A small collective of highly connected brain regions is of fundamental importance for the exchange of information in the brain. This is the main finding of new study, published in The Journal of Neuroscience, by Brain Center Rudolf Magnus researchers Marcel de Reus and Martijn van den Heuvel.
Using new mathematical methods, the researchers re-analyzed an almost twenty year old, but very accurate map of the brain regions and neural connections of the cat. This 'road map' of the cat brain comprises a large number of so-called neural tract-tracing studies from the '70s and '80s and is, despite its age, still one of the most detailed brain maps available.
“Our mathematical analyses of this road map show that brain regions from different functional zones are predominantly connected by a small number of central hub regions. Together, these hub regions form a densely connected network, known as the 'rich club'”, says De Reus. In their study, the researchers demonstrate that 90% of all communication between functional zones passes through this network of strongly interconnected hub regions, which all maintained direct connections to each functional zone.
“The importance of our study is two-fold”, adds Van den Heuvel. “On the one hand, it confirms our earlier MRI-based findings on rich club formation in the human brain. And, on the other hand, it provides a firm foundation for the idea that the rich club plays a central role in the integration of information in the brain”.
In a different study published earlier this year, Van den Heuvel and colleagues already showed that similar hub regions in the human brain tend to be less densely connected in schizophrenia patients. The current study therefore delivers an important contribution to the question how such alterations in connectivity could lead to a reduced capacity of patients to combine various cognitive functions.