Author: Julie Pryor

Emile Bruneau: Tweaking the Empathy Gap

Anne Trafton |

Emile Bruneau, a postdoctoral associate in Rebecca Saxe’s lab at the McGovern Institute, is interested in the psychology of human conflict. He is working with Saxe to figure out why empathy — the ability to feel compassion for another person’s suffering — often fails between members of opposing conflict groups. Bruneau is also trying to locate patterns of brain activity that correlate with empathy, in hopes of eventually using such measures to determine how well people respond to reconciliation programs aimed at boosting empathy between groups in conflict.

Read more about Emile Bruneau’s work in the New York Times magazine.

MIT researchers join Obama for brain announcement

Anne Trafton |

Four MIT neuroscientists were among those invited to the White House on Tuesday, April 2, when President Barack Obama announced a new initiative to understand the human brain.

Professors Ed Boyden, Emery Brown, Robert Desimone and Sebastian Seung were among a group of leading researchers who joined Obama for the announcement, along with Francis Collins, director of the National Institutes of Health, and representatives of federal and private funders of neuroscience research.

In unveiling the BRAIN (Brain Research through Advancing Innovative Neurotechnologies) Initiative, Obama highlighted brain research as one of his administration’s “grand challenges” — ambitious yet achievable goals that demand new innovations and breakthroughs in science and technology.

A key goal of the BRAIN Initiative will be to accelerate the development of new technologies to visualize brain activity and to understand how this activity is linked to behavior and to brain disorders.

“There is this enormous mystery waiting to be unlocked,” Obama said, “and the BRAIN Initiative will change that by giving scientists the tools they need to get a dynamic picture of the brain in action and better understand how we think and how we learn and how we remember. And that knowledge could be — will be — transformative.”

To jump-start the initiative, the NIH, the Defense Advanced Research Projects Agency, and the National Science Foundation will invest some $100 million in research support beginning in the next fiscal year. Planning will be overseen by a working group co-chaired by Cornelia Bargmann PhD ’87, now at Rockefeller University, and William Newsome of Stanford University. Brown, an MIT professor of computational neuroscience and of health sciences and technology, will serve as a member of the working group.

Boyden, the Benesse Career Development Associate Professor of Research in Engineering, has pioneered the development of new technologies for studying brain activity. Desimone, the Doris and Don Berkey Professor of Neuroscience, is director of MIT’s McGovern Institute for Brain Research, which conducts research in many areas relevant to the new initiative. Seung, a professor of computational neuroscience and physics, is a leader in the field of “connectomics,” the effort to describe the wiring diagram of the brain.

 

2013 Scolnick Prize Lecture: Thomas Jessell

Anne Trafton |

Dr. Thomas Jessell of Columbia University is the winner of the 2013 Scolnick Prize in Neuroscience for his pioneering work on synaptic plasticity, the process by which the brain’s connections are modified in response to experience.

On April 1, 2013, he delivered the Scolnick Prize lecture, entitled “Sifting Circuits for Motor Control.”

Brain Scan Cover Image: Winter 2013

Anne Trafton |

The cover of the Winter 2013 issue of Brain Scan features an artist’s representation of a new genome editing technique developed by Feng Zhang. The method allows researchers to disrupt or replace genes at will.

2013 Sharp Lecture in Neural Circuits: Karel Svoboda

Anne Trafton |

On March 14, 2013, Dr. Karel Svoboda of HHMI delivered the second annual Sharp Lecture in Neuroscience. Dr. Svoboda’s lab is working on the structure, function and plasticity of neocortical circuits.

Martha Constantine-Paton to receive top honors from Tufts University

Anne Trafton |

Martha Constantine-Paton will receive the Dean’s Medal from Tufts University’s School of Arts and Sciences for her “exceptional contributions to the field of developmental neuroscience.” Constantine-Paton, a Tufts alumna, refers to her time at the university as a “turning point” in her life and credits the school for giving her the self-confidence she needed to pursue a career in science. The Dean’s Medal is the highest honor available at each school at Tufts, reserved only “for those select individuals who have made outstanding contributions to the university and to the greater community.”

Constantine-Paton will be awarded the Dean’s Medal on March 25, 2013.

Ed Boyden to share prestigious brain prize

Anne Trafton |

Ed Boyden, a faculty member in the MIT Media Lab and the McGovern Institute for Brain Research, was today named a recipient of the 2013 Grete Lundbeck European Brain Research Prize. The 1 million Euro prize is awarded for the development of optogenetics, a technology that makes it possible to control brain activity using light.

The Brain Prize is awarded annually by the Denmark-based Lundbeck Foundation for outstanding contributions to European neuroscience. Boyden is recognized for work done in collaboration with Karl Deisseroth at Stanford University, which builds on earlier discoveries by four European researchers: Ernst Bamberg, Georg Nagel and Peter Hegemann in Germany, and Gero Miesenböck, now in Oxford, U.K. The prize will be shared equally between all six researchers.

The idea of using light to control brain activity was suggested by Francis Crick in 1999, and Miesenbock performed a proof of concept demonstration in 2002, showing that light-sensitive proteins obtained from the eyes of fruit-flies could be used to activate mammalian neurons. A further breakthrough was enabled by the discovery of channelrhodopsin-2 (ChR2), a light-activated ion channel from a common pond algal species that had been characterized by Hegemann in Martinsried and by Nagel and Bamberg in Frankfurt.

The application of ChR2 to neuroscience was pioneered by Boyden and Deisseroth at Stanford University, where Deisseroth is now a faculty member. In a collaboration that began when Boyden was a graduate student and Deisseroth a postdoctoral fellow, they obtained the ChR2 gene from Nagel and Bamberg, expressed it in cultured neurons, and pulsed the dish with blue light to see whether it could trigger neural activity. The first experiment was performed in August 2004, and it worked first time; as Boyden recounted in a recent historical article, “serendipity had struck — the molecule was good enough in its wild-type form to be used in neurons right away.”

They reported this result in 2005, in a landmark paper in Nature Neuroscience that has now been cited more than 600 times. Their method, later dubbed “optogenetics,” is now used by hundreds of labs worldwide and is also being explored for a wide range of potential therapeutic applications. In announcing the Brain Prize, the chairman of the selection committee, Professor Colin Blakemore, described optogenetics as “arguably the most important technical advance in neuroscience in the past 40 years.”

Boyden joined the MIT faculty in 2006, where he is now the Benesse Career Development Professor in the Media Lab, with joint appointments at the McGovern Institute for Brain Research and in the Departments of Biological Engineering and Brain and Cognitive Sciences. His contributions have been recognized by numerous awards and honors, including the inaugural AF Harvey Prize and the 2011 Perl/UNC prize (shared with Karl Deisseroth and with Feng Zhang, also at MIT). He continues to develop novel optogenetic tools, along with many other technologies for understanding and manipulating neural circuits within the living brain.

Boyden’s work was supported by the Fannie and John Hertz Foundation, the Helen Hay Whitney Foundation, the McKnight Foundation, Jerry and Marge Burnett, DARPA and the Department of Defense, Google, Harvard/MIT Joint Grants Program in Basic Neuroscience, Human Frontiers Science Program, IET A. F. Harvey Prize, MIT McGovern Institute and MIT Media Lab, NARSAD, New York Stem Cell Foundation-Robertson Investigator Award, NIH, NSF, Paul Allen Distinguished Investigator in Neuroscience Award, Shelly Razin, SkTech, Alfred P. Sloan Foundation, the Society for Neuroscience Research Award for Innovation in Neuroscience (RAIN), and the Wallace H. Coulter Foundation.

Thomas Jessell named winner of 2013 Scolnick Prize

by Charles Jennings |

The Scolnick Prize is awarded annually by the McGovern Institute to recognize outstanding advances in the field of neuroscience.

“We congratulate Tom Jessell on this award,” says Robert Desimone, director of the McGovern Institute and chair of the selection committee. “He has been a pioneer in transforming developmental neuroscience from a descriptive to a mechanistic and molecular science.”

Jessell received his PhD from Cambridge University, and has held faculty appointments at Harvard Medical School and at Columbia University, where he is now the Claire Tow Professor of Neuroscience. He is also an investigator of the Howard Hughes Medical Institute.

Since moving to Columbia University in 1985, Jessell’s primary interest has been the embryonic development of the nervous system, specifically the spinal cord, which because of its relative simplicity and evolutionary conservation offers an ideal system for understanding general principles of neural development.

Jessell’s work has revealed the molecular mechanisms responsible for establishing the spatial organization of the spinal cord. He showed that the cord is shaped during embryonic development by diffusible signaling molecules known as “morphogens.” Two different classes of molecules are secreted by the most dorsal and ventral parts of the developing cord respectively, forming two opposing concentration gradients in the dorso-ventral axis. The concentrations of these signaling molecules provide “positional information” to embryonic cells, instructing them to differentiate in ways that are appropriate for their specific locations within the cord.

Jessell has also studied the molecular mechanisms by which developing cells respond to positional signals. Spinal motor neurons, for example, are known to cluster into “pools,” groups of neurons that form at stereotypic locations within the ventral spinal cord and which innervate a common target muscle. There are at least 50 different muscles in a vertebrate limb, each of which must be correctly innervated to allow precise control of movement. Jessell has shown that the identities of different motor pools are specified by combinations of transcription factors which are activated in different spatial domains in response to positional cues. These transcriptional “master regulators” work by controlling the expression of downstream genes that determine the distinctive properties of different neurons, including their shapes, their biochemical and electrical properties, and their choice of peripheral and central connections.

The discovery of these genetic mechanisms has made it possible to identify and manipulate the activity of specific classes of neurons with great precision, and Jessell has used this approach to reveal the link between functional circuitry and motor behavior.

In addition to fundamental questions, Jessell’s work has important practical implications for the emerging field of regenerative medicine. There is great interest in stem cells as a renewable source of cells for transplantation therapy, but for this approach to succeed, stem cells must be converted to the desired cell type. Jessell’s work on transcriptional control of neural identity provides a roadmap for such efforts, and he has demonstrated its feasibility in the case of spinal motor neurons, which degenerate in diseases such as amyotrophic lateral sclerosis. In collaboration with his former postdoc Hynek Wichterle, Jessell recently showed that embryonic stem cells can be induced to form a wide variety of motor neuron subtypes, and that when these neurons are transplanted into host embryos they can settle at the correct locations in the spinal cord and form appropriate axonal projections toward their normal targets. The implications of this result go well beyond motor neuron diseases; many disorders of the nervous system affect particular cell types, and the ability to convert stem cells to specific classes of neurons may eventually find wide applications in clinical neuroscience.

In addition to his many research contributions, Jessell also had great influence as a teacher and mentor. He is a coauthor of the classic textbook Principles of Neural Science, now in its fifth edition, and he has trained dozens of students and postdocs, many of whom are now recognized leaders in the field of neural development. Among the most notable is Marc Tessier-Lavigne, now president of Rockefeller University, whose pioneering work on the molecular basis of axon guidance was begun during a postdoctoral fellowship in Jessell’s lab.

The McGovern Institute will award the Scolnick Prize to Dr Jessell on Monday April 1, 2013. At 4.00 pm he will deliver a lecture entitled “Sifting Circuits for Motor Control,” to be followed by a reception, at the McGovern Institute in the Brain and Cognitive Sciences Complex, 43 Vassar Street (building 46, room 3002) in Cambridge. The event is free and open to the public.

Neuroscience and the Year of the Snake

Anne Trafton |

In the Chinese calendar, 2013 is the Year of the Snake, and to celebrate we’ve compiled a list of interesting facts about how snakes have contributed to brain research. [Click for English version of graphic.]

Snake venom

Snake venom has been a rich source of reagents for neuroscience research. Venom from the many-banded krait, a species found in Taiwan and Southern China, led to the identification of the first neurotransmitter receptor. In 1963 Chang and Lee at the National Taiwan University isolated a toxin, known as alpha-bungarotoxin, that binds strongly to the receptor for acetylcholine, the main neurotransmitter at neuromuscular synapses. This toxin, used by snakes to paralyze their victims’ muscles, was used by researchers to purify the acetylcholine receptor, and is still widely used today to study the biology of synapses.

Snake venom played central role in the identification of nerve growth factor (NGF) by Stanley Cohen and Rita Levi-Montalcini, who shared the 1986 Nobel Prize for their work. They discovered that the venom of the moccasin snake (a species of pit viper from the Southeastern US) was a rich source of a factor that could induce outgrowth of fibers from cultured neurons. This enabled them to characterize and eventually purify NGF, the first growth factor to be identified and the prototype for a large family of signaling molecules.

Snake venom has also led to several important advances in pain research, an area of great therapeutic interest. A protein complex isolated from the Texas coral snake has recently been shown to activate acid-sensitive ion channels (ASICs) in pain neurons, which is why bites from these snakes are so painful.  A peptide from the venom of a different species (the black mamba of East Africa, among the most venomous of all snakes) blocks the same channels and shows powerful analgesic effects – suggesting a promising new direction for drug development.

There are hundreds of species of venomous snakes, whose venoms contain a rich diversity of substances that have evolved specifically to interfere with the nervous systems of their victims and predators – a diversity that has only begun to be explored.

Snake evolution and behavior

Several families of snakes, including pit vipers, boas and pythons, can hunt at night using infrared (IR) radiation emitted by their warm-blooded prey. This ability arises from pit organs below the eyes, which allow these snakes to locate IR sources, sometimes with great accuracy. The molecular basis of IR detection was recently identified, and found to be an ion channel of the TRP family that is highly sensitive to warmth. The corresponding channel in other species is not strongly temperature-sensitive and is used mainly to detect chemical irritants (in humans, it responds to wasabi and mustard).  During snake evolution the same channel appears to have been co-opted for IR detection on several independent occasions in different snake families.

Another example of the evolutionary flexibility of brain and behavior comes from the tentacled snake of South-East Asia. This species hunts underwater, lying in wait for fish and detecting their location through a combination of vision and vibration. The snake captures a fish by exploiting its startle reflex – by making a feint with its body, the snake induces the fish to make a stereotypical escape response, directly toward the snake’s jaws. The snake can predict the fish’s behavior and makes a lunge to swallow it, all within about 25ms, or 1/40th second [video]. Remarkably a naïve snake, raised in captivity with no prior experience of fish, can do the same. Thus, the snake’s brain has been pre-wired by evolution to perform this behavior without the need for learning.

Snake phobia

Some people have a phobia for snakes, as do some animals, providing a useful model for understanding the neural basis of fear and anxiety. In one study, researchers even scanned volunteer subjects as they confronted a live snake inside the MRI scanner. These phobic responses are at least partly innate; monkeys, for example, will respond fearfully to a snake-like object even if they have never encountered one before. This raises interesting questions about how our brains are pre-wired to recognize specific stimuli, and also provides an opportunity to study how innate and leaned responses interact to control behavior.

These days snakes have more to fear from humans than vice versa, and many species around the world are now endangered. Awareness of their biology and potential for neuroscience discovery may strengthen efforts to conserve these remarkable creatures.