title: Visually Evoked Spiking Evolves While Spontaneous Ongoing Dynamics Persist.
abstract: Neurons in the primary visual cortex spontaneously spike even when there are no visual stimuli. It is unknown whether the spiking evoked by visual stimuli is just a modification of the spontaneous ongoing cortical spiking dynamics or whether the spontaneous spiking state disappears and is replaced by evoked spiking. This study of laminar recordings of spontaneous spiking and visually evoked spiking of neurons in the ferret primary visual cortex shows that the spiking dynamics does not change: the spontaneous spiking as well as evoked spiking is controlled by a stable and persisting fixed point attractor. Its existence guarantees that evoked spiking return to the spontaneous state. However, the spontaneous ongoing spiking state and the visual evoked spiking states are qualitatively different and are separated by a threshold (separatrix). The functional advantage of this organization is that it avoids the need for a system reorganization following visual stimulation, and impedes the transition of spontaneous spiking to evoked spiking and the propagation of spontaneous spiking from layer 4 to layers 2-3.
authors.affiliation: Centre National de la Recherche Scientifique CerCo UMR 5549, Pavillon Baudot CHU Purpan Toulouse, France.
authors.forename: Raoul
authors.initials: R
authors.lastname: Huys
authors.affiliation: Faculté de Médecine, Institut de Neurosciences des Systèmes, Aix-Marseille UniversitéMarseille, France; INSERM UMR1106, Aix-Marseille UniversitéMarseille, France.
authors.forename: Viktor K
authors.initials: VK
authors.lastname: Jirsa
authors.affiliation: Department of Neuroscience, Karolinska Institutet Solna, Sweden.
authors.forename: Ziauddin
authors.initials: Z
authors.lastname: Darokhan
authors.affiliation: Department of Neuroscience, Karolinska Institutet Solna, Sweden.
authors.forename: Sonata
authors.initials: S
authors.lastname: Valentiniene
authors.affiliation: Department of Neuroscience and Pharmacology, University of Copenhagen Copenhagen, Denmark.
authors.forename: Per E
authors.initials: PE
authors.lastname: Roland
keywords: cortical dynamics; cortical states; neuron network stability; spike trains; spontaneous activity; visual transients