Van der Zwaag Group

With a background in molecular sciences and a fascination for imaging, Wietske van der Zwaag found her way into neuroscience through MRI. Now she leads a research group that uses ultra-high-field MRI scanners to study the brain in unprecedented detail, with a special focus on the cerebellum — a region that is often still overlooked in research.

For whom and how?
The Van der Zwaag group uses ultra-high-field MRI scanners to visualise brain structures that are incredibly small and difficult to see, thereby revealing what has remained hidden for so long. In doing so, the group’s work forms a link between technological innovation, fundamental neuroscience, technological innovation, and future clinical applications.

The limits of what we can see

“To better understand the brain, you need to be able to see which structures are active, what they look like, and how different brain regions work together. If you want to study this in humans, MRI is the best technique, because it allows you to look at the brain without causing any harmdamage. With ultra-high-field MRI, such as 7 Tesla, we can look in much greater detail than with conventional scanners. These extra-strong magnets provide more signal, which allows us to visualise smaller structures.”

“But tThe sharper closer you want to look, the more complex the technology becomes. You can compare it to a Formula 1 car: it goes faster than an ordinary car, but it is not automatically suitable for every situation. A large part of our work is about making the technology reliable and usable — also for research involving people, and ultimately for helping patients. Scans should not take too long, not be too burdensome, and should still provide enough detail.”

“What fascinates me most are the parts of the brain that we often skip because they are harder to measure. The cerebellum is a good example. Cerebellum literally means ‘little brain’, and that is what it is: a kind of a mini -brain. It only accounts for around ten percent of the brain’s volume, but contains 80 percent of its neurons. And yet it is ignored in a lot of research. This is partly because it is so compact and the cerebellar cortex is so intricately folded. You really need high resolution to see what is happening there. But if you want to understand the human brain, you cannot leave out the cerebellum. It plays a role in movement, but also in attention, language, and behaviour.”

“In addition, another major technical question remains: what exactly are we measuring? In a lot ofmany functional MRIstudies, we look at changes in the oxygen concentration in the blood. That tells us a lot about brain function, but it is not the brain activity itself. It is more like an echo of it — something that follows activity in the brain.

A real breakthrough would be if we could measure signals that are closer to the source, closer to the electrical activity of brain cells. We are not there yet, but that is the direction in which the field is moving. We not only want to look in sharper detail, but also to better understand what we are actually looking at.”