An international team of researchers has created a high-resolution, 3-dimensional map of gene expression in human brains, using donated, whole brains from two males and a single hemisphere from a third man’s brain, according to a new study published last week (September 19) in Nature.
The researchers, led by Michael Hawrylycz of the Allen Institute for Brain Science in Seattle, created the atlas by assembling transcription data—collected using DNA microarrays—from around 900 precisely cut brain pieces and overlaying them on MRI brain scans of the donated brains taken before dicing. The maps—freely available online—could help scientists test hypotheses of brain function, disease, and evolution.
"By themselves these data do not hold all of the answers for understanding how the brain works," Ed Lein, a neuroscientist at the Allen Institute and co-author of the study, told LiveScience. "However, we hope they serve as a catalyst in human brain research for understanding the brain's complex chemistry and cellular makeup."
For example, scientists studying particular disorders could use imaging techniques, such functional MRI, to assess brain areas involved, then consult the new atlas to evaluate the genes expressed in those regions, which are displayed by a simple, color-coded guide to show the relative level of gene expression. Currently researchers rely on piecemeal studies of mouse brains for such expression information.
Coauthor Seth Grant of Edinburgh University told BBC News that for brain research to progress it is "essential to understand how it makes all of the genes and where they are expressed in the human brain.”