Housekeeping in the Brain

New imaging technique reveals the brain’s waste-removal system in action

A cross-section through the brain reveals the symmetric architecture of the vascular network (cyan-green) and the tracer highlighting the glymphatic system (red-yellow) along the brain's surface and drainage routes — imaged through the intact skull with 3D-PAULM.
The 3D-PAULM image shows both the vascular network of the brain (blood/oxygen) while the red and yellow shows the movement of cerebrospinal fluid through the glymphatic system.

This is a summary of a story written by Michaela Martinez on Pratt School of Engineering.

Often described as the brain’s cleaning system, the glymphatic system uses cerebrospinal fluid to wash away waste, damaged proteins, and other debris that accumulate during normal brain activity.

Duke University biomedical engineers have developed a new way to noninvasively visualize the brain’s waste-clearing system in detail.

The new imaging technology combines light and sound to track cerebrospinal fluid movement across the brain’s network of blood vessels. The approach allows researchers to examine how the brain’s waste-clearing system changes in animal models during aging, after stroke, and under anesthesia, offering new insights into a process recognized as critical to brain health.

The process is especially active during sleep and plays an important role in maintaining brain health. Disruptions to the glymphatic system have been linked to aging, stroke, traumatic brain injury, and neurodegenerative diseases such as Alzheimer's.

“When we’re sleeping, it’s like a garbage truck going through our neighborhood and collecting all the garbage cans,” said Junjie Yao, associate professor of biomedical engineering. “The longer and better we sleep, the more garbage it can collect. The brain can remove this waste when we’re awake, but it’s much more active when we’re asleep.”

Existing imaging tools can visualize parts of the brain, but they often require invasive procedures or fail to provide a detailed view of how fluid moves throughout the entire brain.

“Given this system’s importance for brain health, we hope this technology will help us learn more about these diseases and contribute to the development of targeted therapies for Alzheimer’s and other brain disorders,” Yao said.

To learn more about this new procedure, visit Pratt School of Engineering.