Dumb flies (and perhaps people) may need a little more shuteye, or a shot of dopamine, to boost their brain power.

Fruit flies need sleep in order to learn, a study in the August 5 Current Biology shows. Keeping Drosophila up for hours after their normal bedtime impaired the flies’ ability to learn a complex task.

But activating a particular receptor for the neurotransmitter dopamine in a brain structure called the mushroom bodies erased the learning deficits, researchers