Studying mice sleeping provides clues to insomnia

CHICAGO (Xinhua) – Studying mice genetically modified to mimic the genetic disease neurofibromatosis type 1 (NF1) that is associated with sleep problems, researchers at Washington University School of Medicine in St Louis found that the animals, like some people with NF1, slept in short and irregular spurts.

The study may help identify the molecular and cellular mechanisms that go awry and cause fragmented sleep patterns in people with and without the disease, the researchers noted.

The researchers bred mice with a mutation in their NF1 gene similar to what is seen in people with NF1. Then, they fitted onto the mice miniature versions of the caps people wear for sleep studies to measure brain waves and identify sleep patterns of the mice.

Mice normally sleep during the day. Like people, mice cycle several times from deep, dreamless sleep to REM sleep or dreaming and back again. However, mice with an NF1 mutation tended to wake up soon after they entered deep sleep, and the result was a fragmented, and probably not restful, day of sleep.

“Throughout the whole night and day, they fell asleep and woke up when they shouldn’t have,” said co-first author Corina Anastasaki, an instructor in neurology at the university. “They fell into deep sleep, but they didn’t stay there.”