Human brain viewed from below.Dr. Johannes Sobotta, Wikimedia CommonsTheir findings were reported this week in the journal Nature.

In the study led by Drs. Sarah Medland, Margie Wright, Nick Martin and Paul Thompson of the QIMR Berghofer Medical Research Institute in Australia, nearly 300 researchers analyzed genetic data and magnetic resonance imaging (MRI) scans from 30,717 individuals from around the world. They evaluated genetic data from seven subcortical brain regions (nucleus accumbens, caudate, putamen, pallidum, amygdala, hippocampus and thalamus) and intracranial volume from MRI scans.

This is the largest analysis of brain structure and genetics ever done, said Dr. Jessica Turner, associate professor of psychology and neuroscience at Georgia State, who organized some of the teams collecting and evaluating data from participants with schizophrenia.

The goal was to determine how common genetic variants affect the structure of these seven subcortical brain regions, which are associated with memory, movement, learning and motivation. Changes in these brain areas can lead to abnormal behavior and predisposition to disease. 

Previous research has shown the brain’s structure is strongly shaped by genetic influences. Identifying genetic variants could provide insight into the causes for variation in human brain development and help to determine how dysfunction in the brain occurs.

“The team looked at several million base pairs or locations on the human genome,” Turner said. “Through a large-scale, international data sharing and data-analysis-sharing effort, we were able to actually successfully identify genetic effects on the hippocampus, putamen and other brain regions that no one had ever successfully identified genetics effects on before.”