To many of us, the brain looks a bit like a cauliflower. Yet the verb I most often use to describe the development of the neocortex is ‘flowering’, stark and simple. The advent of this amazing structure evokes in me a sense of beauty, exuberance, even fragrance. This remarkable research shows that it has also been a multidimensional flowering. The time span that marks the appearance of new genes in the mammalian lineage is the same that sees the emergence of our most advanced neurological feature – the prefrontal cortex. Here I quote Eric Vallender, a neurogeneticist at Harvard Medical School who was not involved in the research, and University of Chicago evolutionary geneticist Manyuang Long, who led the study.
“We were very shocked that there were that many new genes that were upregulated in this part of the brain,” said Long, who added that he was also taken aback by synchronicity of the origin of the genes and the development of novel brain structures. It seems that around the same time that the neocortex and the prefrontal cortex arose, and then expanded in humans, a large collection of genes also popped up.
“You always have the correlation versus causation question,” Vallender cautioned. “But it’s very consistent that these genes were all arising at the same time as these new anatomical structures that we know are very important in cognition and behavior.”
Simply imagining to be a living cauldron where new genes and breathtaking form of organization are simultaneously concocted is kinda hot. Kinda cool. And definitely smells good.