Sleep helps cement and strengthen new memories according to a new study published in the journal Science. The study argues that sleep causes very specific structural changes in the brain after it has learned something new — namely growth of connections between brain cells that help them pass information to each other.
It has been clear for some time that sleep is important for learning and memory. But as senior investigator Wen-Biao Gan, professor of neuroscience and physiology at NYU Langone Medical Center in New York, says “the underlying mechanism was not clear”.
“We have shown that sleep helps neurons in specific connections on dendritic branches. These neurons facilitate long-term memory,” he says. “The study suggests that learning causes specific structural changes in the brain by showing that different types of learning form synapses on different branches of the same neurons.”
When we slip into deep sleep, a spell when brain waves slow down to a crawl and rapid eye movement cease, the brain cells that were active receiving new information during waking hours, reactivate.
A brain cell has many thousands of dendrites connected to other neurons via synapses. They carry information in the form of electrical impulses. Mouse brain sprouted new dendritic spines within six hours of learning new task. Further investigations revealed that the mice that did not sleep after learning a new task showed significantly less new dendritic spine growth than the mice that had snoozed post learning