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Introduction from Chair - Bruce Rosen, MD, PhD
The Human Brain at Work - Marcus Raichle, MD
Mapping the Connectome at the Synaptic Level - Jeff W. Lichtman, MD, PhD
Nerve cells are connected together in a complicated circuit. This circuit underlies fundamental functions of the brain such as its behavioral repertoire and memory storage capability. A range of human psychiatric, traumatic, learning, and degenerative brain disorders maybe be “connectopathies” in which some or all of the abnormality is related to miswired or incomplete circuits in most animals, including humans and all other mammals these circuits have remained out of reach both due to their very compact organization and the absence of techniques to systematically map them. New optical and electron microscopical approaches are providing detailed views of the complete circuitry of relatively small brain volumes. Soon these technologies will be scaled up to provide whole brain connectomes. Obtaining and analyzing these vast data sets require expertise in a wide range of disciplines including computer science, mathematics, engineering, and molecular- and neurobiology. Therefore this kind of project is reminiscent of the other large scientific endeavors (such as the sending men to the moon or the human genome project).
The portion of this session given by Karl Deisseroth is not included in this video.
Bruce Rosen is Director of the Athinoula A. Martinos Center at Massachusetts General Hospital.
Marcus Raichle is Professor of Radiology, Neurology, Neurobiology and Biomedical Engineering at Washington University in St Louis. He is a member of the National Academy of Sciences, The Institute of Medicine and the American Academy of Arts and Sciences and a Fellow of the American Association for the Advancement of Science. He and his colleagues have made outstanding contributions to the study of human brain function through the development and use of positron emission tomography (PET) and functional magnetic resonance imaging (fMRI). Their landmark study (Nature, 1988) described the first integrated strategy for the design, execution and interpretation of functional brain images. It represented 17 years of work developing the components of this strategy (e.g., rapid, repeat measurements of blood flow with PET; stereotaxic localization; imaging averaging; and, a cognitive subtraction strategy). Another seminal study led to the discovery that blood flow and glucose utilization change more than oxygen consumption in the active brain (Science, 1988) causing tissue oxygen to vary with brain activity. This discovery provided the physiological basis for subsequent development fMRI and caused researchers to reconsider the dogma that brain uses oxidative phosphorylation exclusively to fuel its functional activities. Finally seeking to explain task-induced activity decreases in functional brain images they employed an innovative strategy to define a physiological baseline (PNAS, 2001; Nature Reviews Neuroscience, 2001). This has led to the concept of a default mode of brain function and invigorated studies of intrinsic functional activity, an issue largely dormant for more than a century. An important facet of this work was the discovery of a unique fronto-parietal network in the brain that has come to be known as the default network. This network is now the focus of work on brain function in health and disease worldwide. In summary, the Raichle group has consistently led in defining the frontiers of cognitive neuroscience through the development and use of functional brain imaging techniques.
Jeff W. Lichtman is the Jeremy R. Knowles Professor of Molecular and Cellular Biology at Harvard University.
A one-on-one interview with Karl Deisseroth can be found here.
A one-on-one interview with Marcus Raichle can be found here.