Jon Hamilton

For six years now, life has been really good for James. He has a great job as the creative director of an advertising firm in New York City. He enjoys spending time with his wife and kids.

And it has all been possible, he says, because for the past six years he has been taking a drug called ketamine.

For the first time, the U.S. military is speaking publicly about what it's doing to address potential health risks to troops who operate certain powerful shoulder-mounted weapons.

These bazooka-like weapons produce forceful explosions just inches from the operator's head.

A new application of artificial intelligence could help researchers solve medical mysteries ranging from cancer to Alzheimer's.

It's a 3D model of a living human cell that lets scientists study the interior structures of a cell even when they can only see the exterior and the nucleus — the largest structure in a cell. The model was unveiled to the public Wednesday by the Allen Institute for Cell Science in Seattle.

Military personnel may be endangering their own brains when they operate certain shoulder-fired weapons, according to an Army-commissioned report released Monday.

The report, from the Center for a New American Security, says these bazooka-like weapons pose a hazard because they are powered by an explosion just inches from the operator's head.

Bits of human brain tissue no larger than a pea are forcing scientists to think about questions as large as the nature of consciousness.

These clusters of living brain cells are popularly known as minibrains, though scientists prefer to call them cerebral organoids. At the moment, they remain extremely rudimentary versions of an actual human brain and are used primarily to study brain development and disorders like autism.

The words "dog" and "fog" sound pretty similar. Yet even a preschooler knows whether you're talking about a puppy or the weather.

Now scientists at Georgetown University Medical Center in Washington, D.C., have identified a two-step process that helps our brains learn to first recognize, then categorize new sounds even when the differences are subtle.

An international coalition of brain researchers is suggesting a new way of looking at Alzheimer's.

Instead of defining the disease through symptoms like memory problems or fuzzy thinking, the scientists want to focus on biological changes in the brain associated with Alzheimer's. These include the plaques and tangles that build up in the brains of people with the disease.

But they say the new approach is intended only for research studies and isn't yet ready for use by most doctors who treat Alzheimer's patients.

The Afghan boy arrived at the U.S. military hospital in Kandahar with severe burns from the chest down. He was about 5.

"I knew as soon as I saw him it was just too much surface area," says Kit Parker, who, at the time, was an Army Civil Affairs officer working with Afghan villagers. "I knew he was going to die."

Even so, Parker and his team sergeant, Aaron Chapman, stayed at the hospital throughout that night in 2003, while military doctors worked to keep the boy alive.

Updated March 8 at 1:53 p.m. ET

A major study is challenging the widely held view that adult human brains make new neurons.

The study of 59 samples from 29 brains of people of various ages found no immature neurons in anyone older than 13, scientists report online Wednesday in the journal Nature.

The chemical BPA isn't living up to its nasty reputation.

A two-year government study of rats found that even high doses of the plastic additive produced only "minimal effects," and that these effects could have occurred by chance.

The finding bolsters the Food and Drug Administration's 2014 assessment that water bottles and other products containing BPA are not making people sick.

Beer has fueled a lot of bad ideas. But on a Friday afternoon in 2007, it helped two Alzheimer's researchers come up with a really a good one.

A little electrical brain stimulation can go a long way in boosting memory.

The key is to deliver a tiny pulse of electricity to exactly the right place at exactly the right moment, a team reports in Tuesday's Nature Communications.

"We saw a 15 percent improvement in memory," says Michael Kahana, a professor of psychology at the University of Pennsylvania and an author of the study.

When Sarah Jay had her first seizure, she was in her mid-20s and working a high-stress job at a call center in Springfield, Mo.

"I was going to go on break," she says. "I was heading towards the bathroom and then I fell and passed out."

Scientists have found specialized brain cells in mice that appear to control anxiety levels.

The finding, reported Wednesday in the journal Neuron, could eventually lead to better treatments for anxiety disorders, which affect nearly 1 in 5 adults in the U.S.

Older brains may forget more because they lose their rhythm at night.

During deep sleep, older people have less coordination between two brain waves that are important to saving new memories, a team reports in the journal Neuron.

Pages