Complex network structure can affect the balance of excitation and inhibition in large directed networks of cortical neurons and synapses

Abstract

Event Abstract Back to Event Complex network structure can affect the balance of excitation and inhibition in large directed networks of cortical neurons and synapses Mark D. McDonnell1* 1 University of South Australia, Institute for Telecommunications Research, Australia There are two fundamentally important aspects of brain network connectivity about which very little is known. The first is whether complex network structure is embedded in microscale neuronal networks, where nodes represent individual neurons, and edges represent synaptic connections between neurons. The second unknown is how complex network structure at the micro-scale impacts on neuronal dynamics in terms of aspects such as plasticity, synchronization, hyperexcitability and learning. These two questions are unanswered because current imaging techniques are unable to resolve the sufficiently large numbers of individual neurons, and their 1000s of synaptic connections, and these are needed to create a mathematical network model. In the absence of such information, many simulations of large cortical networks and their electrical activity assume simple random connectivity. Here we highlight how large networks of spatially embedded neurons in the cortex exhibit a unique set of features that are unparalleled in other network models beyond neuroscience. A key feature is the presence of two main classes of neurons: excitatory and inhibitory. We propose new methods that are specifically tailored for simulating and statistically characterising such networks and describe simulation results that employ these methods in order to study hypothesised “non-random” connectivity in both visual cortex area V1, and in the primary olfactory cortex. It is demonstrated that incorporation of a variety of complex structural features, such as directed clustering, can unexpectedly influence the balance of excitatory and inhibitory activity amongst the neurons in the network. In particular, we present results on networks that exhibit population oscillations due to sparse synchronization, and show that hyper-excitability (an indicator of epilepsy) that is not present in random networks can be induced when the network is instead highly clustered. Acknowledgements Mark D. McDonnell's contribution was supported by the Australian Research Council under ARC grant DP1093425 (including an Australian Research Fellowship). Keywords: Complex Network, cortical networks, population oscillations, small world network Conference: Bernstein Conference 2012, Munich, Germany, 12 Sep - 14 Sep, 2012. Presentation Type: Poster Topic: Other Citation: McDonnell MD (2012). Complex network structure can affect the balance of excitation and inhibition in large directed networks of cortical neurons and synapses. Front. Comput. Neurosci. Conference Abstract: Bernstein Conference 2012. doi: 10.3389/conf.fncom.2012.55.00224 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 18 Sep 2012; Published Online: 12 Sep 2012. * Correspondence: Dr. Mark D McDonnell, University of South Australia, Institute for Telecommunications Research, Mawson Lakes, SA, 5087, Australia, mark.mcdonnell@unisa.edu.au Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Mark D McDonnell Google Mark D McDonnell Google Scholar Mark D McDonnell PubMed Mark D McDonnell Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.