title: Anatomical plasticity of adult brain is titrated by Nogo Receptor 1.
abstract: Experience rearranges anatomical connectivity in the brain, but such plasticity is suppressed in adulthood. We examined the turnover of dendritic spines and axonal varicosities in the somatosensory cortex of mice lacking Nogo Receptor 1 (NgR1). Through adolescence, the anatomy and plasticity of ngr1 null mice are indistinguishable from control, but suppression of turnover after age 26 days fails to occur in ngr1-/- mice. Adolescent anatomical plasticity can be restored to 1-year-old mice by conditional deletion of ngr1. Suppression of anatomical dynamics by NgR1 is cell autonomous and is phenocopied by deletion of Nogo-A ligand. Whisker removal deprives the somatosensory cortex of experience-dependent input and reduces dendritic spine turnover in adult ngr1-/- mice to control levels, while an acutely enriched environment increases dendritic spine dynamics in control mice to the level of ngr1-/- mice in a standard environment. Thus, NgR1 determines the low set point for synaptic turnover in adult cerebral cortex.
authors.affiliation: Cellular Neuroscience, Neurodegeneration and Repair Program, Departments of Neurology and Neurobiology, Yale University School of Medicine, New Haven, CT 06536, USA.
authors.forename: Feras V
authors.initials: FV
authors.lastname: Akbik
authors.forename: Sarah M
authors.initials: SM
authors.lastname: Bhagat
authors.forename: Pujan R
authors.initials: PR
authors.lastname: Patel
authors.forename: William B J
authors.initials: WB
authors.lastname: Cafferty
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Strittmatter
mesh_terms: D000375:Aging / Q000502:physiology; D000818:Animals; D001519:Behavior / Q000502:physiology; D001921:Brain / Q000033:anatomy & histology* / Q000254:growth & development; D001923:Brain Chemistry / Q000235:genetics / Q000502:physiology*; D002540:Cerebral Cortex / Q000254:growth & development / Q000502:physiology; D049229:Dendritic Spines / Q000502:physiology; D003714:Denervation; D005239:Fear / Q000523:psychology; D049452:Green Fluorescent Proteins / Q000235:genetics; D007091:Image Processing, Computer-Assisted; D051379:Mice; D018345:Mice, Knockout; D008822:Mice, Transgenic; D018613:Microscopy, Confocal; D009154:Mutation / Q000235:genetics / Q000502:physiology; D009185:Myelin Proteins / Q000235:genetics / Q000502:physiology*; D009473:Neuronal Plasticity / Q000235:genetics / Q000502:physiology*; D000070798:Nogo Proteins; D004856:Postural Balance / Q000235:genetics / Q000502:physiology; D014738:Vibrissae / Q000294:innervation
chemical_list: D009185:Myelin Proteins; D000070798:Nogo Proteins; C000603201:Rtn4 protein, mouse; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins