More than six years ago, the University of Minnesota spearheaded the technological advances behind the most ambitious brain imaging study ever conducted, the Human Connectome Project. It mapped the vast network of about 90 billion neurons and trillions of interconnections in the brains of young, healthy adults at the millimeter scale.

The U’s Center for Magnetic Resonance Research (CMRR) developed the imaging methods and directions on reconstructing the images to make sense of the data. Colleagues at Washington University in St. Louis did the bulk of the brain scanning — in total, 1,200 volunteers, made up of 300 sets of twins and two non-twin siblings — and, together with investigators from Oxford University, developed the image processing pipelines. 

Findings from this National Institutes of Health (NIH)–funded project, now complete and celebrated as a success, are publicly available to scientists and anyone else who wants them. The insights gleaned so far are fascinating.

“Our consortium [found] that the brain networks that we can detect very much correlated with behavioral measures, lifestyle measures,” says CMRR director Kamil Ugurbil, Ph.D. “For example, they are correlated very strongly with IQ, with education, with drug use or alcoholism, etcetera.”

Other researchers used the Human Connectome Project data to show that brain networks are unique to individuals, much like fingerprints. That’s encouraging, Ugurbil says, because if researchers can identify networks unique to individuals, they may be able to identify abnormalities unique to individuals as well.

What’s next? Extensions of this immense undertaking. The NIH is now funding a Life-span Human Connectome Project, designed to track normal brain changes in humans from infancy to “as old as we can get,” Ugurbil says.

• The Baby Connectome Project focuses on children from birth to early childhood to map structural and functional changes that occur in the brain during typical development. The U’s Jed Elison, Ph.D., McKnight Land Grant Professor, and Ugurbil will lead this effort with partners at the University of North Carolina.
• The Lifespan Human Connectome Project: Development targets ages 5 to 21 and will track changes in the brain, behavior, and mood as children move through puberty. The U’s Essa Yacoub, Ph.D., and Kathleen Thomas, Ph.D., will lead this arm of the study, which will also take into account physical and mental health, thinking and decision-making skills, and behavioral and emotional regulation.
• The Lifespan Human Connectome Project: Aging will characterize several factors that influence cognitive function alongside the comprehensive brain connectivity mapping in healthy volunteers aged 36 and up. This study — led by Ugurbil and the CMRR’s Melissa Terpstra, Ph.D. — will track risk factors for Alzheimer’s disease, cognitive symptoms associated with perimenopause, and key aspects of socioeconomic and health status.

The NIH is also funding 13 connectome projects focused on specific neuropsychiatric diseases to identify where and how alterations occur — and potentially to find ways to intervene in the disease processes. 

“Predominantly, this drive comes from the hypothesis that all neuropsychiatric diseases are circuitry diseases and you cannot study them with just normal magnetic resonance imaging,” says Ugurbil.

U psychiatry professor Scott Sponheim, Ph.D., is leading one such project on schizophrenia (see sidebar). 

The CMRR’s experts will continue to refine and develop the technologies needed for all of the connectome studies — and they’re disseminating these techniques to scientists around the world (at nearly 300 sites) in the name of advancing brain science. 

“At the expense of sounding immodest, I think there has been a revolution in imaging the brain through the Human Connectome Project,” says Ugurbil, adding that anyone who uses functional imaging and diffusion imaging — the two imaging types used in the studies — in their research will benefit. “The technological development has been really fantastic.”