Going to Sleep After Learning Improves Memory Power: Study

Learning before going to sleep improves memory and brain health, finds a study.

Scientists from the New York University Langone Medical Center discovered dendritic spines or tiny profusions in brain cells that ensure information transfer to other cells or synapses grow during sleep after learning a new task. This not only helps retain memory of the task but also causes physical variations in the motor cortex, a brain region related to controlling body movement.

For the study, experts used a mice model that was genetically modified to have fluorescent protein in neurons to observe growth in dendritic spines and dendrites before and after learning to spin on rods. The mice soon mastered the task and were divided in to two groups- a group that slept for seven hours after learning and the rest that remained awake for seven hours after practicing to balance the rod.

It was found that within six hours after learning the task, new dendritic spines grew across the synapses causing structural changes in the brain. Mice that slept after learning had significantly higher amount of spine growth than sleep deprived mice.

During deep sleep, our brain repeats new information and data we gathered when we were awake. This is also called as slow wave sleep when the brain waves slow down and rapid eye movement and dreaming completely stops. The replay of learning and studying strengthens our ability to create new memories. But reducing sleeping hours can hamper the growth of spine and complete registration of new tasks in our memory in the form of neuronal replay in motor complex.

"We've known for a long time that sleep plays an important role in learning and memory. If you don't sleep well you won't learn well," said Wen-Biao Gan, study author and professor of neuroscience and physiology and a member of the Skirball Institute of Bio-molecular Medicine at NYU Langone Medical Center in a news release.

"Our data suggest that neuronal reactivation during sleep is quite important for growing specific connections within the motor cortex."

More information is available online in the journal Science.