Researchers at the Allen Institute for Brain Science have generated a high-resolution blueprint for how to build a human brain, with a detailed map of where different genes are turned on and off during mid-pregnancy at unprecedented anatomical resolution.
This is the first major report using data from the BrainSpan Atlas of the Developing Human Brain and it shines a light on where genes are turned on in the brain during mid-pregnancy, what goes wrong in developmental disorders like autism, and what makes human brains unique.
What Makes Humans Unique?
Understanding what makes humans unique involves deciphering a complex puzzle—one that begins during the earliest phases of development. The richness of the BrainSpan Atlas gives scientists a new set of tools to assess how the human brain develops compared to other species.
“We know that some important regions of the genome show striking sequence differences in humans compared to other species. Since where a gene is expressed in the brain can give insight into its function, we can use our map to begin to figure out the roles of those genes in making humans distinct,” says Lein. “Our analysis of the data showed that these genes are enriched in the frontal cortex, as well as in several specific specialized cell types including inhibitory GABAergic interneurons and neurons of the transient subplate zone that serves as a scaffold during early circuit formation. These features are all known to be expanded or show developmental differences in humans compared to other species, so our data gives unprecedented clues about the molecular underpinnings of what makes human neocortex unique.”
Reference atlas plate of the human fetal brain, color-coded by structure (credit: Allen Institute)