Researchers sketching out a 'wiring diagram ' for rat brains have discovered its structure is organized like the Internet . They say the animal 's cerebral cortex is 'like a mini-Internet ' . The first comprehensive picture of how neurons connect to one another found local networks of neurons layered like the shells in a Russian nesting doll . The Internet has countless local area networks that then connect with larger , regional networks and ultimately with the backbone of the Internet . The brain operates in a similar way , the researchers found . 'The cerebral cortex is like a mini-Internet , ' said Larry Swanson , professor at the USC Dornsife College of Letters , Arts and Sciences , and corresponding author of a paper on the discovery . 'The Internet has countless local area networks that then connect with larger , regional networks and ultimately with the backbone of the Internet . 'The brain operates in a similar way . ' The study was published on April 6 in the Proceedings of the National Academy of Sciences . For years , scientists looking for clues to brain function through its structure focused on what could be seen — the brain 's lobes , grooves and folds . 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 . 'The data was already out there ; it just needed to be compiled into a more useful format , ' Swanson said . Lead author Mihail Bota of USC Dornsife created the database from more than 16,000 reports of connections , which he weighted both on the strength of the connection and the reliability of the methodology used to discover it . The process took more than 4,000 hours to complete , yielding a database that is free and available . Olaf Sporns of Indiana University subsequently performed a network analysis of the connections . A color-coded flat map of 1,923 rat cortical association macroconnections ( RCAMs ) . The team used studies of rat brains because of the sheer volume of detailed information available . Swanson believes that the database can create an important link between human brain studies — which are largely done as non-invasive functional magnetic resonance imaging scans — and rat brain studies , which can be more in-depth . 'Having a wiring diagram for the brain will allow knowledge to flow both ways between human and animal studies , ' Swanson said . 'This allows us to take theories from human brain scan studies and experimentally verify them in animals , and discoveries made in animal studies are likely to have an analogue in humans . ' 'We 're bridging the gap between our work in rat brains and the Stevens Institute 's work with human brains , ' Swanson said . 'If we can connect these two veins of neuroscience in a concrete and meaningful way , then we can dramatically expand our reservoir of information about the brain practically overnight . ' In the future , Swanson hopes to be able to expand the neural-connection map of the rat brain beyond the cerebral cortex , some day mapping the entire nervous system .
Researchers say the cerebral cortex of rats is ' like a mini - Internet ' Team able to look at human brains in the same way .