Medical Research Council - London Institute of Medical Sciences

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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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