REM sleep is characterized by an active mind in a paralyzed body. This paralysis protects you from acting out the content of your dreams. Dysfunction may result in various sleep disorders. People who are not properly paralyzed may experience REM behavior disorder. Others may have the paralysis persist into wakefulness, often with associated symptoms such as hallucinations, causing sleep paralysis.
The study, published in The Journal of Neuroscience, details the chemicals involved in this process. The scientists used several techniques to isolate and explain how sleep paralysis occurs in rats. They have discovered that two powerful neurotransmitters - called GABA and glycine - play a key role. They act to switch off the nerve cells that control the body's muscles. When this inhibition stops, the muscles wake up and sleep paralysis ends.
When problems occur with this system, the above sleep disorders may ensue.