Inside the Lab That Studies NFL Brains

PM got a look inside the lab as its scientists walked us through their research.

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As long-term brain injuries in NFL players and other athletes get more attention, so does the Boston-based lab that studies the brains athletes donate to try to figure out brain diseases that come from repeated blows to the head.

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Inside the Lab That Studies NFL Brains
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Last season was the one in which the NFL got serious, at least publicly, about its brain-injury problem, and instituted new rules about how and when a concussed player could reenter a game. Yet the season was still plagued by head injuries, including a concussion that sidelined eventual Super Bowl MVP, Aaron Rodgers, and it ended with a tragedy: Just weeks after the Super Bowl in February, former Chicago Bear Dave Duerson committed suicide, apparently after suffering symptoms associated with repeated head injuries.

The degenerative brain disease Duerson probably suffered from is called chronic traumatic encephalopathy (CTE). It's accompanied by memory loss, blurred vision and pain as a result of repeated blows to the head. Duerson's last request was that his brain be donated to the VA (Veterans Affairs) CSTE (Center for the Study of Traumatic Encephalopathy) Brain Bank in Bedford, Mass., a facility where researchers try to understand and cure this disease. More than 70 other brains have gone to the brain bank.

Here's a look inside the brain bank, and the process of getting athletes' brains to Boston so they can be examined and, one hopes, offer doctors clues to how CTE develops.


"At first it was a little bit creepy, but I just look at it as the same thing as being an organ donor," Matt Birk says. Birk is an offensive lineman for the NFL's Baltimore Ravens and a Harvard grad who has had three concussions during his NFL career, now entering his 14th season. Eventually, he says, he got over the squeamishness that comes from donating one's own brain. "I'm not going to need it anymore when I'm dead, so if it can help future generations and save some lives, then why not?"

Birk is one of the few players who has pledged his brain to the brain bank during his lifetime, promising it will receive his brain for research after his death. However, it is often the family members of deceased athletes who choose to donate a player's brain, because they observed personality changes or memory problems in the years before the player's death.

"The usual system was, once an athlete had died, we'd try to find someone who knew the family, like a coach, and ask for an introduction to explain what we were after and why we were interested in the brain being donated," Dr. Ann McKee says. McKee is head researcher at the VA CSTE Brain Bank, which is associated with Boston University and funded by a gift from the NFL.

When I visited her office, it was covered in brains, from the digital photographs on her iMac to the slides all over her desk. In recent years, she says, the donation process has gotten much easier. Many families will contact the lab themselves now that the brain bank, and the worries over athletes and brain injury, have been in the public eye. "Now they actually know what we're doing, that we're a bona fide outfit, not just a group with a weird interest in brains," she says.

Bringing the Brains to Boston

Before any research can commence, of course, the actual brain must be brought to the lab. McKee says that a qualified surgeon performs the extraction, then puts everything back in place so the donor can have an open-casket funeral.

The next step is to get the brain to the lab in Bedford. If a donor died in the VA hospital where the brain bank is located, researchers at the lab do the extraction themselves in a room with four metal doors and a sign that reads, "Feet first, head out." If the person dies in the Boston area, someone from the lab will go pick it up.

If the brain is out of town, however, the brain bank must use a courier service that's accustomed to moving organ transplants to bring the brain to Boston, according to research coordinator Christine Baugh. It's a delicate process. During transport, the tissue is placed in two sealed bags surrounded by ice to preserve it, brain bank co-director Chris Nowinski says. "It's never left unattended," he says. "It's handed person to person with identity checks so it's never lost or misidentified." The lab keeps funds on hand for transportation costs—families do not pay anything to donate a loved one's brain.


Inside the quaint brick building that houses the lab is a scene that takes some getting used to. Brains float in jars of a yellowish liquid on shelves lining the walls of the lab. Others, in freezers kept at -80 degrees C, await their turn on the lab table.

McKee and her colleagues must prepare the brains for research. Brains are placed in formalin, a fixative made of formaldehyde and water, to firm up. That maintains structural integrity and makes the organ easier to cut for research purposes later, McKee says. If a brain were cut in half right after extraction, each side would turn into an amorphous glob.

Once the brain has firmed up for a few days, researchers begin by looking at the whole brain, noting whether it is the proper size, or if there are any contusions on the surface. McKee's team will also cut off a small slice of the brain and freeze it for future research. In many kinds of brain research, she says, scientists will freeze half the brain for later use. But when trying to understand the damage to athletes' brains, she likes to see as much of them as possible. "We're still trying to define [this] disease, so I like being able to see both halves," she says.

The Search for Tau

Once all this work is done, the scientists can begin the hunt for the offender in CTE: the tau protein. Though CTE is a mysterious condition, one thing researchers like McKee do know is that brains of CTE sufferers show an abnormal distribution of this protein, which occurs naturally in neurons. An accumulation of tau can be a sign of other degenerative brain disorders, such as Alzheimer's disease, says Dr. Robert Cantu, co-director of the brain bank and a professor at Boston University's School of Medicine. But CTE has a distinctive pattern, one that's visible to him with the naked eye simply by looking at slides of brain samples from CTE sufferers. "The distribution of the tau is unique in CTE," Cantu says. "It's mostly in the medial temporal lobe," an area involved with both long- and short-term memory as well as behavior. "It's mostly in the superficial layers... rather than deeper layers."

McKee first encountered this protein very early in her career while working with the Alzheimer's Framingham Heart study. "One of the brains that came through [had] this really weird disease. I'd never seen anything like it before. It was just tau—none of this protein called beta amyloid, which is the protein that builds up in Alzheimer's disease," McKee said. "Then, after I finished looking at it, I went back, and it turned out it was the brain of a boxer, which just got me interested in the disease in general."


To find tau, researchers must stain the brain samples, which involves placing small slices of the brain into an amino staining. This can be done in two ways: by placing cross sections of the brain in small paraffin blocks or by submerging cross sections of the brain in a bath.

With the first technique, McKee encloses pieces of the brain within in a paraffin block. She then slices off cross sections about 10 microns thick—a process McKee calls an art form. Researchers place the slices in a staining bath, where areas that have tau buildup will turn a dark brown. These patches of color are where researchers look for the tau protein.

Researchers can also stain larger cross sections for tau by placing them in a staining bath. The process of mounting these larger cross sections on slides is extremely tedious. McKee says the slice has the consistency of a very thin, wet leaf, making it wrinkly and delicate. Scientists work for hours with paintbrushes to smooth out all the wrinkles, making the slide suitable for viewing under a microscope.

An advantage of using a larger slice is that researchers can get a better idea of how much of the brain is involved. "We still don't get a feel for the anterior and posterior, but by studying a series of these you can get an idea of exactly how much of the brain is affected," McKee says.

The Goal Line

The Bedford researchers' ultimate goal is to be able to diagnose CTE before death, or even investigate a treatment or cure. Their research could also potentially reveal whether a person has genetic factors that predispose them to CTE, meaning they ought not play contact sports, Cantu says.

The Ravens' Matt Birk says the chance to help create a test for CTE or for CTE predisposition was a big factor in his decision to donate his brain. But what if someone had told him as a teenager to end his football career? "I think I would've," he says. "You hear these stories about guys in their 30s and 40s and the pain and anguish they've gone through, even ending their own lives. Nothing is worth your health."

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