Good night's sleep cleans out gunk in brain

LOS ANGELES — When we sleep, our brains get rid of gunk that builds up while we're awake, suggests a study that may provide new clues to treat Alzheimer's disease and other disorders.

This cleaning was detected in the brains of sleeping mice, but scientists said there's reason to think it happens in people too.

If so, the finding may mean that for people with dementia and other mind disorders, "sleep would perhaps be even more important in slowing the progression of further damage," Dr. Clete Kushida, medical director of the Stanford Sleep Medicine Center, said in an email.

Kushida did not participate in the study, which appears in Friday's issue of the journal Science.

People who don't get enough shut-eye have trouble learning and making decisions, and are slower to react. But despite decades of research, scientists can't agree on the basic purpose of sleep. Reasons range from processing memory, saving energy to regulating the body.

The latest work, led by scientists at the University of Rochester Medical Center, adds fresh evidence to a long-standing view: When we close our eyes, our brains go on a cleaning spree.


The team previously found a plumbing network in mouse brains that flushes out cellular waste. For the new study, the scientists injected the brains of mice with beta-amyloid, a substance that builds up in Alzheimer's disease, and followed its movement. They determined that it was removed faster from the brains of sleeping mice than awake mice.

The team also noticed that brain cells tend to shrink during sleep, which widens the space between the cells. This allows waste to pass through that space more easily.

Though the work involved mouse brains, lead researcher Dr. Maiken Nedergaard said this plumbing system also exists in dogs and baboons, and it's logical to think that the human brain also clears away toxic substances. Nedergaard said the next step is to look for the process in human brains.

In an accompanying editorial, neuroscientist Suzana Herculano-Houzel of the Federal University of Rio de Janeiro said scientists have recently taken a heightened interest in the spaces between brain cells, where junk is flushed out.

It's becoming clearer that "sleep is likely to be a brain state in which several important housekeeping functions take place," she said in an email.

The study was funded by the National Institute of Neurological Disorders and Stroke. In a statement, program director Jim Koenig said the finding could lead to new approaches for treating a range of brain diseases.

source: philstar.com

Sleep helps brain stay fit by clearing waste

WASHINGTON - Like a janitor sweeping the halls after the lights go out, major changes occur in the brain during sleep to flush out waste and ward off disease, researchers said Thursday.

The research in the journal Science offers new answers to explain why people spend a third of their lives asleep and may help in treating dementia and other neurological disorders.

In lab experiments on mice, researchers observed how cellular waste was flushed out via the brain's blood vessels into the body's circulatory system and eventually the liver.


These waste products included amyloid beta, a protein that when accumulated is a driver of Alzheimer's disease.

In order to help remove the waste, cerebral spinal fluid is pumped through brain tissue.

The process is sped along during sleep because the brain's cells shrink by about 60 percent, allowing the fluid to move faster and more freely through the brain.

The whole operation takes place in what researchers call the glymphatic system, which appears to be nearly 10 times more active during sleep than while awake.

"The brain only has limited energy at its disposal," said lead author Maiken Nedergaard of the University of Rochester Medical Center.

"You can think of it like having a house party. You can either entertain the guests or clean up the house, but you can't really do both at the same time."

Co-authors of the study, which was funded by the US National Institutes of Health, came from Oregon Health and Science University and New York University.

source: interaksyon.com

Fresh fruits, vegetables keep young people happy: NZ research

WELLINGTON - An apple a day not only keeps the doctor, but also the psychiatric counselor away for young people, according to a New Zealand study.

Eating more fruit and vegetables could make young people calmer, happier and more energetic in their daily life, researchers at the University of Otago found.

Psychology researcher Dr. Tamlin Conner, and Dr. Caroline Horwath and Bonnie White, of the Department of Human Nutrition, investigated the relationship between day-to-day emotions and food consumption.

A total of 281 people with an average age of 20 completed an Internet-based daily food diary for 21 consecutive days, said a statement from the university Thursday.

Each day, they rated how they felt using nine positive and nine negative adjectives, and answered five questions about what they had eaten that day.

Specifically, participants were asked to report the number of servings eaten of fruit and vegetables (excluding juices and dried fruit) and several categories of unhealthy foods like cookies, potato crisps and cakes.

The results showed a strong day-to-day relationship between a more positive mood and higher fruit and vegetable consumption, but not other foods.

"On days when people ate more fruits and vegetables, they reported feeling calmer, happier and more energetic than they normally did," Conner said in the statement.

The researchers also found that eating fruits and vegetables predicted improvements in positive mood the next day, suggesting that healthy foods could improve mood.

"After further analysis we demonstrated that young people would need to consume approximately seven to eight total servings of fruits and vegetables per day to notice a meaningful positive change," said Conner.

The study was published in the British Journal of Health Psychology on Thursday.

source: interaksyon.com

Epilepsy drug has long-term effect on child IQ - study

PARIS - A drug found to affect the cognitive ability of toddlers born to women who took the medication for epilepsy has a longer-term impact on their IQ, a study said on Wednesday.

Researchers in the United States carried out follow-up tests among the same group of children whose investigation in 2009 led to warning by the US health watchdog about the potential risks of the drug valproate in pregnancy.

The children -- examined at the age of three -- had below-par cognitive skills, which prompted the US Food and Drug Administration (FDA) to issue a warning about its use in pregnancy.

The new research, published in the journal The Lancet Neurology, examined the same children at the age of six.

Children born to mothers who had used valproate in pregnancy had an IQ that was seven to 10 points lower than children whose mothers had used one of three other epilepsy drugs, it found.

The higher the dose of valproate the mother took in pregnancy, the greater the IQ discrepancy. Verbal skills and memory were also affected.

The study, conducted between October 1999 and February 2004, by Kimford Meador at Emory University in Atlanta, Georgia, covered 305 pregnant women who had been using either valproate, carbamazepine, lamotrigine, or phenytoin.

The first analysis looked at 311 children in the United States and Britain; in the followup at the age of six, it covered 224 of them.

Counteracting measures

However, the study also suggested that IQ may improve with age for infants exposed to any of these drugs.

And by taking folic acid supplements, expectant mothers may improve IQ scores. This is the first time a boost has been shown in a study of pregnant women with epilepsy.

Valproate is, for some people, the only drug that can control their epilepsy, so the findings on dosage and the beneficial effects of folic acid could be useful.

"Valproate usage during pregnancy has a significant negative effect on children's IQ, which lasts beyond their earliest years. IQ at age six is strongly predictive of adult IQ and school performance, so our research suggests that valproate use during pregnancy is likely to have long-term negative effects on a child's IQ and other cognitive abilities," Meador said.

"For many antiepileptic drugs, there is simply no research available on their effects on women and their children during pregnancy, and given that many women do not have the option of stopping medication during pregnancy, more research in this area is urgently needed."

source: interaksyon.com