During sleep, the brain cleanses itself of toxins accumulated during the day
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Sleeping pills may help you sleep, but the sleep you get may not be as restorative. When the mice were given zolpidem, a medication commonly found in sleeping pills like Ambien, it effectively blocked their brains. cleaning waste during sleep.
Sleep is essential for brain waste removal. At night, a clear liquid called cerebrospinal fluid circulates around the brain tissues, removing toxins through some thin tubes the glymphatic system. Think of it as the dishwasher that your brain turns on when you sleep, he says Maiken Nedergaard at the University of Rochester Medical Center in New York. However, the mechanism that drives fluids in this network was not well understood until now.
Nedergaard and his colleagues implanted optical fibers into the brains of seven mice. By illuminating chemical compounds in the brain, the fibers allow them to follow the flow of blood and cerebrospinal fluid during sleep.
They found that as levels of a molecule called norepinephrine (also called norepinephrine) rise, blood vessels in the brain constrict, decreasing blood volume and allowing cerebrospinal fluid to enter the brain. When norepinephrine levels drop, blood vessels dilate, pushing cerebrospinal fluid out. In this way, fluctuations in norepinephrine during non-rapid eye movement (NREM) sleep stimulate blood vessels to act as pumps. the glymphatic systemsays Nedergaard.
This finding reveals that norepinephrine plays a key role in brain waste clearance. Previous research has shown that, while we sleep, our brain releases norepinephrine in a slow, oscillating pattern. These waves of norepinephrine occur during NREM, which is the crucial stage of sleep for memory, learning and other cognitive functions.
The researchers then treated six mice with zolpidem, a sleep medication sold under the brand names Ambien and Zolpimist. While the mice fell asleep faster than those treated with a placebo, the flow of cerebrospinal fluid in the brain decreased by approximately 30 percent, on average. That is, “their brain is not cleaned very well”, says Nedergaard.
Although the experiment tested zolpidem, almost all sleeping pills inhibit the production of norepinephrine. This suggests that they may interfere with the brain’s ability to remove toxins.
It is too early to say whether these results will translate to humans. “The architecture of human sleep is still quite different from the mouse, but we have the same brain circuitry that was studied here,” he says. Laura Lewis at the Massachusetts Institute of Technology. “Some of these underlying mechanisms are likely to apply to us as well.”
If sleeping pills interfere with the brain’s ability to clear toxins during sleep, that means we need to develop new sleep medications, says Nedergaard. Otherwise, we risk escalating sleep problemsit can worsen brain health in the process.
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