Fig. 3: Inhibition of the vLGN/IGL-Re circuit blocks the effects of 40 Hz blue light treatment.

a The experimental timeline of AAV infusion, C21 injections, blue light treatment, behavioral tests, injection of the OVA-Alexa Fluor 647 tracer into the cisterna magna (i.c.m.), and sacrifice (sac). b A representative image of hM4Di-mCherry expression in Re neurons receiving inputs from the vLGN/IGL projection. Red: mCherry; blue: DAPI; scale bar: 200 μm. Two biological replicates of animal cohorts were performed with similar results. c The spontaneous alternation and total numbers of arm entries in the Y-maze test (n = 6, 7). d Representative heatmaps of animals’ traveling paths during the test session of the novel object recognition (NOR). e Quantification of the discrimination index (DI) and the total time spent on exploring both objects (total exploration) during the training and the test sessions of NOR (n = 6, 7). f Representative images depicting OVA tracer (red) and DAPI staining (blue) in the deep cervical lymph nodes (dCLNs). Scale bar, 250 μm. g Quantification of the fluorescence intensity and the percentage of area covered by the OVA tracer in the dCLNs (n = 6, 7). h Representative images of AQP4 staining in cornu ammonis 1 (CA1) and the primary visual cortex (VC). Scale bars, 50 μm. i Quantification of the polarization index of AQP4 in CA1 and VC (n = 6, 7). AD-BLUE-Sal, 5xFAD mice that received blue light treatment and saline injection; AD-BLUE-C21, 5xFAD mice that received blue light treatment and C21 injection. All data are presented as the mean ± SEM and analyzed by two-tailed unpaired Student’s t test.