title: Visual-tactile processing in primary somatosensory cortex emerges before cross-modal experience.
abstract: The presumptive unisensory neocortical areas process multisensory information by oscillatory entrainment of neuronal networks via direct cortico-cortical projections. While neonatal unimodal experience has been identified as necessary for setting up the neuronal networks of multisensory processing, it is still unclear whether early cross-modal experience equally controls the ontogeny of multisensory processing. Here, we assess the development of visual-somatosensory interactions and their anatomical substrate by performing extracellular recordings of network activity in primary sensory cortices in vivo and assessing the cortico-cortical connectivity in pigmented rats. Similar to adult animals, juvenile rats with minimal cross-modal experience display supra-additive augmentation of evoked responses, time-dependent modulation of power and phase reset of network oscillations in response to cross-modal light and whisker stimulation. Moreover, the neuronal discharge of individual neurons is stronger coupled to theta and alpha network oscillations after visual-tactile stimuli. The adult-like multisensory processing of juvenile rats relies on abundant direct visual-somatosensory connections and thalamocortical feedforward interactions. Thus, cellular and network interactions ensuring multisensory processing emerge before cross-modal experience and refine during juvenile development.
authors.affiliation: Developmental Neurophysiology, University Medical Center Hamburg-Eppendorf, Hamburg, 20251, Germany.
authors.forename: Malte
authors.identifier: 0000-0001-5685-0109
authors.initials: M
authors.lastname: Bieler
authors.affiliation: Developmental Neurophysiology, University Medical Center Hamburg-Eppendorf, Hamburg, 20251, Germany.
authors.forename: Kay
authors.initials: K
authors.lastname: Sieben
authors.affiliation: Developmental Neurophysiology, University Medical Center Hamburg-Eppendorf, Hamburg, 20251, Germany.
authors.forename: Sandra
authors.initials: S
authors.lastname: Schildt
authors.affiliation: Biological Psychology and Neuropsychology, University Hamburg, Hamburg, 20146, Germany.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Röder
authors.affiliation: Developmental Neurophysiology, University Medical Center Hamburg-Eppendorf, Hamburg, 20251, Germany.
authors.forename: Ileana L
authors.initials: IL
authors.lastname: Hanganu-Opatz
mesh_terms: D000818:Animals; D005073:Evoked Potentials, Somatosensory; D005074:Evoked Potentials, Visual; D025461:Feedback, Physiological; D005260:Female; D008297:Male; D051381:Rats; D013003:Somatosensory Cortex / Q000254:growth & development / Q000502:physiology*; D055698:Touch Perception; D014793:Visual Cortex / Q000254:growth & development / Q000502:physiology; D014796:Visual Perception
keywords: development; neuronal networks; neuronal spiking; oscillations; phase reset