Researchers at the University of Tokyo have discovered two genes responsible for nightmares and dreams, which occur during the deep sleep known as REM (Rapid Eye Movement) sleep, according to the British newspaper, the Daily Mail.
REM sleep occurs in mammals, including humans, and is believed to play a crucial role in maintaining well-being, as well as in memory consolidation.
However, when researchers isolated two genes that induce REM sleep in mice, they were surprised to find that the rodents lived normally, despite the critical importance of REM sleep, according to previous studies.
By removing the genes responsible for the mice's dreams, researchers could theoretically stop nightmares in humans in the future.
The researchers genetically modified mice so that they no longer had genes that code for the chemical messenger acetylcholine, which is released in high quantities in mammals during REM sleep.
The genetic modification process involved removing two genes known as Chrm1 and Chrm3, which are widely distributed in different areas of the brain. When Chrm 1 was removed, the mice experienced short, fragmented REM sleep periods, while the absence of the Chrm 3 gene reduced the duration of REM sleep.
After removing both genes, the mice did not experience REM sleep but were still able to survive.
Based on these recent findings, published in the journal Cell Reports, the researchers believe that REM sleep may not be essential for survival, at least in domesticated animals.