title: Multiple patterns of spatiotemporal changes in layer-specific gene expression in the developing visual cortex of higher mammals.
abstract: The mammalian cerebral cortex, which is stratified into six layers, has functional domains that vertically span the six layers, thereby requiring tight interlaminar connectivity within a domain. The synaptic connections in individual layers are first broadly formed under predetermined programs and later reinforced between neurons which reside in the same functional domain via experience-dependent reorganization during the critical period. However, the molecular mechanisms that control these two processes within each layer are still unclear. Therefore, we performed a differential screen for candidates and found seven genes with layer-specific expression during postnatal development of cat visual cortex. APLP1, a transmembrane protein mediating synaptogenesis, started dual-layer expression in layers 2/3 and 5 before the critical period, suggesting that it might execute coarse synapse formation of these layers. STMN2 (SCG10), which promotes microtubule turnover, was unique, as it dramatically shifted its dual-layer distribution from layers 2/3 and 5 to the deeper layers 4 and 6 at the onset of the critical period; it lost this new expression pattern in the adult. Surprisingly, brief dark rearing disturbed the shift in its dual-layer distribution around the onset of the critical period. Thus, by accelerating structural remodeling, STMN2 (SCG10) might launch experience-dependent reorganization of particular layers.
authors.affiliation: Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, 5-1 Higashiyama, Myodaiji-cho, Okazaki, Aichi 444-8787, Japan. ktomita@nips.ac.jp
authors.forename: Koichi
authors.initials: K
authors.lastname: Tomita
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Gotoh
authors.forename: Kaoru
authors.initials: K
authors.lastname: Tomita
authors.forename: Naoko
authors.initials: N
authors.lastname: Yamauchi
authors.forename: Makoto
authors.initials: M
authors.lastname: Sanbo
mesh_terms: D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D002415:Cats; D016922:Cellular Senescence / Q000235:genetics; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D006801:Humans; D009434:Neural Pathways / Q000166:cytology / Q000254:growth & development* / Q000502:physiology; D055495:Neurogenesis / Q000235:genetics; D009473:Neuronal Plasticity / Q000235:genetics; D046709:Pattern Recognition, Physiological / Q000502:physiology*; D013569:Synapses / Q000235:genetics; D059467:Transcriptome / Q000235:genetics*; D014793:Visual Cortex / Q000166:cytology / Q000254:growth & development* / Q000502:physiology