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You're listening to shortwave from NPR.

Hey shortwaivers, Regina Barbara here, and it's time to talk about brainwashing.

But not the kind you get in a cult.

We're going to talk about how the brain literally washes itself.

And PRO science correspondent John Hamilton has been covering the latest research.

Hey John.

Hey Gina.

So what kind of waste does the brain need to get rid of?

Well, a lot of it is just stuff left over from all the processes that keep cells alive.

So for example, cells combine oxygen with glucose to make energy that produces water and carbon dioxide and the cells need to get rid of that.

Cells also need to clear away these toxic proteins like beta amyloid

which can form these sticky plaques in the brain that are a hallmark of Alzheimer's

which is of course that disease that gradually erodes your memory and thinking.

Right, so maybe that disease is coming from all that garbage kind of getting built up in your brain?

That is the idea. That is what most scientists believe right now.

How does stuff build up in the brain?

Well, it can build up in two places. It can build up

inside of cells which is what happens with tau protein which is one of the proteins

involved in Alzheimer's. It can also build up in the fluid that's between cells, this interstitial fluid, and that's where

amyloid plaques form, you know, those plaques that are associated with Alzheimer's.

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