Enhancing brain waste removal improves memory in older mice

As people age, their brains struggle to remove waste, which may lead to diseases like Alzheimer's and Parkinson's. Researchers at Washington University School of Medicine in St. Louis have discovered a way to address this issue. By enhancing the lymphatic vessels that drain waste from the brain, they improved memory in older mice. The study, published online on March 21 in the journal Cell, marks a significant step toward finding new treatments for cognitive decline. Current medications often face obstacles in reaching the brain, but this research targets the drainage system outside the brain, potentially improving treatment effectiveness. The lead researcher, Jonathan Kipnis, noted that enhancing the function of these lymphatic vessels could help develop therapies that prevent or slow cognitive decline. The study builds on earlier work that identified a network of lymphatic vessels around the brain that helps manage waste and fluid drainage. In their experiments, the researchers found that older mice with improved lymphatic function showed better memory. They tested the mice's memory by observing how long they explored new objects. The treated mice spent more time with new objects, indicating better memory retention. Additionally, the study revealed that when the lymphatic system is not working well, brain-cleaning cells struggle to keep up with waste, leading to cognitive problems. The treatment not only improved memory but also reduced distress signals in the brain that contribute to cognitive decline. Overall, these findings may pave the way for new approaches to support brain health in aging individuals. By focusing on the lymphatic vessels outside the brain, researchers hope to improve cognitive function without needing to repair damaged neurons directly.