Extended Data Fig. 1: Supporting information related to Fig. 1.

A) Immunostaining of Per1 in the SCN at different circadian times. Experiments were independently repeated 4 times for ZT 1 and 5, and 3 times for ZT 9, 13, 17, and 21. Scale: 50 μm. B) Development of depressive-like behavior, as measured in the FST, during chronic exposure to LAN. The immobility time (mean ± SD) progressively increased after 2 weeks (wks) under LAN conditions compared to the baseline before LAN treatment (Pre), and remained significantly elevated after 3 wks (n = 8 mice). Data obtained at 3 wks was plotted in Fig. 1. One-way ANOVA followed by Sidak’s test: F (3, 28) = 5.3, p = 0.0051. Pre vs 3wks, p = 0.0097; Pre vs 4wks, p = 0.0083. C-D) Persistence of 3wk LAN-induced depressive-like phenotype after 3wks, 6wks, and 9wks of recovery. LAN was given during the first 3 wks and removed afterwards. The immobility of LAN exposed animals (n = 10 mice) remained significantly higher than baseline at 6wks (or 3 wks of recovery), and returned to baseline level at 9-12 wks (or 6-9 wks of recovery, respectively). Repeated Measure One-way ANOVA with Tukey’s test: F (1.99, 17.91) = 23.71, p < 0.0001, Pre vs 3wks, p = 0.0008; Pre vs 6wks, p = 0.0030; 3wks vs 6wks, p = 0.1162, ns; 3wks vs 9wks, p = 0.0077; 3wks vs 12wks, p = 0.0005. Sucrose preference only recovered after 6wks (or 3wks of recovery). Repeat Measure One-way ANOVA with Tukey’s test: F(1.63, 14.67)=15.96, p = 0.0004. Pre vs 3wks, p = 0.0052; 3wks vs 6wks, p = 0.9034; 3wks vs 9wks, p = 0.1504; 3wks vs 12wks, p = 0.0003. E) Retinal projections to the pHb in WT and ipRGC-ablated animals. Retinal projections were visualized using intravitreally injected CTB-555. In WT animals, RGC terminals in the pHb were observed (n = 3 mice). Whereas in Opn4-Cre::rosa-DTA (DTA) animals, in which ipRGCs were ablated, retinal innervation to the pHb was completely eliminated (n = 3 mice). Scale: 100 μm. F) Retinal innervations of the SCN in WT and ipRGC-ablated animals. RGC terminals within the SCN were visualized using intravitreally-administered CTB-555.In WT animals, typical dense innervation of the SCN was observed (n = 3 mice). In DTA animals, the retinal innervation of the SCN was substantially diminished but not completely eliminated (n = 3 mice). The scarce innervation may come from regular RGCs or few residual ipRGCs, and was likely adequate for normal photo-entrainment of DTA animals. Bar: 100 μm. G) 3wks of LAN exposure did not affect overall locomotor activity level. Locomotor response to novelty (mean ± SD) was assessed in an open field apparatus (n = 10 mice) before (pre) and after (post) 3wk LAN exposure, both during the light phase (D) or the dark phase (N). One-way ANOVA: F (2.482, 22.34) = 0.8581, p = 0.4586. H) The effect of LAN was examined using FST conducted at night in the dark. LAN exposure for 3 wks (post/blue, in comparison to the baseline (pre/pink) before LAN) induced an elevation of immobility (mean ± SD) even when assessed during the dark phase. N = 10 mice, P = 0.0002, t = 5.85 df=9, two-tailed paired t-test. I) Total water consumption (mean ± SD) expressed as the ratio of total water consumption (water+sucrose) in SPT after LAN exposure (post) over that before LAN exposure (pre), corresponding to experiments in Figs. 1i, 1e, 1m, 1q, and 1u. None was significantly changed after LAN, with p values of 0.0532, 0.6930, 0.9683, 0.1770, and 0.0640, respectively, as determined by the two-tailed paired t-test comparing total consumptions pre vs. post within each group. ^**: p < 0.01; ***: p < 0.001.