Help might be on the way for 135,000 Americans who suffer from narcolepsy, a neurological disorder that causes people to fall asleep suddenly and unexpectedly during the day and have vivid hallucinations. In research published in the journal Cell, psychiatry associate professor Emmanuel Mignot and his colleagues detail the discovery of a gene, dubbed hypocretin receptor 2, that causes narcolepsy in dogs. The Doberman pinschers and Labrador retrievers the team studied have a faulty version of the gene, which, when working properly, produces neurochemicals that tell the brain to stay awake.
People with narcolepsy have trouble holding a job or even driving a car. They experience symptoms including extreme daytime sleepiness, sleep paralysis -- a frightening inability to move shortly after awakening or dozing off -- as well as hallucinations while sleeping or falling asleep. The most dramatic symptom, however, is sudden episodes of muscle weakness that may cause people to collapse. "Patients fail at school; they fail in their jobs," says Mignot. "They've lost their lives." Doctors can prescribe drugs to treat the symptoms, but none of the current treatments get at the underlying cause.
Mignot and his colleagues searched for the narcolepsy gene in dogs because the genetics of the disease are simple in some breeds. These animals are affected only when they inherit a defective copy of the gene from both parents. Although the condition works differently in humans -- it involves the interaction of several genes and environmental triggers -- scientists believe the finding will eventually lead to a drug to counteract the defective gene.
What's more, the research may help anyone who has spent a day yawning after a restless night. Today's sleeping pills may knock you out, but they generally interfere with the more restful REM sleep, Mignot says. Using the findings from the Stanford study, pharmaceutical companies may be able to create a drug that mimics healthy brain chemistry to encourage deep sleep. Such advances, says Mignot, are probably years away, but achieving them would be a dream come true.
