When you're learning something new, a solid seven hours of sleep may help you achieve your goals. (PM Images/Getty Images)

When you’re learning something new, a solid seven hours of sleep may help you achieve your goals. (PM Images/Getty Images)

If you’re struggling to learn a new concept or ace an exam, be sure to get a good night’s sleep. That may sound like a simple prescription, but research shows that African Americans, especially black professionals, are less likely than other groups to get the recommended seven hours of sleep each night.

But cutting back on the zzz’s you need may make it harder for you to retain new information. New research, published in the journal Science, reported that sleeping after learning contributes to the growth of dendritic spines in the brain. The spines are tiny structures that protrude from brain cells and assist in the transmission of electrical signals and information. The spines play a critical role in learning and memory.

Wenbiao Gan, Ph.D., a professor of neuroscience and physiology and member of the Skirball Institute of Biomolecular Medicine at NYU Langone Medical Center, found that during deep sleep, the neurons in the brain work to form connections that may contribute to long-term memory and learning. The study, conducted in mice, offers physical evidence to support previous research showing that people do not learn well if they do not sleep well. Folks who sleep less than 7 hours a night also have more difficulty performing daily activities.

“We show how different types of learning form synapses on different branches of the same neurons, suggesting that learning causes very specific structural changes in the brain,” Gan said in an NYU interview.

Learning and Sleep

To reveal how the brain works while we rest, Gan and his team used mice genetically engineered to express a fluorescent protein in neurons. Using a special laser-scanning microscope that illuminates the glowing fluorescent proteins in the motor cortex, the scientists tracked the growth of dendritic spines along individual branches of dendrites before and after the mice learned to balance on a spin rod. Over time mice learned how to balance on the rod as it gradually spun faster. “It’s like learning to ride a bike. Once you learn it, you never forget,” Gan told NYU.

There were two sets of mice. One group slept for seven hours after spinning on the rod. The other group was kept awake for seven hours. The scientists found that the sleep-deprived mice experienced significantly less dendritic spine growth than the well-rested mice.

Learning specific tasks also produced specific changes in the brain. “Now we know that when we learn something new, a neuron will grow new connections on a specific branch,” Gan explained.

The research team also found that brain cells that activated when mice learned a task reactivated during deep sleep. Disrupting the sleep prevented dendritic spine growth.

The research suggests that the common habit of staying up late to work or study is not a bad idea; just don’t skimp on sleep. Make sure you get a solid, sound seven hours. It may help you accomplish your goals.