An entropic measure of diverse specialisation highlights multifunctional neurons in annotated connectomes

The creation and curation of synaptic-level neuronal networks, or connectomes, enables the study of the relationship between structure and function of these networks. Topological characteristics of neuronal networks have been studied extensively. Separately there have been considerable efforts to classify the morphology, cell types, and lineages of neurons. Here we introduce a network metric that combines topological analysis with node metadata. This entropic quantity measures the diversity of incoming or outgoing connections to a node in terms of the metadata distribution. We find that in C. elegans , the top-scoring neurons in terms of this metric have known functions that integrate and disseminate multimodal information involved in sensorimotor functions. In the nerve cord of Drosophila melanogaster , we find that the top-scoring neurons are located in the abdominal neuropil, where sensorimotor coordination is required for complex innate behaviour such as mating.