Ions may be in charge of when you sleep and wake

Potassium spike in the brain, not nerve activity, causes eye-opening jolt

a sleepy mouse

ION COCKTAIL Changing levels of certain ions in the brain may lull mice (and probably humans) to sleep and rouse them again, a new study suggests. 

Chris Clogg/flickr 

To rewrite an Alanis Morissette song, the brain has a funny way of waking you up (and putting you to sleep).