Surprise with the latest evidence that explains why we need sleep

According to sleep scientists in the United States, good night sleep is not the "dead" time of the brain. It is really an important job to do.

According to two new studies, the purpose of sleep is to forget some memories so that other memories can be stored later.

In the first study , the mice will be put to live in an unfamiliar area. They will then have mild electric shock. Some will take medicine to prevent memory arrangement in the brain (anesthesia), while the second group will sleep the night as usual.

When these mice were released into the same unfamiliar environment, there were two different reactions. The anesthetized mice seem to still remember the shock and most of the time are lying motionless. Meanwhile, the mice that were sleeping enough seemed hesitant at first but then quickly spent time exploring the surroundings.

The purpose of sleep is to forget some memories.

Dr Graham Diering, a member of the Johns Hopkins research team, said: "We think the memory of electric shock is too strong while the other memory is fuzzy, so the anesthetized mice are confused. and it cannot be easily distinguished from being in another environment ".

"Our findings show that rats, and perhaps humans, will store information only before it is recalibrated. Without sleep and without recalibration while sleeping, memories will be lost , " said Dr. Diering.

In the second study , Wisconsin Sleep and Conscious researchers used electron microscopy to record the neural joints of mice while they were awake and sleeping because of the view that the information would "contained" in nerve joints - which are responsible for connecting cells in the brain.

They found specific evidence of the "elastic" process - the synapses grow and expand when the mouse is active and then shrink about 20% during sleep.

And the effect of sleep continues until the next day, creating many "spaces" to "contain" new memories. However, there are still 20% synapses that never "transform" and are believed to be the ones that hold the most stable memories.

If you do not sleep and there is no recalibration during sleep, the memory will be lost.

Dr. Chiara Cirelli, a member of the research team, said: "This indicates that with very clear structural limitations, the balance between size and growth of synapse will be overturned by wake up and recover when sleeping ".

"It is noteworthy that most synapses in the cortex undergo large changes in size within hours after sleeping," Dr. Chiara said.

Thus, this new study adds evidence to the view that sleep is an important part for the brain to collect information.

Previously, for many years, scientists had to work hard to figure out why humans need to sleep 1/3 of the time each day.