There has always been a lot of discussion on why do we sleep. Now Boston researchers have found that it's when neurones get most of their food, showing very high levels of adenosine triphosphate (ATP), dubbed the "cell currency" of energy transfer, up to 3-4 times the normal levels.
When the experiment's rats had their sleep delayed by several hours this peak of ATP did not happen.
The neurones show in sleep period this high level of activity but brain's activity overall drops down. So I understand that their activity is selfish and relatively isolate unlike that of wake time, when they are working hard for the whole system to function properly.
Source: Science Daily.
I wonder: if sleep is neurones' lunch time, does that mean that dreams are their play time?