Parts of the brain shrink faster from the age of 30, researchers at the University of Oslo found. These brain changes are accelerated in people with Alzheimer’s disease.
Cortical inconsistency serves a cause
The researchers were particularly interested in the cerebral cortex because thinning in this part of the brain has been linked to cognitive decline and Alzheimer’s disease. This is the most isolated part of the brain – a thin layer of “gray matter” – essential for high-level mental activity such as memory.
The left and right sides of the cortex are less dense in younger brains – something called “cortical asymmetry”. Inconsistency seems like a good thing because it allows the brain to function optimally, as the left and right brains are specialized to do slightly different jobs.
As we age, the cortex shrinks and causes gradual mental decline, which is a normal part of growing older.
So far, scientists have thought that the left and right sides of the thin cortex are at the same level, but this study shows that the thicker side of the brain at the age of 20 shrinks more. soon.
Thinner cortex linked to Alzheimer’s disease
The research team, part of an international consortium of brain researchers called Lybrain, measured the thickness of each area of the cortex using brain scans from more than 2600 healthy people across Europe and the US, and in an Australian sample with depression.
The researchers found that cortical inconsistency is lost as we age, confirming that both sides of the brain shrink at different rates. In the same brain regions as they were in normal age, they found the left side of the brain declining faster in Alzheimer’s disease.
“It is too early to conclude, but cortical instability could be used as a marker to detect early brain changes in Alzheimer’s Disease, which are thought to occur before psychiatric symptoms begin to subside. The study’s lead author James Roe said.
Brain thinning begins early
The loss of asymmetry appeared at the same age in most people (around the early 30s) and continued throughout adult life, with an accelerated decline around the age of 60.
“Loss of cortical inconsistency occurs gradually over a lifetime. We saw this with remarkable consistency in all samples,” says Roe.
“The effect is that at least some of the brain changes associated with Alzheimer’s disease may play out over long periods of life, perhaps on the order of decades, and ‘may show a high overlap with those that occur gradually in normal age, “Roe says.
World’s largest lifelong data set
The researchers, based at the University of Oslo’s Center for Lifelong Change in Brain and Cognition (LCBC), used a “long-term” approach, making it possible for them to study human brain scans at various times in their lives. The study is part of the EU-funded project Lifebrain, a collaboration between many of the world’s oldest aging databases.
The study’s lead author, James Roe, says the study is underpinned by:
“The data we have thanks to Lifebrain is financial. We were able to measure the thickness of each area of the cortex in more than 2600 healthy participants from five countries, up to six times in the same person over time. Other brains.Each data only has one brain scan for each person, so they cannot see changes occurring in the same person throughout their lives.Follow-up scans of the same people were absolutely crucial in the study us. “
About the Lifebrain project
The Lifebrain project brings together many of the most comprehensive databases for observing brain changes over a lifetime, from 0 to 100 years old. The main goal of the Lifebrain consortium is to ensure full research, harmony, and enrichment in some of the largest long-term studies of age differences in brain and cognition in Europe.