Research Report: UCSD study gives insights on anorexia nervosa

Researchers at the Eating Disorders Program at UCSD, using new imaging technology, report evidence of dysfunction in certain neural circuits of the brain which may help explain why some people develop the eating disorder anorexia nervosa.

Imaging studies suggest that individuals with anorexia have an imbalance between circuits in the brain that regulate reward and emotion and the circuits associated with consequences and planning ahead.

Researchers anticipate that understanding the underlying neurobiology of how behavior is coded in the brain and contributes to anorexia will lead to more effective treatments. The findings appear online in Nature Reviews Neuroscience.

Invasive wasps display new life cycles

A new study by ecologists from UCSD on invasive yellowjacket wasps on two Hawaiian islands has revealed both how the wasps have altered native insect and spider populations and how the environment itself has altered yellowjacket behavior and life cycle in ways that magnify its ecological harm.

In their native range, Western yellowjackets typically form nests in the spring that become dormant before winter. In Hawaii’s mild climate, however, up to 20 percent of colonies persist for years, grow to enormous sizes, and have become major pests. UCSD researchers conducting the study documented one Maui colony with upwards of 600,000 individuals, compared to the usual size of a few thousand wasps.

Scientists also found that introduced yellowjacket wasps kill or scavenge prey from 14 different taxonomic orders of animals, including reptiles and birds.

On a positive note, nearby populations of caterpillars and spiders rebounded when wasp nests were removed. The study appears in the Proceedings of the National Academy of Sciences.