When Detlef Heck, PhD, looks at the cerebellum, he sees an orchestra, not a single instrument.
And that puts the associate professor of Anatomy and Neurobiology at the University of Tennessee Health Science Center (UTHSC) on the front lines of a new wave of brain research that is looking not just at how individual cells of the brain and parts of the brain respond and perform, but how they work together. The ultimate goal: to better understand the brain as a whole in order to treat it, repair it, or even, possibly, replicate its parts.
The cerebellum has long been known to contribute to motor control, balance and coordination. Much of the research on the “code” of the cerebellum, or the signaling of neurons that trigger action, has focused on individual cells and how they act or react, Dr. Heck noted. But unlike other areas of the brain, neurons in the cerebellum fire constantly, 90 to 100 times a second, whether we are awake or asleep. Understanding this constant action or electrical signaling necessitates a different approach to research.
“People have been listening to one violin for decades, and now it’s time to start listening to the whole orchestra and try to understand the complete symphony that comes out of it,” said Dr. Heck, a native of Cologne, Germany, who has spent the past 20 years researching the cerebellum.
A UTHSC faculty member since 2003, Dr. Heck was selected to organize a symposium on his studies and new approaches to brain research at the most recent Society for Neuroscience meeting in San Diego in November. The world’s largest annual brain research convention draws some 30,000 scientists from around the globe. His paper summarizing the symposium, “The Neuronal Code of the Cerebellum,” was published in the Journal of Neuroscience. Dr. Heck has also been asked to edit a book about the symposium and current research on the cerebellum.
“The question of this coding has been for many decades addressed by recording just one cell, and then asking what is this particular cell in the cerebellum interested in,” he said. “These researchers that I invited to the symposium, they took new approaches to that. They recorded more than one cell, and they asked is there something that these cells do together?”
Dr. Heck said he believes the symposium amplified the need to move away from the one-cell philosophy in researching the brain. “People are realizing there is something really new going on, something worth looking at.”
Dr. Heck works with awake mouse models using behavioral and electrophysiological approaches to study coordination of motor and cognitive processes in the cerebellum. His research is funded by grants from the National Institutes of Health (NIH).
He chaired the symposium and wrote the introduction and summary of the paper that contains contributions from each panelist. Panelists were Chris I. DeZeeuw, PhD, Netherlands Institute for Neuroscience, who studies the role of the cerebellum in learning and in the control of eye movements; Dieter Jaeger, PhD, Emory University, who is building a computer model of the cerebellum based on data from experiments in his lab and Dr. Heck’s lab; Kamran Khodakhah, PhD, New York University, who is interested in disease aspects of coding in the cerebellum; and Abigail L. Person, PhD, University of Colorado at Denver, who does in vitro experiments on how the cortex of the cerebellum and the nuclei communicate.
Dr. Heck said this kind of comprehensive research of the cerebellum is important on several levels. “The cerebellum fails in many brain disorders that we know,” he said, citing impaired movement, schizophrenia, and autism.
“If we want to do something about that, and we want to be able to manipulate the brain and maybe reinstall the function of the cerebellum, for example by using brain stimulation, we can only do that if we understand what type of activity we have to bring back into the brain to make it function,” he said.
There is motivation beyond the clinical aspect. “Of course, ultimately we would like to understand the brain as a whole, just out of curiosity and understanding what does it mean to be a human,” Dr. Heck said. “The cerebellum is definitely a part of that, because it affects cognition and it affects brain functions that we perceive as being uniquely human. And we can only understand if we understand the code the cerebellum produces.”