A newly discovered neural circuit in the brain of the common fruit fly seems to serve as a sort of "volume control," turning up and down the perception of sound and light. Nicholas Monu/iStockphoto hide caption

itoggle caption Nicholas Monu/iStockphoto

A technique called optogenetics is being used in the laboratory to observe and control what brain circuits are doing in real time. Henning Dalhoff/Getty Images/Science Photo Library RM hide caption

itoggle caption Henning Dalhoff/Getty Images/Science Photo Library RM

There's data to support the notion that pot, or a drug based on its active ingredient, could help ease the fears of PTSD. Ted S. Warren/AP hide caption

itoggle caption Ted S. Warren/AP

President Obama has pledged millions of dollars to fuel research into understanding the workings of the human brain. Zephyr/Science Source hide caption

itoggle caption Zephyr/Science Source

When researchers at Weill Cornell Medical College scanned teenage brains, they found that the area that regulates emotional responses has to work harder to keep impulses in check. Courtesty Kristina Caudle/Developmental Neuroscience hide caption

itoggle caption Courtesty Kristina Caudle/Developmental Neuroscience

Girls are particularly vulnerable to brain changes caused by stress or trauma, researchers say. Allen Johnson/iStockphoto.com hide caption

itoggle caption Allen Johnson/iStockphoto.com
Illustration by Daniel Horowitz for NPR

Bob Adams is a lab animal veterinarian at Johns Hopkins University. Maggie Starbard/NPR hide caption

itoggle caption Maggie Starbard/NPR

Scientists have discovered four new DEET-like mosquito repellents. Three of them are safe to eat. Courtesy of Pinky Kai/University of California, Riverside hide caption

itoggle caption Courtesy of Pinky Kai/University of California, Riverside
Goddard Space Flight Center Scientific Visualization Studio/NASA

Does a glass or two of wine during pregnancy really increase the child's health risks? Epigenetics may help scientists figure that out. Katherine Streeter for NPR hide caption

itoggle caption Katherine Streeter for NPR