Pioneering scientist speaks about brain mapping

This is an example of an fMRI map produced from data collected on the OHSU Brain Institute’s 7 Tesla MRI instrument showing auditory brain areas activated during a passive listening task.

Those of us who work within the OHSU Brain Institute are honored to have Dr. Marcus Raichle visit us May 13 to present an evening seminar in the Brain Awareness Lecture Series, entitled “How Do We Peer Deeply into the Brain.”

Raichle has been at the forefront in the development and application of advanced brain imaging techniques to advance neuroscience for four decades. He is a pioneer in the use of innovative positron emission tomography, or PET, studies to explore brain structure and function relationships.

Functional neuroimaging studies – or studies that show real-time imaging of the human brain in action — have grown tremendously over the last two decades and have contributed substantially to understanding function in the living human brain. Functional magnetic resonance imaging, or fMRI, has found widespread application in neuroscience, surgical planning before brain surgery and even non-medical applications like marketing research.

The fundamental experimental design strategies inherent in these studies can be traced to work from Raichle and his colleagues, who have used water that has been scientifically “marked” to allow the researchers to watch and investigate changes in blood flow in various parts of the brain as it performs specific tasks.

Raichle’s work has consistently shifted neuroscience paradigms. Studies from Raichle’s group have quantified blood flow and glucose utilization and found that these increase to a greater extent than oxygen utilization in activated brain areas — a principle central to essentially all fMRI experiments.

Most recently, Raichle and his colleagues have turned their attention to studies of the “resting” brain — that is, the brain not engaged in any outward directed activity. Remarkably, these neuroimaging studies have revealed that the brain is quite active – even at rest.  Indeed, the amount of energy expended at rest is much greater than incremental energy change required to attend to a specific task. Additional studies have revealed common modes of activity in the resting brain — a “default mode” that is deactivated during task-specific demands.

These findings have generated substantial excitement in the neuroscience community. We at the OHSU Brain Institute are actively pursuing research based on what Raichle has discovered, as are other top neuroscience institutions throughout the world.

That research, and further advances that spring from it, could lead someday to better treatments — and even cures — for a wide range of brain diseases and disorders.

Raichle will speak at 7 p.m. Monday at the Newmark Theater, 1111 S.W. Broadway in downtown Portland.

Bill Rooney, Ph.D.
Director, Advanced Imaging Research Center
OHSU Brain Institute