A good night's sleep with the flip of a switch?

The flip of a switch could become all it takes to get a good night's sleep, according to a study released Monday. Researchers at the University of Wisconsin-Madison have found a way to stimulate the slow waves typical of deep sleep by sending a harmless magnetic signal through the skulls of sleeping volunteers.

 

Sleep remains one of the big mysteries in biology. All animals sleep, and people who are deprived of sleep suffer physically, emotionally and intellectually. But nobody knows how sleep restores the brain.

 

Now, Giulio Tononi, a professor of psychiatry at the University of Wisconsin-Madison School of Medicine and Public Health, has discovered how to stimulate brain waves that characterize the deepest stage of sleep. The discovery could open a new window into the role of sleep in keeping humans healthy, happy and able to learn. The study was published in the April 30 edition of the Proceedings of the National Academy of Sciences.

 

The brain function in question, called slow wave activity, is critical to the restoration of mood and the ability to learn, think and remember, Tononi says.

 

During slow wave activity, which occupies about 80 percent of sleeping hours, waves of electrical activity wash across the brain, roughly once a second, 1,000 times a night. In a paper being published this week in the Early Edition of the scientific journal PNAS, Tononi and colleagues, including Marcello Massimini, also of the UW-Madison School of Medicine and Public Health, described the use of transcranial magnetic stimulation (TMS) to initiate slow waves in sleeping volunteers. The researchers recorded brain electrical activity with an electroencephalograph (EEG).

 

A TMS instrument sends a harmless magnetic signal through the scalp and skull and into the brain, where it activates electrical impulses. In response to each burst of magnetism, the subjects' brains immediately produced slow waves typical of deep sleep, Tononi says. "With a single pulse, we were able to induce a wave that looks identical to the waves the brain makes normally during sleep."

 

Original Article