Why Sleep is Precious for Staying Sharp You really are harming your brain when you dont get enough ZZZs By Gabrielle DeGroot Redford, AARP The Magazine, Dec. 2014/Jan. 2015 Night owls, take note. Night owls, take note. That sleep deficit youve been accumulating has real and dangerous implications for your brain, and not just because it makes you sleepy during the day. Sleeping less than seven or eight hours a night has been linked to cognitive decline, memory loss and possibly even Alzheimers, new research shows. P. Murali Doraiswamy, M.D., a brain researcher at Duke University in Durham, N.C., explains what your brain does during sleep. Clears out toxins Most people think that when you sleep, your brain goes to sleep, too. But it turns out that parts of your brain are several times more active at night than during the daytime. One of them is a newly discovered drainage system called the glymphatic system, which is kind of like your citys sewage and recycling system; its job is to clear out and recycle all your brains toxins. One protein very actively recycled during sleep is involved in developing amyloid plaque, the hallmark of Alzheimers. No one is saying that Alzheimers is all caused by sleep deprivation, but it may be a factor. Repairs daily wear and tear New research indicates chronic sleep deprivation can lead to irreversible brain damage. A University of Pennsylvania animal study found that extended wakefulness can injure neurons essential for alertness and cognition — and that the damage might be permanent. Short sleep may also be linked to shrinking brain volume, though its not clear whether the lack of sleep causes the brain to shrink or whether a smaller brain makes it harder to sleep. Other studies have led scientists to conclude that chemicals secreted during the deeper stages of sleep are crucial for repairing the body — including the brain. Makes order from chaos As you go about your daily activities, your brain is exposed to thousands of stimuli — auditory, visual, neurosensory. And it cant possibly process all that information as it comes in. A lot of the tagging and archiving of memories occurs at night while youre sleeping. Its a bit like what goes on in a library. All the books dropped off in the book repository during the day are dusted off and cataloged at night. People who think theyve adapted well to sleeping just four or five hours a night are often wrong; memory tests show they are not functioning optimally. Creates memories One of the chemicals involved in creating memories — acetylcholine — is also involved in sleep and dreaming. What happens in people who start to develop Alzheimers is that the brain cells that produce acetylcholine are destroyed, so people stop dreaming as much. Interestingly, a side effect of the most commonly used drug to treat Alzheimers — Aricept — is its ability to induce vivid dreams.
Posted on: Tue, 30 Dec 2014 19:21:44 +0000