It's a simple question that you'd think would have a simpleanswer. We know that sleep has restorativeeffects on our bodies down to the cellular level, but how it all works froma biological perspective has been somewhat of a mystery.
Now we've got more details to help tell the story of justwhat exactly goes on. New research suggests that during the initial stages ofsleep, energy levels increase dramatically in brain regions that are activewhen we're awake. The scientists behind this latest studybelieve that this surge of cellularenergy may replenish the brain'sprocesses that we need to function normally during the day.
"Energy," by the way, refers to ATP (adenosine triphosphate), which is our body's chief energy molecule. It's also thesame energy currency in other animals like rats, which were used in the study.The researchers found the following:
- ATPlevels increased in four key brainregions that are normally active during wakefulness, when the rats were in non-REM sleep.
- During this time, however, an overall decrease in brain activity occurred.
- When the animals were awake, ATP levels remainedsteady.
- When the rats were gently nudged to stay awake three or six hours past theirnormal sleep times, there was no increase in ATP levels.
What does all this mean?
The authors concluded that sleep is necessary for this ATP energy surge, as keeping the ratsawake (depriving them of sleep to mimic a sleep deprived human) prevented thesurge. The energy increase may power restorative processes absent duringwakefulness, because brain cells consume large amounts of energy just toperform daily waking functions.
Indeed, there's a lot to do when we're awake. In addition toall the tasks we complete consciously, think about all the things we dopractically subconsciously like breathing, think about things we do almost onautopilot: surfing the net, walking the dog, sometimes even driving a familiarroute. All this activity requires--yougot it-- the ATP energy that appears to be produced by a good night's sleep. Anda good night's sleep is exactly what the doctor ordered to prepare us for therigors of our day. No sleep, no energy expended in the brain to help us recoverfrom the day and, in essence, rechargeour minds for the next adventures of the next day.
It's also worth noting that the precise mechanics of thebrain also remain a mystery to some degree. There's no doubt that the brain requires a lot of energy tofunction as the body's master of ceremonies. We already know that sleep loss can actually resultin brain loss. In fact, the obligations of the brain may be the only reasonwe need sleep: because without a brain the body isn't worth much. And itcertainly can't do much.
In addition to food, water and oxygen, the brain clearlyneeds sleep. If only sleep-deprivation were as compelling of a sensation asfeeling famished or thirsty. We always seem to be able to put off sleep. Buteating or drinking, well...
Sweet Dreams,
Michael J. Breus, PhD
The Sleep Doctor™