Mouse, insect or worm — in all these creatures, the same principle guides the formation of super strong connections between neurons in the brain, a new study confirms. The research helps validate the idea that, regardless of species, there’s a universal mechanism that underlies how brain networks form.
Different animals carry contrasting numbers of neurons in their brains, ranging from hundreds in worms to tens of billions in humans. Neurons form connections with each other, called synapses, that enable information to pass from one region of the brain to another in the form of electrical signals. Together, these connections form a network that enables animals to function and process information about the world.
This network is flexible; it is always changing and rearranging. Some of the connections between neurons are fairly weak and thus easily broken and replaced, while a small group are super strong. These strong links are known as “heavy-tailed” connections because, on a graph of connection density in the brain from low to high, they’re the outliers plotted at the dense end of the scale — like the tail of an animal.
These heavy-tailed connections play a bigger role in controlling major cognitive processes, such as learning and memory, compared with the weaker connections that far outnumber them in the brain. However, it was unknown whether these strong links formed via simple, known principles of network organization or via mechanisms that were species-specific, according to the authors of the new study, published Wednesday (Jan. 17) in the journal Nature Physics. [Continue reading…]