As of October, more than 500 current and former professional athletes agreed to donate their brains to the VA Brain Bank, which works in affiliation with the Boston University's Center for the Study of Traumatic Encephalopathy.
Annese said the Brain Observatory at UCSD has been in contact with several athletes who are considering participating in the brain donation program.
"Like Mr. Seau, they feel that they personally hold many of the answers needed to know how to make their sport safer for future generations," said Annese. "The examination of the brain is only the final and definitive chapter of a long narrative that we create working with our participants."
While Seau was never listed on any NFL injury report as having a concussion, according to ESPN, his family tells a different story. When asked whether Seau had experienced any concussions in his career, his ex-wife, Deboer, said last week, "Of course he had," according to the Associated Press. "He always bounced back and kept on playing. He's a warrior. That didn't stop him. I don't know what football player hasn't. It's not ballet. It's part of the game."
Repeated blows to the head may disturb neurotransmitters that affect mood, and may also damage parts of the brain that have to do with impulse control and the ability to weigh the long-term consequences of decisions.
But until more research has been done, experts caution against definitively linking the hits Seau took on the field and his suicide.
In 2009, the NFL instituted new rules that require clearance from independent neurologists to allow players who suffered concussions to return to the field. The league also imposed stricter guidelines to reduce the number of helmet-to-helmet hits.
"What happened to Junior Seau is terribly sad," said Annese. "The least us scientists can do is to match his dedication to his sport and his community with our own dedication to research, finding the reasons for such tragedy, so that it does not have to happen again."