Without sufficient sleep, mood and intellectual performance are impaired. Various central-nervous-system conditions, including migraines and seizures, become more frequent and severe. When animals are kept from sleeping, they ultimately die.
We need to sleep. But why ?
Investigators from New York developed a technique for measuring the space between brain cells in brains of living mice. That space is bathed by cerebrospinal fluid that is produced in the brain ventricular and later pumped back into the blood. The investigators found that, during sleep and general anesthesia, this particular space between the brain cells increased by 60%. The result of this expansion is that many metabolic (waste) products of the brain cells which spill into that space are cleared from the space much more rapidly, enter the blood stream and get detoxified by the liver. These metabolic waste products of brain cell metabolism include molecules such as beta-amyloid and tau, which build up in brains of patients with Alzheimer disease.
When sleeping animals were roused, clearance of toxic metabolic substances slowed markedly (Science 2013, Oct18, 342:316 + 373).
The investigators speculate that, at least in mice, buildup of toxic metabolites in the brain’s interstitial space is a trigger for sleep and that a key purpose for sleep is to clear such metabolites.
Perhaps we feel refreshed in the morning (?) after a good night’s sleep because the brain has freed itself of toxins. This hypothesis could prove to be profoundly important in human biology as long as we are close enough to our neighbor, the mouse.
So: rather than spending trillions on supposed detox-medicines, invest in a good mattress and a sound-proof bedroom with a non-snoring companion.
Detox-meds could turnout to be easier to achieve though…
For me ( and maybe Chinese medicine ) simple things possess a great elegance and a good night’s sleep is surely amongst them.
The mind boggling second thought about a similar effect of a general anesthesia may well explain why even very mild sleeping tablets tend to improve general well-being enormously.
In many cases they enable the person to steer a safe course through the choppy seas of our daily life.
There will surely be more on Mice & Men – to be continued…