From the article above:

To answer these questions, a team of scientists led by EPFL’s Blue Brain Project used the mathematical language of algebraic topology to describe just how rat neurons connect to each other – and respond to stimuli – providing the first geometrical insight into how information is processed in a rodent brain. The results are published 12 June 2017 in the open-access journal Frontiers in Computational Neuroscience.

"Our previous mathematical approaches struggled to make sense of the activity generated by neurons,”

And:

• "... Conducting virtual experiments on Blue Brain’s digital reconstruction of a microcircuit in the rat brain, a computer model consisting of 31 000 neurons – and a whopping 8 million connections – all based on physiological data, the scientists discovered and described quantitatively the astonishingly rich geometric organization of neurons, providing a new and powerful tool for understanding the brain. The way neurons network together can actually be described using multi-dimensional mathematical objects. Moreover, these objects respond to external stimuli with a characteristic pattern through time, never before observed.

Neurons are organized according to abstract shapes ..."