According to surveys done by the National Sleep Foundation, the majority of Americans are sleep deprived. This might not sound so terrible if we didn’t already know that it’s been closely linked to a long list of ailments including heart disease, increase in appetite, hormone imbalance, obesity, diabetes, and even Alzheimer’s.
And if you’ve ever skipped out on hours of sleep (whether you meant to or not) then you know how it hinders your ability to think quickly, messes with your memory, and just makes you feel less than your normal sharp self. A recently published study in The Journal of Neuroscience may explain why this happens.
The research team studied the effects of sleep deprivation in mice. They compared the brains of mice that had either been allowed to sleep for as long as they wanted or had been kept awake for a further eight hours. Another group of mice were kept awake for five days in a row – mimicking the effects of chronic sleep loss.
They specifically looked at glial cells, which form the brain’s housekeeping system. Earlier research had found that a gene that regulates the activity of these cells is more active after a period of sleep deprivation.
One type of glial cell, called an astrocyte, prunes unnecessary synapses in the brain to remodel its wiring. Another type, called a microglial cell, prowls the brain for damaged cells and debris.
After an undisturbed sleep, they found that astrocytes appeared to be active in around 6 per cent of the synapses in the brains of the well-rested mice. But astrocytes seemed to be more active in sleep-deprived mice – those that had lost eight hours of sleep showed astrocyte activity in around 8 per cent of their synapses, while the cells were active in 13.5 per cent of the synapses of the chronically sleep-deprived animals.
They also found that microglial cells were more active after chronic sleep deprivation. Michele Bellesi of the Marche Polytechnic University in Italy says;
This is a more worrying find. Excessive microglial activity has been linked to a range of brain disorders. We already know that sustained microglial activation has been observed in Alzheimer’s and other forms of neurodegeneration.
By contrast, only chronic sleep loss activates microglia cells and promotes their phagocytic activity … suggesting that extended sleep disruption may prime microglia and perhaps predispose the brain to other forms of insult.
Many questions remain, such as if this process is replicated in human brains, and if catching up on sleep can reverse the damage.
But the fact that Alzheimer’s deaths have increased by an incredible 50 percent since 1999, together with the struggle that many of us have in getting a good night’s sleep, means this is something we need to get to the bottom of – and fast.
Note to self: Get. More. Sleep.
And if you’ve had difficulty sleeping, make sure to check out our article “Eight Signs You Are Sleep Deprived And How To Fix It.”