(ORDO NEWS) — For the first time, scientists have been able to track the brain activity of wolves during sleep and compare it to how dogs sleep.
One of the mysteries of the physiology of sleep is the changes that occurred to him during the transition from life in the wild to “civilization”.
Such a transition was made not only by people, but also by domesticated animals. Therefore, scientists are trying to compare their sleep with the sleep of wild relatives. Ethologists from the University of Budapest (Hungary) managed to carry out such work on wolves for the first time.
At night, people settle into their homes – warm, dry and safe – so that after a good night’s sleep, they can begin the day’s activities. Such conditions are rare in the wild, and our ancestors slept under other, more disturbing circumstances.
This could not but affect the mode and nature of sleep itself. Most likely, modern people sleep differently than in the distant past.
To find out whether this is true and how exactly sleep has changed with the development of the economy, scientists turn to domesticated animals that have experienced similar changes in living conditions.
The idea is to compare the sleep physiology between them and their wild relatives and find the difference. From this point of view, dogs and wolves look like the most suitable objects – animals that are still very close, but have long been leading completely different lifestyles.
However, wolves remain wild, and so far no one has been able to attach electrodes to them for electroencephalography (EEG) and at the same time place them in such conditions that the animal falls asleep peacefully.
Recently, Hungarian ethologists led by Vivien Reicher managed to do such work for the first time. Scientists took advantage of the fact that wolves that grew up among people, although they do not adore them, like dogs, get used to the human presence and care and feel quite comfortable.
Therefore, the experiments were carried out on seven wolves, which were bred in captivity. EEG electrodes were attached to the scalp of the animals in order to track all phases of sleep.
The wolves slept in the presence of their keepers, who comforted them when the animals woke up. Similar data were collected for dogs of the same age as wolves.
Recordings of brain wave activity have shown that wolves experience similar “dog” sleep stages. The main difference was the duration of the REM phase , which lasts longer in wolves, and this difference increases with age.
Recall that during a night’s rest, the brain of mammals exhibits different types of activity, which replace each other in a certain order, passing through the corresponding phases. The most notable of these are slow-wave and fast-paced (REM-) sleep.
During the fast, there are frequent fluctuations in electrical activity in the brain, almost like during wakefulness, even the eyes are actively moving under the eyelids. It is believed that in this phase there is a consolidation of memory – the transition of important experiences from temporary to long-term storage.
Unfortunately, the amount of data that the authors of the experiments managed to collect is still insufficient to draw serious conclusions about the difference in the nature of sleep in wild and domesticated animals, including humans.
Vivien Reicher and her co-authors hope that their work encourages colleagues to do similar experiments and that in the near future we will have enough information to better understand sleep.
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