Fig. 5: BRN3B is a central regulator of ipRGC-driven behaviors.

A Schematic showing the optokinetic tracking (OKT) behavioral assay. B Contrast sensitivity curve at different spatial frequencies. Brn3bcKO mice (green, n = 6) showed decreased contrast sensitivity compared to control (Opn4^Cre/+; Brn3b^+/+) mice (black, n = 12) (0.031 cpd, P = 0.176; 0.064 cpd, P = 0.006; 0.092 cpd, P = 0.011; 0.272, P = 0.128). C Spatial frequency threshold measured by OKT at 100% contrast in control (black, n = 9) and Brn3bcKO (green, n = 5) mice. No differences between Brn3bcKO and control littermates (P = 0.106). D Representative PLR images from control (left) and Brn3bcKO (right) mice in darkness (top), dim light (middle, 13.8 log quanta cm−2 s − 1), and bright light (bottom, 14.8 log quanta cm−2 s − 1). Pupils are highlighted with dashed ellipses. E Control and Brn3bcKO (n = 6 mice/group) pupil area in the dark (P = 0.626). F Irradiance-response relationship of PLR in control (black) and Brn3bcKO (green) mice (n = 6 mice/group) (12.1 log quanta/cm²/s, P = 0.997; 13.8 log quanta/cm²/s, P = 0.673; 14.2 log quanta/cm²/s, P = 0.190; 14.8 log quanta/cm²/s, P = 0.010). G Representative double-plotted actograms from control (top) and Brn3bcKO (bottom) mice. Mice were initially exposed to a 12:12 LD cycle with 100 lux light during the light phase. Then, the mice were exposed to a 6 h phase advance. H Circadian amplitude measured using the peak amplitude of the χ² periodogram in control (black, n = 8) and Brn3bcKO mice (green, n = 7) (P = 0.002). (Left); and percent activity during the light phase (Right) in control (black, n = 8) and Brn3bcKO mice (green, n = 7) (P = 0.006). Source data are provided as a Source Data file. All data are Mean ± SEM, n.s. (not significant) P > 0.05; *P < 0.05; **P < 0.01. Two-tailed Mann-Whitney U test and two-way repeated measures ANOVA with Tukey’s multiple comparisons test.