How Does Alzheimer's Impact a Brain

Alzheimer's disease leads to changes in the brain and scientists are trying to understand those changes

(RxWiki News) Alzheimer’s Disease (AD) is associated with loss of thinking and memory, and changes in the brain structure and function appear for people with AD. Understanding these changes may lead to better treatments. 

Research has reported that parts of the brain are overactive in people with AD, and it is thought that the overactivity may be the brain’s way of trying to make up for problems with function that are created by AD.

New research questions this idea and adds to the knowledge about how brain function is changed in AD.

"Discuss any memory problems with your physician"

Researchers at the Université de Caen Basse-Normandie in France, led by graduate student Alexandre Bejanin with Francis Eustache, looked at the brains of 11 patients with AD and compared them to the brains of 12 healthy people of similar ages.

They imaged the brain using positron emission tomography (PET) while people were at rest and while they were doing a memory task.

They found that people with AD had a different pattern of activity compared to healthy people. Specifically, certain regions for learning and memory were less active in people with AD during the memory task. Other regions of the brain were more active in people with AD.

When comparing healthy people to people with AD, they found that what looked like overactivity in many areas was actually faulty deactivation. 

In other words, some areas looked more active in people with AD than healthy people, but it was really that the activity of these brain regions did not shut down in people with AD.

The complicated neural networks of the brain show patterns of activity, then the activity slows. The waxing and waning of activity is thought to be part of the way that information is processed through large, complex networks.

The authors concluded, “Altogether, our findings suggest that hyperactivations in AD must be interpreted with caution and may not systematically reflect increased activity.”

“Thus, although genuine compensatory mechanisms may exist in AD, our work emphasizes the caution that is necessary to interpret hyperactivations in this way.”

This research helps to understand changes in brain function for people with AD, which may ultimately lead to better treatments for the disease.

The study was published in May in Frontiers in Human Neuroscience. The authors did not report any financial relationships with conflicts.

Review Date: 
May 18, 2012