Body & Brain

The brain sleeps in shifts, plus thinking better with folate, how brains feel the beat and more in this week's news

Pork processing linked to cancers
Pork butchers and processors appear to face elevated risk forlung cancer and other diseases, according to a study that followed 500 workers at a Baltimore facility for an average of 33 years each. Although pigs can carry viruses and other pathogens, workers involved in slaughtering the animals didn’t show elevated levels of disease, report researchers at the University of North Texas Health Science Center in Fort Worth. Meat processors and butchers, however, did exhibit higher risks for certain cancers, senility and brain hemorrhages. This suggests that chemical exposures in processing plants may be responsible for elevated rates of these diseases, the researchers conclude online July 2 in Environmental Research.Janet Raloff

Teens think better on folate
Pregnant women aren’t the only people who need plenty of folate. Among 386 Swedish 15-year-olds, the lower the concentration of this B vitamin in the blood, the more poorly teens tended to perform in school. Researchers at Swedish universities correlated the students’ grades in 10 subjects with a range of nutritional, lifestyle and economic factors. Low income was related to lower academic achievement, the data showed. But grades for teens scoring in the lowest third for folate levels scored worse than kids consuming more folate, and this association proved independent of family income, the authors report online July 11 in Pediatrics.Janet Raloff

Brain feels the beat
The brain feels musical beats, and even makes up its own when interpreting songs. Researchers asked volunteers to listen to a somewhat ambiguous musical beat and then to imagine it as either a march or a waltz while scientists recorded electrical activity in the brain. Listening to the beat as if it were a march (one-two, one-two) caused neurons to fire in a one-two pattern, whereas a waltz triggered a one-two-three pattern of brain activity, researchers from Belgium and Canada report in the July 13 Journal of Neuroscience. —Laura Sanders

Brain links drugs to places
A neuron tracing study in rats may help explain why visiting a particular street corner can spur an addict to relapse. Neuron extensions travel from the place-remembering hippocampus directly to a brain region that doles out rewarding hits of the chemical dopamine, a new study shows. Blocking this pathway caused rats to consume less cocaine when they encountered a place where they had received the drug in the past, researchers led by Alice Luo of the National Institute on Drug Abuse in Baltimore report in the July 15 Science. Interrupting this brain connection in humans may reduce drug relapses, the researchers suggest. —Laura Sanders

Patchwork sleep for the brain
Like dolphins, humans keep parts of their brain awake while the rest sleeps, a new study shows. Five people with epilepsy had electrodes implanted in their brains to find the source of their seizures, which also allowed scientists to monitor brain activity in select brain regions during sleep. Nerve cells in the motor cortex, which controls movement, occasionally showed bursts of activity lasting from five to over 60 seconds, while other brain regions remained deeply asleep. The results suggest that human sleep is a balancing act between waking and sleeping brain regions, Italian authors write in an upcoming NeuroImage. —Laura Sanders

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