An internationally significant study of healthy twins, 65 years of age or older, has unlocked important clues about how genes influence the development of key grey matter structures, paving the way for a genetic blueprint of the human brain. A team led by researchers from University of New South Wales (UNSW) Medicine analyzed the MRI scans of 322 individuals from the Older Australian Twins Study. The objective was to map the genetic relatedness (or heritability) of cortical and subcortical structures in their brains. These structures are responsible for functions ranging from memory and visual processing, to motor control. The new work was reported online on September 6, 2016 in Scientific Reports. The open-access article is titled “Distinct Genetic Influences on Cortical and Subcortical Brain Structures.” "We know that genes strongly underpin brain development," says lead researcher Associate Professor Wei Wen from the Centre for Healthy Brain Ageing (CHeBA) at UNSW. "But we still don't understand which specific genes are implicated, or how they contribute to different brain structures. In order to identify these genes, we need to first know whether they are shared by different parts of the brain, or unique to a single structure," he says. "This is the first attempt to examine genetic correlations between all of the brain's structures, using the twin design." The UNSW-led team analyzed MRI scans of 93 sets of identical twins and 68 sets of fraternal twins. These participants were all Caucasian men and women without dementia, with an average age of 70, living in the Eastern states of Australia. The scientists measured the volume of their brain structures (12 structures in total) and, using statistical and genetic modeling, determined the heritability for each.Login Or Register To Read Full Story