Alzheimer's Disease Possibly Linked To Sleep Deprivation 164
sonnejw0 writes "NewScientist is reporting a link between sleep deprivation and Alzheimer's Disease via an increased amyloid-beta plaque load thought responsible for a large part of the symptoms of the disease, in mice. Medication to abrogate insomnia reduced the plaque load. Also discussed is a recently discovered sleep cycle of amyloid-beta deposition in the brain, in which levels decrease while asleep. 'Holtzman also tried sending the mice to sleep with a drug that is being trialled for insomnia, called Almorexant. This reduced the amount of plaque-forming protein. He suggests that sleeping for longer could limit the formation of plaques, and perhaps block it altogether.'"
Re:Why do we sleep? (Score:3, Insightful)
Sleeping is basically a good chance to get eaten.
I suspect sleeping has a higher level function as well, like getting rid of all the crap you accumulate in your head throughout the day. Maybe some (perhaps non-essential, just useful) chemicals in our brain tend to run out when awake, and sleep is needed to restock them.
However, awake is only one state of mind out of many, it'd be foolish to disregard most of them. (I don't consider "auto-pilot on the highway" awake, for example.)
Re:Why do we sleep? (Score:4, Insightful)
Sleeping is basically a good chance to get eaten.
Not necessarily. Wandering around in the open is probably a lot more dangerous than being holed up in a lair - especially if your sensory organs are optimized for night and it is day or vice versa. Plus, animals and people are very highly attuned to certain noises while asleep - basically if it sounds like something is approaching or entering the lair most animals will quickly transition from sleep to fully awake.
Re:Why do we sleep? (Score:4, Insightful)
Healthy old folks are directly beneficial to social groups. They remember how to solve problems. They can take care of grandchildren while the parents are off gathering food. And many social groups had old folks. Sure, most people didn't live to get very old. But some did.
That's absolutely true of grandparents, but we're talking about great-great grandparents here, from a bio-evolutionary standpoint.