Stochastic Amplification of Fluctuations in Cortical Up-States Hidalgo, Jorge Seoane, Luis F. Cortés, Jesús M. Muñoz Martínez, Miguel Ángel Cognifive science Depression Eigenvalues Membrane potential Neural networks Neurons Simulation and modeling Synaptic membranes Cortical neurons are bistable; as a consequence their local field potentials can fluctuate between quiescent and active states, generating slow Hz oscillations which are widely known as transitions between Up and Down States. Despite a large number of studies on Up-Down transitions, deciphering its nature, mechanisms and function are still today challenging tasks. In this paper we focus on recent experimental evidence, showing that a class of spontaneous oscillations can emerge within the Up states. In particular, a non-trivial peak around Hz appears in their associated power-spectra, what produces an enhancement of the activity power for higher frequencies (in the Hz band). Moreover, this rhythm within Ups seems to be an emergent or collective phenomenon given that individual neurons do not lock to it as they remain mostly unsynchronized. Remarkably, similar oscillations (and the concomitant peak in the spectrum) do not appear in the Down states. Here we shed light on these findings by using different computational models for the dynamics of cortical networks in presence of different levels of physiological complexity. Our conclusion, supported by both theory and simulations, is that the collective phenomenon of “stochastic amplification of fluctuations” – previously described in other contexts such as Ecology and Epidemiology – explains in an elegant and parsimonious manner, beyond model-dependent details, this extra-rhythm emerging only in the Up states but not in the Downs. 2014-03-25T10:32:11Z 2014-03-25T10:32:11Z 2012 info:eu-repo/semantics/article Hidalgo, J.; Seoane, L.F.; Cortés, J.M.; Muñoz, M.A. Stochastic Amplification of Fluctuations in Cortical Up-States. Plos One, 7(8): e40710 (2012). [http://hdl.handle.net/10481/31085] 1932-6203 doi: 10.1371/journal.pone.0040710 http://hdl.handle.net/10481/31085 eng http://creativecommons.org/licenses/by-nc-nd/3.0/ info:eu-repo/semantics/openAccess Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License Public Library of Science (PLOS)