Updated: Jan 8
Have you ever wondered if those late-night infomercials actually work? Neuroscience tells us that pitching those cheesy products in the middle of the night is the best way to trick your brain.
It is well established that the brain uses more energy than any other organ in the body, accounting for up to 20% of the body's total energy supply. It was once widely accepted that all that energy fueled neural connectivity. It turns out there is much more to it. Neuroscience has proven that two thirds of the brain's energy supply is used to help neurons communicate. The remaining third, however, is used for "housekeeping," or cell-health maintenance. Much of that housekeeping happens when we are sleeping and the neurons aren't as active.
If you’ve ever suffered from insomnia, then you’ve probably seen those gimmicky infomercials featuring bad actors over dramatizing some mild inconvenience until they discover the life-changing inventions like the Potty Putter to improve putting while on the toilet, or the Hawaii Chair to build rock hard abs doing the hula at your desk. (I promise I did not make these up. Google them… you’ll see.)
I always thought these cheezy informercials were on late at night because those were the cheapest time slots. As it turns out, the ads are more effective in the middle of the night than during the day. Anyone watching them isn’t letting their glial cells work and resting the brain. Without enough sleep and time for the brain to reset and recharge, we just don’t have the mental energy the rational brain needs to analyze the options. Rather, the emotional brain gets triggered leading to quick, emotional decisions.
Synaptic Pruning - Use it or Lose it
Cognition is not just about building neural connections; it is also about getting rid of old ones. Such a process is called “synaptic pruning,” and the “use-it-or-lose-it” principle applies here. Think back to studying for a high school history test covering the Reconstruction, the election of 1876, and the 14th Amendment. If none of that sounds at all familiar, just know that these topics were real lessons. No doubt the material was covered in the textbook several times and also explained by the teacher. Read, reread, outline, highlight, rinse and repeat. That whole process created new neural pathways to sear the information to memory.
Neural connections that are no longer engaged get pruned away; if nurtured, however, these connections continue to grow and connect with other neural circuits. Glial cells, or astrocytes, play an important role in this process. Little was known about glial cells until the 1980’s when Dr. Marian Diamond discovered that Albert Einstein had more of them than the average person. Glia comes from the Greek word for glue, and it was assumed that they were just that, brain glue that connected the neurons. It is now known that these cells are essential for brain development and function but also in getting rid of dead brain cells that clutter those connections.
Glial cells have a full-time job, working during the day to facilitate neural connectivity and communication. As they do, they are also on the lookout for circuits that aren’t pulling their weight. When they see an unused connection, like the 1876 election, they mark it with a protein. At night, glial cells act as the brain’s housekeeping crew. They look for the circuits marked with proteins as well as neurotoxins and cells killed with cortisol. Their job is to sweep all of that debris away; however, they can only do that during sleep, when neural cells shrink to make the interstitial spaces larger thus giving the glial cells room to work and flush everything out.
When sleep is interrupted, the glial cells cannot do their job. The neurotoxins and dead cells clutter the brain, and the unused connections prevent new and stronger connections from growing, similar to neglecting a vegetable garden and letting the weeds take over, eventually choking out the flowers.
So the next time you can't sleep, hide the credit card and turn off the tv. Pick up a book instead. Might I suggest MY book...