ISLAMABAD – Researchers at the University of Tsukuba in Japan have discovered a group of neurons in the mouse brainstem that suppress unwanted movement during rapid eye movement sleep.We laugh when we see Homer Simpson falling asleep while driving, while in church, and while even operating the nuclear reactor. In reality though, narcolepsy, cataplexy, and rapid eye movement (REM) sleep behavior disorder are all serious sleep-related illnesses. Researchers at the University of Tsukuba led by Professor Takeshi Sakurai have found neurons in the brain that link all three disorders and could provide a target for treatments.REM sleep correlates when we dream. Our eyes move back and forth, but our bodies remain still. This near-paralysis of muscles while dreaming is called REM-atonia, and is lacking in people with REM sleep behavior disorder.
Instead of being still during REM sleep, muscles move around, often going as far as to stand up and jump, yell, or punch. Sakurai and his team set out to find the neurons in the brain that normally prevent this type of behavior during REM sleep.Working with mice, the team identified a specific group of neurons as likely candidates. These cells were located in an area of the brain called the ventral medial medulla and received input from another area called the sublaterodorsal tegmental nucleus, or SLD. “The anatomy of the neurons we found matched what we know,” explains Sakurai. When the researchers blocked the input to these neurons, the mice began moving during their sleep, just like someone with REM sleep behavior disorder.