That the brain is a powerful and complex organ is no mystery. But what researchers have begun to discover is that there are select areas of the brain that are so dense in their activity and interconnections that researchers have dubbed them the “rich clubs” of the brain.
The rich club network is like the 'G8 summit of our brain. It's a group of highly influential regions that keep each other informed and likely collaborate on issues that concern whole brain functioning...'
A new study used a special type of MRI scan to map out the connections in the brains of 21 men and women. There are regions of the brain in which connectivity is extraordinarily dense – that’s been known for some time. What the present study set out to do was visualize how these dense regions might be connected to one another, possibly forming a elite network between these distinct and powerful regions of the brain.
They found exactly that: Twelve discrete hubs in the brain were interconnected with one another across hemispheres, forming what the researchers call a “rich club,” distinct from the regular or “lower” network of the brain.
This image shows the group connectome, with the nodes and connections colored according to their rich-club participation. Green represents few connections. Red represents the most.
Reprinted with permission: Van den Heuvel, et al. The Journal of Neuroscience 2011
But what’s going on in this special network? That’s a good question. "You sort of wonder what they're talking about when they're communicating with each other," said Sporns. "All these regions are getting all kinds of highly processed information, from virtually all parts of the brain."
This part is still somewhat up for debate, but many areas of the rich club are involved in complex cognitive and behavioral processes. For this reason, the researchers suggest that damage to the rich club would lead to disproportionately large problems in brain function, while damage to the lesser networks would be relatively less severe. The team did find that the rich club network overlapped with several “functional modules” of the brain, like those involved in executive planning, vision, audition (hearing), and salience (relevance).
Study author Martijn van den Heuvel, sums it up nicely by saying that the rich club network is like the "G8 summit of our brain. It's a group of highly influential regions that keep each other informed and likely collaborate on issues that concern whole brain functioning," he said. "Figuring out what is discussed at this summit might be an important step in understanding how our brain works."
Clearly more research will look into this elite network in the brain. Researchers have made a lot of recent progress in mapping out the brain’s inordinate number of connections in what’s referred to as the “connectome,” and this study is one more piece in the massive puzzle.
The researchers published their study in the November 2, 2011 issue of the Journal of Neuroscience. It was carried out at Indiana University and at the Rudolf Magnus Institute of Neuroscience in The Netherlands.