Scientists discover a hidden brain “cleaning” effect triggered by movement
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Scientists discover a hidden brain “cleaning” effect triggered by movement
Just moving your body might quietly “rinse” your brain—and help keep it healthy.
Date:
May 1, 2026
Source:
Penn State
Summary:
Scientists have uncovered a surprising link between simple body movement and brain health: every time you tighten your abdominal muscles—even slightly—your brain may gently sway inside your skull. This subtle motion, triggered by pressure changes in connected blood vessels, appears to help circulate cerebrospinal fluid around the brain, potentially flushing out harmful waste.
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Using microCT scanning, which allows for high-resolution imaging of an organism's internal structures, and other imaging techniques, researchers found that a network of veins serve as a mechanical connection between the abdominal cavity and the brain. Here, the veins in red run through the interior of a vertebrae and around the spine. Credit: Penn State
Scientists have discovered that the brain is more physically linked to the body than previously understood. In findings published April 27 in Nature Neuroscience, researchers used experiments in mice along with computer simulations to uncover a possible reason why physical activity supports brain health.
The study shows that when abdominal muscles tighten, they press on blood vessels connected to the spinal cord and brain. This pressure causes the brain to shift slightly within the skull. That gentle motion appears to help cerebrospinal fluid move across the brain, which may carry away waste that can interfere with normal brain function.
A Mechanical Link Between Movement and Brain Health
Patrick Drew, a professor of engineering science and mechanics, neurosurgery, biology, and biomedical engineering at Penn State, said the findings build on earlier research into how sleep and neuron loss affect the timing of cerebrospinal fluid flow in the brain.
"Our research explains how just moving around might serve as an important physiological mechanism promoting brain health," said Drew, corresponding author on the paper. "In this study, we found that when the abdominal muscles contract, they push blood from the abdomen into the spinal cord, just like in a hydraulic system, applying pressure to the brain and making it move. Simulations show that this gentle brain movement will drive fluid flow in and around the brain. It is thought the movement of fluid in the brain is important for removing waste and preventing neurodegenerative disorders. Our research shows that a little bit of motion is good, and it could be another reason why exercise is good for our brain health."
Drew, who is also associate director of the Huck Institutes of the Life Sciences, compared the process to a hydraulic system. In this case, the abdominal muscles act as the pump. Even small actions, such as bracing your core before standing up or taking a step, can create this effect. The pressure is transmitted through the vertebral venous plexus, a network of veins linking the abdomen to the spinal cavity, which leads to slight brain movement.
Imaging Reveals Brain Motion Triggered by Muscle Contractions
To observe this process, the researchers studied moving mice using two advanced imaging techniques. Two-photon microscopy provided detailed images of living tissue, while microcomputed tomography offered high-resolution 3D views of entire organs.
They found that the brain shifted just before the animals moved, immediately after the abdominal muscles tightened to initiate motion.
To confirm that abdominal pressure was the key factor, the team applied gentle, controlled pressure to the abdomens of lightly anesthetized mice. No other movement was involved. The level of pressure was lower than what a person experiences during a blood pressure test, yet it still caused the brain to move.
"Importantly, the brain began moving back to its baseline position immediately upon relief of the abdominal pressure," Drew said. "This suggests that abdominal pressure can rapidly and significantly alter the position of the brain within the skull."
Simulations Show How Fluid May Flow Through the Brain
After confirming that abdominal contractions drive brain motion, the researchers turned to the next question: how this movement influences fluid flow. At the time, no imaging methods could capture the rapid and complex behavior of cerebrospinal fluid in detail.
"Luckily, our interdisciplinary team at Penn State was able to develop these techniques, including conducting the imaging experiments of living mice and creating computer simulations of fluid motion," Drew said. "That combination of expertise is so important for understanding these types of complicated systems and how they impact health."
Francesco Costanzo, professor of engineering science and mechanics, biomedical engineering, mechanical engineering, and mathematic