A Tutorial in Connectome Analysis: Topological and Spatial Features of Brain Networks

TL;DR

This tutorial introduces methods for analyzing the topological and spatial features of brain connectomes at multiple scales, aiding in understanding brain organization and differences in clinical studies.

Contribution

It provides a comprehensive overview of topological and spatial analysis techniques for connectomes, including new methods for characterizing network types and wiring lengths.

Findings

Different network archetypes can be distinguished at the global scale.

Topological features vary across local, regional, and global levels.

Spatial analysis of wiring lengths offers insights into neural organization.

Abstract

High-throughput methods for yielding the set of connections in a neural system, the connectome, are now being developed. This tutorial describes ways to analyze the topological and spatial organization of the connectome at the macroscopic level of connectivity between brain regions as well as the microscopic level of connectivity between neurons. We will describe topological features at three different levels: the local scale of individual nodes, the regional scale of sets of nodes, and the global scale of the complete set of nodes in a network. Such features can be used to characterize components of a network and to compare different networks, e.g. the connectome of patients and control subjects for clinical studies. At the global scale, different types of networks can be distinguished and we will describe Erd\"os-R\'enyi random, scale-free, small-world, modular, and hierarchical archetypes of networks. Finally, the connectome also has a spatial organization and we describe methods for analyzing wiring lengths of neural systems. As an introduction for new researchers in the field of connectome analysis, we discuss the benefits and limitations of each analysis approach.