A new research conducted by researchers at The Columbia University Medical Center (CUMC) suggest that there are clear differences in brain function between healthy people who carry a genetic risk factor for Alzheimer's disease and those who lack the factor.
People who carry the genetic risk factor, the e 4 allele of the Apolipoprotein (APOE) gene, have higher risk of developing the disease than non-carriers and usually show symptoms earlier.
"It is possible that what we're seeing in the APOE- e4 carriers are early changes in the brain caused by Alzheimer's disease," lead researcher Yaakov Stern was quoted as saying.
The researchers looked at six people who carried the APOE- e4 risk factor and 26 non-carriers. None of the 32 participants, mostly in their 60s and 70s, had any signs of dementia or memory.
PET scans taken while the subjects were performing a memory task, however, showed clear differences between the two groups. As the participants tried to remember if they'd seen a particular shape before, one pattern of brain activation appeared in the APOE- e4 carriers while a different pattern appeared in the non-carriers.
The difference may indicate that APOE- e4 carriers have to compensate for early damage done by Alzheimer's by switching to an alternate brain network to complete the task. It could also be that their different genetic makeup results in different patterns of brain activity.