OUP user menu

Towards network substrates of brain disorders

Olaf Sporns
DOI: http://dx.doi.org/10.1093/brain/awu148 2117-2118 First published online: 23 July 2014

This scientific commentary refers to ‘The hubs of the human connectome are generally implicated in the anatomy of brain disorders’, by Crossley et al. (doi:10.1093/brain/awu132).

A growing number of studies approach brain anatomy and function from the perspective of complex networks, with an explicit focus on the distributed layout of neural elements and their interconnections in the healthy, as well as diseased brain (Sporns, 2014). Network analysis has revealed a number of characteristic features of brain network organization, such as the presence of densely connected clusters or modules of brain regions, and of highly connected network hubs. In this issue of Brain, Nicolas Crossley and colleagues report the results of an extensive meta-analysis of MRI data, including a large set of observations of grey matter lesions in various brain disorders. They reveal that the disorders are associated with damage to distinct sets of hubs, and propose that disruption of network hubs may be a common factor contributing to brain dysfunction (Crossley et al., 2014).

Network approaches to brain function capitalize on the advances that have been made across a broad range of social, technological and biological systems using the concepts and computational tools of network science. Brain networks consist of nodes and connections; these are derived from brain imaging data by first applying a parcellation to derive node boundaries, and then estimating the presence and strength of connections between pairs of nodes. Structural networks capture network anatomy, based on data obtained via techniques such as diffusion imaging and tractography. In contrast, functional networks are built from estimates of statistical dependencies between time series of neuronal activity, as recorded for example with functional MRI. The complete set of structural connections is defined as the brain’s connectome (Sporns et al., 2005), a whole-brain structural network that …

View Full Text