Distinct patterns of electrical activity in the sleeping brain may influence whether we remember or forget what we learned the previous day, according to a new study.
In the new study, published online October 3 in the journal Cell, a research team led by Karunesh Ganguly, MD, PhD, an associate professor of neurology and member of the UCSF Weill Institute for Neurosciences, used a technique called optogenetics to dampen specific types of brain activity in sleeping rats at will.
This allowed the researchers to determine that two distinct types of slow brain waves seen during sleep, called slow oscillations and delta waves, respectively strengthened or weakened the firing of specific brain cells involved in a newly learned skill — in this case how to operate a water spout that the rats could control with their brains via a neural implant.
“We were astonished to find that we could make learning better or worse by dampening these distinct types of brain waves during sleep,” Ganguly said. “In particular, delta waves are a big part of sleep, but they have been less studied, and nobody had ascribed a role to them. We believe these two types of slow waves compete during sleep to determine whether new information is consolidated and stored, or else forgotten.”
