Planck Society, the National Academy of Sciences and the Royal Society. The recommendations of these prize committees are then confirmed by the Norwegian Academy of Science and Letters.

The Kavli Prizes were initiated by and named after Fred Kavli, founder and chairman of the Kavli Foundation, which is dedicated to advancing science for the benefit of humanity, promoting public understanding of scientific research, and supporting scientists and their work.

For more detailed information on each of the prizes including a video of the 2012 award ceremony, see the Kavli Prize website.

2012 Scolnick Prize Lecture: Roger Nicoll, MD

Anne Trafton |

Dr. Roger Nicoll of the University of California, San Francisco delivered the 2012 Scolnick Prize lecture, entitled “Deconstructing and reconstructing an excitatory synapse,” at the McGovern Institute for Brain Research at MIT on Thursday April 19. 2012.

Dr. Okihide Hikosaka: 2012 Sharp Lecture in Neural Circuits

Anne Trafton |

The inaugural Sharp Lecture was given on March 1, 2012 by Okihide Hikosaka of the NIH, a leading expert on brain mechanisms of motivation and learning.

Many objects around us have values which have been acquired through our life-long history. This suggests that the values of individual objects are stored in the brain as long-term memories. Our recent experiments suggest that such object-value memories are represented in part of the basal ganglia including the tail of the caudate nucleus (CDt) and the substantia nigra pars reticulata (SNr). We had monkeys look at many visual objects repeatedly in association with different but consistent reward values: half of the objects associated with a large reward (good objects) and the other half associated with a small reward (bad objects). Initially there was little effect of the object-reward association learning. However, after learning sessions across several days, CDt and SNr neurons started showing differential responses to the good and bad objects. In the end, SNr neurons reliably classified surprisingly many visual objects (nearly 300 in each monkey, so far tested) into good and bad objects. This neuronal bias remained intact even after >100 days of no training, even though the monkey continued to learn many other objects. The object value signals in the CDt and SNr are likely used for controlling saccadic eye movements, because many of the SNr neurons projected to the superior colliculus and electrical stimulation in the CDt induced saccades. Our results suggest that choosing good objects among many depends on the basal ganglia-mediated long-term memories. This basal ganglia mechanism may play an underlying role in visuomotor and cognitive skills.

Video Profile: Michale Fee

Anne Trafton |

Michale Fee, an investigator at the McGovern Institute for Brain Research, studies birdsong in order to understand how the brain learns and generates complex sequences of behavior.

Detecting the brain’s magnetic signals with MEG

by Charles Jennings |

Magnetoencephalography (MEG) is a noninvasive technique for measuring neuronal activity in the human brain. Electrical currents flowing through neurons generate weak magnetic fields that can be recorded at the surface of the head using very sensitive magnetic detectors known as superconducting quantum interference devices (SQUIDs).

MEG is a purely passive method that relies on detection of signals that are produced naturally by the brain. It does not involve exposure to radiation or strong magnetic fields, and there are no known hazards associated with MEG.

MEG was developed at MIT in the early 1970s by physicist David Cohen. Photo: David Cohen

Magnetic signals from the brain are very small compared to the magnetic fluctuations that are produced by interfering sources such as nearby electrical equipment or moving metal objects. Therefore MEG scans are typically performed within a special magnetically shielded room that blocks this external interference.

It is fitting that MIT should have a state-of-the-art MEG scanner, since the MEG technology was pioneered by David Cohen in the early 1970s while he was a member of MIT’s Francis Bitter Magnet Laboratory.

MEG can detect the timing of magnetic signals with millisecond precision. This is the timescale on which neurons communicate, and MEG is thus well suited to measuring the rapid signals that reflect communication between different parts of the human brain.

MEG is complementary to other brain imaging modalities such as functional magnetic resonance imaging (fMRI) and positron emission tomography (PET), which depend on changes in blood flow, and which have higher spatial resolution but much lower temporal resolution than MEG.

Our MEG scanner, an Elekta Neuromag Triux with 306 channels plus 128 channels for EEG, was installed in 2011 and is the first of its kind in North America. It is housed within a magnetically shielded room to reduce background noise.

The MEG lab is part of the Martinos Imaging Center at MIT, operating as a core facility, and accessible to all members of the local research community. Potential users should contact Dimitrios Pantazis for more information.

The MEG Lab was made possible through a grant from the National Science Foundation and through the generous support of the following donors: Thomas F. Peterson, Jr. ’57; Edward and Kay Poitras; The Simons Foundation; and an anonymous donor.

Video Profile: Yingxi Lin

Anne Trafton |

Yingxi Lin, a member of the McGovern Institute for Brain Research, uses molecular, genetic, and electrophysiological methods to understand how inhibitory circuits form within the brain, and how they are shaped by activity and experience.