JAN 08, 2018

How Quality Sleep Impacts Memory

WRITTEN BY: Brenda Kelley Kim

Without enough sleep, the brain cannot function at peak levels. A few miserable nights with no sleep might not make a huge difference, but on a regular basis, the amount and quality of sleep we get matters very much.

We've all days when we struggle through with coffee and energy drinks or perhaps catch a quick power nap, but if sleeplessness continues, the brain pays a high price. More than a few studies show that prolonged sleep deprivation is a factor in depression, anxiety and even an increase in car accidents or injuries from falls. Research has shown the significant cell damage and death can result from not getting enough sleep.

Recent research from a study completed in Europe shows that sleep is also a factor in neuroplasticity, which is the brain's ability to form new synaptic connections. New synapses are created when we learn new skills, form memories or experience something for the first time. Getting a proper amount of rest is crucial for this process. When we sleep, the brain is actually hard at work. A night's sleep, both in quality and quantity, allows the brain to complete several important tasks such as forming these new memories, clearing out cellular debris and strengthening connections that prime the brain for learning.

RELATED: Sleep and The Brain

A team of neuroscientists at Humboldt and Charité Universities in Berlin, led by Dr. Julie Seibt from the University of Surrey in the UK recorded brain activity in the dendrites of the brain. Dendrites are the branches that reach outward from neurons. These parts of brain cells carry electrical messages throughout the brain. They are very active when a person is sleeping, forming waves of electrical signals that convert short-term memory in the hippocampus, to long-term memories stored in the pre-frontal cortex. There is a particular sleep phase where this happens, a non-REM (Rapid Eye Movement) phase where the body is deeply asleep.

Dr. Julie Seibt is the lead author of the study and explained, "Our brains are amazing and fascinating organs – they have the ability to change and adapt based on our experiences. It is becoming increasingly clear that sleep plays an important role in these adaptive changes. Our study tells us that a large proportion of these changes may occur during very short and repetitive brain waves called spindles. Sleep spindles have been associated with memory formation in humans for quite some time, but nobody knew what they were actually doing in the brain. Now we know that during spindles, specific pathways are activated in dendrites, maybe allowing our memories to be reinforced during sleep."

Since the research was able to uncover exactly what the dendrites and synapses are doing during different phases of sleep, treatments for some memory disorders might be developed. In some forms of dementia, the process of consolidating memories is disrupted because of poor sleep, injury or neurodegeneration. Seibt's team hopes to find ways to stimulate dendrites directly, through transcranial magnetic stimulation (TMS) or transcranial direct current stimulation (tDCS) at the same frequency as the spindle waves, as a possible treatment for memory disorders. Check out the video below to see more.

Sources: University of Surrey, Nature Communications, Miami Herald