September 10, 2009
Why Alzheimer’s patients set in their ways
Those with Alzheimer's disease or obsessive-compulsive disorder may be trapped in routines and kept from adapting to new environments, U.S. researchers say.
Senior author Michael Platt Duke of University Medical Center in Durham, N.C., says brain scans in monkeys indicated nerve cells in the part of the brain known as the posterior cingulate cortex fire up more strongly when the monkeys decided to explore new alternatives.
The experiment began with the monkeys being given four rewards to choose from -- each the same size cup of juice. Gradually, the four targets began to become larger or smaller in value.
The study, published in Current Biology, says by tracking individual neurons, the researchers could predict whether a monkey would stay with the initial target -- whose value was known for certain -- or explore the other targets.
These data are interesting from a human health perspective, because the posterior cingulate cortex is the most metabolically active part of the brain when we are daydreaming or thinking to ourselves, and it is also one of the first parts of the brain to show damage in Alzheimer's disease, Platt says in a statement.
Perhaps, he says, those with Alzheimer's, become set in their ways because of damage in this part of the brain.