In 2015, Kipnis identified lymphatic vessels connecting the brain to the immune system, vessels long thought not to exist. His recent research shows the role these vessels play in Alzheimer’s disease and cognitive decline. By improving the function of these vessels, Kipnis’ team dramatically enhanced the ability of older mice to learn and improve their memories. The discovery may lead to new ways to treat or prevent Alzheimer’s disease, age-related memory loss, and other neurodegenerative diseases.

Kipnis’ team also discovered that lymphatic vessels appear to carry previously unknown messages from the brain to the immune system—messages that ultimately trigger multiple sclerosis symptoms. The team was able to block these messages in mice, preventing more widespread damage to the nervous system and offering doctors a new way to treat this devastating condition.