Why does our brain need sleep, what if sleep is not enough?

Most of us have tasted the consequences of lack of sleep: fatigue, unstable center of gravity and difficulty concentrating. In fact, sleep is more important to our brain than you can imagine.

Although our body is "off" during sleep, the brain does not cease to be active. By detecting brain waves during sleep, we found that there are two different types of states in the brain during sleep: rapid eye movement (REM) and slow-wave sleep.

Slow-wave sleep mainly occurs at the beginning of the night, and its main feature is the slow-rhythm electrical signals (appearing one to four times per second) in a large number of brain cells. With the deepening of sleep, the proportion of REM will gradually increase. During REM sleep, dreams appear in our brain, and the brain wave signals of the brain are very similar to those of waking.

What does the brain do when we sleep?

Sleep has many functions. One of them is to help us remember our experiences during the day. REM is very important for emotional memory (for example, fear-related memories) or procedural memory (for example, cycling). On the other hand, slow wave sleep can reflect our storage of so-called "normal" memories (such as what we ate for breakfast).

We know that our past experiences in sleep are actually "replayed" in the brain, and the memories of these experiences can be played back and forth like movie clips. The hippocampus area, which is closely related to the brain's memory function, regulates this process. Research results based on rats have shown that when rats are trained to escape the maze, the brain will appear in the previous route when the rats are resting. This "replay" mechanism will help brain cells to strengthen connections, thereby enhancing the strength of memory.

But what is the use of remembering what we eat for breakfast? In fact, this is just a manifestation of selective memory in the brain. Sleep will help the brain to selectively form memories, forget the unimportant, and write down the relatively important things.

There are many theories about the function of sleep, the most mainstream of which is the so-called "synaptic homeostasis theory." The theory is that there are weak connections between brain neurons during sleep. This kind of connection is used to balance the connection that we make in the process of learning when we are awake. Through the counteracting effect, sleep can effectively "clear" less important information, thereby helping us to better accept new information the next day. In some cases, this can lead to deepening of memory.

The importance of sleep is to keep our brain in the best state. As our age changes, our sleep state begins to change, which will also have a corresponding impact. Babies and young children sleep a long time, which may be because their brains need to learn more. And as we get older, sleep time will gradually decrease.

Sleep also has the effect of "cleaning the brain". A mouse-based study showed that sleep can effectively remove toxins produced in the brain of mice when they are awake. During sleep, the space between brain cells gradually increases, which facilitates the release of toxic molecules. Therefore, adequate sleep can also effectively prevent the occurrence of neurodegenerative diseases.

What are the effects of poor sleep?

Ensuring adequate sleep is very important for the improvement of concentration and learning ability. When we are sleep deprived, it is difficult to concentrate on obtaining a lot of information, our reaction will slow down, and creativity will also decline, and the ability to solve problems will be affected.

If the sleep time is not enough, the brain will be forced to enter the "off" state when awake, this state will make us temporarily lose consciousness. Wandering while driving can cause serious traffic accidents, and its harm is no less than drinking alcohol. Lack of sleep can also cause accidents at work, and these events often occur in people who work shifts.

The positive effect of sleep on attention is especially important for children. A study shows that insufficient sleep time can have a serious negative effect on children's classroom performance.

What are the long-term effects of lack of sleep?

Long-term lack of sleep-related clinical research is difficult to conduct due to ethical restrictions, but current clinical evidence shows that chronic sleep disorders can cause abnormalities in the brain, such as schizophrenia, autism, and Alzheimer's disease. However, the causal relationship remains to be further explored.

In short, various evidences show that having adequate sleep habits is essential to ensure the health and function of the brain.

The above content is reproduced from: Biological Valley