Written by Online therapist Dr. Gloria Vanderhorst, Ph.D.

NEUROSCIENCE YOU CAN USE!

Sleep, Cleansing, and the Brain’s Built-In Dishwasher

Sleep isn’t just rest—it’s repair. For individuals in Maryland and DC, this reflection explores how neuroscience reveals the brain’s nightly cleaning cycle, and why sleep is essential for emotional and cognitive health.

Does anyone know Maiken Nedergaard? Well, you should. Maiken Nedergaard, M.D., D.M.Sc., is fascinated with sleep. How many of you also focus on sleep because you have trouble getting there? Dr. Nedergaard, a researcher at the University of Rochester Medical Center, studies sleep.

Here are some reports from my clients about their sleep:

• I cannot fall asleep until about 3 a.m. I do not know why, but no matter what I do, I cannot seem to change it.
• I sleep for 2 hours and then am up for two hours, just like when I was on guard duty in the military. It is driving me up the wall.
• My sleep pattern is crazy. I wake up at about the same time in the middle of the night about every night.

Sleep is critical for our physical and mental health. Sleep is like a dishwasher for the brain. Many of us turn the dishwasher on before bed and wake up to clean dishes in the morning. Your brain wants to do the same thing. At night, your brain wants to flush out the waste matter that has accumulated during the day. That is fascinating. My brain discerns the junk I have picked up during the day and flushes it out! Yes, we collect junk and stuff during the day and do not need to keep it. Our brains can do a clean sweep for us if we just let them.

When we fall asleep, our brains work, just like the dishwasher. Blood and cerebrospinal fluid team up to do the work. This is a marvelous system. Here is the process in a nutshell (no pun intended). As we sleep, the blood vessels in the brain constrict. They tighten up. Cerebrospinal fluid rushes into the space, removing the bad stuff. Then the fluid retreats, and the blood vessels expand. Then, the whole thing repeats over and over, cleansing the brain. You can think of it as a form of breathing with fluid. Your brain becomes a washing machine to remove the waste or junk accumulated during the day.

Sleep becomes an especially important part of brain health. Do you know those pills that are advertised for brain health? Guess what? You came into the world with a brain health maintenance system. But you must get good sleep for the system to work. What is good sleep? You must get a chunk of non-rapid eye movement sleep (NREM) for your brain’s washing machine to work. NREM sleep is the part of sleep where you are not dreaming. In this sleep phase, your brain can be in either deep sleep or in the stage of light sleep as you are falling asleep or just waking up. Our brains need this stage of sleep to maintain health.

You must get there naturally. Your brain can do this for you. Sleeping pills will interfere with this process, leaving your brain to struggle to “self-clean.” Developing a sleep routine is critical. As humans, we like and benefit from routines. Look at how you approach sleep. Repeat the same sequence and process every night, and your brain will thank you!

Want to explore how sleep supports brain health and emotional resilience? Visit Neuroscience News’ guide to sleep and brain health, Medical News Today’s breakdown of sleep stages and memory, and NeuronUP’s insights on sleep and cognitive performance.

If you’re reflecting on sleep, emotional clarity, or brain health, therapy can help. Learn more about individual therapy in Maryland and DC or explore therapeutic approaches that support insight, healing, and restorative living.