Sweet Dreams Are Made of Memories

Brain solidifies memories during sleep

Though insufficient sleep may not seem like a big deal, new findings suggest that getting enough sleep may be more important to our waking lives than we knew.

According to a press release issued by the University of Bristol, researchers at Bristol's Centre for Synaptic Plasticity discovered that our brains sort through the previous day’s experiences while we sleep, filing the important ones to memory. The findings suggest that a bad night’s sleep can lead to impaired mental function, to which both the mentally healthy and unhealthy are susceptible.

During sleep, the brain plays back the day’s events in fast-forward. It sorts through daily experiences to determine which information is important to store. This sorting process happens in the hippocampus, the brain’s center of memory, and is critical for consolidating memories. Replaying daily events is vital to memory retention and strengthens the connections between active nerve cells.

“These findings are about the fundamental processes that occur in the brain during the consolidation of memory during sleep,” said lead researcher Dr. Jack Mellor in an interview with Trends in Neuroscience. Dr. Mellor is with the School of Physiology, Pharmacology and Neuroscience at the University of Bristol.

“It also seems that the successful replay of brain activity during sleep is dependent on the emotional state of the person when they are learning," Dr. Mellor said. "This has major implications for how we teach and enable people to learn effectively.”

According to the Centers for Disease Control and Prevention (CDC), a variety of chronic diseases and conditions, including diabetes, cardiovascular disease, obesity and depression, are also associated with insufficient sleep. The study’s findings may encourage people to make quality, sufficient sleep a priority.

The study was published February 19 in Cell Reports. It was funded by the MRC, Wellcome Trust, EPSRC and Eli Lilly & Co.

The authors disclosed no conflicts of interest.