In the brain of a zebrafish, lymphatic “scavenger” cells (shown in red) wrap around blood vessels (shown in green). The scavenger cells, or mural lymphatic endothelial cells, discovered by scientists at the University of Queensland, are believed to protect the brain from cellular waste, such as excess fats, leaking from the bloodstream.

“It is rare to discover a cell type in the brain that we didn’t know about previously, and particularly a cell type that we didn’t expect to be there,” says lead researcher Ben Hogan, of UQ’s Institute for Molecular Bioscience.