Left: Section of the cerebellum with 40-fold magnification, obtained with electron microscopy (Dr. E. Zunarelli, Modena University Hospital); right: Excerpt from a cosmological simulation with an extension of 300 million light years on each side (Vazza et al. 2019 A & A). Photo credit: University of Bologna
In their work published in Limits of physicsFranco Vazza (astrophysicist at the University of Bologna) and Alberto Feletti (neurosurgeon at the University of Verona) studied the similarities between two of nature’s most challenging and complex systems: the cosmic network of galaxies and the network of neural cells in the human brain.
Despite the significant scale difference between the two networks (more than 27 orders of magnitude), their quantitative analysis, located at the interface between cosmology and neurosurgery, suggests that different physical processes can build structures characterized by similar levels of complexity and self-complexity Organization.
The human brain works thanks to its wide neural network, which contains approximately 69 billion neurons. On the other hand, the observable universe can count on a cosmic network of at least 100 billion galaxies. In both systems, only 30% of their masses consist of galaxies and neurons. In both systems, galaxies and neurons are arranged in long filaments or nodes between the filaments. After all, in both systems 70% of the distribution of mass or energy consists of components that seem to play a passive role: water in the brain and dark energy in the observable universe.
Based on the common features of the two systems, the researchers compared a simulation of the galaxy network with sections of the cerebral cortex and cerebellum. The aim was to observe how fluctuations in matter are distributed over such different scales.
“We calculated the spectral density of both systems. This technique is often used in cosmology to study the spatial distribution of galaxies, ”explains Franco Vazza. “Our analysis has shown that the distribution of fluctuations within the neural network of the cerebellum on a scale from 1 micrometer to 0.1 millimeter follows the same course as the distribution of matter in the cosmic network, but of course on a larger scale from 5 million to 500 million light years ”.
The two researchers also calculated some parameters that characterize both the neural network and the cosmic web: the average number of connections in each node and the tendency to group multiple connections in relevant central nodes within the network.
“Structural parameters have again identified unexpected levels of compliance. It is likely that connectivity within the two networks will develop on similar physical principles, despite the striking and obvious difference between the physical forces that regulate galaxies and neurons, ”adds Alberto Feletti. “These two complex networks are more similar than those shared between the cosmic web and a galaxy or a neural network and the interior of a neural body.”
The encouraging results of this pilot study lead the researchers to believe that new and effective analytical techniques in both fields, cosmology and neurosurgery, will enable a better understanding of the routing dynamics that underlie the evolution of these two systems over time.
This study was published in Limits of physics entitled “The quantitative comparison between the neural network and the cosmic network.” Its authors are Franco Vazza from the Institute of Physics and Astronomy at the University of Bologna and Alberto Feletti from the Institute of Neuroscience, Biomedicine and Movement at the University of Verona.
Reference: “The quantitative comparison between the neural network and the cosmic network” by F. Vazza and A. Feletti, November 16, 2020, Limits of physics.
DOI: 10.3389 / fphy.2020.525731
