title: Neurotransmitter release at the thalamocortical synapse instructs barrel formation but not axon patterning in the somatosensory cortex.
abstract: To assess the impact of synaptic neurotransmitter release on neural circuit development, we analyzed barrel cortex formation after thalamic or cortical ablation of RIM1 and RIM2 proteins, which control synaptic vesicle fusion. Thalamus-specific deletion of RIMs reduced neurotransmission efficacy by 67%. A barrelless phenotype was found with a dissociation of effects on the presynaptic and postsynaptic cellular elements of the barrel. Presynaptically, thalamocortical axons formed a normal whisker map, whereas postsynaptically the cytoarchitecture of layer IV neurons was altered as spiny stellate neurons were evenly distributed and their dendritic trees were symmetric. Strikingly, cortex-specific deletion of the RIM genes did not modify barrel development. Adult mice with thalamic-specific RIM deletion showed a lack of activity-triggered immediate early gene expression and altered sensory-related behaviors. Thus, efficient synaptic release is required at thalamocortical but not at corticocortical synapses for building the whisker to barrel map and for efficient sensory function.
authors.affiliation: Institut National de la Santé et de la Recherche Médicale, UMR-S 839, 75005 France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Narboux-Nême
authors.forename: Alexis
authors.initials: A
authors.lastname: Evrard
authors.forename: Isabelle
authors.initials: I
authors.lastname: Ferezou
authors.forename: Reha S
authors.initials: RS
authors.lastname: Erzurumlu
authors.forename: Pascal S
authors.initials: PS
authors.lastname: Kaeser
authors.forename: Jeanne
authors.initials: J
authors.lastname: Lainé
authors.forename: Jean
authors.initials: J
authors.lastname: Rossier
authors.forename: Nicole
authors.initials: N
authors.lastname: Ropert
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Südhof
authors.forename: Patricia
authors.initials: P
authors.lastname: Gaspar
mesh_terms: D000818:Animals; D001369:Axons / Q000502:physiology; D002540:Cerebral Cortex / Q000502:physiology*; D005260:Female; D008297:Male; D051379:Mice; D009473:Neuronal Plasticity / Q000502:physiology; D018377:Neurotransmitter Agents / Q000378:metabolism*; D013003:Somatosensory Cortex / Q000502:physiology*; D013569:Synapses / Q000502:physiology; D009435:Synaptic Transmission / Q000502:physiology*; D013788:Thalamus / Q000502:physiology*; D014110:Touch / Q000502:physiology*; D014738:Vibrissae / Q000294:innervation / Q000502:physiology*
chemical_list: D018377:Neurotransmitter Agents