Brain scans of over 100 mammalian species, together with humans, reveal that the efficiency of data transfer within the brain is the same in all mammals, regardless of size. The mammalian brain consists of 2 sides, or hemispheres, which nerve tracts, additionally known as axons, connect. The 2 hemispheres share data along these axons.
How quickly data spread in the brain depends on the number of synapses — the junctions between nerve cells — it has to pass through. An ideal system would have a multitude of long connections to allow the fast transfer of data between all elements of the brain. However, producing this many neuronal connections comes at a price to the animal. The development of the brain, consequently, outlines a compromise.
People usually believe that human beings, because of our advanced evolution, have higher levels of brain connectivity than different animals, enabling the more efficient and fast transfer of data throughout the brain.
A brand new analysis that researchers from Tel Aviv University in Israel led challenges this assumption. They scanned the brains of over 120 completely different mammals and found that brain connectivity is neither higher in humans nor dependent on the dimensions of the brain. The idea that brain connectivity — and, therefore, potency — is bigger within the human brain has been around for a long time.
To test this assumption, Prof. Assaf and his team used a kind of brain scan referred to as diffusion MRI to scan the brains of 123 completely different species of mammal, as well as humans. It was the first time that researchers had placed the majority of those animals’ brains within an MRI scanner. The animals within the study included rodents, monkeys, and even dolphins. The brain volumes of the species ranged from 0.1 milliliters (ml) to over 1,000 ml.
The researchers additionally scanned the brains of 32 individuals. They used a scanning program to reconstruct the neural network of every species, as well as the neurons that transfer data and therefore the synapses wherever they meet. To estimate the brain connectivity of every species, the researchers applied a mathematical approach based on the number of synapses that data must cross to get from 2 points within the brain.
The team derived a price known as the mean-short path, or MSP, that indicates the minimum range of connections that data has to pass to get between 2 elements of the network. A high MSP indicates low brain connectivity. Comparing these values among species, the researchers found that brain property is independent of the dimensions and structure of a mammal’s brain.
