Body & Brain

Long naps make longer babies Sleeping babies are growing babies. An increase in the number of naps or the total hours of sleep a baby gets each day usually coincides with a growth spurt in body length, a study in the May 1 Sleep shows. Parents of 23 infants kept daily sleep diaries and their babies were measured often. Growth spurts followed close on the heels of increased sleep, usually within a day or two, researchers Michelle Lampl of Emory University in Atlanta and Michael L. Johnson of the University of Virginia Health System found. — Tina Hesman Saey Separating body and brain Activity at the junction of two brain lobes tells the body where it is and which way it’s looking, a study finds. Researchers led by Olaf Blanke of the University Hospital in Geneva used video cameras and carefully timed touches to trick people who were in an fMRI scanner into thinking their bodies were floating above their actual locations. Brain scans revealed that activity where the temporal lobe meets the parietal lobe seems to keep track of where a person’s body is in space and whether it is facing up or down. People with damage to this brain region frequently have out-of-body experiences, the researchers report April 28 in Neuron . — Laura Sanders Prostate cancer surgery boosts survival Young and middle-aged prostate cancer patients who get surgery to remove the gland survive longer than men assigned to “watchful waiting.” Researchers randomly assigned 695 men in Iceland, Finland and Sweden to get one of the treatment courses. After 12.8 years, 201 men in the watchful-waiting group had died, compared with 166 in the surgery group. The watchful-waiting group deaths included 81 from prostate cancer, while the surgery group lost only 55 from the cancer, scientists report in the May 4 New England Journal of Medicine . In men older than age 65, however, the treatment didn’t influence survival. — Nathan Seppa Women’s daily clocks tick faster Women’s daily, or circadian, clocks tick about 6 minutes faster than men’s do, a Harvard Medical School team says. In general, people’s circadian clocks take slightly longer than 24 hours to make a full cycle. But the 6-minute difference means more women than men have daily clocks that run slightly shorter than 24 hours, the team reports online May 2 in the Proceedings of the National Academy of Sciences . Even such a small timing difference could throw off women’s sleep patterns more easily than men’s. — Tina Hesman Saey Bacteria feed colon cells Intestinal microbes feast on what their hosts eat, but a new study shows that bacteria also return the favor. Friendly bacteria produce a type of fat called butyrate that some cells lining the colon use for energy, researchers from the University of North Carolina at Chapel Hill report in the May 4 Cell Metabolism . In mice raised without any bacteria, the colon cells starve and must start digesting themselves to survive, the researchers found. Only one in 30 colon-lining cells in mice with normal bacteria munch on themselves, but all the intestinal-lining cells in bacteria-free mice turn to self-cannibalism. — Tina Hesman Saey