Abdominal contractions trigger brain motion via a hydraulic-like mechanism, study finds

A Nature Neuroscience study in awake mice shows abdominal muscle contractions compress a network of veins called the vertebral venous plexus, pushing fluid and causing the brain to shift slightly within the skull. Using two-photon microscopy and computer simulations, researchers suggest this mechanical pumping could drive cerebrospinal fluid flow to clear waste, offering a potential mechanism for how exercise benefits brain health. The work used head-fixed mice on a spherical treadmill with abdominal pressure applied by a pneumatic belt, and notes limitations such as imaging only the top cortex and simplified anatomy, with human relevance still to be determined.