The lymphatic vessels long thought not to exist are essential to the brain's ability to cleanse itself. UVA researchers were able to use a compound to improve the flow of waste from the brain to the lymph nodes in the neck of aged mice. The vessels became larger and drained better, and that had a direct effect on the mice's ability to learn and remember.

This is the first time that we can actually enhance cognitive ability in an old mouse by targeting this lymphatic vasculature around the brain.

The researchers determined that obstructing the vessels in mice worsens the accumulation of harmful amyloid plaques in the brain that are associated with Alzheimer's. This may help explain the buildup of such plaques in people, the cause of which is not well understood.