“So our study suggests that we need to sleep because we have a macroscopic cleaning system that remove many of the toxic waste product from the brain.”

The brain’s cleaning system could be studied only by using a new imaging technology because the test animal must be alive to observe this process. Doctor Nedergaard says the next step is to find out if the human brain has a similar cleaning system.

The results demonstrate how important sleep is in the areas of health and disease. They may lead to treatment to prevent or undo neurological disorders.

WORLD FOOD PRIZE WINNERS RECOGNIZED

The World Food Prize was recently awarded to three developers of genetically modified crops, or GMOs. Mary Dell Chilton, Marc van Montagu and Rob Fraley received the award last month.

The award praises the technology they created for being able to increase the quantity and availability of food. It also says GMOs help deal with a growing world population and changes in weather patterns. But the selection of the three scientists has been criticized by people who question the safety and value of GMOs.

Genetic engineering can add information to plants to produce different kinds of things, such as a protein that kills insects.

Farmers quickly accepted and supported the new technology, first used in 1996. Nearly all the corn and cotton grown in the United States is made with GMOs.