A University of Colorado at Boulder study of landlocked salmon indicates they possess a genetically programmed "aging clock" timed by reproduction, which may provide insight into human aging and Alzheimer’s disease.....
.....Both salmon and humans exhibit remarkably similar aging symptoms, including brain decay, cardiovascular disease, muscle atrophy, skin lesions and the resorption of internal organs. Laboratory studies of APP and beta-amyloid molecules obtained from salmon brains and from a small piece of brain tissue from a human who died with Alzheimer’s disease showed the molecules "to be very similar if not identical," said Maldonado.
In the study, young, castrated kokanee salmon were shown to live to be 7 years to 9 years old, instead of dying at age 2 or 3 like normal, spawning kokanee salmon, suggesting that salmon have an "aging alarm" timed to go off at reproduction. Massive surges of a stress hormone known as cortisol occur in both reproducing and sterile salmon just prior to the onset of the rapid aging process and subsequent death, Norris said.