Researchers have discovered a “neural workaround” in the human brain that can compensate for the buildup of beta-amyloid, a destructive protein associated with Alzheimer’s disease.
According to researchers at the University of California-Berkeley, the findings could help explain why some people with beta-amyloid deposits retain normal cognitive function while others develop dementia.
“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,” said study principal investigator Dr. William Jagust, a professor at University of California Berkeley’s Helen Wills Neuroscience Institute, the School of Public Health and Lawrence Berkeley National Laboratory.
The study, published in the journal Nature Neuroscience, included 22 healthy young adults and 49 older adults who had no signs of mental decline. Brain scans showed that 16 of the older subjects had beta-amyloid deposits, while the remaining 55 adults did not, the researchers report.
The researchers used functional magnetic resonance imaging (fMRI) to track brain activity while each of the subjects memorized pictures of various scenes.
Afterwards, the researchers tested the subjects’ “gist memory” by asking them to confirm whether a written description of a scene — such as a boy doing a handstand — corresponded to one of the pictures. The subjects were then asked to confirm whether specific written details of a scene, such as the color of the boy’s shirt, were true.
“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.”
What remains unclear is why some people with beta-amyloid deposits are better at using different parts of their brain than others, he noted. Previous studies suggest that people who engage in mentally stimulating activities throughout their lives have lower levels of beta-amyloid, he added.
“I think 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,” said Jagust.