Gene expression patterns in visual cortex during the critical period: synaptic stabilization and reversal by visual deprivation.
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.
Lyckman
Alvin W
AW
Massachusetts Institute of Technology, Picower Institute for Learning and Memory, Cambridge, MA 02139, USA. alvin.lyckman@tufts.edu
Horng
Sam
S
Leamey
Catherine A
CA
Tropea
Daniela
D
Watakabe
Akiya
A
Van Wart
Audra
A
McCurry
Cortina
C
Yamamori
Tetsuo
T
Sur
Mriganka
M
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*
D019209:Troponin C