Katie Couric's Notebook: Dave Duerson

In the NFL, a safety is the last line of defense. He's that guy who covers a pass and protects the line of scrimmage.

But who's protecting him in a rough and tumble sport where head injuries are all in a days work?

Former Bears and Giants safety  Dave Duerson died way too young, just 50. He committed suicide by shooting himself in the chest - and wants his brain to be donated for research.

Experts will determine if he was suffering from chronic traumatic encephalopathy. CTE can cause cognitive problems and early dementia and it's most common in people who experience repeated head trauma like pro athletes.

Concussions in the NFL were up 21 percent last year.

Duerson's brain might help doctors see the harm that comes from too many concussions. But more needs to be done to protect professional athletes and provide a little more safety for the safety, tackle, wide receiver and everyone else on the field

That's a page from my notebook.

I'm Katie Couric, CBS News.