RENEE MONTAGNE, HOST:
Today in Your Health, bringing the battlefield into the lab. Last week, we met Kit Parker, a biophysicist who put his academic career on hold to fight in Afghanistan. When Parker returned, he was determined to explain the signature wound of recent wars, an invisible brain injury caused by blast waves from roadside bombs. The military had assumed the damage was purely psychological.
Parker had a hunch that blast waves were affecting individual brain cells. NPR's Jon Hamilton explained how the Harvard scientist set out to test his idea.
JON HAMILTON, BYLINE: Kit Parker was convinced that somehow, the energy from a bomb was physically disrupting entire networks in the brain.
KIT PARKER: Networks that allow you to recognize your grandmother's face, to count your change at a fast food restaurant.
HAMILTON: And Parker was pretty sure the trouble started when special proteins in brain cells began sending abnormal signals. But proving this was going to take years of costly research. Parker needed money. So in 2006, he went to see Dr. Geoffrey Ling at the military's Defense Advanced Research Projects Agency in Arlington, Va.
Parker says he and Ling just got each other.
PARKER: Geoff and I both carried a gun for a living. That might be part of it (laughter). It changes - once you've carried a gun for a living, it kind of changes your perspective on everything.
HAMILTON: Also, both men were world class scientists and unconventional thinkers. Parker brought Ling a prototype of a device that could simulate the effect of a blast wave on brain tissue. It's a tube about the size of a scuba tank. And when I visit Ling...
GEOFFREY LING: I've got to show you this, man.
HAMILTON: ...He still has it.
LING: This is the Kit Parker blast chamber. What it is is in this thing, what you're able to do is blow the pressure wave with the exact same pressure time profile as a blast would be, which is critical.
HAMILTON: If Parker was right, that pressure wave would cause the special proteins in brain cells to malfunction. Ling says he liked the idea of funding someone with a highly personal stake in the research.
LING: I mean, this guy had a Ph.D. from Vanderbilt. This guy was on the faculty of Harvard. And yet, he stopped and said our country's under attack. I'm going to go do something about it. And when he came home, he said, I'm not done.
HAMILTON: With money from DARPA, Parker's lab got to work. His team tweaked brain cells in every way imaginable while monitoring signals coming from the special proteins. The lab worked with a sense of urgency. Parker says by this time, IEDs had become the weapon of choice for attacking coalition forces in Iraq and Afghanistan.
PARKER: The IED is a great weapon system because it hits us at our scientific weak point, and that's the brain. They have a good weapon.
HAMILTON: Parker got a reminder of that in 2009, the year he returned to Afghanistan. This time, he was part of an Army effort to figure out how to protect troops from IEDs. Parker was assigned to a platoon looking for bombs along major travel routes. And one day in the Tangi Valley, they found one the hard way.
PARKER: Had an IED blow up, blew over an MRAP vehicle. Four dudes inside, four concussions, brain injuries. Some of these guys were even blown up a dozen times.
HAMILTON: When Parker returned to his lab, the brain injury research was mostly done. Finally, he would find out whether his hunch had paid off.
PARKER: And we were right. We nailed it.
HAMILTON: In 2011, Parker's lab published two papers on how blast waves lead to unhealthy signals in the brain. One explained how these signals could cause the brain's blood vessels to constrict long after an explosion. The other paper showed how the signals could start a cascade of events that would ultimately disrupt the connections among brain cells.
Geoffrey Ling at DARPA says those papers helped show that the damage from blast waves wasn't just psychological.
LING: It was a fundamental insight that Kit did through that project. And that was just amazing.
HAMILTON: Now that the research was published, Parker was certain pharmaceutical companies would be eager to use the findings to develop drugs for TBIs. He was wrong.
PARKER: I was surprised. I was very surprised.
HAMILTON: The drug companies were gun shy. They'd lost billions on failed drugs for brain diseases like Alzheimer's, and they weren't ready to take on traumatic brain injury.
PARKER: No one wanted to get in the fight.
HAMILTON: Flash forward to the present. Parker is addressing the several dozen researchers who work in his disease biophysics lab.
PARKER: Come on, take bold steps. Only the bold win.
HAMILTON: Parker's joking. He's just trying to get the team lined up for their annual picture.
PARKER: Tall people in the back. Short people up front.
HAMILTON: But for many of the people here, military jargon is second nature. And blast injuries are more than an academic pursuit. When everyone sits down for lunch, Parker points out a few of his people.
PARKER: Stacey got back about a year ago from Afghanistan. John Ferrier was in the Air Force in Afghanistan. Angie Greer was in Iraq and got a Bronze Star over there.
HAMILTON: Greer, who came to the lab a couple of years ago, says she saw IED explosions on a daily basis and a lot of traumatic brain injuries.
ANGIE GREER: We lost one soldier to blast. So the research system here, it's special to me.
HAMILTON: Parker has made a point of recruiting scientists who've been in combat.
PARKER: There's a bond between me and the ones who are overseas. It's pretty strong. I don't really know how to describe it. You love them.
HAMILTON: Parker's new mission is to figure out how to interrupt the cascade of events that starts with a bomb blast and ends with a damaged brain.
BEN MAOZ: In this lab, we are working on a traumatic brain injury.
HAMILTON: So members of his team are sifting through thousands of proteins looking for the ones that might make an easy target for a drug. Ben Maoz is a postdoc who served in the Israeli military.
MAOZ: So it's basically, it's a needle in a haystack to trying to understand exactly what protein is doing and when and where. And we don't know the answer. Funding for this research is scarce now that the U.S. has less involvement in Iraq and Afghanistan.
Parker says there's not much interest in battlefield brain injuries, even though tens of thousands of veterans are still trying to recover from these wounds.
PARKER: It's painful for me, personally, because you get this impression that, you know, no one cares. And it sucks. It's an awful feeling. It's, like, the war's over. And now people are worried about football players again.
HAMILTON: But Parker says there's no chance he and the other veterans in his lab will stop searching for a treatment.
PARKER: It's a very personal issue for us. This is not an occupation. This is an obsession, really. These are our friends.
HAMILTON: Jon Hamilton, NPR News. Transcript provided by NPR, Copyright NPR.