The brain works like this: if you want to remember, sleep to forget! At least that would be the conclusion of the newest studies on this topic. Scientists found biological evidence on how our brain deals with memory during the sleep.
Everybody knows that we need to sleep to reset our brain and body. It is beneficial for preventing disease such as Parkinson’s, diabetes type 2 or cardiovascular disease. We can even learn while we sleep. Also, sleep is there to collect information that we’ve learned a previously day. What was unknown was how brain exactly consolidates all this information. Two group of scientists from the University of Wisconsin and Johns Hopkins University conducted research on this matter and found that our brain actually sharpens memories during the sleep.
Scientists relied on the decade-old hypothesis called synaptic homeostasis – wich explains that slow-wave activity in the cerebral cortex during the sleep allows us to make our memories clearer. By the way, the synopses are the build connection that links brain cells – there we store and develop our behavior and memories. Depending on its size and strength, they transfer messages more or less effectively.
Every synopsis is equal to the one experience, so there is a bunch of them that our brain needs to process. This is difficult to be done while we are awake and the sleep is quiet opportunity to finish selection. The researchers from the University of Wisconsin analyzed thin brain shavings from mice in different situations. One mouse is analyzed during the sleep, the second during the toy play and the third during awakeness but unstimulated. Slices taken from the sleeping mouse contained synapses which were 18 percent smaller than the synapses in those which were awake. This practically means established learning was being spared the chop.
Researchers from Hopkins University differently approached. They marked with marker proteins on the synapses of mouse and watched his brain while he slept. As the synopsis shrunk, the markers decreased. Eventually, synopsis reduced to 20 percent. To confirm their results, researchers genetically engineered mice without a type of protein called Homer1A – a chemical that removes receptors in synapses. Although the mouse slept normally as the one with Homer1A protein, his synapses held onto its receptors. This has an impact on its memories. In the box experiment, a mouse without Homer protein couldn’t remember the box and constantly was afraid to run through it.
Both groups of researchers have come to the same conclusion. Among other benefits of sleeping, there is one more reason: processing and distinguishing important from irrelevant information and sharpening memories. As we are living in the modern urban cities where our sleep cycle is seriously disturbed, this should be a reason more to take care of it. After all, we all want to keep our precious memories safe from the oblivion.