(A) Schematic of CLOCK:BMAL1-mediated circadian gene expression.
(B) Assessment of circadian mRNA expression profile (3 mice per timepoint) in primary visual cortex (V1) just before eye-opening (P10–P11), at pre-critical period (CP) (P17–P18), CP (P27–P28) and adult ages (P70–P90).
(C) Neither Clock nor Pvalb mRNA expression exhibit circadian rhythmicity at any age. ZT, zeitgeber time.
(D) Circadian expression patterns for Dbp, Per1, and Per2 mRNAs emerge after eye-opening.
(E) Genetic reduction of Clock (exon 5–6) or Dbp mRNA expression in V1 at CP (P27–P30, 4–6 mice) or adult ages (P70–P90, 3–5 mice). **P < 0.01; ***P < 0.001 (one-way ANOVA, Dunnett’s post-hoc analysis for Clock; two-way ANOVA, Bonferroni’s post-hoc analysis for Dbp). Values are mean ± s.e.m.