title: In vivo two-photon imaging reveals a role of arc in enhancing orientation specificity in visual cortex.
abstract: Cortical representations of visual information are modified by an animal's visual experience. To investigate the mechanisms in mice, we replaced the coding part of the neural activity-regulated immediate early gene Arc with a GFP gene and repeatedly monitored visual experience-induced GFP expression in adult primary visual cortex by in vivo two-photon microscopy. In Arc-positive GFP heterozygous mice, the pattern of GFP-positive cells exhibited orientation specificity. Daily presentations of the same stimulus led to the reactivation of a progressively smaller population with greater reactivation reliability. This adaptation process was not affected by the lack of Arc in GFP homozygous mice. However, the number of GFP-positive cells with low orientation specificity was greater, and the average spike tuning curve was broader in the adult homozygous compared to heterozygous or wild-type mice. These results suggest a physiological function of Arc in enhancing the overall orientation specificity of visual cortical neurons during the post-eye-opening life of an animal.
authors.affiliation: Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Kuan Hong
authors.initials: KH
authors.lastname: Wang
authors.forename: Ania
authors.initials: A
authors.lastname: Majewska
authors.forename: James
authors.initials: J
authors.lastname: Schummers
authors.forename: Brandon
authors.initials: B
authors.lastname: Farley
authors.forename: Chengcheng
authors.initials: C
authors.lastname: Hu
authors.forename: Mriganka
authors.initials: M
authors.lastname: Sur
authors.forename: Susumu
authors.initials: S
authors.lastname: Tonegawa
mesh_terms: D000818:Animals; D003598:Cytoskeletal Proteins / Q000235:genetics* / Q000502:physiology*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006579:Heterozygote; D006720:Homozygote; D051379:Mice; D018345:Mice, Knockout; D008817:Mice, Mutant Strains; D036641:Microscopy, Fluorescence, Multiphoton; D009419:Nerve Tissue Proteins / Q000235:genetics* / Q000502:physiology*; D009949:Orientation / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D014793:Visual Cortex / Q000502:physiology*; D014795:Visual Pathways / Q000502:physiology
chemical_list: D003598:Cytoskeletal Proteins; D009419:Nerve Tissue Proteins; C092069:activity regulated cytoskeletal-associated protein; D049452:Green Fluorescent Proteins