You wake up feeling terrified, helpless, your heart pounding. You have just had a nightmare. Maybe you even have them frequently, and have tried every manner of sleeping pill, alteration to your sleep schedule, and variation on chamomile tea you can find. But nothing keeps that boogeyman out of your noggin at night.

What if we told you there is a gene that controls your night terror, and that it could be switched off?

That's the happy thesis driving the work of researchers at the University of Tsukuba and the University of Texas who have just discovered two genes that control dreaming and deep sleep. One regulates the amount of rapid eye movement (REM) sleep, the other controls the amount of non-rapid eye movement (NREM) sleep.

REM is the period of sleep that encompasses “vivid dreaming,” and involves intense brain activity that is almost like being awake. NREM is the remaining 75 percent of your sleep time – your deepest sleep. Both REM and NREM are important for your health and well-being, each contributing to tissue growth and repair and ensuring the brain and body are able to function effectively during the day. Science knows a lot about both stages, but the underlying control mechanisms have always been a bit murky.

Until now.

The scientists believe their findings will explain how sleep works and could treat sleep disorders. Control the genes, and you control sleep, they believe, and vivid dreams and nightmares could be switched off like a light switch.

"We hope that the discovery of these key genes is just the beginning of our long journey into the blackbox of sleep regulation,” wrote co-author Dr. Joseph Takahashi from the University of Tsukuba. “It is amazing that we know almost nothing about the simple question of what is 'sleepiness' physically in our brain. We will start from these genes and try to solve the great mystery."

The researchers identified the sleep genes after monitoring brain waves in 8,000 mice, checking for sleep disorders. When thy discovered one mouse had 50 percent more deep sleep than the others, and that a second mouse was severely deficient in its amount of deep sleep, their real work began. They discovered that each rodent had discrete gene mutations in single different genes. When the scientists introduced these genetic mutations into other mice, they saw their sleep patterns change accordingly.

"At least in theory, this study opens up future possibilities to create new sleep-regulating drugs, but doing so will occur in the distant future," notes senior author Dr. Masashi Yanagisawa, professor of molecular genetics at UT Southwestern.