Applying Network Theory to Neural Connections
Much effort has been put towards mapping the neural networks of our brains. In recent years, an international team of researches has been putting together what’s been called the “connectome,” which would be the most complete and comprehensive neural map to date. A team led by Olaf Sporns of Indiana University and Martijn ven den Heuvel of University Medical Center Utrecht in The Netherlands, a team of researches has used a form of MRI called diffusion imaging to map the large scale network connectivity of the neurons in the brain.
Through their mappings, Sporns and ven den Heuvel have found something unexpected; there are 12 very strongly connected hub regions in various locations in our brains. These hubs, which in general control complex tasks such as behavior and the integration of information between our senses, have disproportionally dense connections compared to other regions of the brain. In fact, these regions are so strongly connected to the rest of the brain, that at any given time they seem to be able to receive “all kinds of highly processed information, from virtually all parts of the brain,” according to Sporns. These hubs have been dubbed “Rich Clubs” of the human brain, due to their disproportionate influence in terms of interactions within our minds.
While this is surely a very complex subject, a very simple analogy can be drawn to what we have studied in class regarding strength of connections within a network. In fact, our example of corporate hierarchy needs only slight modification to fit these findings. The sections of our brains that handle highly processed, specific information are connected strongly, but are relatively isolated from other regions with different tasks. This can be compared to a small group of lower level employees, working on one specific project within their department. These highly specialized regions pass their information to the strongly connected “Rich Clubs,” just as individual departments of a corporation report their findings to an executive higher in the company. Just as these “Rich Clubs” receive information from all over the brain, employees higher in rank tend to have more connections to various parts of a corporation.
Another analogy holds true; Sporns and ven den Heuvel believe that any damage to one of these “Rich Clubs” carries disproportional amount of damage to the entire nervous system, just as it hurts a company more to lose its executives than to lose a low-level employee. So far, prior research has shown that the overarching network of “Rich Clubs,” and therefore damage to the overarching brain network, tends to be disturbed in patients with schizophrenia. The team plans to research further the relationship between neural networks and brain disorders. It is very possible that many of the secrets of the brain are fundamentally due to the same phenomena we have studied in class regarding the theory of connections within a network.
http://gizmodo.com/5860199/there-is-a-super+entity-inside-the-human-brain
http://www.eurekalert.org/pub_releases/2011-11/iu-sar103111.php
http://www.jneurosci.org/content/31/44/15775