Jon Hamilton

Everybody knows that you're not supposed to smoke while you're pregnant because it's bad for the baby. But nicotine patches often used to help women quit may pose a risk, too, researchers say. Other forms of nicotine replacement may do less harm.

President Obama has launched basic research to help scientists peer deep into the individual nerve circuits in the brain. There's also a more practical effort to restore the memories of injured soldiers by outfitting them with specialized brain implants.

Criminal lawyers increasingly turn to brain science to explain their clients' actions. It's a tactic that's kept defendants out of jail. But neuroscientists say scans can be easily misused or misinterpreted. Now judges must decide whether the evolving science is being used in a sensible way.

Physical exercise can ease depression, slow age-related memory loss and prevent Parkinson-like symptoms, researchers reported at a meeting in San Diego. The findings suggest that people may be making a mistake if they're relying on crossword puzzles and brain-training games for mental wellness.

Brain scans may help people who were ill treated as children realize that they process fear differently than others. They may have a harder time realizing what's truly a threat and what's not. Researchers say that can lead to increased risk of anxiety and depression.

Humans and other primates have really good vision. One scientist thinks that ability evolved in part to help monkeys and humans quickly recognize venomous snakes. When monkeys see photos of snakes, neurons in a specific part of the brain light up. The neurons respond to photos of the reptiles more than to monkey faces.

While mice sleep, their brain cells shrink, allowing cerebrospinal fluid to flow easily around them. The fluid can then clear away toxins. This finding appears to offer the best explanation yet of why animals and people need sleep.

Scientists have figured out how DEET repels mosquitoes. The finding has led the researchers to candidate repellents that are safer and cheaper than DEET and may provide new weapons against mosquito-borne scourges, such as malaria and dengue fever.

The usually well-behaved ribbon of high winds that runs eastward across North America has wandered all over the place recently, and even split in two. That's caused a whole host of extreme weather in the Northern Hemisphere, including the recent rains in Colorado, bitter cold in Florida and a heat wave in Alaska.

Pregnant women are told not to drink, smoke or stress out. But it hasn't been clear how those choices may affect a fetus. By studying how genes are turned on and off, scientists say they are getting closer to understanding what experiences in the womb really affect a child's health.