BRAIN BANK
The researchers began with eight brains from the New York Brain Bank at Columbia University donated by people aged 33 to 88 who were free of brain disease when they died. They extracted two structures in the hippocampus, a vital cog in the brain’s memory machinery: the dentate gyrus, a boomerang-shaped region whose function declines with age but is not affected by Alzheimer’s, and the entorhinal cortex, which is largely unaffected by aging but is where Alzheimer’s first takes hold, killing neurons.
The scientists then measured which genes had been active in each structure, and found one suspicious difference: 17 genes in the dentate gyrus became more active, or less, as the age of the brain increased.
The most significant change was that the gene for a protein called RbAp48 had essentially retired: The gene’s activity tailed off dramatically the older a brain got. As a result, old brains had about half the RbAp48 of young brains, the scientists report online in the journal Science Translational Medicine.