# Micro-connectomics: Probing the organizational principles of neuronal networks at the cellular scale

Publication Date: 2016

Journal Title: Nature Reviews Neuroscience

Publisher: Nature Publishing Group

Volume: 18

Pages: 131-146

Language: English

Type: Article

This Version: AM

Citation: Schröter, M., Paulsen, O., & Bullmore, E. (2016). Micro-connectomics: Probing the organizational principles of neuronal networks at the cellular scale. Nature Reviews Neuroscience, 18 131-146. https://doi.org/10.1038/nrn.2016.182

Description: This is the author accepted manuscript. It is currently under an indefinite embargo pending publication by the Nature Publishing Group.

Abstract: Defining the organizational principles of neuronal network s at the cellular scale, or $\textit{micro-connectomics}$, is a key challenge of modern neuroscience. Accelerated by methodological advances, recent experimental studies have generated rich data on anatomical, physiological and genetic factors determining the organization of neuronal networks. In this Review, we will focus on graph theoretical parameters of micro-connectome topology, often informed by economical principles that conceptually originate with Ramón y Cajal’s conservation laws. First, we summarize results from experimental studies in intact small organisms and in tissue samples from larger nervous systems. We then evaluate the evidence for an economical trade-off between biological cost and functional value in the organization and development of neuronal networks. In general, the wiring cost of neuronal networks was nearly, but not strictly, minimized by the spatial positioning and connectivity of neurons. Features that reduce the number of synaptic connections between neurons , such as hubs, were more expensive to wire than the theoretical minimum. It seems reasonable to infer from contemporary micro-connectomics that many aspects of intricately detailed neuronal network organization are indeed the outcome of competition between two fundamental selection pressures: low biological cost and high functional value. Future studies will be needed to clarify which aspects of network topology are most functionally valuable and to identify the biological mechanisms controlling expression of cost and topological pressures on the development and evolution of micro-connectomes.

Sponsorship: This work was supported by the National Institute of Health Research (NIHR) Cambridge Biomedical Research Centre.

Identifiers:

External DOI: https://doi.org/10.1038/nrn.2016.182

This record's URL: https://www.repository.cam.ac.uk/handle/1810/261058

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Author: Schröter, ManuelPaulsen, OleBullmore, Ed

Source: https://www.repository.cam.ac.uk/handle/1810/261058