RDB, a neurological disorder that causes violent twitches and muscle contractions during rapid eye-movement (REM) sleep, can lead to serious injuries. John Peever, Assistant Professor at the University of Toronto, discovered that an inhibitory brain chemical called glycine is responsible for actively suppressing muscle twitches in REM sleep. Deficiency in glycine levels in the brain cells that control muscles (motoneurons) was found to cause the violent muscle contractions that mimic the primary symptom of RBD.
"This study shows the mechanism that suppresses muscles twitches in REM sleep and this will lead to better treatments and potential cures for this disorder," says Peever. "Treating REM sleep disorder may have much broader implications, since within five to eight years of being diagnosed with this disorder, 60-80% of individuals eventually develop Parkinson's disease."