US researchers said Wednesday they have identified a new protein in the brain that triggers age-related memory loss, a finding that may someday lead to new treatments to reverse it.
Using live lab mice and eight human brains that were donated for science, the team led by Nobel laureate Eric Kandel at Columbia University found that a gene called RbAp48 was linked to the kind of memory loss associated with aging.
The amount of protein the gene produced was almost 50 per cent lower in old brains than in younger ones, said the study in the US journal Science Translational Medicine.
The RbAp48 changes were the most significant seen among all the 17 genes that appeared to lead to age-related changes in a part of the hippocampus known as the dentate gyrus.
When the researchers took their findings to the lab for further study on transgenic mice set loose in a maze, they found that switching off the protein in younger mice made them forgetful, while increasing the protein in older mice boosted their memory.
"We were astonished to find out that this increase not only improved the memory of these mice but it led to young-like performance," said co-author Elias Pavlopoulos.
"The old mice performed as well as young mice."
The findings provide the first molecular evidence of the difference between age-related memory loss and Alzheimer's disease (AD), said the researchers.
"Our studies support the idea that age-related memory loss is a disorder independent of AD," said the study.
While the research is still in its early stages, scientists were hopeful that since the gene expression was detected in both mice and human brains, that a pathway to treating humans is a future possibility.
"Our findings have a strong potential to be translated into new therapies," said Pavlopoulos.
Kandel, who won the Nobel in 2000 for his work on the physiological basis of memory storage in neurons, said the "fact that we were able to reverse age-related memory loss in mice is very encouraging."
He said it is too early to say whether this protein is the only one involved in age-related memory loss, or if there are others.
"But at the very least, it shows that this protein is a major factor, and it speaks to the fact that age-related memory loss is due to a functional change in neurons of some sort," Kandel said.
"Unlike with Alzheimer's, there is no significant loss of neurons."