The human brain has the plasticity to compensate for the accumulation of the protein beta-amyloid that causes Alzheimer’s disease, which explains that some individuals develop it and others don’t, as concluded by research conducted at the University of California in Berkeley (UC Berkeley). The researchers analyzed adults with and without beta-amyloid deposits in their brain and believe to be able to explain why some retain normal cognitive function while others develop dementia. The findings of the study were published at the Nature Neuroscience journal.
“This study provides evidence that there is plasticity or compensation ability in the aging brain that appears to be beneficial, even in the face of beta-amyloid accumulation,” explained the study’s main investigator Dr. William Jagust, who is a professor with joint appointments at UC Berkeley’s Helen Wills Neuroscience Institute, the School of Public Health, and Lawrence Berkeley National Laboratory.
The patients enrolled in the study were examined using functional magnetic resonance imaging (fMRI) to evaluate their brain activity during the process of memorizing pictures of a series of scenes. To test their “gist memory,” the researchers conducted a questionnaire where they described a scene and the patients had to correspond it to a picture previously viewed, as well as to confirm certain details about the pictures.
“Generally, the groups performed equally well in the tasks, but it turned out that for people with beta-amyloid deposits in the brain, the more detailed and complex their memory, the more brain activity there was,” said Jagust. “It seems that their brain has found a way to compensate for the presence of the proteins associated with Alzheimer’s.”
The researchers conducted the study with 22 healthy young adults and 49 older adults who had no signs of mental illness. According to the data from the brain scans, 16 of the older subjects had beta-amyloid deposits, while the remaining 55 adults did not. Other studies had already established a relation between brain activity and beta-amyloid deposits, however, it hasn’t been explained how or if the activity is also linked to a improved mental performance.
Despite the findings of the study, Jagust noted that the researchers failed to explain why some individuals with beta-amyloid deposits are able to use parts of their brain more efficiently than others. The scientist believes, however, that, “it’s very possible that people who spend a lifetime involved in cognitively stimulating activity have brains that are better able to adapt to potential damage.”