As he pledged to donate his brain to scientists studying the long-term effects of repeated head hits, Nick Buoniconti, one of football’s most famous and revered players, lashed out at the N.F.L. for failing players and not doing enough to support research.

Buoniconti, a Hall of Fame linebacker and leader of the Miami Dolphins during their heyday in the 1970s who is declining mentally, made the announcement Friday in Boston, the home of his first team, the Patriots, as well as the country’s leading brain bank for the study of chronic traumatic encephalopathy, or C.T.E., a degenerative brain disease linked to head trauma.

Researchers at the C.T.E. Center at Boston University, led by Dr. Ann McKee, have examined hundreds of brains, including those of many football players, to help determine the links between head hits and C.T.E. Buoniconti said he hopes that donating his brain will ultimately help doctors better understand the disease.

“The fact that the N.F.L. pulled its funding from Ann McKee’s research prompted me to come up here and make a statement that the N.F.L. is only in it for the money, and they don’t care about the guys who preceded me,” Buoniconti, speaking haltingly, said in an interview before the announcement. “I’m really angry because they turned their backs on us and it’s not a responsible way to do things.”