We know that people with Alzheimer's often have sleep problems. But does it work the other way? Do problems with sleep set the stage for this degenerative brain disease? Jon Hamilton introduces us to some scientists looking into that connection. In a recent study, researchers observed a key role deep sleep potentially plays in maintaining brain health and protecting the brain against Alzheimer's. Follow host Maddie Sofia on Twitter @maddie_sofia. Email the show at shortwave@npr.org.