title: Gene expression patterns in visual cortex during the critical period: synaptic stabilization and reversal by visual deprivation.
abstract: The mapping of eye-specific, geniculocortical inputs to primary visual cortex (V1) is highly sensitive to the balance of correlated activity between the two eyes during a restricted postnatal critical period for ocular dominance plasticity. This critical period is likely to have amplified expression of genes and proteins that mediate synaptic plasticity. DNA microarray analysis of transcription in mouse V1 before, during, and after the critical period identified 31 genes that were up-regulated and 22 that were down-regulated during the critical period. The highest-ranked up-regulated gene, cardiac troponin C, codes for a neuronal calcium-binding protein that regulates actin binding and whose expression is activity-dependent and relatively selective for layer-4 star pyramidal neurons. The highest-ranked down-regulated gene, synCAM, also has actin-based function. Actin-binding function, G protein signaling, transcription, and myelination are prominently represented in the critical period transcriptome. Monocular deprivation during the critical period reverses the expression of nearly all critical period genes. The profile of regulated genes suggests that synaptic stability is a principle driver of critical period gene expression and that alteration in visual activity drives homeostatic restoration of stability.
authors.affiliation: Massachusetts Institute of Technology, Picower Institute for Learning and Memory, Cambridge, MA 02139, USA. alvin.lyckman@tufts.edu
authors.forename: Alvin W
authors.initials: AW
authors.lastname: Lyckman
authors.forename: Sam
authors.initials: S
authors.lastname: Horng
authors.forename: Catherine A
authors.initials: CA
authors.lastname: Leamey
authors.forename: Daniela
authors.initials: D
authors.lastname: Tropea
authors.forename: Akiya
authors.initials: A
authors.lastname: Watakabe
authors.forename: Audra
authors.initials: A
authors.lastname: Van Wart
authors.forename: Cortina
authors.initials: C
authors.lastname: McCurry
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Yamamori
authors.forename: Mriganka
authors.initials: M
authors.lastname: Sur
mesh_terms: D000818:Animals; D003423:Critical Period, Psychological; D023882:Dominance, Ocular / Q000235:genetics; D015536:Down-Regulation / Q000235:genetics; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D053444:Inhibitory Postsynaptic Potentials / Q000235:genetics; D051379:Mice; D009186:Myelin Sheath / Q000235:genetics; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D015203:Reproducibility of Results; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012683:Sensory Deprivation / Q000502:physiology*; D013569:Synapses / Q000235:genetics* / Q000378:metabolism*; D019209:Troponin C / Q000235:genetics / Q000378:metabolism; D015854:Up-Regulation / Q000235:genetics; D014793:Visual Cortex / Q000254:growth & development / Q000378:metabolism*
chemical_list: D019209:Troponin C