Scientists have learned that the brain is more tightly linked to the rest of the body than we once thought. In a study released on April 27 in Nature Neuroscience, researchers used mouse experiments and computer models to find out why moving our bodies is good for the brain.
When the muscles in our belly tighten, they press on veins that run up to the spinal cord and brain. This pressure nudges the brain just a little inside the skull. That tiny motion helps the fluid that surrounds the brain—called cerebrospinal fluid—flow and carry away waste that can slow brain work.
How a Small Pump Helps the Brain
Patrick Drew, a professor at Penn State, says the belly muscles act like a tiny pump. Even a simple action such as bracing your core before you stand or take a step creates a gentle push. The push travels through a network of veins called the vertebral venous plexus, which connects the abdomen to the spine, and it makes the brain shift ever so slightly.
Seeing the Brain Move
To watch this happen, the team looked at live mice with two special cameras. One camera (two‑photon microscopy) gave a close‑up view of living tissue, while the other (micro‑CT) built a 3‑D picture of the whole body.
They saw the brain move just before the mouse started to move, right after the belly muscles tightened. To be sure the pressure was the key, they gently pressed on the bellies of lightly anesthetized mice—no other movement involved. The pressure was even less than what you feel during a blood‑pressure check, yet it still made the brain shift.
When the pressure was released, the brain bounced back to its original spot right away, showing how quickly the abdomen can change the brain’s position.
Computer Models Show Fluid Flow
Because current imaging can’t capture the fast, complex flow of cerebrospinal fluid, the researchers built computer simulations. Francesco Costanzo, another Penn State professor, led the modeling work.
He described the brain as a sponge: a soft skeleton full of tiny holes that let fluid move through. By treating it like a sponge, the team could see how fluid travels through different sized spaces—much like water flowing through a sponge’s pores.
In the model, squeezing a dirty sponge under a tap cleans it. Similarly, the brain’s tiny motion from belly‑muscle squeezes pushes fluid across the brain, helping wash away waste.
What This Means for You
More studies are needed to prove the idea in people, but the findings suggest that everyday movements—walking, stretching, or simply tightening your core—might help the brain’s cleaning fluid move, reducing the buildup of harmful waste. This could lower the risk of diseases that happen when waste piles up in the brain.
“Even the smallest motion, like the one you make when you walk or tighten your belly, could make a big difference for brain health,” says Drew.
Funding
The research was supported by the National Institutes of Health, the Pennsylvania Department of Health, and the American Heart Association.