Jon Hamilton

H-1B visas, the kind many foreign scientists need to work in the U.S. became harder to get in the first Trump Administration. That's likely to happen again.

Military personnel who fire certain powerful weapons may put their brains at risk. Two veterans who had repeated exposure to blasts developed the same rare brain malformation.

New research shows that the anesthetic ketamine keeps fish from giving up -- and the way it works may help figure out how it works in humans and lead to better medications for depression.

New research shows that the anesthetic ketamine keeps fish from giving up — and the way it works may help figure out how it works in humans and lead to better medications for depression.

Some weapons used by the U.S. military are so powerful they can pose a threat to the people who fire them. Today, we meet two Marines, William Wilcox and Michael Lozano, who spent years firing missiles and rockets, then developed the same rare brain condition: arteriovenous malformation, or AVM. The condition sends high pressure blood from a tangle of abnormal blood vessels directly into fragile veins, which can leak or burst. Most AVMs are caused by genetic changes that affect the growth of blood vessels, so the connection between weapon blasts and AVM isn't always immediately clear. But NPR's brain correspondent Jon Hamilton reports that recent research suggests that blast waves can alter genes in the brain — and that the evidence is even stronger for less extreme blood vessel changes.Have questions or story ideas? Let us know by emailing [email protected]!Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave.

In zebrafish, ketamine causes changes a brain circuit involved in "giving up." That may help explain how the drug helps people with depression.

Some weapons used by the U.S. military are so powerful they can pose a threat to the people who fire them. Today, we meet two Marines, William Wilcox and Michael Lozano, who spent years firing missiles and rockets, then developed the same rare brain condition: arteriovenous malformation, or AVM. The condition sends high pressure blood from a tangle of abnormal blood vessels directly into fragile veins, which can leak or burst. Most AVMs are caused by genetic changes that affect the growth of blood vessels, so the connection between weapon blasts and AVM isn't always immediately clear. But NPR's brain correspondent Jon Hamilton reports that recent research suggests that blast waves can alter genes in the brain — and that the evidence is even stronger for less extreme blood vessel changes. Have questions or story ideas? Let us know by emailing [email protected]!Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave.

During William Wilcox's service in the Marines, he fired heavy weapons, including shoulder-mounted missile launchers, hundreds of times. The blast waves from those weapons may have led to an arteriovenous malformation (AVM) in his brain. As a result of the malformation and subsequent surgery, he now has epilepsy, memory problems, and other symptoms.

Spravato, the brand name for esketamine, has a newly approved indication for treatment-resistant depression.

When military personnel fire certain powerful weapons, they may be exposed to blast waves that damage blood vessels in the brain.