Investigators used automated neuroimaging analysis techniques to characterise the impact of an AD-risk gene, apolipoprotein E (ApoE4), on gray and white matter in the brains of cognitively healthy elderly from the KU Brain Aging Project.
They found that healthy elderly individuals carrying a risk-allele of the ApoE4 gene had reduced cognitive performance, decreased brain volume in the hippocampus and amygdala (regions important for memory processing), and decreased white matter integrity in limbic regions. These type of brain changes are also found in people with AD. Therefore, brain changes, usually found in AD patients, are also evident in nondemented individuals who have a genetic risk of later developing AD.
Lead investigator, Robyn Honea, DPhil, Research Assistant Professor, University of Kansas School of Medicine, Department of Neurology, Alzheimer's and Memory Group, comments, "It is important to note that findings of imaging phenotypes of risk variants, such as with this gene, have been shown in a number of studies. The unique element of our study is that we used several new neuroimaging analysis techniques. In addition, the individuals in our study have been well-characterised in a clinical setting."