title: Spontaneous neuronal network dynamics reveal circuit's functional adaptations for behavior.
abstract: Spontaneous neuronal activity is spatiotemporally structured, influencing brain computations. Nevertheless, the neuronal interactions underlying these spontaneous activity patterns, and their biological relevance, remain elusive. Here, we addressed these questions using two-photon calcium imaging of intact zebrafish larvae to monitor the neuron-to-neuron spontaneous activity fine structure in the tectum, a region involved in visual spatial detection. Spontaneous activity was organized in topographically compact assemblies, grouping functionally similar neurons rather than merely neighboring ones, reflecting the tectal retinotopic map despite being independent of retinal drive. Assemblies represent all-or-none-like sub-networks shaped by competitive dynamics, mechanisms advantageous for visual detection in noisy natural environments. Notably, assemblies were tuned to the same angular sizes and spatial positions as prey-detection performance in behavioral assays, and their spontaneous activation predicted directional tail movements. Therefore, structured spontaneous activity represents "preferred" network states, tuned to behaviorally relevant features, emerging from the circuit's intrinsic non-linear dynamics, adapted for its functional role.
authors.affiliation: Ecole Normale Supérieure, Institut de Biologie de l'ENS IBENS, 75005 Paris, France; INSERM, U1024, 75005 Paris, France; CNRS, UMR 8197, 75005 Paris, France.
authors.forename: Sebastián A
authors.initials: SA
authors.lastname: Romano
authors.affiliation: Ecole Normale Supérieure, Institut de Biologie de l'ENS IBENS, 75005 Paris, France; INSERM, U1024, 75005 Paris, France; CNRS, UMR 8197, 75005 Paris, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Pietri
authors.affiliation: Ecole Normale Supérieure, Institut de Biologie de l'ENS IBENS, 75005 Paris, France; INSERM, U1024, 75005 Paris, France; CNRS, UMR 8197, 75005 Paris, France.
authors.forename: Verónica
authors.initials: V
authors.lastname: Pérez-Schuster
authors.affiliation: Ecole Normale Supérieure, Institut de Biologie de l'ENS IBENS, 75005 Paris, France; INSERM, U1024, 75005 Paris, France; CNRS, UMR 8197, 75005 Paris, France.
authors.forename: Adrien
authors.initials: A
authors.lastname: Jouary
authors.affiliation: Ecole Normale Supérieure, Institut de Biologie de l'ENS IBENS, 75005 Paris, France; INSERM, U1024, 75005 Paris, France; CNRS, UMR 8197, 75005 Paris, France.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Haudrechy
authors.affiliation: Ecole Normale Supérieure, Institut de Biologie de l'ENS IBENS, 75005 Paris, France; INSERM, U1024, 75005 Paris, France; CNRS, UMR 8197, 75005 Paris, France. Electronic address: sumbre@biologie.ens.fr.
authors.forename: Germán
authors.initials: G
authors.lastname: Sumbre
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D000818:Animals; D030801:Animals, Genetically Modified; D009415:Nerve Net / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods*; D013477:Superior Colliculi / Q000502:physiology; D014795:Visual Pathways / Q000502:physiology*; D015027:Zebrafish