Alzheimer’s Protein Linked To Increased Brain Activity In Healthy Older People

New research has shown that older adults with build-up of a hallmark Alzheimer’s protein have increased brain activity while performing memory tasks. The study, which suggests that the brain adapts to compensate for early damage caused by the protein, is published on Sunday 14 September in the journal Nature Neuroscience online.

The protein amyloid is a key feature of Alzheimer’s disease, and its accumulation in the brain is thought to be an early trigger for the disease. However, brain scanning techniques have shown that some older people without thinking or memory problems may still have amyloid present in the brain, and researchers at the University of California set out to understand the reasons for this.

The team followed three groups of people:

  • 22 people in their early 20s
  • 33 people in their 70s with no amyloid build-up in the brain
  • 16 people in their 70s who had a build-up of amyloid but no memory problems.

Each participant was asked to memorise a series of pictures while they underwent an MRI scan to measure brain activity, before being asked a series of questions about the pictures. All three groups performed well in the memory tests, with no difference between each group.

However, the MRI results showed a greater level of activity in certain brain regions in the younger group, and in older people who had amyloid present in the brain. Older people without amyloid build-up showed relatively low levels of brain activity. The researchers suggest that as amyloid accumulates in the brain, it may cause the brain to work harder as a way of compensating for damage caused by the protein.

Dr Laura Phipps of Alzheimer’s Research UK said:
“This small study suggests that our brains may have ways of resisting early damage from these Alzheimer’s proteins, but more research is needed to know how to interpret these results. Amyloid build-up occurs early in Alzheimer’s, many years before symptoms such as memory loss appear, and it would be useful to know whether the people in this study developed symptoms later on. Longer term studies are needed to confirm whether the extra brain activity seen in this research is a sign of the brain compensating for early damage, and if so, how long the brain might be able to fight this damage.

“An understanding of the early changes in the brain as Alzheimer’s develops could help scientists find ways to stop the disease, but investment in research is crucial. With half a million people in the UK currently living with Alzheimer’s and that number set to grow, we urgently need ways to prevent and treat the disease.”