5 Amazing Things Your Brain Does While You Sleep

We spend a third of our lives sleeping, an activity as crucial to our health and well-being as eating. But exactly why we need sleep hasn't always been clear. We know that sleep makes us feel more energized and improves our mood, but what's really happening in the brain and body when we're at rest?

Research has identified a number of reasons that sleep is critical to our health. When we're sleeping, the brain is anything but inactive. In fact, during sleep, neurons in the brain fire nearly as much as they do during waking hours -- so it should come as no surprise that what happens during our resting hours is extremely important to a number brain and cognitive functions.

Here are five incredible things your brain does while you're asleep -- and good reason to get some shuteye tonight: