Body & Brain
Sour news for cranberries, libido-sapping drugs, the social brain and more in this week’s news
By Science News
Boosting kidney function
The drug bardoxolone methyl improves blood filtration in people with chronic kidney disease, researchers at the University of Texas Southwestern Medical Center at Dallas and other scientists report in the July 28 New England Journal of Medicine. Scientists randomly assigned 227 adult kidney patients to get bardoxolone methyl while 57 others received a placebo pill. Filtration rates, a measure of kidney function, increased substantially on average in people getting the drug but not in people getting a placebo. Gains showed up mainly in patients getting high doses of the drug. Bardoxolone methyl works by taming inflammation and acting as an antioxidant. —Nathan Seppa
Drug beats berries for urinary infections
A common antibiotic outperforms cranberry capsules for preventing urinary tract infections in women, Dutch scientists report in the July 25 Archives of Internal Medicine. The researchers randomly assigned 110 women with chronic urinary tract infections to take the antibiotic trimethoprim-sulfamethoxazole and 111 others to take capsules containing cranberry extract. Over the subsequent year, women on the drug averaged slightly less than two infections per person while those on cranberries averaged four. On the downside, bacteria in those getting the drug every day developed some antibiotic resistance. —Nathan Seppa
Clues to social dysfunction
A study in mice offers new clues about how the brain goes awry in mental illness. Karl Deisseroth of Stanford University and colleagues used light to boost the activity of nerve cells in the prefrontal cortex. This heightened activity caused the mice to abruptly stop interacting with other mice, and the brains showed electrical signatures similar to those observed in people with schizophrenia and autism spectrum disorders. The results, published online July 27 in Nature, suggest that upsetting the brain’s balancing act between activity and silence could play an important role in mental illness. —Laura Sanders
Nerve cells for breathing
Scientists have pinpointed nerve cells that keep breathing regular and body temperature stable in mice. These life-sustaining cells also produce the chemical messenger serotonin, Russell Ray of Harvard Medical School and colleagues report in the July 29 Science. The researchers used a genetic trick to shut down these neurons’ activity in the brains of mice. Just minutes later, the mice began to have breathing problems and their body temperatures plummeted. Knowing more about how these nerve cells operate may help scientists better understand sudden infant death syndrome, or SIDS, which has been linked to serotonin deficiency. —Laura Sanders
How SSRIs ruin mojo
Widely prescribed antidepressants dampen activity in brain areas important for libido. The new finding may help explain why a popular class of drugs called serotonin reuptake inhibitors, which includes the antidepressant Paxil, dampens sex drive. In a randomized, double-blind trial, 18 healthy men took either an SSRI, another kind of antidepressant or a placebo for seven days. The men who took an SSRI had dampened responses to erotic videos in key brain regions compared with men who took the other class of antidepressants or a placebo, a German research team reports in the August Neuropsychopharmacology. —Laura Sanders