This content is archived, it could be outdated.
Crowd-sourcing connects genes, brain volume, and intelligence
In the largest collaborative study of the brain to date, world-leading experts at the Donders Institute for Brain, Cognition, and Behaviour and the MPI for Psycholinguistics (Peter Hagoort and Martine Hoogman), together with more than 200 international colleagues of the ENIGMA and CHARGE consortia, pooled and analysed brain imaging results from about 21,000 people. "This large-scale study is really unique," says Professor Barbara Franke of the Radboud University Nijmegen Medical Centre, one of the senior authors. Nature Genetics published the series of papers online on April 15.
April 16, 2012
In the series of papers published in Nature Genetics (for reference see below), the authors for the first time identify the specific genes that influence brain size (volume) of people in the population. MRI data from 21,000 people was included in the study. Never before has such a large database been compiled. The study was also unique because of its large number of collaborating researchers, as scientists at more than 100 centres worldwide participated in the studies, pooling their genetic and extensive brain imaging results in one large database.
"This movement toward crowd-sourcing brain research is an example of social networking in science, and it gives us a power we have not had," said Paul Thompson, Professor of Neurology at the University of California, Los Angeles, and also senior author of the Nature Genetics papers, in The New York Times on Sunday, April 15.
Scientific publications about genetics usually have large numbers of contributing authors, but the paper 'Identification of common variants associated with human hippocampal and intracranial volumes' has more than 200 authors, and the accompanying paper 'Common variants at 12q14 and 12q24 are associated with hippocampal volume' had about 100 contributing scientists.
In the studies, the collaborators specified a gene variant, carried by about 20% of the population, correlated with the size of the hippocampus, which is critical for memory formation. The researchers also found a gene variant that strongly correlated with overall brain size. They also demonstrated that this variant is correlated with I.Q. People with larger brains scored slightly higher on a standardized test. The brain structure of people who carried one copy of this brain-size gene variant (about half of the population) was 0.6% smaller than that of people who did not carry it.
"These large-scale studies are very important, because the effects of the gene variants on the brain are expected to be relatively small," says Professor Barbara Franke of the Radboud University Nijmegen Medical Centre. "In this way Mother Nature has ensured that our brain is flexible, and that our species can easily adapt to the environment. The large number of collaborators and analyses of the collective data gave us excellent opportunities for tracing the genes linked to brain structure."
Hippocampus. Photo by Laura B. Dahl.
See also the article in The New York Times.