It's widely known that sleep is crucial to the formation of memories but scientists haven't understood exactly why that was the case until now. According to a news release, researchers at the Pennsylvania School of Medicine have discovered the answer at the molecular level. The discovery was made by studying the neural response of animals with one eye blindfolded to a color bar pattern (represented in the optical polar maps of the visual cortex above). Researcher Marcos G. Frank commented:

"We find that the biochemical changes are simply not happening in the neurons of animals that are awake. And when the animal goes to sleep it's like you’ve thrown a switch, and all of a sudden, everything is turned on that's necessary for making synaptic changes that form the basis of memory formation. It's very striking."

It turns out a molecule called an N-methyl D-aspartate receptor triggers a series of enzymes that allow neurons to make and break connections, reorganizing the neural network. Not surprisingly, the first thing suggested after the discovery was the development of drugs that could mimick the molecular events of sleep, eliminating the effects of not sleeping.