Two local networks — one governing vision and learning, and another tapped into bodily concerns like muscle and organ function — make up the inner shell of the rat’s cerebral cortex. Two others — one governing smell, and another that assembles and makes sense of the information from the other three networks — make up the outer shell.
This means that certain flows of information are genetically “hardwired” into the brain, Swanson said. The discovery is the result of a massive, labor-intensive effort to organize 40 years’ worth of data from peer-reviewed research articles detailing connections in rat brains.
In addition to finding the local networks, the team also discovered hubs — highly interconnected and crucial centers of neural traffic linking local networks together. Previous research has shown that the regions the team identified as hubs can be, when damaged, the source of neurodegenerative diseases and epilepsy.