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Pia mater – meningeal tissue surrounding the brain – filters cerebrospinal fluid

20 August 2022

Along the Pia

Forming pockets that stretch along the brain’s blood vessels, perivascular spaces serve as outlets for sluicing waste chemicals, but exactly how they work throughout our lives is a little mysterious. Investigating inside this mouse’s brain (with its cells highlighted in blue), researchers find clues in the pia mater (green) – a tender layer of brain tissue that blood vessels (red) pass through on their way into or out from the brain. It was previously thought that pia acts as a barrier, restricting the flow of brain fluids, but the scientists now believe pia acts more like a filter, adjusting the flow of chemicals in cerebrospinal fluid flowing around perivascular spaces, and potentially changing as we age. Investigating further may help to guide pia’s role in sieving out waste chemicals that may contribute to Alzheimer’s disease in later life.

Written by John Ankers

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BPoD stands for Biomedical Picture of the Day. Managed by the MRC Laboratory of Medical Sciences until Jul 2023, it is now run independently by a dedicated team of scientists and writers. The website aims to engage everyone, young and old, in the wonders of biology, and its influence on medicine. The ever-growing archive of more than 4000 research images documents over a decade of progress. Explore the collection and see what you discover. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.

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