“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,” he said.
“These cells appear to be the zebrafish version of cells described in humans called “mato” or lipid laden cells, which clear fats and lipids from the system but were not known to be lymphatic in nature.
“When wastes such as excess fats leak out of the bloodstream, it is the job of the lymphatic system to clean them out to avoid damaging our organs.”
Dr Hogan said the study focused on the presence and development of “scavenger” cells in zebrafish, however there was good reason to believe that equivalent cells surrounded and protected the human brain from a build-up of cellular waste.
“Zebrafish are naturally transparent, which means we can use advanced light microscopes to see directly into the zebrafish brain,” Dr Hogan said.
“Examining the zebrafish brain up close allowed us to find these cells and see how they form and function in detail.
“Normally, lymphatic endothelial cells will group together to form lymphatic vessels to carry fluid, but impressively, in the adult zebrafish brain these cells exist individually, independent of vessels and collect waste that enter the brain from the bloodstream.
“Our focus now is to investigate how these cells function in humans and see if we can control them with existing drugs to promote brain health, and improve our understanding of neurological diseases such as stroke and dementia.”
The study was published today in Nature Neuroscience (DOI: 10.1038/nn.4558) and involved researchers from UQ’s Institute for Molecular Bioscience, The University of Melbourne, Monash University and Japan’s National Cerebral and Cardiovascular Centre.
The National Health and Medical Research Council and UQ funded the research.