WD increased Opn3 abundance in the cytoplasm and nucleus of both AVP and OXT neurones (Figure 1A, C, E; AVP cytoplasm F(4, 15) = 4.113, p = .0191, one‐way ANOVA, Tukey post‐hoc test control vs. WD p = .0116; AVP nucleus F(4, 15) = 6.815, p = .0025, one‐way ANOVA, Tukey post‐hoc test control vs. WD p = .0030; OXT cytoplasm F(4, 15) = 3.633, p = .0292, Tukey post‐hoc test control vs. WD p = .0203; OXT nucleus F(4, 15) = 4.850, p = .0104, Tukey post‐hoc test control vs. WD p = .0072). Here, OPN3 is linked to Wilson disease.