Scientists have long been puzzled by how the brain cleans itself, a process known as glymphatic clearance. Recent studies on mice suggested that this mechanism involves cerebrospinal fluid flushing out waste products during sleep. However, previous research was hampered by using anesthetized mice.
A recent study led by neuroscientist Natalie Hauglund at Oxford University aimed to resolve this issue. The team found that glymphatic clearance is mediated by a hormone called norepinephrine and occurs almost exclusively during non-rapid eye movement (NREM) sleep phase. However, it only works naturally – anesthesia and sleeping pills significantly reduce its effectiveness.
The discovery was made possible by using anesthetized mice to mimic human-like conditions. By controlling the mouse’s environment, researchers could minimize other brain activity while still observing the glymphatic system at work. This allows for clearer insights into this complex process that has puzzled scientists for years.
Source: https://arstechnica.com/science/2025/01/how-sleeping-pills-interfere-with-the-brains-internal-cleaning-mechanism