title: A Diffusive Homeostatic Signal Maintains Neural Heterogeneity and Responsiveness in Cortical Networks.
abstract: Gaseous neurotransmitters such as nitric oxide (NO) provide a unique and often overlooked mechanism for neurons to communicate through diffusion within a network, independent of synaptic connectivity. NO provides homeostatic control of intrinsic excitability. Here we conduct a theoretical investigation of the distinguishing roles of NO-mediated diffusive homeostasis in comparison with canonical non-diffusive homeostasis in cortical networks. We find that both forms of homeostasis provide a robust mechanism for maintaining stable activity following perturbations. However, the resulting networks differ, with diffusive homeostasis maintaining substantial heterogeneity in activity levels of individual neurons, a feature disrupted in networks with non-diffusive homeostasis. This results in networks capable of representing input heterogeneity, and linearly responding over a broader range of inputs than those undergoing non-diffusive homeostasis. We further show that these properties are preserved when homeostatic and Hebbian plasticity are combined. These results suggest a mechanism for dynamically maintaining neural heterogeneity, and expose computational advantages of non-local homeostatic processes.
authors.affiliation: Institute for Adaptive and Neural Computation, School of Informatics, University of Edinburgh, Edinburgh, United Kingdom; Department of Computational Biology, School of Computer Science and Communication, Royal Institute of Technology, Stockholm, Sweden.
authors.forename: Yann
authors.initials: Y
authors.lastname: Sweeney
authors.affiliation: Department of Computational Biology, School of Computer Science and Communication, Royal Institute of Technology, Stockholm, Sweden.
authors.forename: Jeanette
authors.initials: J
authors.lastname: Hellgren Kotaleski
authors.affiliation: Institute for Adaptive and Neural Computation, School of Informatics, University of Edinburgh, Edinburgh, United Kingdom.
authors.forename: Matthias H
authors.initials: MH
authors.lastname: Hennig
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000818:Animals; D003198:Computer Simulation; D006706:Homeostasis / Q000502:physiology*; D006801:Humans; D008959:Models, Neurological; D009415:Nerve Net / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology*; D018377:Neurotransmitter Agents / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism*
chemical_list: D018377:Neurotransmitter Agents; D009569:Nitric Oxide