Molecular rhythms in the SCN of Vipcre/cre mice are altered due to the loss of VIP signaling. (A) Representative PER2∷LUC time series illustrating SCN bioluminescence rhythms under standard culture conditions. For the color version, see Supplementary Figure S4. (B-D) The SCN of Vipcre/cre mice display PER2∷LUC rhythms with a shorter period (B), but precision (C) and amplitude (D) did not differ by genotype. (E) Representative PER2∷LUC time series illustrating SCN bioluminescence rhythms during VPAC2 antagonism. (F) VPAC2 inhibition did not shorten period in Vipcre/cre SCN. (G, H) Precision increased in Vipcre/cre SCN during VPAC2 inhibition (G), but amplitude was not markedly affected (H). Italicized numbers below the abscissa in (B) and (F) indicate the sample size for all related panels. *Differs from Vip+/+ (same condition): Tukey’s HSD, p < 0.05; + differs from vehicle control (within genotype): one-sample t test, p < 0.05.