How Does the Brain Renew Itself During the Night?

28th January 2025

1 minute read

How Does the Brain Renew Itself During the Night?

When you lie down to sleep tonight and dream of strange and wonderful things, scientists believe your brain undergoes a delicate process that washes away the equivalent of an entire day’s worth of toxic by-products, preparing it for another day of forward thinking. However, the mechanisms behind this neurological cleansing system have yet to be fully detailed.

Researchers from the University of Copenhagen, according to Science Alert, applied a set of techniques to map the precise rise and fall of neurotransmitters, blood volume, and cerebrospinal fluid in mice during their daily activities.

The findings not only enhance our understanding of how the brain rejuvenates itself at night but also reveal an unexpected downside to common sleeping aids like Ambien.

The research highlighted the “biological sanitation system,” technically known as the glymphatic system, which is colorfully referred to as the brain’s “waste disposal network.” This system is, in many ways, an anatomical novelty.

Since then, ongoing studies have successfully mapped this network in human brains, uncovering how the glymphatic system draws cerebrospinal fluid deep into the brain to carry away substances that could be harmful at high concentrations. Some of these waste materials are linked to Alzheimer’s disease.

This “wastewater removal” process also helps balance water levels throughout the brain and facilitates the delivery of potentially harmful pathogens to the immune system.

Maiken Nedergaard, the study’s lead author and co-director of the University of Rochester Center for Translational Neuromedicine, stated:

“The motivation behind this research was to better understand what drives lymphatic flow during sleep, and the insights from this study have broad implications for understanding the components of restorative sleep.”