Your Brain Is Like Facebook

The neurons in the mind are wired in a social network, just like Facebook, according to new research. Every nerve cell has links with many others, but the strongest bonds are formed between the few cells that are most similar to each other, according to sciencedaily.com.

Researchers from Biozentrum, University of Basel, discovered that every nerve cell is linked with many others, yet the strongest bonds are between like-minded cells. The results of them all are published in the journal Nature.

All the neurons are connected like a mesh through links called synapses, which may total upto thousands per cell. However, not all the connections are equally strong. Most of them are weak, with just a few forming strong links. "We wanted to see if there are rules that explain how neurons connect in complex networks comprising millions of neurons," says Professor Thomas Mrsic-Flogel, the leader of the research team from the Biozentrum (University of Basel) and UCL (University College London). "It turns out that one of the rules is quite simple. Like-minded neurons are strongly coupled, while neurons that behave very differently from each other connect weakly, or not at all."

The researchers studied the visual area of the cerebral cortex, which keeps getting information from eyes and leads to a lot of "visual perception". Neurons in this part of the brain act in response to definite visual designs, however, it is tough identify the cells whose synapses are linked, as hundreds of thousands of nerves are so densely packed, at about 100,000 per cubic millimeter.

With the balanced use of high resolution imaging as well as sensitive electrical measurements, the team found that just as a social media network helps us to bond only with like-minded friends, neurons in the brain tend to communicate with other nerves that are similar.

"Weak contacts in the brain have little impact, despite being in the majority," says Mrsic-Flogel. "The few strong connections from neurons with similar functions exert the strongest influence on the activity of their partners. This could help them work together to amplify specific information from the outside world."

The logic behind weak connections is to help the brain to strengthen and adapt to changes in the environment. "We think this might have to do with learning," says Dr Lee Cossell, one of the lead authors of the study. "If neurons need to change their behavior, weak connections are already in place to be strengthened, perhaps ensuring rapid plasticity in the brain."

A global effort to see how the brain generates what we feel, think and perceive can be done by mapping the brain's wiring, "it reveals how networks of neurons interact together to process information. Understanding how neurons connect will pave the way for building detailed computer simulations of the brain," says Mrsic-Flogel.

Understanding how neurons connect will also help us to understand neurological diseases. "If we know what the pattern of connections in the brain should look like, then we can start to figure out what happens when things go wrong, for example, in schizophrenia or autism," adds Mrsic-Flogel.