by Shelly Fan at Singularity Hub: A new study comparing neurons from different primates pinpointed several genetic changes unique to humans that buffer our brains’ ability to handle everyday wear and tear. Dubbed “evolved neuroprotection,” the findings paint a picture of how our large brains gained their size, wiring patterns, and computational efficiency.
It’s not just about looking into the past. The results could also inspire new ideas to tackle schizophrenia, Parkinson’s disease, and addiction caused by the gradual erosion of one type of brain cell. Understanding these wirings may also spur artificial brains that learn like ours.
The results haven’t yet been reviewed by other scientists. But to Andre Sousa at the University of Wisconsin-Madison, who wasn’t involved in the work, the findings can help us understand “human brain evolution and all the potentially negative and positive things that come with it.”
Bigger Brain, Bigger Price
Six million years ago, we split from a common ancestor with our closest evolutionary relative, the chimpanzee.
Our brains rapidly exploded in size—but crucially, only in certain regions. One of these was at the front of the brain. Called the prefrontal cortex, it’s an “executive control” center that lets us reason, make difficult decisions, and exercise self-control. Another region, buried deep in the brain, processes emotions and gives us the ability to easily move with just a thought.
The two regions are in ready communication, and their chatter may give rise to parts of our intellect and social interactions, such as theory of mind—where we can gauge another person’s emotions, beliefs, and intentions. Dopamine neurons, a type of brain cell, bridge this connection.
They may sound familiar. Dopamine, which these neurons pump out, is known as the “feel-good” molecule. But they do so much more. Dopamine neurons are spread across the entire brain and often dial the activity of certain neural networks up or down, including those regulating emotion and movement. Dopamine neurons are like light dimmers—rather than brain networks flipping on or off like a simple switch, the neurons fine-tune the level of action.
More here.
