Transatlantic Connectome Project Unites People and Machines to Map the Mind
Kavli Prize Laureate Winfried Denk and connectomist Sebastian Seung discussed microscopy and their quest to map the connectome.
First publicized in a 2005 paper by Olaf Sporns, the term “connectome” refers to a structural description of the neuronal connections in a brain. According to a doctrine known as “connectionism,” the properties of the human mind, from memories to mental disorders, are encoded in a distinctive pattern of neural connections. Since the connections of individual neurons differ from brain to brain, they contribute to a person’s uniqueness. For years, connectionism has inspired a new generation of scientists to search for the connectome, a map of links between individual neurons in the brain. To date, the only connectome that is known in its entirety is the one of the worm, c. elegans. Twelve years were required to identify the worm’s 302 neurons and its over 7,000 connections. The human brain consists of 100 billion neurons that are interconnected in 10,000 different ways. To map a human connectome would require extensive use of supercomputers and untold man-hours.
Prof. Seung, who is the author of the recently published book, Connectome: How the Brain’s Wiring Makes Us Who We Are, states the hypothesis that every individual is his or her connectome. In order to visualize the wiring of the human brain, to understand its workings and malfunctions, he has founded Wired Differently, an online citizen science community which enlists volunteers from the general public to map connectomes by analyzing neural images via an online gaming experience. The German-U.S. collaboration Eyewire, which is built around datasets from Prof. Denk’s laboratory in Heidelberg, Germany, is Wired Differently’s first project. With the goal of mapping the neural connections of the retina, Eyewire volunteers trace neuron branches through images of mouse brain scans by playing a simple online game, helping the computer to color a neuron as if the images were part of a three-dimensional coloring book.“Humans collectively spend 600 years each day playing Angry Birds. We harness this love of gaming for connectome analysis,” Prof. Seung said.
Winfried Denk and Sebastian Seung are both physicists turned neuroscientists. While Prof. Denk’s background is rooted in experimental physics, Prof. Seung studied theoretical physics. Their first encounter was at Bell Laboratories in the 1990s. Prof. Seung, who is now Professor for Computational Neuroscience at the Massachusetts Institute of Technology, remembers Prof. Denk as “the laser guy” who liked to experiment with new technologies. Since then, Prof. Denk, who is the Director of the Biomedical Imaging Department at the Max Planck Institute for Medical Research in Heidelberg, has revolutionized the high resolution imaging of cells inside tissues. To better follow neural connections, he co-developed two-photon microscopy and contributed to the invention of serial block-face scanning electron microscopy that allows the tracking of neural processes across long distances, both essential techniques for neuroscientists. On May 31, 2012, Winfried Denk was announced a 2012 Kavli Prize Laureate in Neuroscience. He is sharing the prize with Cornelia Bargman (Rockefeller University) and Ann Graybiel (Massachusetts Institute of Technology).
Jim Sharp, the President of Carl Zeiss Microscopy, LLC, and CEO of Carl Zeiss, Inc., moderated this popular GCRI event.