An Allen Institute for Brain Science-led team says it has uncovered gene expression patterns that hint at how humans have developed language and problem-solving abilities, NPR reports.
The Allen Institute's Ed Lein and his colleagues write in Nature Neuroscience that they examined gene expression patterns across 132 structures in six brains.
Usually, NPR notes, such studies then look for genetic differences between their samples."[But] we sort of flipped this question on its head and we asked instead, 'What's really common across all individuals and what elements of this seem to be unique to the human brain?'" Lein says.
From this, they found a set of 32 reproducible consensus co-expression gene networks that explain the vast majority of transcriptional variation in the adult human brain. Genes with the most consistent patterning, the researchers report, appear to be important for brain function and disease. For instance, module 1 is highly enriched in the cortex, hippocampus, amygdala, and striatum, and it includes genes involved in synaptic transmission and genes that are down-regulated in Alzheimer's disease.
The researchers compared these co-expression networks to those in mice, finding a high level of preservation of genes in neuron-associated, as compared to those in non-neuronal networks. But glial cells appeared to differ.
"The patterns that are more related to the neurons, the sort of information carriers in the brain, tend to be better conserved across species," Lein says. "Those that are related to the support cells, the glial cells, are actually less conserved. This was somewhat of a surprise."
And glial cells have recently been implicated in learning and intelligence, NPR notes.