The U.S. Centers for Disease Control and Prevention declared sleep deprivation as a public health epidemic in 2013. Considering the effects of sleeplessness are similar to that of being intoxicated, having an inadequate sleep is a serious problem. It can not only reduce work performance of students and those with desk jobs, but it can also lead to injuries and accidents for some occupations like long-distance truck drivers.

According to research, lack of sleep impairs the brain’s capabilities because the exhausted neurons are slower to respond and send signals that are weaker. Brain waves similar to that when sleeping are also found in exhausted areas of the brain. They also suggest that some parts of the brain are sleep while the rest are awake, disrupting the brain activity and reducing its performance.

A lot of studies show different ways in which sleeplessness can reduce performance. But what exactly happens during sleep that helps the brain function properly?

Consolidates Gathered Information

One way that sleep facilitates our brain function is by allowing us to remember information. Scientists from the University of Geneva, led by Dr. Sophie Schwartz, studied two groups of volunteers who learned a new skill or shown images that they would have to remember. One group was then allowed to sleep normally for 8 hours while the other group was sleep derived or only allowed a nap.

Using functional magnetic resonance imaging, the scientists were able to determine that the group who had slept properly had better performance when asked to repeat their task or to remember the image shown to them.

The results show that a period of sleep after a earned experience allows the brain to consolidate these experiences and transform them into information to be stored for the long-term. These manifest as changes in activity in specific regions of the brain that are responsible for “coding” newly learned or experienced material into the brain.

Improves Creation Of Dendritic Spines

More research on the phenomena regarding memory was done by scientists from New York University, led by Wen-Biao Gan, by experimenting on mice. The mice were trained to balance on top of a rotating rod for an hour after which one group was allowed to sleep for 7 hours while the other group was kept awake.

By using a two-photon microscope to view the motor cortex of the mouse, they were able to monitor the growth of dendritic spines in each mouse before, during and after sleep/sleep deprivation. Dendritic spines grow when awake and when learning a new task. For the study regarding mice, the spines correlated to their capability to balance on the rotating rod.

They were able to observe that sleep-deprived mice grew less dendritic spines and also theorized that neuronal branches involved in the rod balancing task was reactivated in sleep and stabilizes the grown dendritic spines.

Furthermore, reversing the rotation of the log caused to grow dendritic spines from dendritic branches that are different from that of those in the original rotation. This means that the production of these dendritic spines is not random and is specific to the task being learned.

Simply put, a good sleep prior to training allows you to learn a new skill better. Furthermore, during sleep after learning a new skill your brain engages the new dendritic spines, essentially “practicing” them while you are sleeping, so that when you wake up, you are able to recreate the skill that you have learned.

Clears Waste Material

Another process that occurs when we sleep that improves our mental function is the clearing of waste material by the glymphatic system. This system uses perivascular tunnels to eliminate waste material from the brain while we sleep and is disengaged when we are awake.

Scientists from the University of Rochester Medical Center, led by Dr. Maiken Nedergaard, studied this phenomenon by injecting dye in the cerebrospinal fluid of mice and watching it flow through their brain while monitoring the brain activity. The dye flowed rapidly when mice were asleep but did not flow when mice are awake.

They then injected beta-amyloid, a brain protein associated with Alzheimer’s disease and measured how long the toxin would remain in the brain and observed that the toxin was removed faster while asleep.

This means that sleep functions as a way to clear toxins that reduce brain performance through a system that allows extracellular fluid to flush the brain.

How To Enter Sleep

If you want to function properly in your daily life, it is necessary to have good sleeping habits. This not only involves the act of sleeping but also extends to your routine before going to bed.

Strenuous exercise as well as eating large meals is not recommended before going to bed. If you feel that you are tired but cannot sleep, this may be due to other stressors. Try to avoid emotional conversations before going to bed; you can also invest in a massage chair where you can do some light reading and help you relax. Light stretching exercise like yoga can also release physical and mental tension that prevents you from dozing off.