Recently, scientists have proven how important sleep is to the brain, and the harmful effects of sleep deprivation. In “Goodnight. Sleep Clean,” by Maria Konnikova, she shows that sleep is a necessity for a long, healthy life.
Why do humans sleep? Maiken Nedergaard, a Danish biologist, has researched sleep functions at the University of Rochester’s medical school. From her research, she has found the reasons behind our sleeping needs. Throughout the eras of human life, humans have maintained their need to sleep. Even though humans are more vulnerable while sleeping, it hasn’t been evolutionarily excluded from our daily lives. Early theories have shown that sleep is vital for creating and storing memories. It has also been found that sleep generates new neuronal connections, while cleansing the brain of old connections. Recently, Nedergaard’s studies determined that sleep upholds our physiological maintenance, and clears out unneeded information to make room for more. While the body’s lymphatic system cleanses toxins out of our bodies, the glymphatic system, composed of glial cells, flushes out the waste in the brain with cerebrospinal fluid.
In Nedergaard’s mice studies, she discovered that when a mouse is sleeping or sedated, it’s brain is draining the waste gathered throughout the day. She started by injecting small fluorescent tracers into the cerebrospinal fluid of sedated mice. Nedergaard then observed the tracers enter, and then exit, the brain though precise routes. While the mouse is awake, the cerebrospinal fluid only reaches the brain’s surface. But when asleep, the fluid clears the brain’s waste twice as fast, moving freely and farther into the brain. This study has gotten similar results with larger animals, such as baboons, dogs, and goats. Therefore, it can be predicted that humans’ brains act similar.
Sleep deprivation, especially long-term, can have damaging effects on the brain. Though adults should receive between seven and nine hours of sleep a night, they are actually getting one to two less hours of sleep than adults did 50 to 100 years ago. In the United States alone, 50 to 70 million people experience some type of chronic sleep disorder. These disorders disrupt our sleep, causing our cleaning system to shut down. Though not proven, frequent sleep disturbance has a close connection to neurodegenerative diseases, like Alzheimer’s and Parkinson’s. Proteins linked...