Canadian and Swiss neuroscientists have carried out an investigation, whose thesis has recently been published in the journal Science , which would demonstrate that quality sleep at night, in addition to improving our mental and physical health, helps to consolidate our memory, and, specifically , what we have learned the day before . For this it is important that our sleep, when it is in the REM phase (the deep phase of sleep, the one in which we dream), is not interrupted.
In this research, the scientists carried out their experiments with mice and confirmed that when their sleep was disturbed in their REM phase during the night, the next day they could not remember the experiences they had lived the previous day, which goes to show that deep sleep helps to consolidate a part of our memory, increase our ability to retain recently learned information.
The neurobiologists in this study turned to optogenetics, a technique that combines the genetics and the use of optical methods to act on the activity of cells by, for example, light pulses. It normally consists of straining the gene for a light-sensitive protein into the DNA of the cell under study. In this research, the objective was the GABAergic neurons, that is, nerve cells that secrete GABA (an inhibitory neurotransmitter) and that are found in an area of the brain that limits and influences the hippocampus.
When they illuminated these neurons in a certain way, they managed to activate or turning them off , and, as their main signal, the so-called theta waves, is clearly visible on an EEG while we are in REM sleep, that allowed the researchers to observe their functionality.
After the scientists deactivated the GABAergic neurons – at which point theta waves were not visible on the EEG – the mouse was still asleep, but was no longer in REM phase. If under normal conditions, after a night of sleep, the animal managed to remember where the objects of the previous day were, when the functioning of the GABAergic neurons was altered, being in the REM phase, the rodent’s spatial memory was altered : he remembered almost nothing of what he had learned.
According to Professor Antoine Adamantidis, a researcher at the University of Bern (Switzerland) and one of the authors of the study, this is proof that REM sleep plays an important role in the consolidation of spatial memory .
Other previous studies in this field of sleep have explained how important it is, on a physical and psychological level, to sleep well, since when a person is not able to have a deep sleep, a increased anxiety, lack of concentration and irritability of the individual.
