The flies surprised us with how close they were in many ways.

That means that at the end of the day, you have a brain that costs you more energy. That's where sleep would kick in.

They rest for 10 hours a night, and if you keep them awake longer, they need to sleep more.

The brain breaks down into little islands that can't talk to one another.

Essentially, we activate an area, ... We can do this anywhere in the brain. Once an area is activated, it responds by sending signals, waves that travel through the axons (nerve fibers) to other regions of the brain. At the same time, we can record how the rest of the brain is responding.

Essentially, we activate an area. We can do this anywhere in the brain. Once an area is activated, it responds by sending signals, waves that travel through the axons (nerve fibers) to other regions of the brain. At the same time, we can record how the rest of the brain is responding.

During deep sleep early in the night, ... the response is short-lived and doesn't propagate at all.

What we needed to do was stimulate an area of the brain and see if it talks to another part. We have a tool to do that now.

He put his ear to his own chest and listened to the heart. How could the pulse go on, beat after beat, for all of life? No machine could run that long without a stumble. Ask not if the beating cranks are going to jam, but when.

Sleep is the price we pay for learning