"Sleep Shrinks the Brain" Newsletter # 20 Volume 7; 5/1/2017
April 13th, 2020
So says a new article in the February 2017 edition of Scientific American.
New research by Dr. Cirelli in the Journal Science is shedding light on the way that we formulate memories while cleaning up our brain's storage from cluttered information. Dr. Cirelli and her team studied mice and the effects of sleep on the brain's circuit connections called synapses. They found that during sleep the brain shrinks as weak neuronal synapses are cleaned out or pruned. They hypothesize that by removing these synapses the brain allows for new memories to be made.
They looked at the brain slices of formerly sleeping and awake mice under high powered electron microscopy and noted that the synaptic connections shrank by 18% for 4 out of every 5 neurons. The larger and more stable neuronal synapses were left alone. This is likely because these neurons hold significant information that the brain has deemed necessary for preservation, i.e. serious memory for self preservation. I would think of a bull chasing you and you survive the event. That is a memory that you do not want pruned as it is advantageous to remember an event that is life threatening. In the study, all other neurons were paired down in size in a nightly ritual of restoration that allows for lots of new synaptic connections to be made for new memories.
This may be the first clear anatomic evidence that we are consolidating important memories while removing less important ones while we rest. This scientific discovery adds more fuel to the, "we need to sleep and recharge adequately" debate.
Knowing this new science makes this next part all the more problematic!
In the Journal JAMA Pediatrics, Dr. Czeisler wrote a piece entitled, "Problems associated with use of mobile devices in the sleep environment - streaming instead of dreaming." This article states, "the mere presence of a mobile device in the sleeping environment at bedtime, and certainly its use, increases the risk of inadequate sleep quantity, poor sleep quality, and - most important - excessive daytime sleepiness the next day in children 6 to 19 years old."
Dr. Czeisler noted that when a screen based device is in the sleeping environment, the likelihood of poor sleep and daytime somnolence roughly goes up 2 fold. Do we have a scenario now where media devices are altering our memory pruning mechanism? Likely to be true based on the proposed science.
Furthermore, we know that devices that emit a blue light spectrum wavelength have a negative effect on the release of the sleep inducing hormone melatonin. These devices are effectively telling the brain that it is NOT time to go to bed despite the fact that the sun is down and we should be winding down into a memory consolidating slumber.
In the JAMA article below they list the many physical diseases that are related to altered sleep and circadian rhythms including obesity, diabetes, reduced immunity and attention disruption.
I can not think of a single reason why my children need a single device in their sleep environment at night. We choose to keep all devices in a docking station in the main area of our house where they sit unused at night.
1) No screens around the dinner table. Especially when you are out at a restaurant. Children do not need a device to have good behavior at a public establishment. They need love, conversation and your time.
2) Keep all devices in a main docking station in full view and never in a child's room. Definitely, no TV's or screens in the bedroom.
3) Enable the blue light suppressor option on all devices from 6PM to 8AM.
4) Encourage a routine at bedtime with a consistent "lights out" time that is adjusted by age. Keep bedrooms as dark as possible to induce melatonin production and promote sleep onset.