In a shocking new finding, proteins associated with Alzheimer's were discovered in young brains for the first time.
A hallmark protein of Alzheimer's disease, dubbed amyloids, was found to be accumulating in brains of people as young as 20, which is much younger than scientists would have ever expected, Northwestern University reported.
"Discovering that amyloid begins to accumulate so early in life is unprecedented," said lead investigator Changiz Geula, research professor at the Cognitive Neurology and Alzheimer's Disease Center at Northwestern University Feinberg School of Medicine. "This is very significant. We know that amyloid, when present for long periods of time, is bad for you."
To make their findings the researchers looked at basal forebrain cholinergic neurons to gain insight into why they are one of the first places damage is observed in cases of Alzheimer's. They analyzed these neurons in three groups of deceased individuals: 13 cognitively health young individuals between the ages of 20 and 66; 16 non-demented individuals between the ages of 70 and 99; and 21 individuals with Alzheimer's between the ages of 60 and 95.
The findings revealed amyloid molecules started accumulating inside these neurons in early adulthood and continued throughout the lifetime. The amyloid molecules in these cells formed toxic clumps, called amyloid oligomers, that were observed in health study subjects as young as 20.
"This points to why these neurons die early," Geula said. "The small clumps of amyloid may be a key reason. The lifelong accumulation of amyloid in these neurons likely contributes to the vulnerability of these cells to pathology in aging and loss in Alzheimer's."
The researchers believe these clumps eventually kill of neurons by triggering excess calcium leaking into the cell. The clumps could also damage these key neurons by secreting amyloid outside the cells, leading to the formation of damaging amyloid plaques.
"It's also possible that the clumps get so large, the degradation machinery in the cell can't get rid of them, and they clog it up," Geula said.
The findings were published in a recent edition of the journal Brain.
