Reasons for sleeping

2009/10/25 Korta Hernandez, Nerea - Elhuyar Zientziaren Komunikazioa

• Zoologia
• Anatomia/Fisiologia
• Osasuna

E All animals sleep (Photo: Photoxpress_StyezInk ).

Sleeping has been seen as a barrier or danger to survival, as it is easier for predators to attack sleeping animals. And besides, being asleep, they cannot carry out the necessary activities to survive, they cannot eat, they cannot reproduce or care for their family. Therefore, it has been considered that sleeping has some unknown psychological or cerebral function, which cannot be performed while the animals remain awake.

A theory that defends it is that of reparation and restoration. According to this theory, it is necessary to sleep to strengthen and restore the psychological processes that keep the mind and body healthy. This theory suggests that the NREM phase of sleep (phase in which the eye movement is not fast) is important for the recovery of psychological functions, while the REM phase (phase in which the eye movement is fast) is necessary for the recovery of brain functions. Research has shown that for long periods of sleep after periods of unsleep physical activity, the body increases the rate of cell division and protein production.

Another theory relates the dream to the fixing of information. This means that people sleep to process the information they received during the day and prepare the brain for the next day. Some also believe that sleeping helps to strengthen in long-term memory the knowledge acquired during the day. In fact, research has shown that the lack of sleep influences the ability to remember information.

Evolutionary theory

The human brain consumes 20% of the energy, so it is important to save energy (Photo: Nils Merkel ) .

Known as evolutionary or adaptation theory, it suggests that periods of activity and periods of inactivity evolved to conserve energy. In a study on the dream published in Nature Reviews Neuroscience, Professor Jaerome Siegel, who works at the University of California's Dorsal Research Center, has defended this fact. According to this theory, all the species that adapted to sleep in a time of danger of being awake.

On the one hand, animals with few natural predators, such as bears and lions, often sleep between 12 and 15 hours a day. On the other hand, animals with a lot of natural predators have short ligatures, usually 4 or 5 hours a day.

But, in addition to reducing risk, the theory points out that sleep has more advantages to survive: saving energy, reducing wounds and reducing resource consumption, among others.

Animals with few natural predators sleep longer hours (Photo: Rodolfo Clix ).

Some animals make them lethal for months. Hibernation is a behavior that regulates behavior toward survival. A small animal cannot migrate in winter to warmer climates, so it hibernates. It reduces energy consumption and is hidden to be safe from predators.

In humans, for example, energy saving is important. The brain only weighs 2% of the body, but consumes 20% of the energy. The dream makes that during a few hours a day this energy consumption is reduced.

Therefore, it is not clear what is the main function of sleep. Repair and recovery, information consolidation, and risk reduction can be the causes of sleep. Only with more evidence will the mystery be solved and scientists have not yet achieved it.

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