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The Switch for Sleep

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  • In terms of overall health, for a long time, sleep wasn’t considered to be all that important. Today, that’s all changed. Sleep is key to keeping us healthy and yet, getting enough of it is elusive for more than 50 million Americans.  Sleep deprivation puts us at risk of high blood pressure, heart disease, kidney issues, obesity and even depression.  

    Sleep is a highly structured part of our circadian rhythm and that daily rhythm works as a biological clock signaling our body to work or rest based on daylight and nightfall. We need sleep to restore our cells, especially our neurons.  

    Now a new study helps us better understand “sleepiness” or that pressure you feel to sleep when you’re tired and it’s tied to the cells’ powerhouse, the mitochondria.  

    When we start to feel tired, the mitochondria in our brain cells ramp up energy production. The overworked mitochondria break down into pieces and produce oxidized fats inside the cell. To repair this, these pieces connect to another structure in the cell called the endoplasmic reticulum for repair. All this activity flips the sleepy switch and the only way to ease this feeling is to get sleep.  

    Once we do, the mitochondria are repaired and this cycle repeats itself, which indicates that the changes in the cell is a temporary response to sleep loss. We’re learning that healthy mitochondria are essential for keeping our sleep–wake system in balance.  This finding could provide a new lead to come up with better treatments for the nearly one billion sleep deprived people around the world.    

More Information

Mitochondrial origins of the pressure to sleep
To gain a comprehensive, unbiased perspective on molecular changes in the brain that may underlie the need for sleep, we have characterized the transcriptomes of single cells isolated from rested and sleep-deprived flies. Here we report that transcripts upregulated after sleep deprivation, in sleep-control neurons projecting to the dorsal fan-shaped body (dFBNs) but not ubiquitously in the brain, encode almost exclusively proteins with roles in mitochondrial respiration and ATP synthesis. 

Sleep as a determinant of health
A growing body of research shows the importance of sleep for health, but millions of people don’t get enough of it.

Scientists may have just solved the mystery of sleep
New research shows mitochondria in neurons track energy stress to trigger sleep, revealing potential treatments.