Allen Institute researchers have identified a small set of just 32 gene-expression patterns for all 20,000 genes across 132 functionally distinct human brain regions, these patterns appear to be common to all individuals. Researchers used data for six brains from the publicly available Allen Human Brain Atlas.
They believe the study is important because it could provide a baseline from which deviations in individuals may be measured and associated with diseases, and could also provide key insights into the core of the genetic code that makes our brains distinctly human.
While many of these patterns were similar in human and mouse, many genes showed different patterns in human. Surprisingly, genes associated with neurons were most conserved (consistent) across species, while those for the supporting glial cells showed larger differences.
The most highly stable genes (the genes that were most consistent across all brains) include those associated with diseases and disorders like autism and Alzheimer’s, and these genes include many existing drug targets. These patterns provide insights into what makes the human brain distinct and raise new opportunities to target therapeutics for treating disease.
The researchers also found that the pattern of gene expression in cerebral cortex is correlated with “functional connectivity” as revealed by neuroimaging data from the Human Connectome Project.
“The human brain is phenomenally complex, so it is quite surprising that a small number of patterns can explain most of the gene variability across the brain,” says Christof Koch, Ph.D., President and Chief Scientific Officer at the Allen Institute for Brain Science.
“There could easily have been thousands of patterns, or none at all. This gives us an exciting way to look further at the functional activity that underlies the uniquely human brain.”