A new study implicates 160 genes in brain shrinkage seen on MRIs of 45,000 healthy adults. The shrinkage is in the cortex, the dimply outer layer of the brain that gives rise to thinking, awareness and action, and largely consists of gray matter. The study, published in the journal Nature Communications, examined 34 regions of the cortex in a discovery group of 22,894 individuals, then confirmed the findings in a replication group of 22,635 individuals.
“It is important to understand the biology of multiple regions of the cortex because each is affected differently in the various types of neurodegeneration including Alzheimer’s disease,” says Sudha Seshadri, MD, senior study author from The University of Texas Health Science Center at San Antonio (UT Health San Antonio).
“We asked, ‘What are the genes that seem to determine the thickness, area and volume of gray matter in these regions?’“ Seshadri, who directs the university’s Glenn Biggs Institute for Alzheimer’s and Neurodegenerative Diseases, adds. “And the genes we found point to interesting pathways that seem to be involved in brain development, vascular and neurodegenerative disease, and some psychiatric conditions.”
Brain shrinkage occurs with normal aging, but the pattern of shrinkage in healthy individuals differs from the pattern in those who develop disease. The genes represent new targets of study for development of drugs to intervene before the onset of clinical symptoms, Seshadri says.
“This is a very rich resource, and it will be mined for many years to understand the different associations we are seeing,” Seshadri says. “We are excited to share it with the world.”
