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.…