The largest difference between you and a chimpanzee or a monkey can be found in the brain. Despite the fact that all regions of the human brain have very similar molecular signatures to your primate relatives, a new study has found that these regions contain distinct human patterns of gene activity that mark the brain’s evolution. This new study may contribute to our cognitive abilities.
Although human brains are three times larger and have many more cells and therefore more processing power than a chimpanzee, researchers, Zhu and Sousa, have found similarities between humans and our primate relatives in gene expressions in 16 regions of the brain. A gene similarity was even found in the prefrontal cortex, a place where higher order learning takes place that most distinguishes humans from other apes. However researchers have also found that the striatum had the most human-specific gene expression, a region most commonly associated with movement.
A surprising difference was found in the cerebellum, one of the evolutionarily most ancient regions of the brain, and therefore most likely to share similarities across species. Researches found the gene ZP2, a gene active in only the human cerebellum, which is surprising considering the same gene has been linked to sperm selection by human ova. Zhu, a postdoctoral researcher, says that they, “have no idea what it is doing there.”
Researchers Zhu and Sousa have focused on one gene, TH, which is involved in the production of dopamine. TH is a neurotransmitter crucial to higher-order function and depleted in people living with Parkinson’s disease. They found that TH was highly expressed in human neocortex and striatum but absent from the neocortex of chimpanzees.
This research could be important in finding the cure to certain diseases like Parkinson’s disease. Also would be helpful in understanding how the human mind processes higher-order actions.